Neuro

Question 1

What are the three important genes to remember in the transformation of astrocytoma –> glioblastoma multiforme?
What is the stepwise progression?

Answer 1

1. Rb gene Inactivation
2. EGFR amplification
3. Deletion of 10p

Glial cell –> astrocytoma –> anaplastic astrocytoma –> glioblastoma multiforme

Question 2

Commonest CNS tumour, regardless of age, Across-the-board? What %?

Answer 2

Gliomas at 70%

Question 3

Difference in diagnostics between adult and child astrocytoma?

Answer 3

Adult = immunostain for mutated IDH1
Child = BRAF mutation

Question 4

Which is the aetiology of glioblastoma multiforme?

Answer 4

Mutation in chromosome 10 in 80% of cases (deletion of 10p or 10q!)

Question 5

What is pachymeningitis? What does it follow? How common?

Answer 5

Pachymeningitis = infection of dura.
Follows sinusitis or skull fracture.
Rarer than leptomeningitis (clinical meningitis)

Question 6

Microbiology of acute pyogenic meningitis - infants, adolescent, adults?

Answer 6

infant - e coli
adolescents - (1) neisseria meningitidis, (2) strep pneumoniae
adults - strep pneumoniae

Question 7

Treatment of acute pyogenic meningitis?

Answer 7

IV ceftriaxone - do not delay rx for imaging

Question 8

Most common pathogen causing fungal meningitis? Name 4 other fungal pathogens that can

Answer 8

Cryptococcus neoformans

Candida, histoplasma, aspergillus, mucor mycosis

Question 9

What are the stages of herniation and what clinical findings at each?

Answer 9

1. Subfalcine (common):
   - Headache
   - Contralateral leg weakness
2. Transtentorial central:
   - Small but reactive pupils
   - Drowsiness – when the thalamus and midbrain are pushed down towards the 4th ventricle
3. Transtentorial with temporal/uncal herniation – compression of CN III  ipsilateral dilated pupil
4. Tonsillar herniation:
   - Obtundation
   - decerebrate posture.
   - Cardiorespiratory arrest with cerebellar herniation.

Question 10

What is the microscopic feature of a craniopharyngioma? How to remember this

Answer 10

Stratified squamous epithelium nests with internal lamellar keratin deposits - craniopharyngioma is derived from pharyngeal roof of Rathke’s pouch

Question 11

Red flags in a red eye presentation

Answer 11

Red flags in a red eye

• Unilateral disease
• Blurred vision
• Pain
• Photophobia

Question 12

What is the pathogenesis of MCA deep penetrating branch haemorrhagic stroke?

Answer 12

Hypertensive arteriolosclerosis/microaneurysms - small BV changes

Question 13

Which lesion is hemispatial neglect most commonly associated with?

Answer 13

lesion of the right parietal lobe

Question 14

PCA stroke signs depending on whether cortical or central (deep)

Answer 14

Peripheral (cortical)
	Memory deficits 
	Visual deficits 
o	Homonymous hemianopia 
o	Cortical blindness (if both occipital lobes destroyed)
o	Lack of depth perception
o	Hallucinations

Central (penetrating)
 Thalamus – contralateral sensory loss, spontaneous pain, mild hemiparesis
 Cerebral peduncle – CN 3 palsy with contralateral hemiplegia
 Brain stem – CN palsies, nystagmus, pupillary abnormalities

Question 15

Commonest location of glioblastoma multiforme?

Answer 15

R) frontoparietal region

Question 16

Aetiology of meningioma + what do you look for on clinical fts

Answer 16

50% of meningiomas have NF2 gene mutation - look for signs of neurofibromatosis type 2 - multiple meningiomas and bilateral 8th nerve schwannomas

Question 17

Mutation in going from glial cell –> astrocytoma

Answer 17

P53 inactivation

Question 18

Differential diagnosis for ring-enhancing lesion on brain CT?

Answer 18

DR MAGICAL
 Demyelinating disease – classically an incomplete ring of enhancement
 Radiation necrosis/rapidly growing tumour
 Metastasis
 Abscess
 Glioblastoma
 Infarct subacute phase
 Contusion
 AIDS –
 Lymphoma = esp in aids pt, or immunocompromised

Question 19

Tetrad of kernicterus features

Answer 19

tetrad of kernicterus

• Vertical gaze palsy
• Choreoathetosis – movement disorder
• Dental enamel hypoplasia
• Sensorineural hearing loss

Question 20

Most seizure prone areas of brain?

Answer 20

Temporal lobe + hippocampus

Question 21

Seizure-specific bloods

Answer 21

Prolactin - raised 15mins after tonic-clonic

CK - peaks around 6hrs after seizure

Question 22

Most common two types of seizures?

Answer 22

Partial complex + tonic-clonic

Question 23

3 different antiepileptic drugs and their first line indications

Answer 23

Lamotrigine – first-line Rx focal seizures, and tonic-clonic generalised seizures
Valproate – first-line rx generalised seizures (atypical absence, myoclonic, atonic)
Ethosuximide – first-line rx in typical absence seizures

Question 24

Senile degeneration - pathophysiology

Answer 24

Progressive neuronophagia (hippocampus + cerebral cortex) –> decreasing brain mass, slowly progressive

Question 25

3 clinical features of dementia pugilistica? What is it known as?

Answer 25

Dementia pugilistica = Chronic traumatic encephalopathy Progressive dementia Tremor Focal neurological deficits

Question 26

Binswanger disease - wtf is it? pathophys?

Answer 26

Binswanger disease (subcortical arteriosclerotic encephalopathy/ subcortical vascular dementia)= small vessel damage (arteriolosclerosis) --> small focal infarcts

Question 27

Frontotemporal dementia story

Answer 27

Uninhibited Mr. Pick is <65yo, he has weird behaviour, weird speech, aphasia but his short-term memory in tact. He has semantic dementia - (hence issue with long-term storage of associating words with their meaning)

Question 28

4 clinical features of Diffuse Lewy body dementia? Prognosis?

Answer 28

Visual Hallucinations Delusions REM sleep disturbances Severe dementia Rapidly progressive, early death

Question 29

MS most common sites of demyelination

Answer 29

Most common sites of demyelination in multiple sclerosis 1. Periventricular areas 2. Brainstem 3. Cerebellum 4. Spinal cord

Question 30

MS risk factors

Answer 30

- UV radiation, insufficient vitamin D consumption, cigarette smoking - Pathogens: EBV, human herpes virus 6

Question 31

When do you do a LP as an investigation in MS? What will it show and what is the meaning of this?

Answer 31

Do LP when MRI result is equivocal. Shows - Lymphocytic pleocytosis - Increased oligoclonal band (IgG fractions) - this means a particularly bad prognosis

Question 32

New drug name for huntingtons

Answer 32

Ionis-HTTRx - it is a gene-silencing DNA

Question 33

Mutation in hereditary pancreatitis?

Answer 33

SPINK1

Question 34

ALS mutation

Answer 34

SOD1 gene on chromosome 21

Question 35

ALS drug?

Answer 35

Riluzole - glutamate antagonist -only drug that slows down the progression of ALS

Question 36

What is the name of the neuropathy that presents similarly to ALS? What is the one difference in presentation? What blood test corroborates it?

Answer 36

Multifocal motor neuropathy – slowly progressing asymmetrical weakness esp in muscles of distal extremities, muscle atrophy rare. Highly elevated anti-GM1-ganglioside antibody titres.

Question 37

Features of 3rd nerve lesion

Answer 37

Ptosis Divergent strabismus = eye is down + out Mydriasis, unresponsive to light (direct reflex negative) Consensual reflex in tact