Investigation in multiple sclerosis include:

• MRI scanning:
  • permits the visualisation of the dissemination of lesions in time and space
• will reliably identify plaques in the cortex, brainstem and spinal cord
• gadolinium enhancement improves sensitivity

• CSF:
  • permits the detection of intrathecal inflammation
• pleocytosis
• slightly raised protein
• 70% of patients hace a raised IgG - electrophoresis reveals oligoclonal bands in the CSF which are not found on serum electrophoresis

• visual evoked potentials:
  • permit the demonstration of conduction changes consistent with demyelination
• are of normal amplitude but show an increased latency in patients who have or have had optic neuritis
• measurement of visual evoked potentials is a good way of demonstrating a previous, often subclinical, episode of demyelination in order to make the diagnosis of multiple sclerosis
• auditory brainstem evoked potentials and somatosensory evoked potentials may also be measured