EEG characteristics of central nervous system graft-versus-host disease.

In this multicenter retrospective study, we analyzed the EEG characteristics of 17 patients with possible CNS graft-versus-host disease (pCNS-GvHD). All EEGs were abnormal. Most (11/17 patients) showed background activity slowing. Sporadic epileptiform discharges were rare (2 patients) and observed only in chronic pCNS-GvHD. Sporatic non-epileptiform discharges, often generalized, frontally predominant, and triphasic, were common (15/17 patients). Two patients presented generalized rhythmic delta activity, one showed lateralized rhythmic delta activity, and one exhibited lateralized periodic discharges. Background activity slowing was statistically associated with higher one-year overall mortality (P=0.026). These findings suggest that EEG may serve as a prognostic tool in CNS-GvHD.