last min Flashcards
GCS
used to diagnose coma
what tracts are affected in dcroticate posurimng
lateral corticospinal tracts are affected so rubrospinal tract takes over causing abnormal flexion of upper limbs and reticulpspinal tradct takes over causing extension of legs
in decerbrate both teh alteral corticospinal and rubro spinal tract are affected so what tract takes over
reticulospinal
what is generally spared in decorticate as opposed to decerebrate
midbrain
total volume of csf
150ml and about 450 ml is produced daily
as ICP rises what decreases to compensate (autoregulation)
cerebral blood flow and cerebral perfusion pressure
crus cerebri causes
contralateral hemiparesis
tonsillar herniation causes
neck stiffness, abnormal neck posture and cheyne stokes breathing ( periods of tachypnoea and tachycardia followed by periods of bradycardia and bradypnea)
central herniation of brainstem can cause
diplopia due to 6th nerve palsy
subfalcine
weaknes in legs
dural venous sinus is between
periosteal and meningeal layers of dura
in the spine what layer of dura only exxists
the meningeal layer
what meninges is highly vascualrised
pia
temporoparietal skull fracture
extradural
in extradural haematoma what is tehn compressed to cause headahce, vomitting and contralateral hemiparesis
cerebral peduncle
bilateral subdural haematoms are more common in
chidlren due to absence of adhesions in subdural space
in chronic subdural what is considered the driving factor
brain atrophy
aspirin is a predisposing factor for subdural
most comnonpresentation for chronic subdural
headhace and confusions but can also have urianry incontince
gait in normal pressure hydrocephalus
shuffling
clue that suggests a obstructive hyrocephalus
4th ventricle is small in comparison the to lateral and third
congenital hydrocephalus is aminly due to
aqueductal stenossi
dialted scalp veins, setting sun appearance (downward devaition of the globe on lid retraction), Macewen sign (cracked pot sound on head percusiion)
congenital hydrocephalus
MRI best for
hydorcephalus however ct can confirm in acute situation
endoscopic third ventrculostomy is a type of VP shunt opnly likely to be successful in
obstructive hydrocephlaus
chaiiri 1 malformation- more common -
suboccipital pain
headache borugh on by neck extension
cape like loss of paina nd temp (due to synringomyelia)
downbeat nystagmus
chairi 2 malformation associated with
more frequnelty in children and clear associated with myelomeningococele (spina bifida) - there is also hernaition of the 4th ventricle
- causes dysphasia, apnoea stridor in kids
IIH headache is relieved on
standing
after weight loss what drug for IIH
diuretics such as acetazolamide
slit like ventricles can be seen in
IIH
lateral horns contain
autonomic neurons
contraletal sematosensry cortex
DCLM and spinothalamic whereas spinocerebellar is ipsilateral
anterior and posterior spinocerebellar si aminly to lower limbs and which is to upper limbs
Cuneocerebellar
anterior corticospinal decusaate at levvel via
anterior white comissure
hypoglossal and lower facial are innervated
contralateral only
what tract innervates anti gravity
vestibuspinal - extensors for legs and oppsite for arms
vesitublo - think anti gravity
reticulo - think voluntary response and tone and takes over in decerbrate
— reticulospinal incrases tone and facilatates response
pontine
medial malleous - L4
dorsum of foot and toes 1-3 = L5
toes 4 and 5 and lateral malleolis = S1
perineal = s3,4,5
facet joint- inferior articualr processes fo teh vertebra above artiucalte with the superior articualr processes fo the vertebra below
intervertebral disc is a
secondary cartilaginous
nucleus pulposus is maily
water
– helps maintain an upright posture and assists in straightening the spine after felxion
ligamnetum flavum
mornign stiffness whcih resolves with movement and pain made worse by prolonged sitting
mechanical
when facet joints are hypertrophies in mechanical back pain can get referred pain that mimics sciatica - however it does not radiate below the knee
most common locations for lumbar disc herniation
L4/5 and L5/S1
paramedian hernaited disc at L4/5 affects L5 - more common (posterolateral)( nerve root that exists below the level fo the prolapsed disc
far lateral herniated disc at L4/5 affects L4 - nerve root that exits at the level of the prolapse (extraforaminal)
radiculopathy - sensory deficit with weakness of the muscle
straight leg raise is postive in
sciatica
l4/5 root is l5 causes paraesthesia
in big toe
l3/4 - pain in anterior thigh (root is L4)
bilateral disc prolapse suggested by
bilateral sciatica and sphincter disturbance and dimished perineal sensation
prolapsed disc causing cauda equina is normally at
L4/5
if what is present it is highly unlikely to be cauda equina
ankle refexes
cauda equina caused by hernaited disc- discectomy
fracture- decompression and fixation
hematoma- evacuation
even doing surgery for cauda equina within 24-48hrs there is still
