Crash course: Neuro Flashcards
What are the 6 components of the brain?
4 lobes: Frontal, temporal, parietal, occipital
Cerebellum
Brainstem
Frontal lobe
Thinking
Memory
Behaviour
Movement
Temporal lobe
Hearing
Learning
Feelings
Parietal lobe
Language
Touch
Occipital lobe
Sight
Cerebellum
Balance
Coordination
Brainstem
Breathing
HR
Temperature
What is a stroke?
focal neurological deficit of presumed vascular origin that lasts > 24h
What is a TIA?
focal neurological deficit of presumed vascular origin that resolves within 24h
What are the 2 types of stroke? What is the prevalence of each?
Ischaemic 80%
Haemorrhage 20%
Give 4 causes of ischaemic stroke
ATHEROSCLEROSIS
Thromboembolic e.g. AF
Diabetes
Vasculitis
Give 4 causes of haemorrhage stroke
HTN
AV malformation (<50s)
Cavernous angiomas (recurrent low pressure bleed)
Subarachnoid haemorrhage
What is the single most important modifiable factor (and cause) for both haemorrhage an ischaemic strokes?
HTN
What is the difference between ischaemia and infarction?
Ischaemia: lack of O2 supply to tissue
Infarction: death of tissue due to lack of O2 supply
What are the 2 broad aetiologies haemorrhagic stroke?
Traumatic: extradural or subdural haemorrhage
Non traumatic: Intraparenchymal or SAH
Where do Intraparenchymal haemorrhages usually occur? What causes them?
Basal ganglia
Vessel rupture due to HTN
What is the main cause of subarachnoid haemorrhage? Where does this occur?
Ruptured berry aneurysms
Posterior communicating artery
or
Bifurcation of internal carotid
What is the classic history of a patient with SAH?
Bilateral abdominal masses
FH of brain bleeds
(a/w Polycystic kidney disease)
What can be seen on CT in SAH? (buzzword/ phrase)
Hyperattenuation around the Circle of Willis
If NAD on CT head, what further investigation can be performed for SAH? What will be seen?
LP at 12h:
Xanthochromia + oxyhaemoglobin
What causes extradural haemorrhage? What is the pathophysiology?
Fracture of pterion caused by trauma (e.g. RTA, punch to temples)
Rupture of middle meningeal artery
What buzzword describes extradural haemorrhage on CT?
“lemon” shape
What causes subdural haemorrhage? What is the pathophysiology?
Hx of minor head trauma
Rupture of bridging veins leading to collection of blood between dura + arachnoid mater
Give 4 risk factors for subdural haemorrhage
Alcoholics
Anti-coagulations
Elderly
NAI
What buzzword describes subdural haemorrhage on CT?
“Banana” shape
Crescent shape
What is the single largest cause of death in <45s?
Traumatic brain injury
Give 4 red flags of TBI
Otorrhoea
Rhinorrhoea
“Straw-coloured” fluid (CSF) from nose or ears
Battle’s sign
What are the 2 types of TBI?
Diffuse axonal injury
Contusion (more common)
What is diffuse axonal injury?
shear tensile forces tearing axons apart in midline structures
(Corpus callosum, rostral brainstem + septum pellucidum)
What is the commonest cause of traumatic coma?
Diffuse axonal injury
What is a contusion? What are the 2 types?
collision between brain + skull
Coup: impact of brain on skull
Countercoup: injury to opposite side of brain
What is the most common cell type in the brain? What is the most common tumour type in the brain?
Astrocytes
Astrocytomas
What are primary brain tumours? What are 2 subtypes?
Originate within CNS
Extra-axial: Cranium, soft tissue, meninges, nerves
Intra-axial: glia, neurons, neuroendocrine cells
What are secondary brain tumours? (4)
Mets from other parts of body
Commonest form of brain tumour
Well demarcated, solitary nodules
Poor prognosis
Which 3 cancers metastasise most commonly to the brain?
Lung
Skin
Breast
Give 3 genetic risk factors for brain tumours
FH brain tumours
NF 1/2
Tuberous sclerosis
Give 2 features in PMH for brain tumours
Cancer
Radiotherapy
Define staging and grading
S: how far the tumour has spread
G: how differentiated the tumour cells are compared with native cells
What is the survival rate for the 4 grades of brain cancer?
Grade 1 → benign
Grade 2 → >5y survival
Grade 3 → 1-5y survival
Grade 4 → <1y survival
Give 4 features of pilocytic astrocytoma
Indolent
Most common brain tumour in kids 0-20y
Good prognosis
Grade 1
Give 2 features of diffuse gliomas
20-40y
Grade 2-3
Give 3 features of gliomoblastoma multiforme
> 50s
Most common (aggressive) primary tumour in adults
Grade 4
What features on microscopy indicate higher grade in brain tumours?
