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 central nervous system (CNS) graft-versus-host disease (pCNS-GvHD). All EEGs were abnormal. Most (11 of 17 patients) showed background activity slowing. Sporadic epileptiform discharges were rare (2 patients) and observed only in chronic pCNS-GvHD. Sporadic nonepileptiform discharges, often generalized, frontally predominant, and triphasic, were common (15 of 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 1-yr overall mortality (P ¼ 0.026). These findings suggest that EEG may serve as a prognostic tool in CNS-GvHD.NEW & NOTEWORTHY This retrospective study is the first to describe EEG features of central nervous system involvement in graft-versus-host disease (CNS-GvHD). It shows that CNS-GvHD consistently associates with EEG abnormalities at peak disease severity. Epileptiform discharges are rare and mostly occur in chronic CNS-GvHD. Finally, it identifies a statistically significant association between background rhythm frequency and 1-yr survival, suggesting EEG as a potential prognostic tool for CNS- GvHD.