Diagnostic and therapeutic dilemmas

Area of Science:

• Neurology
• Radiology
• Genetics

Background:

• Magnetic Resonance Imaging (MRI) reveals changes suggestive of multiple sclerosis (MS) in asymptomatic individuals, including relatives of MS patients.
• The clinical significance of these asymptomatic MRI findings is debated, particularly given autopsy evidence of MS plaques in asymptomatic individuals.

Purpose of the Study:

• To determine the clinical significance of asymptomatic MRI changes suggestive of MS.
• To evaluate whether individuals with these MRI findings should be considered to have MS or be candidates for immunomodulatory treatment.

Main Methods:

• Review of existing literature on MRI findings in asymptomatic individuals and autopsy studies of neurologically asymptomatic persons.
• Analysis of prevalence data for MS lesions in asymptomatic individuals.

Main Results:

• Asymptomatic individuals with MRI changes suggestive of MS are not clinically ill and do not meet diagnostic criteria for MS.
• Suggestive MRI changes are rare, even in genetically susceptible individuals like unaffected twins.
• A review of autopsy studies found MS lesions in asymptomatic individuals with a prevalence of 0.1%, matching the prevalence of clinical MS.

Conclusions:

• Asymptomatic individuals with MRI changes suggestive of MS should not be diagnosed with MS or considered for immunomodulatory treatment.
• The presence of MS lesions in asymptomatic individuals does not equate to clinical disease.
• The prevalence of unexpected MS lesions in asymptomatic individuals is similar to the prevalence of diagnosed MS.