Radiologically isolated syndrome and multiple sclerosis.

Area of Science:

• Neurology
• Neuroimaging
• Demyelinating Diseases

Background:

• Incidental white matter lesions (WML) on MRI are common.
• Radiologically isolated syndrome (RIS) describes patients with demyelinating lesions without clinical symptoms, suggestive of multiple sclerosis (MS).
• Current diagnostic criteria for RIS help stratify conversion risk but do not define it as a distinct MS phenotype.

Purpose of the Study:

• To review current literature on diagnostic criteria, natural history, and treatment indications for RIS.
• To assess challenges in diagnosing and treating patients with RIS in clinical practice.

Main Methods:

• Literature review of diagnostic criteria, natural history, and treatment of RIS.
• Assessment of clinical practice challenges.

Main Results:

• Approximately one-third of RIS patients convert to clinically definite MS within 5 years; some progress to primary progressive MS (PPMS).
• Key risk factors for conversion include age under 37, male gender, and spinal cord lesions.
• RIS patients exhibit early axonal loss, brain atrophy, cognitive deficits, and subclinical inflammatory disease.

Conclusions:

• Treatment for high-risk RIS patients is controversial but may be considered.
• Prospective follow-up by an MS specialist is recommended for RIS patients.