CNS

Question 1

A lady with albinism finds it difficult to go outside due to finding the sunlight too bright. In which structure is she lacking melanin? Why is this difficult for her?

Answer 1

Retinal pigmented epithelium

Albinism causes loss of pigmentation
Melanin in the retinal pigment epithelium prevents reflections within the eyeball
Loss of melanin in the RPE will cause reflections and everything will appear bright in bright light

Question 2

pt presents with right sided hemianaesthesia. Which lobe has most likely been affected to cause this finding?

Answer 2

Left parietal lobe

Question 3

Name one disorder that causes excessive movement

Answer 3

Huntingtons disease, stroke in subthalamic nucleus,

cerebellar lesion, Sydenham’s chorea

Question 4

Name one condition other than Parkinson’s disease that causes paucity of movement

Answer 4

Stroke of motor cortex, myasthenia gravis, motor

neurone disease, coma, brainstem herniation

Question 5

A stroke affected a pts posterior cerebral artery. Which other artery is involved to ensure that macular vision is preserved?

Answer 5

MCA (middle cerebral artery)

Question 6

technique to increase chance of eliciting tendon reflexes?

Answer 6

Jendrassik manouevre (clench teeth, interlock fingers and pull arms apart)

Question 7

Why do you get macular sparing after a stroke?

Answer 7

⇒ Stroke can affect the posterior cerebral artery

⇒ Most of occipital lobe will be lost

⇒ Middle cerebral artery supplies the occipital pole (represents the macula)

⇒ Macular function (central vision) will be spared

Question 8

How does the facial motor nucleus function?

Answer 8

• The part of the facial motor nucleus that supplies the upper half of the face receives UMNs from both hemispheres
• The part of the facial motor nucleus that supplies the lower face only receives a contralateral UMN input

Question 9

How do UMN lesions involving the face and facial nerve palsies differ?

Answer 9

• UMN lesions involving the face will spare the forehead

- True facial nerve palsies will affect all of the muscles of facial expression

Question 10

Differentiate between meningocoele, meningomylocoele and myeolocoele

Answer 10

Menigocoele = open bubble of just CSF, no spinal cord involvement

Meningomyelocoele- CSF AND spinal cord involved- Cystic lesion protrudes out through defect in the dorsal arches

Myeolocoele= spinal cord completely open due to incomplete vertebral arch
- Rachischisis

Question 11

What does the presence of xanthocromia in CSF suggest?

Answer 11

SAH occurred over 12 hours ago

Question 12

PCA aneurysms can compress which cranial nerve?

Answer 12

Oculomotor - it runs parallel to the PCA

Question 13

Damage where causes inferior quadrantanopias?

Answer 13

Damage to the superior optic radiations which run in the parietal lobe

Question 14

Damage where causes superior quadrantanopias?

Answer 14

Damage to the inferior optic radiations in the temporal lobe

Question 15

Where would you find a lesion that causes a contralateral homonymous hemianopia with macular sparing?

Answer 15

The PCA in the occipital lobe

Question 16

What is the other name for the inferior optic radiations?

Answer 16

Meyer’s loop

Question 17

Other name for absence seizures?

Answer 17

Petit mal

Question 18

Symptoms of temporal lobe seizures?

Answer 18

Olfactory hallucinations and deja vu

Question 19

Commonest cause of excessive daytime sleepiness?

Answer 19

Sleep apnoea - narcolepsy is rare!!

Question 20

What is amaurosis fugax? What artery is most commonly involved?

Answer 20

Transient blindness due to hypoxia of the retina caused by blockage of the central retinal artery

Question 21

What structure does the superior cerebellar artery supply in addition to the cerebellum?

Answer 21

Midbrain

Question 22

Thalamoperforator arteries are branches of which main artery?

Answer 22

Posterior cerebral

Question 23

Where do the lenticulostriate arteries take their origin?

Answer 23

Middle cerebral artery - they branch off of the MCA to supply the basal ganglia and internal capsule

Question 24

The cuneate fasciculus contains fibres from which body region?

Answer 24

C1-T6

The gracile fasciculus contains information from the LOWER part of the body

Question 25

The raphe nuclei in the brainstem produce which neurotransmitter?

Answer 25

5HT- serotonin

Question 26

Where is noradrenaline produced?

Answer 26

The locus coreuleus

Question 27

What is the consequence of blockage of the arachnoid granulations e.g. in SAH?

Answer 27

CSF accumulates and causes raised ICP ( CSF usually drains through granulations

Question 28

Define tract, fasciculus and funinculus

Answer 28

Tract - distinct white matter pathway running between two regions that contains axons travelling in ONE DIRECTION ONLY Fasciculus - a subdivision of a tract A funinculus - kinda funny because it contains axons travelling IN TWO DIFFERENT DIRECTIONS

Question 29

What can you not use long term for anxiety tx?

Answer 29

Benzos- addictive, severe side effects, can be used in suicide attempts

Question 30

Tx for anxiety?

Answer 30

- SSRIs (mainstay) / pregabalin (GABA analogue) | - Cognitive behavioural therapy

Question 31

Describe the epidemiology of OCD

Answer 31

Young people, 75% experience symptoms before 30, M:F 1:1, 2% of the population

Question 32

What structure is commonly enlarged in schizophrenia?

Answer 32

Ventricles

Question 33

Describe distribution of D2 receptors in the brain

Answer 33

Rich in striatum and midbrain, lower in cortex

Question 34

Which dopamine pathway is overactive in schizophrenia?

