26. Limb Weakness Flashcards
How does the time course help you narrow down differentials for limb weakness?
Sudden: trauma, fractures, vascular insults
Subacute: Demyelination (GBS, MS) slowly expanding haematoma
Chronic: MND, slow growing tumour
What should you ask of someone who has presented with limb weakness?
Exact time of onset? thrombolysis window 4.5 hrs
Speech / vision disturbances? problem more likely to be in brain
Headache? SAH, hemiplegic migraine, SOL
Recent trauma? SAH
Seizures/ LOC? Stroke mimics e.g. Todd’s paresis (post-seizure)
Neck or back pain? disc prolapse/ GBS
RF for stroke? hx of stroke, AF, smoking, FH, HTN, DM, dyslipidaemia
What signs would you see in a UMN lesion?
Increased tone
Hyper-reflexia
Upgoing plantars
Sometimes clonus
What language defects should you look out for with limb weakness?
Receptive dysphasia: Wernicke’s (temporal), speaks fluently but can’t comprehend language
Expressive dysphasia: Broca’s (frontal), comprehends language but can’t speak fluently
What would you suspect if a patient is responding to cues on one side?
Lesion in parietal cortex
What eye signs should you look out for in someone with limb weakness?
Complete blindness in 1 eye: optic nerve lesion
Homonymous hemianopia: lesion between optic chiasm + visual cortex on contralateral side
Deviation: if deviates to weak side= brain stem lesion. If deviates away from weakness= cortical lesion
Difference between ACA and MCA infarct?
ACA: weakness in the lower limb more than upper
MCA: weakness in upper limb more than lower
What are first line investigations for a stroke? Why?
CT head: exclude haemorrhagic stroke
FBC: reveal cause of arterial occlusion (polycythaemia/ thrombocytosis) or haemorrhage (thrombocytopenia)
Blood glucose: exclude hypoglycaemia
Blood clotting: if on warfarin + exclude haemophilia
ECG: for AF
How do you manage stroke acutely?
Antiplatelets e.g. aspirin
Admit to stroke unit
VTE prophylaxis e.g. LMWH
What second line investigations will a patient with a stroke need?
Carotid doppler: exclude carotid artery atheromas
Echo: identify cardiac source of emboli like atrial thrombus or patent foramen ovale
What are some medical complications of stroke and how can you reduce them?
Pressure ulcers: regular movement
Aspiration pneumonia: Swallowing assessment + NG tube if needed.
VTE: LMWH
How do you assess disability in stroke patients?
GCS Swallow Speech + language Visual fields Gait
What is seen in LMN lesions?
Decreased tone
Hyporeflexia
Fasciculations
Wasting
Give 2 time frames and 2 causes of limb weakness when the pathology is in the brain
Sudden: Ischaemic stroke, TIA
Subacute: MS, Haematoma
Give 3 time frames and causes of limb weakness when the pathology is in the spinal cord
Sudden: Spinal disc prolapse
Subacute: MS
Gradual: Spinal canal stenosis