Acute Clinical Worsening Without MRI Changes in Multiple Sclerosis

Patients with multiple sclerosis (MS) can have an acute clinical event suggestive of a relapse, but their magnetic resonance imaging (MRI) shows no corresponding changes (labeled by the authors as an acute clinical event with stable MRI [ACES]). These events have not been systematically analyzed. The authors reported that this number is significant, and a quarter of the relapses reported by patients fall under this category. Patients with ACES had higher relapse rates and a greater risk of transition to secondary progressive MS.