What bedside investigations would you perform if suspecting motor neurone disease?
- Respiratory assessment – baseline FVC and peak cough flow.
- Functional assessment – important to determine baseline to monitor disease progression. Supporting tools inc. ALS Functional Rating Scale.
What laboratory investigations would you perform if suspecting motor neurone disease?
- Baseline bloods (FBC, U&Es, TFTs, and glucose) – exclude metabolic or systemic causes of weakness.
- Serum vitamin B12 and folate – exclude neuropathy mimics.
- Creatinine kinase (CK) – may be mildly elevated in ALS, but marked elevation would be more indicative of myopathy than MND.
What imaging investigations would you perform if suspecting motor neurone disease?
MRI brain and spinal cord – exclude structural lesions or demyelination that may cause symptoms.
What specialist investigations would you perform if suspecting motor neurone disease?
Nerve conduction studies and electromyography (EMG) – may show denervation, fasciculations, and/or chronic reinnervation.
What laboratory investigations would you perform if suspecting multiple sclerosis?
- FBC – WCC for infection.
- CRP – non-specific marker of an inflammatory process (e.g., infection, autoimmune), but useful for trend.
- U&Es – exclude electrolyte disturbance, which may mimic MS.
- Calcium and serum ACE – exclude sarcoidosis.
- TFTs – exclude hypothyroidism.
- B12 and folate – exclude as neuropathy mimics.
What imaging investigation would you perform if suspecting multiple sclerosis?
MRI of brain and spinal cord with contrast – MS lesions will appear as hyperdense white matter plaques.
What specialist investigations would you perform if suspecting multiple sclerosis?
- Lumbar puncture – especially useful if there is no clear radiological evidence of MS pathology – high protein content and oligoclonal bands of immunoglobulin are suggestive of MS.
- Evoked potentials.
What beside investigations would you perform if suspecting Parkinson’s disease?
- Lying and standing BP – postural hypotension.
- Formal cognitive assessment, e.g., Montreal cognitive assessment, MOCHA.
What laboratory investigations would you perform if suspecting Parkinson’s disease?
If patient has cognitive impairment, it is important to screen for other reversible causes of confusion/delirium:
- FBC – exclude low Hb (anaemia) or raised WCC (infection).
- U&Es – exclude electrolyte derangement.
- LFTs – exclude hepatic encephalopathy.
- Glucose and HbA1c – exclude hypo/hyperglycaemia.
- TFTs – exclude hypothyroidism.
- Calcium – exclude hyper/hypocalcaemia.
What imaging investigations would you perform if suspecting Parkinson’s disease?
Dopamine active transporter (DaT) scans – measure dopamine uptake in the basal ganglia and hence, specific for primary Parkinsonian syndromes.
However, these are veryyyyy expensive scans and so reserved for diagnostic uncertainty.
