Brainstem lesions in clinically isolated syndromes

Area of Science:

• Neurology
• Neuroimaging
• Clinical Prognostics

Background:

• Baseline lesion load in clinically isolated syndromes (CIS) is a known predictor of disease activity and disability.
• The specific prognostic value of infratentorial lesions in CIS requires further elucidation.

Purpose of the Study:

• To investigate the long-term prognostic significance of baseline infratentorial lesions in patients with CIS.
• To determine if lesion location (infratentorial) and number impact conversion to multiple sclerosis and disability progression.

Main Methods:

• A prospective cohort study included 246 patients diagnosed with CIS.
• Brain MRI scans were performed within 3 months of CIS onset to assess lesion load and location.
• Patients were followed for a median of 7.7 years to track time to a second clinical attack and Expanded Disability Status Scale (EDSS) 3.0.

Main Results:

• Patients with infratentorial lesions exhibited a significantly higher risk of conversion to multiple sclerosis (71.4% vs 29.6%) and disability (32.5% vs 12.4%).
• Presence of brainstem lesions was strongly associated with increased risk of both conversion (HR 2.9) and disability (HR 2.5).
• Infratentorial lesions conferred a markedly higher risk of conversion (HR 22.3) and disability (HR 3.2) in patients with 9 or more baseline lesions.

Conclusions:

• Baseline infratentorial lesions are significant predictors of long-term disability in CIS patients.
• Brainstem lesions appear to be a more critical factor than cerebellar lesions in determining a poor prognosis for CIS.
• Identifying infratentorial lesions, especially in patients with high lesion burden, is crucial for risk stratification and management.