10% chance of permanent incontinece
complete effacement of CSF can be due to
cauda equina
what leads to neurogenci claudication
compression of nerve roots
symptoamtic lumbar stenossi most common at
L4/5 level
hypertrophy of facets joints and ligamentum flavum
protruding intervertebral discs
spondylolisthesis
aetiology of lumbar stenossi
what can precipitate pain in lumbar stenossi
stnading or back extension
what can relieve pain in lumbar stenossi sitting, lumbar flexion or wlaking uphill
patients can develop an anthropoid psutre which is exagerrated flexion of the waist
difference of neurological claudication via vascualr
neurological - normal pulses, burning as opposed to cramping
what provides immediate relief in vascualr claudication
resting
MRI lumbosacral spine for
neurogenic claudication
only thing that relieves vascualr is rest. posture has no effect. In neurogenci however posture can releif. eg wlaking uphill, sitting, waist flexion
cervical spondylosis affects
intervertebral disc adn zygapophyseal joints
cervical spondylosis can either present with degenrate cervical myelpathy which has UMN signs or radiculopath ywhich has
LMNS signs
radiculpathy casues
LMN signs in the upper and lower limbs and can also cause neck pain
radiological findings in cervical spondylosis
narrowing of disc space and osteophyte formation
degenrative cervical myelopathy
causes UMN signs more promiennt in lower limbs
clumsy hands with tingling sensation in finger tips
DCM
cord transection
initally flaccid arrecflexic then UMN signs appear later
ipsialteral loss of what in brown
UMN paralysis and loss of proprioception
contralteral loss of pain and temp is 1-2 segments belwo lesion
in central cord syndrome why is bilateral upper limb weakness more than lower limb
upper limb fibres in lateral corticospianl tract are more medial
- cape like pain and temp loss
anterior cord - paralysis and loss of pain and temp below level of injury
lumbar stenosis can cause legs to feel heavy and become numb when walks
nominal aphasia where is affected
supramarginal gyrus and angular gyrus of parietal lobe
cerebellum derived from
metencephalon
cerebrocerebelllum
corrects errors
scanning dysarthria
patients speak slowly with poor articualtion of speech
hypothalamus
- body temp
- release of hormones
- synthesises ADH and oxytocin
- feeding and starvation
-mamillary nucleus
subthalamus causes
contraletal hemiballism- flinging movements of one side of the body
resting tremor in parkisnosn between what HZ
4-6
cag repeats
Huntingotns
gerstamnn syndrome is what brain lobe
parietal
brain tumours most common
grde 3 or 4 - glioblastoma more so
what can progress to glioblatomas mulitforme
anaplastic astrocytoma
butterfly appearnace
glioblastoma multiforme
after mRI - do molecular analysis to look for MGMT promoter methylation as is predictive for response of
alkylating agents ( temozolamide)
stupp prptocol for
glioblastomas
diffuse astrocytoma and ologodendrogliomas are grade
2
bipolar cells with long hair like projections
pilocytsic astrocytoma
pilocystic astrocytomas can affect
cerebellum or midline structres egg thalamis or optic chiasm
optic pathway gliomas are commonly seen in
NF1
tumours that carries the best prognosis
oligodendrogliomas
oligodendroglial affects what lobe
frontal
who is at risk of developing multiple meningiomas
those with NF type 2 and those who experienced radiation in childhood
foster kennedy
optic atrophy in ipsilateral eye and papilloedema in contralateral eye
microadenoma if smaller than
10mm
acth tumour
do low dose dexamethasone compression test then high dose to differentiate between adrenal and pituitary. causes
prolactinomas are mamaged exlusivelu medically with cabergoline. if fails then quinagolide
Take home message: always preform a prolactin and early morning cortisol for anyone who you suspect to have a pituitary tumour before referring to a neurosurgeon or an endocrinologist.
verocay bodies in acoustin neuroma - palisading nuceli against a fibrillary background
how is surgery done for vestibular schwanoma
retrosigmoid approach in prone psoition
haemangioblastomas develop where
posterior fossa
number of surrounds black flow voids indicating blood vessels suggesst
haemangioblastomas
arteries that comes off internal carotid
opthalamic and anterior choriodal
main branch of the vertebral artery is the
posterior inferior cerebellar arteries
basillary artery branches
anterior inferior cerebellar and superior cerebellar
AVM creates a shunt with no
capillary bed present
AV malformations are
common cause of haemorrhage in under 40
AVM tend to be asymptoamtic until haemorrhage
intracerebral haemorrhages are the most common as a result of
AVM
patients may experience symptoms such as slowly progressive hemiparesis due to the local ischaemic effect of AVMs. It had been shown that AVM ‘steals’ or decreases the cerebral blood flow of the tissue surrounding the nidus leading to ischaemia (steal phenomenon).
