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Block 6: Neuro > B06W11 > Flashcards

Flashcards in B06W11 Deck (401):

What is the difference between endolymph and perilymph?

Perilymph like extracellular fluid and endolymph like intracellular fluid > allows for conduction of actin potential through movement of ions


Each inner hair cell of the ear has terminals for how many afferent fibres?



What mechanical stimulus leads to depolarisation of the ear inner hair cells?

Distortion of the stereocilia


Which structure of the ear generates the active mechanical amplification of basilar membrane vibration?

Outer hair cells


What are the 4 components of clinical assessment of hearing?

1. History 2. Clinical testing 3. Tuning forks 4. Audiometry


List 3 associated symptoms of hearing loss that may be elicited in a history

Tinnitus, hyperacusis and vertigo


Inner hair cells are ____ nerve fibres



What is the role of inner hair cells in the ear?

Transmission of information to auditory nerve


What do outer hair cells in the ear do?

Generate the active mechanical amplification of basilar membrane vibration, leading to large amplitude and sharply tuned mechnical travelling wave


Outer hair cells produce what types of otoacousticemissions?

Spontaneous and evoked


Problems with hearing fall into which 2 major groups? Give an example of each.

1. Mechanical delivery (conductive) as in otitis media with effusion 2. Neurological (sensorineural) as in noise induced hearing loss


In a Weber's tuning fork test, sound will deviate towards the affected ear in ____ hearing loss, but away from the affeted ear in ______ loss

Conductive; sensorineural


The inner ear labyrinth consists of which 3 parts?

Urticle, saccule and 3 semicircular canals


List the 3 planes of movement in the inner ear labyrinth

Yaw, pitch and roll


Describe how the ear perceives acceleration in a clockwise direction

Clockwise acceleration > inertia causes endolymph to lag behind > cupula gets deflected toward the right > perceived clockwise movement


Describe how the ear perceives deceleration

Canal stops moving but endolymph momentum keeps it moving clockwise > cupula becomes deflected


In which 2 situations does the ear not perceive any angular movement?

Constant angular motion and at rest, because in these situation there is no relative motion between the canals and the endolyph, so the cupula is not deflected and there is no perception of movement


Decscribe Ewalds 3 laws

1. Stimulation of a semicircular canal causes a movement of the eyes in the plane of the stimulated canal 2. In the horizontal canal, ampullopetal endolymph flow causes greater response than ampullofugal flow 3. In vertical canals, ampullofugal endolyph flow causes greater response than ampullopetal flow


Each utriculopetal stimulus in one ear canal is matched by an equal but opposite ______ displacemnt in the functionally paired canal



What is nystagmus?

Combination of alterating slow phase and fast saccadic eye movements in opposite directions


For clinical purposes, the direction of nystagmus is defined by which phase?



List the 5 important tests of vertigo

1. Rhombergs 2. Unterbergers (contentious value) 3. Head thrust (vestibulo-occular test) 4. Hallpikes 5. Caloric responses


What systems are tested using Rhomberg's test?

Vestibular, proprioception and cerebellum


When conducting Rhomberg's test, a patient will tend to fall to the side of _____ labyrinth



Which test is used for unilateral vestibular hypofunction?

Head thrust test


What is the specific test for benign paroxysmal positional vertigo?

Hallpikes test


Which 4 skills and 4 lobes are tested in a neuro exam of higher cognitive function?

Orientation, language, attention and memory. Frontal, parietal, temporal and occipital lobes.


Which 4 nerves are tested in the exam of the UPPER cranial nerves?



What does CNI do?

Sense of smell


How is CNI tested in an exam?

Ask patient about their sense of smell or ask patient to smell a strong scent one nostril at a time (only seeing if patient can detect the smell, not if they can identify it)


What are the functions of CNII?



Which tests are used to test CNII?

Visual acuity, visual fields, ophthalmoscopy and pupil reactivity


What are the sympathetic functions of CNII?

Pupillary dilation, lid elevation, facial sweating


What sort of visual field defect would be produced by a lesion of the right optic nerve?

Total visual loss in the right eye, but normal vision in the left


What sort of visual field defect would be produced by a lesion of the right-most side of the optic chiasm?

Loss of central vision in the right eye and loss of the upper outer quadrant of the left eye


What sort of visual field defect would be produced by a lesion of the central optic chiasm?

Loss of lateral field in the right eye and lateral field of the left eye


What sort of visual field defect would be produced by a lesion of the right optic tract? (i.e., behind the optic chiasm on the right)

Loss of nasal half of field in right eye and loss of temporal half of field in left eye


What sort of visual field defect would be produced by a lesion spanning the entire right optic radiators (in the primary visual cortex)?

Loss of nasal half of field in right eye and loss of temporal half of field in left eye


List a test of colour vision

Ishiara plates


Why is documentation of visual fields different from any other documentation of eye function?

These are drown as if patient were looking into the page (i.e., right eye on right side)


A deep space-occupying lesion in the orbit can cause what sign?



How are eyelids examined in a cranial nerve examination?

Ask patient to look up, straight ahead and down.


ist at least 3 conditions in which an abnormality of eyelids may be seen

1. Occulomotor nerve palsy 2. Horner's syndrome 3. Senile dehlescence 4. Myasthenia gravis


List the 3 planes of movement of the eyeball

1. Horizontal 2. Vertical 3. Tortionally


From the adducted position, what are the actions of the inferior oblique and superior oblique?

Inferior oblique elevates the eye, superior oblique depresses the eye


What is the difference between elevation and depression of the eyeball when in the abducted vs adducted position?

Abducted position = superior rectus elevates and inferior rectus depresses; Adducted position = inferior oblique elevates and superior oblique depresses the eye


What 4 features are observed when examining the pupils in a cranial nerve exam?

1. Direct 2. Consensual 3. RAPD 4. Convergence


What sort of defect can be elicited by using the 'swinging torch test' in a cranial nerve exam?

Realtive afferent puillary defect


Which branch of CNV is the motor branch?



Which tests are used to test CNV?

Facial sensation, corneal reflex, jaw movements and jaw jerk


What is the function of CNV?

Sensory to face and ear, and muscles of mastication


Why is vibration sense useless in testing CNV sensation to the face?

Because the skull will transfer the vibration to both sides


Which muscles open the jaw and move it from side to side and protrude?



Why is a patient asked to look up and away from cotton wool in the corneal test (CNV)?

Menace and blink reflexes


Which muscles test jaw closure?

Temporalis and masseter


How is the motor function of CNV tested?

Jaw closure (temporalis and masseter) and jaw opening (pterygoids)


Which side will the jaw deviate to if there is a lesion of CNV on the left?

Jaw deviated toward side of lesion (i.e., toward left)


When would you see an exaggerated jaw jerk?

In an UMN lesion case


What is the function of the facial nerve?

Sensory to ear, muscles of facial expression, stapedius bone, lacrimal gland, salivary glands (except parotid)


What 4 functions are tested in examination of the facial nerve?

