Neurology- Interpretating Findings

Question 1

How to interpret results

Answer 1

1. Localise the lesion to a single system (e.g. CNS vs PNS)
2. Then localise in more detail (nerve vs root vs neuromuscular junction). NB some conditions such as MS may have multiple signs and symptoms
3. Having localised the lesion, consider the underlying pathology (what is the lesion)
4. Draw up a differential diagnosis and consider the Ix required

Question 2

Lumbar puncture

Answer 2

• used for acute and chronic condition
• always measure the opening pressure using a blunt needle
• CSF is routinely checked for protein, glucose, bacterial and viral
• other tests include: meningococcal, pneumococcal, oligoclonal bands or cytology for malignancy

Question 3

Neurophysiological tests

Answer 3

1. electroencephalography (EEG) records spontaneous activity in the brain
   - it is employed in the Ix of epilepsy, encephalopathy or dementia
2. Electromyography (EMG)- involves needle electrodes into the muscles. Shown on an oscilloscope and audio so you can see and hear patterns of activity
   - neurogenic and myopathic pathology causes EMG abnormalities
3. Nerve conduction studies- apply electrodes to the nerves and measure speed of impulse conduction
   - used for motor and sensory nerves useful in diagnosing peripheral nerve disorders (e.g. compressions or polyneuropathies)
   - they can be helpful in distinguishing axonal vs demyelinating neuropathies, were causes and Mx are different