CATHETER ANGIPGRAPHY IS prefered for
AVMS
angiohraphy - of avm
tangle of vessels
large feeding artery
large draining veins
most common cause of sah
head trauma!!! berry aneurysm is most common non traumatic cause
aneurysm where has a higher risk of rupturing
posterior compared with anterior
CT angio done after lumabr(if done) puncture to to indentify lcoation in
SAH
most commn electrolyte abnormaility in SAH
hyponatraemai
cavernous malforamtion are
benign vascualr lesions encompassing sinusoidal spaces and separated by elastin
pathology resembles a mulberry
cavernous malformation
what has a rim of haemoside laiden macrophages surrounding it
cavenrous malformaitn
unlike AVM, cavernous malformation are hard to visualise on angiopgraphy
KRIT1 gene linked to
cavernous malformation
MRI with popcorn - has ring of hypo- intensity consistent with hemosiderin desposition
cavernous malformation
most common location of aneurysm
between anter and ant comm
between poster comm and internal carotid
fusiform - hyeptension
berry - saccular
mycotic - septic emboli
aneurysm on posterior communciating artery
third nerve palsy
if anterior communicating aneurysm is large enough it can compress the
optic chiasm
elderly, multiple comorbodieties and posterior circualtion favours
coiling over clippign
abcd2 greater than 4
stroke specialist within 24hrs
carotid stenosis ix
carotid doppler
glutamte and enxymes causes
cerebral oedeam
conductive
arcuate fasiculis - connects brocas to wernickes
Visual inattention: patients with inattention fail to detect visual stimulus in one half of the visual field when both are tested together. However, when each half is tested alone then they can detect the visual stimulus.
Patients with ischaemic stroke presenting within 4.5 hours of definitive onset of symptoms can be treated with intravenous thrombolysis (alteplase). Stroke affecting the carotid territory should be evaluated for carotid endarterectomy.
(patients who are not suitable for clopidegrol can be put on low dose aspirin (75 mg)+dipyridamole)
– 300 mg daily should be commenced within hours of ischaemic stroke and continued for two weeks then patients should be transferred to clopidegrol for lie
aspirin
edinger wesstphal innervates
sphincter pupillae and ciliary muscles
nerve that travels through the cavernous sinus
abducens
accomodation reflex - increase lens curvature, constriction of pupils and eye convergence
chalky white disc
GCA
enlarged blind spot can be seen in
papilloedema
ptosis is due to dysfunction of what muscle
muller
anhydrosis means lesion is below where
superior cervical ganglion
painful horners syndrome should raise possibiloty of
carotid artery dissection
what is used to confirm a Horners pupil
Apraclonidine - causes horners pupil to dialte whereas normal pupil remaines unaffected
what is posterior inferior cerebellar artery affected in
LAteral medullary syndrome
adies pupil presents as
one pupil is larger and there is blurring on near vision
holmes adie syndrome
absent tendon reflex of lower limb, adie pupil and orthostatic hypotension
what causes adies pupil to constrict
pilocarpine
most common cause of arygll robertson pupil
diabetes
how is arygll robertson pupil different to adies
arygll robertson - pilocarpine does not cause constriction of pupils
tuberculum sellae meningioma has
ipisilateral central scotoma with contralateral superotemporal defects
lesion where causes contralateral homonymous hemianopia
optic tract
what artery affected in contralateral homonymous hemianopia with macualr sparing
calcarine artery
surgical as opposed to medical problems causing 3rd nerve palsy cause what
affect the pupil as pupillomotor fibres are damaged
webers has
ipsilateal 3rd nerve palsy adn contralateral hemiparesis
contralateral hemiparesis affects
cerebral peduncle
benedikts syndrom has ipsilateral 3rd nerve palsy with contralateral
tremor, ataxia or chorea (red nucleus)
what makes trochlear nerve palsy worse
tilting head to the ipsialteral shoulder
affected eye in 4th nerve palsy is
higher than the contrlateral eye
what double vision is seen in abducens nerve palsy
horizontal - worse on looking at distant targets
NF is
autosomal dom
bag of worm senstion on eyelid
NF1
what is treated with botulinum toxin injection and has bilateral involuntary contraction of the orbicualris oculi msucle
benign essential blepharospasm
what 2 thigns pass through the cavernous sinus
internal carotid and abducens
cavernous sinus sydnrome can affect what cn
3,4,5(1)(2),6- maxillary sensory loss