1. Raise eyebrows 2. Close eyes tightly 3. Show teeth 4. Puff out cheeks


Describe the presenation of someone with a right LMN facial palsy

Lower side of face opposite lesion is affected, but upper part of face is not affected


What is the function of CNVIII?

Auditory, vestibular (semicircular canals, otoliths)


List the 4 tests of CNVIII

1. Crude test of acuity (rub fingers together) 2. Rinne test for conductive defect 3. Weber test of lateralisation 4. Look in the ear


In conductive hearing loss, what changes will be observed in the Rinne test?

Air conduction no longer louder than bone conduction (as would be normal)


Describe what will be seen in the Weber test of a patient with a sensoneural lesion vs conductive hearing loss

Sensorineural = sound will localise to the opposite side; Conductive loss = sound localises to the same side (normal is equal input from both ears, so sound is heard centrally when fork is placed in midline)


What 3 tests are used to assess the vestibular components of CNVIII?

1. Look for nystagmus in 9 cardinal positions of gaze 2. Caolric tests (cold, opposite; warm, same) 3. Lesion = opposite


What are the functions of CN IX?

Sensory to ear and fauces. Taste. Motor to stylopharyngeus. Innervates carotid body/sinus, parotid gland and sensory component of gag reflex


What are the functions of CN X?

Multiple autonomic, sensory to ear, pharyngeal plexus, soft palate, larynx


Which 3 tests are used to test CNX?

Palatal elevtation, cough and motor part of gag reflex


Which cranial nerves are responsible for the sensory vs motor component of the gag reflex?

Sensory component via IX (and elicited by gag reflex test), and motor component via CN X


In a lesion of the 10th cranial nerve, to which side does the uvula deviate?

Away from the side of the lesion


Which physical examination finding could point to a lesion of the vagus nerve on the right side?

Palatal elevation where the uvula deviates away from the side of the lesion (i.e., to the left)


What is a bovine cough, and what does it suggest?

Non-explosive cough of a patient who is unable to close his/her glottis. Seen in vagus nerve lesions.


How is CN XI tested?

1. Trapezius tested by shrugging 2. Sternomastoid tested by asking patient to turn head against resistance


What are the functions of CNXI?

Pharyngeal plexus and trapezius, steromastoid


What are the only muscles truly supplied by CNXI?

Constructors of the pharynx (superior, middle and inferior)


What is the function of CN XII?

Motor to the tongue


How is CNXII tested?

Ask patient to stick tongue out in midline (also observe for abnormalities/fasisculations etc)


If there is a CNXII lesion, to which side will the tongue deviate?

To the side of the lesion (because the muscle on that side is now unopposed)


What sign on physical examination may suggest a right-sided nerve palsy of CNXII?

Tongue deviating toward lesion (i.e., to the right)


Give at least 3 examples of eye movement disorders that are classified by having 'too little movement'

Congenital stabismus, neuromuscular disease, neclear lesions and supranuclear lesions


Give at least 2 examples of eye movement disorders that are classified by having 'too much movement'

Saccadic intrusions and nystagmus


Malalignment of the eyes can give rise to which symptoms? Name 3

Blurred vision, ghosting, double vision


Excess movement of the eyes can give rise to which symptoms? Name 3

Blurred vision, double vision, oscillopsia


What is version of the eyes?

Movement of both eyes together


What is strabismus?

A misalignment or deviation of the visual axes


List at least 2 types of strabismus

Tropia, phoria


What is tropia (strabismus)?

Relative deviation of visual axes with both eyes viewing (manifest misalignment)


What is phoria (strabismus)?

Relative deviation of visual axes with one eye covered (latent misalignment)


What is the other name given to congenital strabismus?



List some causes of congenital strabismus

Defective central vision, impared vision in one eye, anatomic disturbance to the orbit, accommodative discrepancy


List at least 3 neuromusclar problems of the eye

CN III nerve palsy, CN IV nerve palsy, CN VI nerve palsy


List the 3 degrees of freedom of the eyeball

Horizontal, vertical and tortional


What are the actions of the superior oblique occular muscle, if the eye is initial in the primary position?

Depression, intorsion and abduction


What are the actions of the superior oblique occular muscle, if the eye is initial in the adducted position?

Pure depression


In what position must the eye be in, in order to elicit pure depression of the superior oblique?



Which occular muscle elevates the eye from the adducted position vs abducted position?

Adducted = inferior oblique; Abducted = superior rectus


Which occular muscle depresses the eye from the adducted position vs abducted position?

Adducted = superior oblique; Abducted = inferior rectus


Describe the clinical manifestations of a CNIII nerve palsy

Complete ptosis of eyelid and failure of elevation, depression and adduction of eye (due to palsy of SR, IO, IR and MR)


What are the 2 divisions of CNIII, and why is this clinically significant?

Superior and inferior - significant because it is possible to get a palsy in only one branch and thus clinical signs will be different


What is the superior division of CNIII responsible for?

Superior rectus muscle and levator palpebrae superioris


What is the inferior division of CNIII responsible for?

IR, IO, MR and pupil/ciliary body


Describe what would be seen in a palsy of only the superior division of CNIII?

Palsy of SR (inabiliy to look up) and levator palpabrae superioris (droopy eyelid), but with preservation of IR, IO, MR and pupil


A patient who is tilting their head may have an underlying palsy of which occular cranial nerve?

CN IV (trochlear) > superior oblique


In a patient with a CNIV palsy, what will the Bielschowsky head tilt test show?

Eye elevates with head tilt to the side with the CNIV palsy


Describe the horizontal gaze pathways

Horizontal eye movements are conducted by the medial rectus and the lateral rectus muscles, which are innervated by the oculomotor nerve (cranial nerve III) and the abducens nerve (cranial nerve VI), respectively. The oculomotor and the abducens nuclei are interconnected by a tract in the brainstem named the medial longitudinal fasciculus (MLF). Through the MLF, the actions of the oculomotor and the abducens nuclei are coordinated, generating conjugate horizontal eye movements.


List the 3 disorders of horizontal eye movements

Lateral gaze palsy, internuclear ophthalmoplegia and one-and-a-half- syndrome


What is lateral gaze palsy caused by?

Lateral gaze palsy is caused by a lesion involving the abducens nucleus (CNVI)


What is internuclear ophthalmoplegia caused by?

Internuclear ophthalmoplegia occurs as a result of a lesion involving the MLF (medial longitudinal fasisculus)


What is one-and-a-half syndrome caused by?

Combination of lateral gaze palsy and internuclear ophthalmoplegia caused by a lesion involving both the ipsilateral abducens nucleus (CNVI) and the ipsilateral MLF (medial longitudinal fasisculus)


What is lateral gaze palsy?

inability to produce horizontal, conjugate eye movements in one or both directions


Discuss the pathophysiology of lateral gaze palsy

Lesions of the cranial nerve VI (abducens) nucleus in the pons cause ipsilateral, horizontal gaze palsy by disrupting motoneurons that innervate the ipsilateral lateral rectus muscle by way of cranial nerve VI, and interneurons that connect to the contralateral cranial nerve III nucleus in the midbrain, via the medial longitudinal fasciculus, to stimulate the medial rectus of the opposite eye


What are the 5 types of eye movement?

