Event-related potential P300 in multiple sclerosis. Relation to magnetic resonance imaging and cognitive impairment
L. S. Honig, R. E. Ramsay and W. A. Sheremata
Department of Neurology, University of Miami (Fla) School of Medicine.
Cerebral involvement in multiple sclerosis may result not only in sensory
and motor symptoms but also in impaired mentation. We hypothesize that
cognitive dysfunction occurs due to cortical deafferentation or
disconnection arising from subcortical white-matter disease. We examined
the P300 event-related potential in 31 patients with multiple sclerosis,
correlating it with disease severity ratings based on magnetic resonance
imaging signal intensity changes, cognitive dysfunction, and disability
status. The patients with multiple sclerosis exhibited significantly
prolonged P300 wave latencies compared with 32 control subjects. The P300
latency was strongly correlated with the presence of demyelinative brain
lesions seen on magnetic resonance imaging scans and with cognitive
impairment, but was only weakly associated with the Kurtzke disability
status score, consistent with this scale primarily reflecting spinal rather
than cerebral demyelination. Our study results support a relationship
between subcortical white-matter lesions and cognitive impairment in
multiple sclerosis.
