Neuro Flashcards
What are the three important genes to remember in the transformation of astrocytoma –> glioblastoma multiforme?
What is the stepwise progression?
- Rb gene Inactivation
- EGFR amplification
- Deletion of 10p
Glial cell –> astrocytoma –> anaplastic astrocytoma –> glioblastoma multiforme
Commonest CNS tumour, regardless of age, Across-the-board? What %?
Gliomas at 70%
Difference in diagnostics between adult and child astrocytoma?
Adult = immunostain for mutated IDH1 Child = BRAF mutation
Which is the aetiology of glioblastoma multiforme?
Mutation in chromosome 10 in 80% of cases (deletion of 10p or 10q!)
What is pachymeningitis? What does it follow? How common?
Pachymeningitis = infection of dura.
Follows sinusitis or skull fracture.
Rarer than leptomeningitis (clinical meningitis)
Microbiology of acute pyogenic meningitis - infants, adolescent, adults?
infant - e coli
adolescents - (1) neisseria meningitidis, (2) strep pneumoniae
adults - strep pneumoniae
Treatment of acute pyogenic meningitis?
IV ceftriaxone - do not delay rx for imaging
Most common pathogen causing fungal meningitis? Name 4 other fungal pathogens that can
Cryptococcus neoformans
Candida, histoplasma, aspergillus, mucor mycosis
What are the stages of herniation and what clinical findings at each?
- Subfalcine (common):
- Headache
- Contralateral leg weakness - Transtentorial central:
- Small but reactive pupils
- Drowsiness – when the thalamus and midbrain are pushed down towards the 4th ventricle - Transtentorial with temporal/uncal herniation – compression of CN III ipsilateral dilated pupil
- Tonsillar herniation:
- Obtundation
- decerebrate posture.
- Cardiorespiratory arrest with cerebellar herniation.
What is the microscopic feature of a craniopharyngioma? How to remember this
Stratified squamous epithelium nests with internal lamellar keratin deposits - craniopharyngioma is derived from pharyngeal roof of Rathke’s pouch
Red flags in a red eye presentation
Red flags in a red eye
- Unilateral disease
- Blurred vision
- Pain
- Photophobia
What is the pathogenesis of MCA deep penetrating branch haemorrhagic stroke?
Hypertensive arteriolosclerosis/microaneurysms - small BV changes
Which lesion is hemispatial neglect most commonly associated with?
lesion of the right parietal lobe
PCA stroke signs depending on whether cortical or central (deep)
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
Commonest location of glioblastoma multiforme?
R) frontoparietal region
Aetiology of meningioma + what do you look for on clinical fts
50% of meningiomas have NF2 gene mutation - look for signs of neurofibromatosis type 2 - multiple meningiomas and bilateral 8th nerve schwannomas
Mutation in going from glial cell –> astrocytoma
P53 inactivation
Differential diagnosis for ring-enhancing lesion on brain CT?
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
Tetrad of kernicterus features
tetrad of kernicterus
- Vertical gaze palsy
- Choreoathetosis – movement disorder
- Dental enamel hypoplasia
- Sensorineural hearing loss
Most seizure prone areas of brain?
Temporal lobe + hippocampus
Seizure-specific bloods
Prolactin - raised 15mins after tonic-clonic
CK - peaks around 6hrs after seizure
Most common two types of seizures?
Partial complex + tonic-clonic
3 different antiepileptic drugs and their first line indications
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
Senile degeneration - pathophysiology
Progressive neuronophagia (hippocampus + cerebral cortex) –> decreasing brain mass, slowly progressive
3 clinical features of dementia pugilistica? What is it known as?
Dementia pugilistica = Chronic traumatic encephalopathy
Progressive dementia
Tremor
Focal neurological deficits
Binswanger disease - wtf is it? pathophys?
Binswanger disease (subcortical arteriosclerotic encephalopathy/ subcortical vascular dementia)= small vessel damage (arteriolosclerosis) –> small focal infarcts
Frontotemporal dementia story
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)
4 clinical features of Diffuse Lewy body dementia?
Prognosis?
Visual Hallucinations
Delusions
REM sleep disturbances
Severe dementia
Rapidly progressive, early death
MS most common sites of demyelination
Most common sites of demyelination in multiple sclerosis
- Periventricular areas
- Brainstem
- Cerebellum
- Spinal cord
MS risk factors
- UV radiation, insufficient vitamin D consumption, cigarette smoking
- Pathogens: EBV, human herpes virus 6
When do you do a LP as an investigation in MS? What will it show and what is the meaning of this?
Do LP when MRI result is equivocal.
Shows
- Lymphocytic pleocytosis
- Increased oligoclonal band (IgG fractions) - this means a particularly bad prognosis
New drug name for huntingtons
Ionis-HTTRx - it is a gene-silencing DNA
Mutation in hereditary pancreatitis?
SPINK1
ALS mutation
SOD1 gene on chromosome 21
ALS drug?
Riluzole - glutamate antagonist -only drug that slows down the progression of ALS
What is the name of the neuropathy that presents similarly to ALS? What is the one difference in presentation? What blood test corroborates it?
Multifocal motor neuropathy – slowly progressing asymmetrical weakness esp in muscles of distal extremities, muscle atrophy rare. Highly elevated anti-GM1-ganglioside antibody titres.
Features of 3rd nerve lesion
Ptosis
Divergent strabismus = eye is down + out
Mydriasis, unresponsive to light (direct reflex negative)
Consensual reflex in tact
