What is the recommended primary care workup for multiple sclerosis?

Primary Care Workup for Multiple Sclerosis

The recommended primary care workup for multiple sclerosis should include brain and spinal cord MRI with and without contrast as the cornerstone of diagnosis, along with a focused neurological examination and appropriate laboratory tests to rule out alternative diagnoses. 1

Initial Clinical Assessment

• Focused neurological examination targeting:

  • Mental status
  • Cranial nerve function
  • Motor strength
  • Sensory function
  • Deep tendon reflexes
  • Coordination
  • Gait assessment

• Key symptoms to evaluate:

  • Sensory disturbances (numbness, tingling)
  • Motor weakness
  • Impaired gait
  • Incoordination
  • Visual symptoms (optic neuritis)
  • Lhermitte sign (electric shock sensation down spine with neck flexion)

Imaging Studies

Brain MRI

• Mandatory sequences 2:

  • Axial T1-weighted sequences (before and after contrast)
  • Axial T2-weighted sequences
  • Proton-density or T2-FLAIR sequences
  • Sagittal 2D or isotropic 3D T2-FLAIR sequences
  • Single dose (0.1 mmol/kg) gadolinium-based contrast with minimum 5-minute delay

• Look for 2, 1:

  • Multiple T2 hyperintense lesions
  • Gadolinium-enhancing lesions (indicating active inflammation)
  • Periventricular, juxtacortical, and infratentorial lesions

Spinal Cord MRI

• Indications for spinal cord MRI 2:

  • Patients with spinal cord symptoms
  • Inconclusive brain MRI findings
  • Strong clinical suspicion of MS with normal brain MRI
  • Nonspecific brain MRI findings
  • Primary progressive MS presentation

• Mandatory sequences 2:

  • Sagittal dual-echo (proton-density and T2-weighted)
  • STIR (Short-Tau Inversion Recovery)
  • Contrast-enhanced T1-weighted spin-echo (if T2 lesions present)

Laboratory Tests

• Blood tests:

  • Complete blood count
  • Comprehensive metabolic panel
  • Inflammatory markers (ESR, CRP)
  • Vitamin B12, folate levels
  • Thyroid function tests

• Cerebrospinal fluid analysis (when diagnosis is uncertain) 2, 1:

  • Cell count and differential (lymphocytic pleocytosis <50/mm³)
  • Protein and glucose
  • Oligoclonal IgG bands (using isoelectric focusing)
  • IgG index
  • Rule out infection with appropriate testing

Additional Diagnostic Tests

• Visual evoked potentials (VEP) 2:
  • Can provide objective evidence of a second lesion
  • Look for delayed but well-preserved waveform
  • Particularly useful when clinical examination doesn't show evidence of visual pathway involvement

Diagnostic Criteria

The 2017 McDonald Criteria require evidence of 1:

1. Dissemination in space (damage in different parts of the nervous system)
2. Dissemination in time (damage occurring at different times)
3. No better explanation for the clinical presentation

Common Pitfalls to Avoid

• Attributing all symptoms to MS without considering other causes 1
• Delaying MRI with contrast which can lead to delayed diagnosis 1
• Missing cerebral venous thrombosis which can be life-threatening 1
• Poor quality CSF analysis leading to unreliable measurements and incorrect diagnosis 2
• Overreliance on MRI findings alone without clinical correlation, which can lead to misdiagnosis in up to one-third of cases 3

When to Refer to Neurology

• Immediately after identifying suspicious findings on MRI
• When clinical presentation suggests MS but diagnosis remains uncertain
• For initiation and management of disease-modifying therapies
• For management of acute relapses requiring high-dose corticosteroids

Follow-up

• Neurology follow-up within 1-2 weeks of initial findings
• Repeat MRI in 3-6 months to assess for new lesions and treatment response 1
• Regular monitoring for disease progression and treatment side effects

The primary care provider plays a crucial role in the initial workup and ongoing management of MS patients, working collaboratively with neurologists and other specialists to ensure comprehensive care and optimal outcomes for patients with this complex neurological condition.