Vestibular, optokinestic, sacacdic, smooth pursuit and convergence


List at least 3 of the inappropriate saccades seen in eye disorders

1. Square wave jerks 2. Macro square wave jerks 3. Flutter 4. Opsoclonus 5. Voluntary nystagmus


What are the 2 physiological types of nystagmus?

1. Physiological nystagmus 2. Pathological nystagmus


What are the 2 types of physiological nystagmus?

Vestibular nystagmus and optokinetic nystagmus


List the 3 common types of pathological nystagmus

1. Vestibular 2. Cerebellar/brainstem 3. Congenital


List 2 different rhythms seen in nystagmus

Pendular, jerk


Pure vertical nystagmus in primary position implies what sort of cause?



What sort nystagmus is unaffected by posture, better on convergence or lid closure but worse with fixation, attention and anxiety?

Congenital nystagmus


What is learning?

Process of acquiring new information and results in an observable change in behaviour


What is memory?

The encoding, storage and retrieval of learned information


List some types of molecular memory

1. DNA, RNA 2. Epigenetic tage on DNA 3. Changes in transcription (programs) 4. Conformational changes of protein (prion) 5. Protein modification 6. Changes in intracellualr signalling cascades


List some types of neuronal memory

Synaptic plasticity, changes in intracellular signalling cascades (kinases, phosphatases), structural changes (growth of dendrites or pruning), changes in excitability, consolidation of memory to achieve storage


What is delarative memory? Give some examples

Items available to consciousness and can be expressed by language ('declare'): phone number, song, images of previous events


What is nondeclarative memory? Give some examples

Items not directly available to consciousness: skills (skiing), associations, priming cues etc. Difficult ot express how procedures are enacted.


What are the 2 major categories of memory?

Declarative and non-declarative


What are the 3 types of delarative memory?

Daily episodes, words and meanings, history


What are the 4 types of non-declarative memory?

Motor skillls, associations, priming cues and puzzle-solving skills


What are the temoral categories of memory?

Immediate memory (retention of experiences for less than 1 second) ; Working memory (holding of experience to achieve behavioural goal - seconds - minutes); Lon-term memory (days to years) - long-term retention - requires transfer from working memory to memory via consolidation


What sort of memories are forgotten fastest?

Those of no particular importance (short-term)


What sort of memories deteriorate over time?

Unused memories (normal process)


What is anterograde amnesia?

Inability to create new memories


What is retrograde amnesia?

Inability to retrieve made memories


List the 2 types of pathalogical amnesia

1. Anterograde 2. Retrograde


Anterograde amnesia affects what type of memory?

Declarative memory


Explain why someone with anterograde amnesia may not remember daily life, words and history, but may be able to learn new motor skills?

Because anterograde amnesia primarily is associated with loss of delarative memory, but not non-declarative memory.


Vascular occlusion of both posterior cerebral arteries causes damage to which sites that can lead to anterograde amnesia?

Bilateral medial temporal lobe and hippocampus (CA1)


Midline tumours can cause damage to which sites that can lead to anterograde amnesia?

Medial thalamus bilaterally (may involve hippocampus is large enough)


There is a tight correlation between ____ damage and anterograde amnedia

Hippocampal (medial temporal lobe)


What functions of the hippocampus are destroyed as a result of damage to the medial temporal lobe?

Formation of memory and processing for consolidation (but not memory storage, as hippocampus not responsible for this)


Trauma, surgery and infections can cause damage to which speicifc site that can lead to anterograde amnesia?

Bilateral medial temporal lobe


Vitamine B deficiency can cause damage to which specific sites that can lead to anterograde amnesia?

Medial thalamus and mammillary bodies


Discuss the brain changes seen in taxi drivers

Larger posterior hippocampal volume (as hippocampus is an encoder and temporary buffer for short-term and working memory)


Which 2 brain areas are considered to be systems for declarative memory?

Hippocampus and parahippocampal gyrus


Discuss the input and output of the hippocampus as a system for declarative memory

Widespread projections from association neocortex converge on the hippocampus. The output is ultimately directed back to the same neocortical areas.


What abnormality occurs in Wernicke's aphasia of the superior temporal lobe?

Inability to link sound with meaning of word


What abnormality of memory occurs in patients with temporal lobe lesions?

Inability of recognise objects and/or faces


What lobe is involved in the attempt to retrieve long term memories?



What part of the brain is specifically activated when recalling vivid memories?

Visual association cortex


List the 5 areas of the brain involved in non-declarative memory

1. Basal ganglia 2. Prefrontal cortex 3. Cerebellum 4. Amygdala 5. Somatosensory cortex


Give an example of an action which proves that there are more integrative systems involved in non-delarative compared to declarative memory

Perceptual priming, eye blinke etc.


Decrease in learning task performance in Parkinson's disease is improved with the use of which NT drug?



Which pathway of the basal gangalia is of special importance to motor skill learning?

Prefrontal cortex loop


Which NT is involved in memory formation of motor skill learning?



Sleep improves what type of memory?



Improved consolidation of nondeclarative memory/learning in sleep is tightly correlated with what sleep stage at what time of night?

NREM stage 2 (deep sleep) in the fourth quarter (towards morning)


The conversion of short-term to long-term declarative memory relied on what specific function?

NREM sleep


Short term declarative memory is sotred in what area?

Hippocampus and related structures


Short term non-declarative memory is sotred in what area?

Unknown, but presumably widespread


Long term declarative memory is offloaded from the hippocampus and stored in what cortical areas?

Variety of cortical areas: Wernicke's area (words), temporal cortex for objects, faces etc.


Long term non-delarative memory is stored in what area?

Cerebellum, basal ganglia, premotor cortex, and other sites related to motor behaviour


What is synaptic plasticity?

Changes in synaptic efficacy, including postysynaptic excitability and spine/cellular growth


In relation to the cellular basis of memory, what is the name given to synapses that become stronger with time? What is the opposite?

Long-term potentiation; long-term depression


List the 4 changes observed as a result of tetanic stimulation of PP (perforin path)

Population spike increase, increase in excitability, increased field EPSP (reflection of synaptic currents) and increased synaptic currents


Tetanic stimulation of PP (perforin path) causes changes that last for how long?

over 12 hours - up to months


List and describe the 3 properties of long-term potentiation

1. Input specific - only stimulated synapses potentiate 2. Associativity: when a weak input is sufficient for induction, strong stimulation of another input induces LTP at both inputs 3. Cooperatively - several small inputs each insufficient for induction, when stimulated together induce a LTP


What occurs in the induction phase of long-term potentiation?

