Preliminary Findings of Single- and Multifocused Epileptiform Discharges in Nonepileptic Psychiatric Patients.

Epileptiform discharges (EDs) in nonepileptic populations remain controversial as to their role in psychopathology. Previous studies have unsuccessfully attempted to correlate specific waveforms of EDs, defined by duration and morphology, with broad diagnostic categories such as depression and anxiety. These diagnostic categories often include heterogeneous patient populations, with potentially divergent biological underpinnings of clinical presentation. This study examined epileptiform activities as a single phenomenon, identifying the relationships between distribution patterns of EDs and endorsement of clinical symptoms across affective, cognitive, and somatic domains. In a sample of 71 nonepileptic psychiatric patients, those with EDs appearing in homologous electrode pairs endorsed significantly fewer symptoms related to affective deregulation. These patients were also significantly less likely to endorse a history of severe symptomatology, including suicidal ideation/previous attempt, self-injurious behavior, psychoses or dissociation, and previous psychiatric hospitalization. Conversely, patients with isolated EDs focused to a single brain region endorsed greater affective deregulation and severe clinical symptoms. These findings offer new possibilities regarding the potentially protective role that EDs may play when distributed across hemispheres, particularly in light of recent theories exploring functional connectivity of neuronal networks. © EEG and Clinical Neuroscience Society (ECNS) 2013.