Increased cellularity
Increased mitotic figures
Microvascular proliferation
What is the location and buzzword associated with Meningioma?
Meninges/ arachnoid cells
Psammoma bodies
What is the location and buzzword associated with medulloblastoma? (embryonal)
Cerebellum
Children, balance problems, Squint
What is the location and buzzword associated with ependyoma?
Posterior fossa
Tuberous sclerosis
What is the location and buzzword associated with craniopharyngioma?
Pituitary sella
Inferior bitemporal hemianopia
What is the location and buzzword associated with pituitary tumour?
Pituitary sella
Superior bitemporal hemianopia
What is the management for primary brain tumours?
Surgical resection
Radiotherapy
NOT chemo (most don’t penetrate BBB)
What is dementia?
global impairment of cognitive function + personality without impairment of consciousness.
(beyond normal ageing)
List the 5A’s of dementia
Amnesia
Apraxia
Aphasia
Agnosia
Anomia
List the 4 types of dementia in order of decreasing prevalence
Alzheimers
Vascular
Lewy body
Frontotemporal
Give the 2 main theories of Alzheimer’s aetiology
Accumulation of β-amyloid plaques: interferes with neuronal communication
Hyperphosphorylation of Tau proteins → formation of neurofibrillary tangles
Which lobes are most commonly affected first in Alzheimer’s?
Medial temporal lobes + hippocampus
What tool is used to stage Alzheimers?
BRAAK staging
What is seen on MRI in Alzheimer’s?
Global atrophy
Give 2 associations of vascular dementia
Mini strokes
Step-wise deterioration
Give 3 associations of Lewy body dementia
Fluctuating course
Little people/ animals running around
Parkinsonian Sx
Give 4 buzzwords associated with Frontotemporal dementia
Personality change
Disinhibition
Overeating
Emotional blunting
Give 3 patient characteristics commonly seen in frontotemporal dementia
Younger: 40-60
Strong +ve FH (autosomal dominant)
Dx of Huntingtons disease
What is seen on microscopy in frontotemporal dementia?
Pick bodies
What is Parkinson’s disease?
Depletion of dopaminergic neurons projecting from basal ganglia to the substantia nigra
What is the pathophysiology of Parkinson’s?
Alpha synuclein mutation + misfolding to form Lewy bodies
Accumulation of Lewy bodies in nigrostriatal pathway
What causes loss of smell in Parkinson’s?
Accumulation of lewy bodies in olfactory bulb
What is seen on microscopy in Parkinson’s?
Lewy bodies
Melanin deposition
What are the 5 Parkinson’s plus syndromes?
Vascular Parkinson’s
Drug-induced Parkinson’s
Multiple system Atrophy (MSA)
Progressive supranuclear palsy (PSP)
Corticobasal dysfunction
What characterises drug-induced Parkinson’s?
Bilateral motor deficit
+ PD
What characterises multiple system atrophy?
Autonomic dysfunction + PD
What characterises progressive supranuclear palsy?
Vertical gaze dysfunction + PD
Describe CSF production and circulation
CSF produced by ependymal cells of choroid plexus (mainly in lateral ventricles)
From lateral ventricles, goes through interventricular foramina to 3rd ventricle
Flows down cerebral aqueduct to 4th ventricle
Enters subarachnoid space (via medial + lateral apertures)
Drains back into superior sagittal sinus via arachnoid granulations
What is communicating hydrocephalus?
Increased production or decreased absorption of CSF
What is non-communicating hydrocephalus?
intraventricular obstruction of CSF flow
What triad characterises normal pressure hydrocephalus ?
Gait disturbance
Urinary incontinence
Confusion
What is seen on MRI in hydrocephalus?
Massive ventricles
What are the 3 types of brain herniation?
Subfalcine: cingulate gyrus pushed under falx cerebri
Uncal/ transtentorial: medial temporal lobe pushed under tentorium cerebelli
Tonsilar: cerebellar tonsils pushed through foramen magnum.
Which type of herniation does not involve the cerebral cortex?
Tonsilar herniation
(cerebellum through foramen magnum)
What are the consequences of tonsilar herniation?
Cardiorespiratory failure + death
What percentage of patients who experience a TIA will have a significant infarct within 5 years?
33%
What is the most common cause of non-traumatic intraparenchymal haemorrhages?
HTN
Give 2 signs of skull fracture
Battle sign: haemorrhage over mastoid process, post traumatic basilar skull fracture
Panda eyes: base of skull fracture in anterior cranial fossa