investigations

Last edited 11/2019 and last reviewed 03/2022

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

Before referring a person suspected of having MS to a neurologist, exclude alternative diagnoses by performing blood tests including (1):

• full blood count
• inflammatory markers for example erythrocyte sedimentation rate, C-reactive protein
• liver function tests
• renal function tests
• calcium
• glucose
• thyroid function tests
• vitamin B12
• HIV serology

Do not diagnose MS on the basis of MRI findings alone (1).

Reference:

• NICE (November 2019). Multiple sclerosis management of multiple sclerosis in primary and secondary care.