26. Limb Weakness Flashcards

1
Q

How does the time course help you narrow down differentials for limb weakness?

A

Sudden: trauma, fractures, vascular insults
Subacute: Demyelination (GBS, MS) slowly expanding haematoma
Chronic: MND, slow growing tumour

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2
Q

What should you ask of someone who has presented with limb weakness?

A

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

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3
Q

What signs would you see in a UMN lesion?

A

Increased tone
Hyper-reflexia
Upgoing plantars
Sometimes clonus

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4
Q

What language defects should you look out for with limb weakness?

A

Receptive dysphasia: Wernicke’s (temporal), speaks fluently but can’t comprehend language
Expressive dysphasia: Broca’s (frontal), comprehends language but can’t speak fluently

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5
Q

What would you suspect if a patient is responding to cues on one side?

A

Lesion in parietal cortex

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6
Q

What eye signs should you look out for in someone with limb weakness?

A

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

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7
Q

Difference between ACA and MCA infarct?

A

ACA: weakness in the lower limb more than upper
MCA: weakness in upper limb more than lower

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8
Q

What are first line investigations for a stroke? Why?

A

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

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9
Q

How do you manage stroke acutely?

A

Antiplatelets e.g. aspirin
Admit to stroke unit
VTE prophylaxis e.g. LMWH

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10
Q

What second line investigations will a patient with a stroke need?

A

Carotid doppler: exclude carotid artery atheromas

Echo: identify cardiac source of emboli like atrial thrombus or patent foramen ovale

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11
Q

What are some medical complications of stroke and how can you reduce them?

A

Pressure ulcers: regular movement
Aspiration pneumonia: Swallowing assessment + NG tube if needed.
VTE: LMWH

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12
Q

How do you assess disability in stroke patients?

A
GCS
Swallow
Speech + language
Visual fields
Gait
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13
Q

What is seen in LMN lesions?

A

Decreased tone
Hyporeflexia
Fasciculations
Wasting

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14
Q

Give 2 time frames and 2 causes of limb weakness when the pathology is in the brain

A

Sudden: Ischaemic stroke, TIA
Subacute: MS, Haematoma

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15
Q

Give 3 time frames and causes of limb weakness when the pathology is in the spinal cord

A

Sudden: Spinal disc prolapse
Subacute: MS
Gradual: Spinal canal stenosis

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16
Q

Give 2 time frames and causes of limb weakness when the pathology is in the nerve roots

A

Sudden: Spinal disc prolapse
Subacute: GBS

17
Q

Give 2 time frames and causes of limb weakness when the pathology is in the peripheral nerve/ nerve plexus

A

Sudden: Acute limb ischaemia
Gradual: Diabetes

18
Q

Give 2 time frames and causes of limb weakness when the pathology is in the neuromuscular junction

A

Subacute: Botulism
Gradual: Myasthenia gravis

19
Q

Give a time frame and cause of limb weakness when the pathology is in the muscle

A

Gradual: Myositis

20
Q

What signs would you see in a LMN lesion?

A

Hypotonia
Hyporeflexia
Fasciculations sometimes
Wasting

21
Q

Which columns are spared in an anterior spinal artery infarct? Which sensory modalities are therefore preserved?

A

Dorsal columns

Light touch, vibration, proprioception

22
Q

How do UMN facial weakness and LMN facial palsy differ?

A

UMN has sparing of forehead wrinkling + blink

23
Q

Describe locations where and characteristics of clots can form due to blood stasis. What drugs are used for preventing these? What adverse outcomes do they prevent?

A

Deep veins/ fibrillating atria
Rich in fibrin + erythrocytes
Drugs that inhibit fibrin mesh formation (anticoagulants) e.g. Warfarin, RIvaroxaban
Venous thromboembolism + atrial clots

24
Q

Give an example of where clots can form due endothelial activation of platelets, what allows this? What drugs are used for preventing these? What adverse outcomes do they prevent?

A

E.g. upon atherosclerotic plaque rupture
Rich in platelets
Drugs that inhibit platelet activation (antiplatlets) e.g. Aspirin, Clopidogrel
MI’s + primary ischaemic strokes

25
Q

Distinguish between the suffixes -paresis and -plegia. What does the prefix para- mean?

A

-paresis: weakness (can still move)
-plegia: complete paralysis
Para-: Lower limbs