Immediate postsynaptic calcium rise; mostly via NMDA receptors


What occurs in the expression phase of long-term potentiation?

Calcium activated; insertion and phosphorylation of AMPA receptors causing larger post-synaptic current and altering receptor cycling > main effect is increase in excitability


What occurs in the maintenance phase of long-term potentiation?

Autoactivation of CaMK II - protein synthesis is activated and there is growth of new excitatory synapses; gene expression is altered (CREB)


Which 3 factors improve memory formation?

1. Association 2. Motivation 3. Forgetting


Declarative memories rely on the _____ as a buffer, and on the ____ as final storage

Hippocampus; cortex


Non-declarative memories rely on specifiv areas of the brain typically involved in what functions?

Motor control and coordination


Long term potentiation is induced ____synaptically via ____ ions via ____ receptor

Post; calcium; NMDA


How is long term potentiation maintained?

Via altered gene expression and protein synthesis


The caudate nucleus is located next to which brain structures?

Latreal walls in lateral ventricles


What are cortico-striatal circuits?

Neural networks that allow organisms to interact adaptively with their environments


Which 2 main components make up neural networks in the brain?

Hubs (nuclei, cortical loci) and spokes (white matter neural connections)


List the 5 cortico-striatal circuits

1 Orbitofrontal circuit 2. Anterior cingulate circuit 3. Occulomotor circuit 4. Dorsolateral prefrontal circuit 5. Supplementary motor circuit


The cortico-cerebellar pathway exists between which major structures?

Cerebellum, cortex, pons, thalamus


Which 2 cortico-striatal circuits regulate motor functions? What are the other functions of these pathways?

SMC and OMC - influence skeletomotor and oculomotor areas of the cortex


Which 3 cortico-striatal circuits regulate non motor areas of the prefrontal cortex?



Discuss the origin, projection and clinical manifestations related to the orbitofrontal circuit

Originates in orbitofrontal regions; projects to the ventromedial caudate nucleus; clinical manifestations are characterised by deficits in social judgement and impulse control


Discuss the origin, projection and clinical manifestations related to the anterior cingulate circuit

Originates in anterior cingulate gyrus; projects to ventral striatum (nucleus accumbens); clinical menifestations are apathy, akinetic mutism and are characterised by lack of motivation


Damage to which cortico-striatal circuit may cause deficits in social judgement and impulse motor control?



Damage to which cortico-striatal circuit may cause apathy, akinetic mutism and lack of motivation?

Anterior cingulate circuit


Discuss the origin, projection and clinical manifestations related to the oculomotor circuit

Originates at the FEF and posterior parietal cortex; projects to the body of the caudate nucleus; clinical menifestations include visuospatial dysfunction and visual apraxia


Damage to which cortico-striatal circuit may cause visuospatial dysfunction and visual apraxia?

Oculomotor circuit


Where does the dorsolateral prefrontal circuit originate and project to?

Originates at the dorsolateral surface of the anterior frontal lobe; projects to dorsolateral had of the caudate nucleus


What are the functional roles of the dorsolateral prefrontal circuit?

Regulate executive function - anticipation, goal selection, planning, use of feedback in task performance, cognitive flexibility


Where does the supplementary motor circuit originate and project to?

Originates at the supplementary motor, premotor and motor cortices; Projects to the putamen


What are the functional roles of the supplementary motor circuit?

Planning and execution of movement as well as regulating overall amount, scale and focus of movement


Huntington's disease is a ____ change in cortico-striatal circuits, whereas Parkinson's disease is a _____ change

Structural; functional


Huntington's disease primarily affects the _____, whereas Parkinson's affects the ______ (both basal ganglia structures)

Caudate; putamen


What is the inheritence pattern of Huntington's disease?

Autosomal dominant


What is the best known disorder affecting primarily the caudate nuclei (although atrophy becomes widespread with disease progression

Huntington's Disease


Describe some of the gross changes in the brain of a patient with Huntington's disease

Dlation of lateral ventricles and atrophy/death of caudate


Compare the motor changes seen in Pre-Huntington's disease vs Huntington's disease

Minor deficits in more complicated tasks vs chorea +/- tics, gait disturbance, incoorination, eye movement disorders


Compare the cognitive changes seen in Pre-Huntington's disease vs Huntington's disease

Executive dysfunction, mild impairment and slower processing speeds vs HD dementia


Compare the psychiatric changes seen in Pre-Huntington's disease vs Huntington's disease

Anxiety, paranoid ideation, psychotic elements vs disibhibition, apathy, depression, anxiety, delusional disorder, psychosis, suicidal behaviour


Huntington's disease disrupts the ______ ______ circuit by damaging the _____ ____ node

dorsolateral prefrontal circuit; caudate nucleus node


Cognitive deficity in huntington's disease reflect involvement of what basal ganglia structure?

Head of caudate nucleus


Which proteins fold abnormally and become neurotoxic in Parkinson's disease?



At diagnosis of Parkinson's, what % of cell death has already occurred?



What are the motor manifestations of Parkinson's disease?

Akinesia, bradykinesia, tremor, rigidity, postural instability


What are the neuropsychiatric manifestations of Parkinson's disease?

Autonomic, REM sleep behaviour, hyposmia, cognitive, depression, demantia


Parkinson's disease disrupts the ____ _____ circuit due to loss of dopaminergic input to _____ node

Supplementary motor; putamen


Insufficient dopamine at the putamen has what effect on the motor cortex? What physical signs correlate with this?

Increased thalamic inhibition of motor cortex = rigidity and bradykinesia


How can deep brain stimulation work as a treatment for parkinson's disease?

DBS mimics a lesion using electrical implants and pacemaker > can be used to minimise abnormal neuronal drive of subthalamic nucleus, globus pallidus internus and thalamus > restores the functioning of the supplementary motor circuit by reducing inhibition of thalamus over motor cortex > enables voluntary movement and reduces rigidity


The cortex of the cerebellym consists of how many layers?

3 layered sheet of organised cells and fibres


Describe the cortico-cerebellar circuit that connects the cerebellum to the prefrontal regions

Cerebellum > ventral dentate nucleus > thalamus > prefrontal cortex > pontine nucleus closes the loop to the cerebellum again


Describe the cortico-cerebellar circuit that connects the cerebellum to the motor regions

Cerebellum > dorsal dentate nucleus > thalamus > motor regions > pontine nucleus closes the gap to the cerebellum again


What is the purpose of cortico-cerebellar circuits and motor inolvement?

Circuits connected to motor regions enable integration of separate movements into a coordinated whole


What is the purpose of cortico-cerebellar circuits and congnitive inolvement?

