Flashcards in BB physiology Deck (102):
Structural changes in epilepsy
Loss of CA2 and 3 cells in the hippocampus
Temporal lobe and hippocampal sclerosis
Causes of secondary epilepsy
Cellular mechanisms of epilepsy
Abnormal neuronal excitability
What is the paroxysmal depolarising shift?
Depolarisation of the membrane causes a sustained burst of action potentials involving activation of NMDA receptors
Which drugs are used for tonic clonic seizures?
Which drugs are used for absence seizures?
Which drugs are used for myoclonic seizures?
Which area is used for DBS in epilepsy?
Anterior nucleus of the thalamus
What diet can be used for epilepsy?
What is optic neuritis?
Inflammation of the optic nerve
Seen in MS
What is internuclear ophthalmoplegia?
Damage to the MLF resulting in impaired adduction of the eye during head rotation
Seen in MS
What is Lhermitte's symptom?
Electric shock sensation down the back of the leg
What is Uhthoff's phenomenon?
Worsening of neurological symptoms in increased temperature due to increased velocity of nerve conduction
Where are MS lesions commonly found?
Cervical spinal cord
Brainstem and cerebellar connections
MS lesions enhance with what?
What does the McDonald's criteria state for MS diagnosis?
Presence of neurological symptoms
Dissemination in time
Dissemnination in space
Exclusion of other causes
HLA molecule implicated in MS
No evidence of disease activity in MS
No increase in disability
No new or active lesions on MRI
Which artery is most commonly occluded in the posterior circulation?
3 layers of the cerebellar grey matter?
Outer molecular layer = axons and densrites
Single middle Purkinje cell layer
Inner thick granule layer
What is within the SCPs?
Output fibres to the thalamus and cortex
What is within the MCPs?
Input fibres from the contralateral cerebral cortex and cranial nerve nuclei
What is within the ICPs?
Input fibres from the spinocerebellar tract
State of reflexes and interneurones
Where is the fastigial nucleus found?
Where is the interpose nucleus found?
What males up the interpose nuclei
Where is the dentate nucleus found?
What is the nucleus for the flocculonodular lobe?
Lateral vestibular nucleus
What tracts does the spinocerebellum use?
Which lobe is the spinocerebellum?
Which lobe is the cerebrocerebellum?
Which lobe is the vestibulocerebellum?
What are the inputs and outputs of the cerebrocerebellum?
Input = MCP
Output = SCP
Medial vs lateral vestibulospinal tracts
Medial = head and neck
Lateral = postural muscles
What does medulloblastoma commonly cause?
Symptoms of FN syndrome
Fall towards side of lesion
Symptoms of anterior lobe syndrome
Incoordination of the limbs
Neocerebellar syndrome symptoms
Loss of eye scanning
Which cerebellar syndrome does alcoholism cause?
Anterior lobe syndrome
What does the premotor cortex do?
Integrates information from the more anterior parts of the frontal lobe and forms motor programs that are sent to the primary motor cortex
What does damage to the premotor cortex cause?
What does damage to the FEFs produce?
Problems with cognitive eye movements
Saccades, smooth pursuit, vergence
What does the dorsalprefrontal cortex do?
Planning of movements where we evaluate possible actions
What does the orbitofrontal cortex do?
Inhibition of motor responses associated with the limbic system
Where does the CST decussate?
What does the reticulospinal tract drive?
Sympathetic preganglionic neurones
Where does the rubrospinal tract originate from?
Where does the tectospinal tract originate from?
What does the tectospinal tract control?
Reflex head movements in response to auditory and visual stimuli
Arms in decorticate vs decerebrate
Decorticate = arms adducted and flexed
Decerebrate = arms adducted and extended
Which lamina is innervated by Ad fibres?
Which lamina is innervated by C fibres?
I and some interneurones in II
What substances do peptidergic C fibres release?
Anterior spinothalamic pathway
Mostly Ad fibres
From lamina V and IV
Discrimination and localisation
Projects to VPL, VPM, VPI, CL
Lateral spinothalamic pathway
Mostly C fibres
From lamina I
Emotionally punishing aspects of pain
Projects to MDvc, POs, VMpo --> anterior cingulate cortex and insula
Input to BG
Cortex --> striatum
Output from BG
--> VA/VL thalamus
Input to medium spiny neurones
Cortical via spines
SNpc --> spines, dendritic shafts, cell body
Cardinal signs of PD
Tremor at rest
Loss of postural reflexes
Cardinal signs of Huntingdon's
Ballismus = jerky
Athetosis = smooth
APOE in AD
E4 = greatest risk
E2 = protective
Beta and gamma secretases
CSF markers of AD
Decreased beta amyloid
Signs of subfalcine herniation
Signs of transtentorial herniation
CN III damage
Signs of tonsillar herniation
Reduced respiratory drive
Rostral vs caudal ACC
Rostral = actions in response to pain
Caudal = registers quality of pain
Posterior cingulate cortex function
Orbitofrontal cortex function
What acts to take in response to pain
Symptoms of Wernicke-Korsakoff syndrome
Some retrograde amnesia
Kluver Bucy syndrome
Bilateral removal of amygdala
Altered sexual behaviour emotional changes
Pre-synaptic changes in LTP
Early = increase in glutamate release in response to anterograde transmitters (NO, CO)
Late = increase in number of glutamate release sites
Post-synaptic changes in LTP
Early = increased number and sensitivity of AMPA receptors
Late = increased number of synapses
Memantine = near to where Mg binds
Ketamine = allosteric site
Persistent vs permanent vegetative state
Persistent = >1 month
Permanent = >1 year
DBS for persistent vegetative state
Drugs for reduced consciousness
Chemicals in the blood affecting sleep
- low glucose
Where are sleep chemicals detected?
Where are diurnal rhythms detected?
Where do the preoptic and suprachiasmatic nuclei project?
What does the tuberomamillary nucleus release?
Where are orexins released from?
Which NT system is active during REM sleep/
Which NT is thought to be involved in remembering dreams?
Time limit for thrombolysis
Percent of strokes that are ischaemic
TOAST stroke classification
1 = large artery atherosclerosis
2 = cardioembolism
3 = small vessel occlusion
4 = other origin
5 = undetermined
ABCD2 score for TIA
Predicts risk of stroke
A = age>60 (1)
B = BP>140/90 (1)
C = clinical features --> hemiparesis (2), speech alone (1)
D = duration --> <1h (1) >1h (2)
D = diabetes (1)
Hospitalise if >4
Detect side to side movement and acceleration
High activity lying down
Detect activity forwards and backwards and up and down
High activity standing up
Endolymph vs perilymph
Endo = high K+, low Na+
Peri = high Na+, low K+
What do the semicircular canals detect?
How is each semicircular canal activated?
Lateral = side to side rotation
Anterior/superior = neck flexion
Posterior/inferior = neck extension
Which was around are the striola directions in the otolithic organs?
Utricle = towards striola
Saccula = away from striola
What does the striola divide the otoliths into?
Utricle = medial and lateral halves
Saccule = anterior and posterior halves
Which direction will nystagmus occur with warm irrigation?
Which direction will nystagmus occur with cold irrigation?
Benign paroxysmal positional vertigo
Can be detected by Hallpike manoeuvre