What are the key clinical features to consider when diagnosing Multiple Sclerosis in a primary care setting?

Key clinical features to consider when diagnosing multiple sclerosis (MS) in primary care include:

• Neurological symptoms affecting different parts of the body, commonly including loss or reduction of vision in one eye with painful eye movements, double vision, ascending sensory disturbance and/or weakness, altered sensation or pain down the back when bending the neck forwards (Lhermitte's sign), and progressive difficulties with balance and gait.
• Presentation typically in people aged under 50 years.
• A history of previous neurological symptoms may be present.
• Symptoms usually evolve over more than 24 hours and may persist for several days or weeks before improving.
• Absence of fever or infection during symptom onset.
• Symptoms consistent with an inflammatory demyelinating process; for example, headache alone is not suggestive of MS.
• Exclusion of alternative, more common diagnoses through history, examination, and possibly targeted laboratory tests if atypical features are present.
• Symptoms should be focal neurological signs rather than nonspecific symptoms such as fatigue, depression, dizziness, or vague sensory phenomena unless accompanied by focal neurological signs.

Before referral, confirm the neurological nature of the episode by history and examination. Refer suspected cases to a consultant neurologist for diagnosis using clinical history, examination, MRI, and laboratory findings following the 2017 revised McDonald criteria. Do not diagnose MS on MRI findings alone.

These features help differentiate MS from other conditions and guide timely referral for specialist assessment.

References: NICE NG220