neuro Flashcards
Limb weakness - what to ask in hx to ensure not anything else?
- clumsy limb (ataxia)
- numb limb (reduced sensation)
- too painful to move.
limb weakness ddx acc to time course?
- Sudden onset : vascular insult (stroke, tia, sah)
- Subacute onset (hr to days) : GBS, venous thrombosis (progressive blockage of vein) , subdural haemoatoma
- chronic onset: slow growing tumour or MND
patterns of weakness and possible lesion sites - full body hemiparesis?
- full body hemiparesis - C/L cerebral motor cortex (widespread stroke) ; C/L corona radiata, internal capsule, pons (stroke)
patterns of weakness and possible lesion sites - limb hemiparesis
- CL cerebral motor cortex
- c/l corona radiata, internal capsule, pons (stroke)
- I/L spinal lateral motor tract (eg. cervical disc prolapse)
patterns of weakness and possible lesion sites - isolated limb weakness (arm or leg)?
- c/l cerebral motor cortex (localised stroke)
- c/l corona radiate, internal capsule, pons
- i/l peripheral nerve root (eg. osteophyte)
- i/l peripheral nerve plaxue (eg. trauam to brachial plexus)
- i/l peripheral nerve (eg. angiogram sheath injury to femoral nerve)
patterns of weakness and possible lesion sites - paraparesis (bottom half of body)
- b/l cerebral motor cortex (parasagittal meningioma)
- b/l motor spinal stracts (cord compression)
- cauda equina (eg. lumbar intervertebral disc prolapse)
- b/l lumbosacral plexus (GBS)
patterns of weakness and possible lesion sites - tetraplegia
- b/l motor tracts of cervical spinal cord (traumatic spinal cord transection at c5)
- peripheral nerves (demylinating deisease ie GBS)
patterns of weakness and possible lesion sites - proximal muscle weakness
- NMJ junction (MG, eaton lambert synd)
- mucle (polymyositis, dermatomyositis) or secondary to other condtiions (eg. hyperparathyroidism) or drugs (statins)
patterns of weakness and possible lesion sites - several episodes seperated in time and space
various sites in CNS - MS
UMN v LMN lesion?
UMN - increased tone, felxes, upgoing plantars (babinski reflex), clonus
LMN - reduced tones, relexes, fasciculations, wasting
pathology at NMJ and muscle , related signs?
proximal muscle weakness with NORMAL tone and reflexes. (neither UMN or LMN)
pyramidal pattern of weakness?
extensors weaker than flexos in upper limb and vice versa in lower limb.
(classic stroke posture of flexed upper limb, extended lower limb)
(UMN)
broca’s v wernicke’s aphasia?
brocas - cannot speak fluently, but understands + follow instructions
(lesion in L frontal lobe)
wernicke’s - speaks but cannot understand.
(lesion in L temporal lobe; receptive dysphasia)
attention defects?
lesion in parietal cortex
neglect - ignores hlaf of sensory world. ask pt to draw clock, only half the clock face drawn
extinction - ignores half sensory world when simultaneous stimuli to both sides.
eye deviation
eye deviation away from weak side - cortical lesion
eye deviation towards weak side- brain stem lesion
bell’s palsy v stroke?
can wrinkle forehead ins stroke.
ddx for stroke?
- cerebral mass (tumor, abscess, potentially with a bleed into it)
- todd’s plasy (post seiaure paralysis)
- migraine
- hypoglycaemia (can present with localising signs!) check BMs in all ?stroke patients.
ACA supplies?
medial primary motor cortex (leg, foot)
MCA supplies?
lateral primary motor cortex (thorax, arm, hand, face, tongue, pharynx)
also, posterior parietal cortex (c/l hemineglect)
Stroke recognition, tool in community and ED?
- FAST for community
- ROSIER for ED >0, stroke possible
Stroke/TIA ischaemic mx
- 300mg aspirin stat
- refer to specialist to be seen within 24 hrs
- non contrast CT head
- carotid imaging
- urgent carotid endarectomy in symptomatic carotid stenosis of 50-99% ; get CT contrast angiography following initial non-enhanced CT. Add CT perfusion imaging (or MR equivalent) if thrombectomy might be indicated beyond 6 hours of symptom onset.
- Thrombolysis within 4.5 hours with alteplase
- thrombectomy within 6 hours if ishcaemic stroke and confrimed occlusion of proximal anterior circulation as shown on CTA or MRA
- thrombectomy within 24 hours if above and potential to salvage brain tissue, as shown by imaging such as CT perfusion or diffusion-weighted MRI sequences showing limited infarct core volume.
stroke/TIA medical mx - ischaemic
- aspirin 300mg stat + ppi if reflux
nb if af dx, aspirin for 2/52 then anticoags - full dose heparin then warfarin if sinus venous thrombosis
- anticoags or antiplatelet if stroke secondary to aortic dissection