Answer 34

The mesolimbic - all "limbered up" ready to cause schizophrenia Mesocortical is underactive Tuberoinfundibular has an endicronological role

Question 35

Who coined the word schizophrenia?

Answer 35

Eugen Bleuler

Question 36

How do you differentiate between different schizophrenia subtypes ?

Answer 36

Simple - self absorbed and socially withdrawn, no hallucinations/ delusions Paranoid - profound hallucinations/delusions Heberphrenic- inappropriate affect, disjointed behaviour and thought disorder ( also caused disorganised schizophrenia)

Question 37

List the first rank symptoms of schizophrenia

Answer 37

- Auditory hallucinations - Somatic hallucinations - Passivity experiences - Thought withdrawal, broadcast or insertion - Delusional perceptions

Question 38

The posterior limb of the internal capsule represents which part of the body?

Answer 38

Trunk and lower limbs

Question 39

Which part of the internal capsule represents the face?

Answer 39

The genu

Question 40

What nerve palsy is caused by herniation of the uncus?

Answer 40

CN 3

Question 41

Which midbrain structure is important for motor control?

Answer 41

The red nucleus

Question 42

Why might a stroke affecting the lateral motor cortex compromise swallowing?

Answer 42

Denervation of the cranial nerve nuclei which distribute LMNs in the vagus nerve

Question 43

Where are pattern generator neurones found?

Answer 43

In the medulla

Question 44

What does the medial lemniscus contain?

Answer 44

Decussating second order sensory fibres in the DCML

Question 45

What does the medial longitudinal fasciculus do? What can damage here cause?

Answer 45

integrates movement of the eyes by linking the 3 CNs involved in eye movements internuclear ophthalmoplegia - an ocular movement disorder that presents as an inability to perform conjugate lateral gaze

Question 46

Which part of the brainstem lies at the level of tentorium cerebelli?

Answer 46

The midbrain

Question 47

What white matter structures in the midbrain connect the cerebral hemispheres to the brainstem?

Answer 47

Crus cerebri

Question 48

What are the superior colliculi?

Answer 48

Features of the dorsal midbrain that deal with reflex actions to visual stimuli

Question 49

Which cranial nerve emerges ventrally from the ponto-medullary junction?

Answer 49

Abducens nerve | Facial nerve emerges laterally

Question 50

CNS shares and embryological origin with which tissue?

Answer 50

Skin - ectoderm Gut derives from endoderm and muscle from mesoderm

Question 51

Potential cause of rapid onset dementia in young people?

Answer 51

Prion disease or an aggressive brain tumour

Question 52

Describe GCS scoring

Answer 52

``` Eye Opening Response • Spontaneous 4 points • To verbal stimuli 3 points • To pain only 2 points • No response 1 point ``` ``` Verbal Response • Oriented 5 points • Confused conversation, but able to answer qs 4 points • Inappropriate words 3 points • Incomprehensible speech 2 points • No response 1 point ``` Motor Response • Obeys commands 6 points • Purposeful movement to painful stimulus 5 points • Withdraws in response to pain 4 points • Flexion in response to pain (decorticate posturing) 3 points • Extension response in response to pain (decerebrate posturing) 2 points • No response 1 point

Question 53

Pt is able to point to an object when asked and can articulate well but not repeat the objects name - site of lesion?

Answer 53

Arcuate fasciculus

Question 54

Site of lesion in hemispatial neglect?

Answer 54

R parietal lobe

Question 55

How do plaques form?

Answer 55

Amyloid precursor protein repairs neurones following damage and is broken down by alpha and gamma secretase If Beta secretase gets involved, the resulting parts of APP are no longer soluble and accumulate between neurones, reducing signal transmission

Question 56

How do tangles form?

Answer 56

Tau proteins play a role in stabilising microtubules within the neuronal cytoskeleton • Microtubules help to mobilise nutrients around the neuron • Beta amyloid plaques (outside the neuron) induce pathological processes within the neuron • Results in hyperphosphorylation of Tau proteins • Causes a change in the shape of Tau proteins

Question 57

What are the three components of the general adaptation syndrome?

Answer 57

Alarm, resistance, exhaustion

Question 58

Outcomes of proximal MCA occlusion? Specifically if left/right sided?

Answer 58

Contralateral hemiparesis Contralateral sensory deficit (often solely face and arms) Contralateral homonymous hemianopia If left sided: Aphasia More commonly right sided: Contralateral (i.e. left sided) hemispatial neglect

Question 59

Outcomes of PCA occlusion?

Answer 59

Contralateral homonymous hemianopia with macular sparing | Contralateral sensory loss (due to thalamic involvement)

Question 60

What is needed to classify as a TACs stroke?

Answer 60

All 3 of: 1. Unilateral weakness (+/- sensory deficit) of the face, arm and leg 2. Homonymous hemianopia 3. Higher cerebral dysfunction • Dysphasia / aphasia • Visuospatial disorder

Question 61

What is needed to classify as a PACs stroke?

Answer 61

Only 2 of: 1. Unilateral weakness (+/- sensory deficit) of the face, arm and leg 2. Homonymous hemianopia 3. Higher cerebral dysfunction • Dysphasia / aphasia • Visuospatial disorder

Question 62

What is needed to classify as a POCs stroke?

Answer 62

One of the following: * Cranial nerve palsy and contralateral motor/sensory deficit * Bilateral motor/sensory deficit * Conjugate eye movement disorder * Cerebellar dysfunction * Isolated homonymous hemianopia (with macular sparing)

Question 63

What is needed to classify as a LACs stroke?

Answer 63

Pure sensory deficit Pure motor deficit Sensory-motor deficit Ataxic hemiparesis