Limb weakness Flashcards
The technical term for a ‘clumsy’ limb
Ataxia
2 key things to establish with acute limb weakness
Time course
Location of the lesion
Sudden onset of limb weakness =>
CVA
Trauma (e.g. displaced cervical fracture)
Could also be in various parts of the nerve pathway -> acute limb ischaemia, Todd’s palsy, spinal cord prolapse!
Chronic onset limb weakness =>
Slow growing tumour
MND
Slow onset limb weakness (hours -> days) =>
Gillian-Barre
MS
Subdural haematoma
Spinal cord disease
Prolapse
Infarction
Spinal canal stenosis
Altered sensation and paralysis peripheral -> central =>
GBS
Where does GBS affect in the nerve pathway?
Nerve root
Causes of gradual onset limb weakness (chronic)
Diabetes
Myasthenia
Vit B12 deficiency
Tumour
Window for thrombolysis
4.5hr
How can you tell the lesion is in the brain?
Cognitive signs such as speech or vision issues
Gradual onset headache =>
Slow growing tumour
Seizure or LOC with limb weakness =>
Haemorrhage
Todd’s paresis
Hypoglycaemia
Hemiparesis with back pain =>
Disc prolapse
Unilateral headache and limb weakness =>
Hemiplegic migraine
3 main RF for stroke
Previous stroke/TIA
AF
Atherosclerotic RF e.g. obesity, HTN, diabetes smoking
UMN signs
Increased tone
Brisk reflexes
Upgoing plantars (Babinski sign)
Clonus
LMN signs
Reduced tone
Absent reflexes
Fasciculations
WASTING
Broca’s area affects…
Articulation of speech
Know what to say but can’t say it
Wernicke’s area affects….
Comprehension of speech
Can speak fluently but its nonsense
Complete blindness in one eye suggests…
Lesion in optic nerve
Optic neuritis
Homonymous hemianopia suggests…
Lesion in the optic chiasm (if bitemporal)
One side => in the cortex (localising sign)
Eye deviating TOWARDS the weak side =>
Brain stem lesion
Eye deviating away from the weak side =>
Cortical lesion
Non-forehead sparing weakness =>
Problem with facial nerve itself (Bell’s palsy)
If the weakness is greater in the arm than the leg, which bit of the motor cortex is it affecting?
Lateral homunculus
Which artery supplies the lateral part of the primary motor cortex?
Middle cerebral artery
Which artery supplies the medial primary motor cortex?
Anterior cerebral artery
How long do TIA usually last?
<1 hour
Definition of TIA
Symptoms and signs of stroke that resolve in <24hr
First-line investigations of stroke
CT head FBC Blood glucose (hypoglycaemia) Blood clotting (emboli) ECG (AF)
Which metabolic abnormality can mimic stroke?
Hypoglycaemia
Main treatment for haemorrhagic stroke
Supportive therapy to aid rehabilitation
What is the management of an ischaemic stroke outside of the 4.5hr thrombolysis window
Anti-platelet drugs (ASPIRIN!) Given as soon as haemorrhagic stroke is excluded
Stroke ward admission
VTE prophylaxis
Ix to do for patients after initial stroke management
ECG for AF/arrhythmia causing emboli
Carotid artery doppler looking for any stenosis
Complications of stroke
Aspiration pneumonia
Pressure sores
VTE and recurrent stroke
Which type of therapist should review stroke patients?
SALT
What is the cut off for carotid endarterectomy?
> 70%!
Who performs carotid endarterectomy?
Vascular surgeons
Acronym for stroke drug prophylaxis
ASA
Antiplatelet (e.g. clopidogrel) (if you start this, no need for the aspirin aswell)
Statin
ACEi
Which drug should be prescribed for ALL TIA patients?
300mg aspirin
Which scoring system is used in TIA?
ABCD2
Drug to control rate in AF
Bisoprolol
Drug to reduce clotting risk in AF
Warfarin or modern drugs such as rivoroxaban
Aspirin and clopidogrel affect which part of the clotting pathway
Platelet aggregation
Name for clots that form due to stasis are called ….
Red clots
Rich in RBC and fibrin
Prophylaxis of red clots from stasis is through use of
Fibrin mesh inhibitors = clotting cascade
= rivoroxaban and warfarin!
Name of clots from ruptured plaques…
White clots
Rich in platelets!!!!!
Prophylaxis of white clots from ruptured plaques is through use of…
Platelet aggregation inhibitors
Clopidogrel
Aspirin
What do rivoroxaban and warfarin prevent?
Formation of fibrin mesh
Help to prevent VTE and atrial clots
What do clopidogrel and aspirin prevent?
Platelet aggregation after ruptured atherosclerotic plaques
Help to prevent myocardial infarction and ischaemic stroke
What is the 300mg aspirin prescribed for in stroke patients?
To prevent emboli
What do you compare the CHADsVASc score against to determine if anticoagulation is wise?
HAS BLED
Presentation of cord compression
Bilateral sensory loss
Weakness
UMN signs
Presentation building over a few days (subacute)
Causes of cord compression
Disc herniation
Spondylolisthesis
SOL (abscess, tumour, haematoma)
Investigation of cord compression
Spinal MRI
Ix for MS
Spinal MRI looking for plaques
Lumbar puncture looking for oligoclonal bands
Humerus fracture can cause damage to which nerve?
Ulnar nerve
Which scale is used to grade limb weakness?
MRC scale
Hemiparesis means…
Half body weakness
Quadraplegic means
Complete paralysis of all 4 limbs
Nerve root responsible for ankle jerk
S1/S2
Nerve root responsible for knee jerk
L3/L4
Nerve root for biceps
C5/C6
Nerve root for triceps
C7/C8
Nerve that innervates the bicep
Musculocutaneous nerve
Nerve that innervates the badge area of the arm and teres minor
Axillary nerve