Circuits connected to prefrontal regions conduct automatic information processes, leaving the prefrontal cortex free to solve new cognitive problems


List 5 manifestations of cerebellar ataxias

Gait/posture: instability, balance issues, falling and tripping; Fine motor incoordiantion: difficulty handwriting, cutting food, buttoning; Speech: slurred and slow (agrammatism); Cognitive: impaired memory, incorporating information, kaing plans and ordering thoughts; Mood: increased irritability, anxiety and depression


What factors are needed to establish a diagnosis of inherited cerebellar ataxia?

Detection of symptoms, positive FHx of ataxia, causatative allelic variant to a gene associated with hereditary ataxia, clinical phenotype characteristic of a genetic form of ataxia


Executive motor movements are under the direction of which brain areas?

Area 6 (primary motor cortex) and basal ganglia


What is area 6 of the brain responsible for?

Skilled voluntary motor movements


The secondary motor area innervates which muscle group directly?

Distal muscle groups


The premotor area of the brain connectes with _____ neurons to innervate _____ motor units

Reticulospinal neurona; proximal motor units


Which area of the brain is involved in the design of movements?

Premotor area


Where does the neostriatum get inputs from?

Cortex and substantia nigra pars compacta


Where is the subthalamic nucleus located?

Below the thalamus and above the hypothalamus


What is the net effect on motor activity from the direct basal ganglia pathway?

Increases motor activity


What is the net effect on motor activity from the indirect basal ganglia pathway?

Decreases motor activity


What signs must be absent in order to diagnose a movement disorder?

Absence of spacticity (i.e., not involving corticospinal tracts), absense of weakenss and decreased coordination


Movement disorders are a groups of neurological conditions which exhibit which 2 major features?

1. Paucity of movement (brady/hypo/a-kinesia) 2. Excess of abnormal involantry movement


What causes the signs seen in movement disorders?

Increased muscle contractions and motor inhibitions (asterixis, cataplexy)


List at least 4 types of bradykinetic movement diroders

Parkinsonism, catatonia (psychomotor depression), neuroleptic malignant syndrome, gait freezing (gait apraxia), stiffperson syndrome and cataplexy


Which system of the brain is mostly affected in Parkinsons?

Extra pyramidal


List the 4 cardinal features that assist in the diagnosis of Parkinsons disease

1. Tremor 2. Rigidity/stiffness 3. Slow movement (bradykinesia) 4. Loss of balance (postural instability)


List at least 5 red flags for minics of Parkinsons' disease

Absence of tremor, symmetrical onset, rapid progression, cognitive decline, pyramidal signs and dysautonomia


List the areas affected by loss of dopamine producting cells in Parkinsons

Substantia nigra, bain stem, olfactor tract and gut


At what % of cell loss does Parkinson's disease cbbecome symptomatic?



Lewy body formation is seen in which neurodegenerative disorder?



Dopamine deplation in Parkinsons causes issues in which 3 major areas?

1. Motor 2. Automonic 3. Cognition


List at least 3 anti-Parkinson medications

Levodopa, dopamine agonists, MAO type B inhibitors, COMT inhibitors, amantadine


What is stiff person syndrome?

Muscle rigidity and spasm involving axial and limb muscles (possibly autoimmune against GABA transmission)


List at least the 4 diagnostic criteria for stiff person syndrome

1. Insidious onset of muscular rigidity with difficulty turning or bending, most prominent in limbs/axial muscles (esp abdo and thoracolumbar) 2. Co-contraction of agonist and antagonist muscles, confrimed clinically and electrophysiologically 3. Episodic spasms superimposed on the underlying rigidity, precipitated by noise, tcile stimuli or emoton upset 4. Absence of other neurologic or systmic disease to explain the symptoms


List the clinical findings of a patient with stiff person syndrome

Rock hard muscles in symptomatic regions, hyperlordosis, paraspinal muscle spasm, stiff gait, stiffness of a single limb, sustained clonus, hyperreflexia, cerebellar syndrome and cock-up toe


Give an example of an immunomodulator drug that may be used to treat a patient with stiff persons syndrome

Predisoone, methylprednisolone, IVIG, plasma exchange


Give an example of an immunosuppresant drug that may be used to treat a patient with stiff persons syndrome

Cyclophosphamide, azathioprine, rituximab


Give an example of synptom-control drug that may be used to treat a patient with stiff persons syndrome

Baclofen, clonazepam, levodopa


What is the tetrad of neuroleptc malignant syndrome?

1. Altered mental status 2. Muscle rigiditiy 3. Fever over 38 degrees 4. Autonomic instability


Discuss the pathophysiology of neuroleptic malignant syndrome

Inhibition of central dopamine receptors in hypothalamus - causing increased heat generation and decreased heat dissipation


What sort of drugs may cause neuroleptic malignant syndrome?

Typical antipsychotics or sudden withdrawal of L-Dopa


Which blood chemistry marker correlates with increased severity of neuroleptic malignant syndrome?

Creatinine Kinase


Discuss the abnormalities seen in investigations for neuroleptic malignant syndrome

Elevated CK, leucocytosis, mildly elevated LDH, ALP and transaminases, increase potassium and/or decreased magnesium


What is the treatment for neuoleptic malignant syndrome?

Stop the offending drug, give a muscle relaxant and supportive therapy (such as antipyretics).


List 3 signs to watch for when treating a patient for neuroleptic malignant syndrome

Dehydration, ARF with rhabdomyolysis, arrythmis respiratory failure, DVT and seizures


The initial therapy for parkinsons disease depends on which patient factor?



List some of the symptoms in late parkinsons disease

Non-motor symptoms and motor fluctuations


What are some of the treatment options for late parkinsons?

Apomorphine, duodopa, DBS


50-60% of patients with stiff persons syndrome have which marker in the serum and CSF?



Give at least 3 examples of hyperkinetic rhythmic movements

Tremor, myoclonus, myorhythmia, dystonic tremor, periodic movements in sleep


Give at least 3 examples of hyperkinetic irregular movements

Tics, chorea, athetosis, dystonia, ballism, hemifacial spasm


What is the definition of tremor?

Involuntary rhythmic, repetitive, oscillatory movement of a body part around a central joint caused by alternate contraction of agonist and antagnosit muscles


What sort of drugs can be used for essential tremors?

Beta blockers, primidone, clonezapam


What sort of surgery may be used to stop essential tremors?

DBS of thalamus


What is the definition of myoclonus/startle?

Sudden brief, shock-like jerky movements of limb/axial muscles


What is restless leg syndrome?

Unpleasant sensation in legs with irresistable desire to move (which provides relief) especially when lying down and mostly when about to sleep.


What may be used in the treatment of restless leg syndrome?

L-Dopa, DA


List some of the disorders that restless leg syndrome is associated with

Hereditary, neuropathy, uraemia, iron deficiency, pregnancy hypothyroidism


What is the definition of tics?

Brief, quick, coordinated, intermittently repetitive movements or sounds of a single muscle group - able to be suppressed


What are the 4 clinical type of tics?

1. Simple motor 2. Complex motor (purposeful) 3. Simple phonic 4. Complex phonic (linguistic)


List 1 drug that may be used to treat tics?



