Functional activation may be useful as a predictive measure of episodic memory loss in patients with multiple sclerosis (MS), a recent study found. Researchers used functional magnetic resonance imaging (fMRI) during a verbal episodic memory task, lesion load, and volumetric measures of the hippocampus and thalamus to assess the relative contributions to verbal and visual-spatial episodic memory in persons with MS (n=32) and healthy controls (n=16). They found:

• After adjusting for disease duration, immediate recall performance on a visual-spatial episodic memory task was significantly predicted by hippocampal volume.
• Delayed recall on the same task was significantly predicted by volume of the left thalamus.
• For both memory measures, functional activation of the thalamus during encoding was more predictive than that of volume measures.