Define chorea

Involuntary, irregular unsustained movements, purposeless and non-rhymic in nature


List some of the primary and secondary causes of chorea

Primary = huntingtons, benign hereditary chorea, neuroacanthocytosis; Secondary = Sydenhams chorea, immune mediated SLE, infecious chorea and from drug use


What is ballism?

Proximal, flinging random movements that are usually unilateral and improve spontaneously


What is athetosis?

Writhing, random, slow chorea induced by voluntary movements


What is the definition of dystonia?

A syndrome of sustained/intermittent contraction of voluntary muscles frequently causing twisting and repetitive movement or tremor/abnormal postures sometimes associated with pain


List at least 3 pharmacological treatments for dystonia

Anticholinergics, antiepileptics, antidopaminergics, muscle relaxants, target-specific (botox)


Describe the mechanism of action of botulinum toxin

Once inside cell, blocks release of ACh transmitter. This results in chemo-denervation


What is a hemifacial spasm?

Unilateral, involuntary contraction of one side of the face. Chronic and progressive caused by compression of the facial nerve by arteriole.


What is hemifacial spasm often misdiagnosed as?

Epilepsia partalis continua


Describe the different clinical signs observed in abductor vs adductor types of laryngeal dystonia

Abductor type = whispering voice; Adductor type = strangled sound (spasmodic dysphonia)


Huntington's disease is an inherited form of ____



Drug-induced movement disorders are commonly due to which class of drug?

Antipsychotic agents


What age groups of men and women are most commonly affected by gout?

Men over 40 and women over 55 (male prevalence 5:1)


List at least 5 risk factors for gout

Hyperuricaemia, obesity, high-prurine diet (red meat), alcohol, high fructose drinks, medications (thiazide diuretics or cyclosporin), renal insufficiency, lead exposure, organ transplantaion, hypertension, diabetes, hyperipidaemia etc.


List at least 3 explanations for why there is an increased prevalence of gout in the elderly

Longevity of population, increased prevalence of vascular disease, increased use of diuretics, immunosuppressive therapies, renal disease and transplants, obesity and associated metabilic syndrome, dietary trends


What is the link between cardiovascular disease and gout?

Both gout and CVD are associated with serum markers of inflammation - CVD risk is increased in people with gout or hyperuricaemia


Uric acid is the end product of what metabolic process?

Purine metabolism


Uric acid is present in the serum and tissues in what form?

Monosodium urate


At what point do uric acid levels supersaturate the serum and precipitate into tissues?

0.4mmol/L monosodium urate


Discuss the basic process that leads to gout

When serum uric acid (monosodium urate) levels rise too high (above 0.4mmol/L), it supersaturates the serum and precipitates into tissues. An acute gouty attack occurs when monosodium urate crystals are released or form de novo in joint spaces. Crystals induce inflammation and phagocytosis by neutrophils (plus the release of Iinflammatory mediators)


List at least 2 medications that can abruptly alter uric acid levels and incite an attack of gout

llopurinol, diuretics


Aside from drugs, what other factors can rapidly change uric acid levels and incite a gout attack?

Trauma, surgery, infections


Discuss the pathophysiology of gout

Serum urate rises and becomes supersaturated > precipitates into tissues, forming monosodium urate crystals > crystals phagocytosed by leucocytes > once inside cell, crystals trigger inflammatory reaction which is mediated by a group of inflammasome proteins > inflammasome potentiates IL-1 converting enzyme, which formed active IL-1 beta > further release of inflammatory cytokines, prostaglandings and vasoactive pepties and local amplification of the process occurs


What is the inflammasome?

A multi-proteins cytoplasmic complex that activates cascades and leads to the processing and secretion of proinflammatory cytokines such as IL-1beta


What mediates inflammasome assembly?

NOD-like receptor protein family members that carry an N-terminal pyrin domain (NLRPs) or a capsase-recruitment domain (NLRCs)


NLRP3 (nod-like receptor with N-terminal pyrin domain) can be activated by what molecular patterns?

Pathogen-assocated (PAMPS) and damage associated (DAMPS)


List the 2 main types of acute gout

Mono-articular, oligo or polyarticular


List a type of chronic or interval gout

Tophaceous gout


What are the initial investigations for asumptomatic hyperuricaemia?

Fasting lipid profile and BSL and 24 hour urine UA


What are the initial investigations for symptomatic gout?

FBC, CRP, blood cultures, serum uric acid, EUC, LFT, fasting lipi profile and BSL. Synovial fluid for gram stain, cells, culture and crystals


What is the gold standard for diagnosing gout?

Demonstration of MSU (monosodium urate) crystals


Discuss the usefulness of US and MRI in gout investigation

Useful when there is a presence of tophii and larger crystal deposits, but no overall improvement in diagnostic sensitivity or specificity


What are the main differential diagnoses for gout?

Rheumatoid arthritis and pseudogout (calcium phosphate deposition disease), septic arthritis, cellulitis, reactive arthritis, ostoarthritis, psoriatic arthritis, sacoidosis


List some of the signs that favour a diagnosis of RA over gout

In RA: symmetrical polyarthritis of small joints common, hand involvement more likley, subcutaneous nodules may be present, imagine will show soft tissue welling, diffuse joint-space narrowing, marginal erosions of small joints


List some of the signs that favour a diagnosis of pseudogout over gout

In pseudogout: appears in unusual places like the wrist or elbow without trauma, loows like RA or osteoarthritis on imaging but shoes signs of repair, there is cartilage calcification


List some of the signs that favour a diagnosis of septic arthritis over gout

Septic arthritis: fever, great tenderness, joint sepsis may be present, may have concommitant rheumatoid arthritis, source often evident, imaging shows swelling and effusion


List some of the signs that favour a diagnosis of cellulitis over gout

In cellulitis: erythema, swelling of extremity, very tender, often febrile, sodt tissue lymphatic drainage abnormal due to peripheral venous insufficiency, soft tissue swelling on imaging


Cellulitis is often due to infection by which pathogens?

Staph or strep


List some of the signs that favour a diagnosis of reactive arthritis over gout

In reactive arthritis: soft tissue swelling, oligoarthritis, weight bearing joints affected at tendon insertions, dactylitis may cause digits to resemble sausages, depending on infecting pathogen, may also see other signs of infection like skin changes, conjunctivitis etc.


List some of the signs that favour a diagnosis of OA over gout

Bony enlargement without acute inflammation, exacterbation of joint symptoms after use, imging shows focal joint space loss, bony repaire with osteophytes and subchrondral sclerosis, central erosions may be present in finger joints and often involves bunions (which is also common in gout)


What is halus valgus?



Compare and contrast MSU crystals vs CPPD crystals

CPPDs are rhomboid or rectangular and have positive birefringence, but less so than MSU (appear blue). MSU crystals are brghtly birefringement and needle shaped and appear yellow.


If suspecting gout and synovial fluid analysis comes back negative for crystals, what could have happened?

Delay in examining unrefrigerated fluids


Why is hyperuricaemia (even when asymptomatic) clinically relevant?

Due to urate-related associations with hypertension, insulin resistance and CVD > therefore require screening and lifestyle modification


Discuss the recommended primary prevention of gout

Dietary modification and weight loss to reduce risk factors and lower serum urate levels. Pharmacologic therapy only recommended in patients on chemotherapy for haematologic malignant conditions


Discuss why pharmacologic therapy is recommended as primary gout prevention in patients on chemotherapy for a haematologic malignant condition

Uric-acid lowering drugs and hydration prevent secondary group due to tumour lysis. Without this treatment, uric acid neuropathy with tubular obstruction can develop


List the symptoms and physical examination findings that suggest gout

Warmth, swelling, redness, severe and episodic self-limiting joint pain, attacks at night or early morning


Acute gout attacks usually subside in what time period?

3-14 days without treatment


What are the common sites for crystal deposition/tophus deposition in gout?

Helix of the ear, lower extremities


List some of the risk factors that increase the liklihood of progression fro asymptomatic hyperuricaemia to gout

Renal impairement, lymphoproliferative or myeloproliferative disorders, psoriasis, vitamin B12 deficiency, current chemotherapy for blood malignancy


What is the long term aim for the management of gout?

Reduce serum uric acid levels to below 0.36mmol/L


What are the general indications for urate-lowering treatment in gout?

Recurrent attacks, chronic tophaceous gout, presence of changes on imaging, coexisting nephrolithiasis, renal insufficiency, presence of metabolic syndrome and coexisting gout with diuretic therapy


What sort of diet should be recommended in patients with gout?

Decrease high-purine foods, reduce alcohol and surgary drinks, lots of water, high fibre, high vit C, high folate


List some high-purine foods

Red meat, seafood, yeast products like baked goods, mushrooms, spinach, asparagus, cauliflower, legumes


List the 3 broad classes of anti-gout drugs and state how each works

1. Xanthine oxidase inhibitors (reduce production of serum uric acid) 2. Uricase enzyme analogues (reduce SUA by converting to allantoin) 3. Uricosuric agents (increase UA excretion)


Which drugs are first-line for treating acute gout?

NSAIDs - due to anti-inflammatory and analgesic effects


What is pseudogout?

A crystal arthropathy associated with ageing, where there is acute arthritis with characteristic calcifications in cartilage (chondrocalcinosis) and calcium pyrophosphate dihydrate (CPPD) crustals in synovial fluid


What is the calcification of cartilage called (as in pseudogout)?



Which joints are commonly involved in pseudogout?

Knees, wrists, shoulder, hips and ankles


Pseudogout has greatest prevalence in which age group?

Over 85 years


What is essential in the diagnosis of pseudogout?

Demonstration of crystals in synovial fluid analysis (supported by radiographic cartilage calcification)


What disorder should be expected when radiological features of OA are evidence in joints not commonly affected in primary OA?

CPPD crystal deposition disease (i.e., pseudogout)


List the 4 radiological features of gout

1. Erosions with overhanging margins 2. Sclerotic margins 3. Relatively well-preserved joint spaces 4. Soft tissue tophi


List the 3 major functions of the cerebellum

1. Maintain synergy of movement (coordination) 2. Maintain upright posture (and maintenance of balance) 3. Monitor and maintain muscle tone


List 3 functions that the cerebellum specifically monitors and adjusts

1. Contraction and relaxation of oppponent muscle groups 2. Intensity and duration of muscle contractions 3. Sequencing of contractions of muscle groups required to execute a specific movement


The cerebellum gets input from the motor cortex via which 2 pathways?

Cortico-pontine and ponto-cerebellar


The cerebellum gets feedback from the peripheral muscles via which pathway? What sort of information is this?

Proprioceptive information via spino-cerebellar tracts


The cerebellum feeds back to the control centres and brainstenabout muscle adjustments via which cortical structure?



Name and describe the 3 lobes of the cerebellar cortex

1. Anterior lobe (most of the superior surface) 2. Posterior lobe (most of the inferior surface) and 3. Flocculonodular lobe (discrete region at the anterior inferior surface


Which fissure separated the anteiror and posterior lobes of the cerebellum?

Primary fissure


Which fissures separates the posterior and flocculonodular lobes of the cerebellum?

Posterolateral fissure


List the important functional units that make up the pons

Pontine nuclei + corticospinal tracts + ponto-cerebellar fibres (middle cerebellar pedundle)


The ponto-cerebellar fibres pass from the pons to the cerebellum via which peduncle?

Middle cerebellar


List the 4 deep nuclei of the cerebellum

1. Dentate 2 & 3. Globose and Emboliform (collectively known as the interposed nulceus) 4. Fastigial


Which is the largest deep nuclei in the cerebellum?



Which deep nuclei of the cerebellum feeds back to motor cortical areas?



The globose and embolifm nuclei of the cerebellum are collectively known as which nucleus?

Interposed nucleus


Describe the location of the deep fastigial nuclei in the cerebellum

Adjacent to midline, sandwhiched between midline and interposed nucleus


The interposed nucleus of the cerebellum is associated with what function?

Spino-cerebellar feedback


The fastigial nuclei of the cerebellum have functions associated with what system?

Vestibular system


All inputs to the cerebellum terminate at what point?

In the cerebellar cortex


The cerebellar corte projects to which structures?

Deep cerebellar nuclei


All output from the cerebellum originates from which structures?

Deep cerebellar nuclei


Deep nuclei outputs in the cerebellum go to which areas?

Thalamus and brainstem nuclei


Describe the pathway that originates from the cortex (or pons) and travells through the cerebellum (include what part of the cerebellum the input is to, nucleus and output)

Input > cerebro-cerebellum > dentate nucleus > to UMNs in premotor cortex


Describe the pathway that originates from the spinal cord and travells through the cerebellum (include what part of the cerebellum the input is to, nucleus and output)

Input from spinal cord > spino-cerebellum > interposed nuclei > outputs to UMNs in the motor cortex and brainstem


Describe the pathway that originates from the vestibular and motor eye cortices and travells through the cerebellum (include what part of the cerebellum the input is to, nucleus and output)

Input > vestibulo-cerebellum > fastigial nuclei > output through vetibular nuclei to LMNs in the medial ventral horn of the spinal cord


What information is provided to the cerebellum via the middle cerebellar peduncle (from cortex via pons)?

Informs cerebellum of plan/intention of movement


The cerebellum receives information from the spinal cord via which structure?

Inferior cerebellar peduncle


Name the 5 sets of fibres with input ot the cerebellar cortex

1. Ponto-cerebellar 2. Reticulo-cerebellar 3. vestibulo-cerebellar 4. spino- and cuneo-cerebellar 5. olivo-cerebellar


Outputs to from the cerebellum are sent to the cortex via the _____, with collaterals sent to the ____ _____ and _____ nucleus

Thalamus; superior colliculus; red nucleus


What are the afferents of the superior cerebellar peduncles?

Ventral spinocerebellar tract (from mechanireceptors in the trunk and lower limbs)


List the 2 output nuclei for efferent information from the superior cerebellar peduncle, along with the primary and secondary target from each nuclei

1. Dentate nuclei > VL thalamus > red nucleus 2. Globose/embomiform nucleus > red nucleus > VL thalamus


Cerebellar terminals in the thalamus map co-register with the terminals of which basal ganglia structure?

Globus pallidus internus


Which is the only cerebellar peduncle to carry ONLY afferent information?

Middle cerebellar peduncle


Decribe the pathway of afferent inputs of the middle cerebellar peduncle?

Cell throughout cerebral cortex send axons through the medial and lateral third of te peduncles > these synapse in pontine nuclei > ponto-cerebellar fibres then cross the midline and enter the cerebellum via MCP and terminate in the cerebellar cortex


What are the afferents of the inferior cerebellar peduncles?

Dorsal spino-cerebellar tract fibres and cuneo-cerebellar tracts (also carries inputs from inferior olivary nucleus, vestibular nuclei and brainstem reticular formation)


What are the efferent of the inferior cerebellar peduncles?

Fastigial nucleus sends axons to terminate in the brainstem vestibular nuclei


Dorsal spino-cerebellar tract fibres originate from cells in what structure? What information do these carry?

Clarke's column (C8-L3); get proprioceptive input from lower limbs and lower trunk


The dorsal spino-cerebellar tract fibres terminate in what part of the cerebellum?

Cortex of the anterior lobe


The cuneo-cerebellar tract fibres terminate in what part of the cerebellum?

Cortex of the anterior lobe


Cuneo-cerebellar tract fibres originate from cells inw hat structure? What information do these carry?

Accessory cuneate nucleus which get input from proprioceptive fibres in levels above C6


The inferior olivary nucleus facilitates what function?

Motor learning


The inferior olivary nucleus gets descending input from which nucleus?



Where does the inferior olivary nucleus send axons to?

C/L cerebellar cortex of the anterior and posterior lobes (olivocerebellar fibres)


The olivo-cerebellar fibres comprise a specific input to the cerebellar cortex known as _____ fibres



What do the climbing fibres of the inferior olivary nucleus do?

Fine tune motor response, especially during learning


What are the 2 sorts of fibre inputs into the cerebellum?

Climbing fibres and mossy fibres


Climbing fibres that provide input to the cerebellum have their cell bodies in which nucleus? Where do thes efibres receive input from?

Inferior olivary nucleus; input from cerebral motor cortex and cerebellum via red nucleus


What is believed to be the function of the climbing fibres supplying the cerebellum? When are they most active?

Encoding of sensory input independently of attention or awareness; most active during learning/training


Climbing fibres excite one ______ cell, whilst mossy fibres excite many _______ cells, which in turn activate many _____ cells

Purkinje; granulate cells; Purkinje cells


List the 5 typical cell types of the intrinsic cerebellar circuitry

Purkinje, granule, asket, stellate and golgi


What do granule cells in the cerebellum do?

Connect many Purkinje and climbing fibres, thereby functionally connecting adjacent structures of the body represented in the cerebellum


Which cells of the intrinsic cerebellar circuitry form parallel fibres? What is the advantage of this?

Granule cells; each parallel fibre contacts tens of thousands of Purkinje cells


What is the orientation of Purkinje cells in the cerebellum? What is the advantage of this arrangement?

Dendrites oriented perpendicular to parallel fibres of granule cells; can contact 200,000 parallel fibres


Purkinje cells impose _____ input to deep nuclei of the cerebellum via ____ neurones

Inhibitory; projection


List the 3 function subdivisions of the cerebellum

1. Cerebro-cerebellum 2. Spino-cerebellum 3. Vestibulocerebellum


Cerebro-cerebellum > _____ > UMNs premotor cortex

Dentate nucleus


In which cortex of the cerebellum is the cerebro-cerebellum? What is it's associated nucleus? What is it's function?

Posterior lobe; dentate nucleus; influences cerebral cortex in the planning of movements, smoothes out execution of fine motor skills and corrects errors, and determines appropriate muscle tone


What are the 2 major inputs and single major output of te cerebro-cerebellum?

Inputs = ponto-cerebellar fibres, inferior olivary nucleus; Output = Thalamus and red nucleus


What would be the resultant clinical features of a lesion of the cerebro-cerebellum?

Hypotonia and intention tremor, dysmetria (overshooting targets), dysdiadochokinesia (loss of rhymic control, especially with alternate limb patterns) and loss of timing and speech control


Spino-cerebellum > ____ nuclei > UMN motor cortex and brainstem



What structures make up the spino-cerebellar cortex? What is its associated nucleus? What is its function?

Anterior lobe, vermis and paravermis; globose and emboliform nuclei; adjusts ventral horn activity and coordinates walking


List the 2 major inputs and 2 major outputs of the spino-cerebellum

Inputs = spino-cerebellar fibres, inferior olivary nucleus; Outputs = red nucleus and thalamus


What clinical features would results from a lesion of the spino-cerebellum?

Ataxic gait, uncoordinated, clumsy movements of the libs (as if drunk) and a stagger to the side of the lesion


______-cerebellum > fastigial nucleus > vestibular nuclei



Which parts of the cerebellar cortex make up the vestibulo-cerebellum? What is it's associated nucleus? What is it's function?

Floculonodular lobe, lingula; fastigial nucleus; coordinates posture, eye movements and head position in response to inputs from semicircular canals, visual pathways and extraocular muscles


List the 2 major inputs and 3 major outputs of the vestibulo-cerebellum

Inputs = semicircular canals, oculomotor nuclei; Outputs = vestibular nuclei, reticular formation and vestibulo and reticulospinal tracts


What clinical features would result from a lesion of the vestibulo-cerebellum?

Ataxic stance (swaying like a todler) and nystagmus (lateral, fast-slow eye movements)


Describe the basic information flow through the cerebellum

Input > cerebellar cortex > deep nuclei > output


Learning is achieved by synaptic tweaking by ____ fibres from the inferior _____ nucleus

Climbing; olivary


List the 4 key circuitry components of the cerebellum

1. Mossy and climbing fibres 2. Granule cells and parallel fibres 3. Purkinje cells 4. Deep cerebellar nuclei


Describe the flow of information through the cerebro-cerebellum

Cortex > pons > cerebellar cortex > dental nucleus > red nucleus/thalamus


Describe the flow of information through the spino-cerebellum

Spinocerebellar pathways > cerebellar cortex > interposed nucleus (globose + emboliform) > ned nucleus/thalamus


Describe the flow of information through the vestibulo-cerebellum

Eye motor cranial nerves and vesticular nuclei > cerbellar cortex > fastigial nucleus > vestibular nucleus/reticular formation