Clinical and quantitative EEG studies of mania

Earlier EEG studies reported essentially normal findings during acute manic episodes but some atypical EEG characteristics and distinctions between familial and sporadic cases were described. Recently quantitative EEG (qEEG) studies differentiating mania from schizophrenia and depression have been published.

Clinical EEGs were obtained in 202 patients hospitalized for acute mania. EEGs were repeated in 75 patients rehospitalized for subsequent manic attacks. Quantitative EEGs were recorded in 37 patients who were able to cooperate after drug washout and again on completion of randomly assigned pharmacotherapy.

Normal EEGs were obtained in most patients. Moderately abnormal EEGs in 16% were significantly associated with absent family histories of affective disorder. Left sided abnormalities were more common than right. "Small sharp spikes" and "microsleep" were encountered in 17% and 10% respectively of patients who drowsed. EEG findings during subsequent episodes did not suggest increasing CNS vulnerability. qEEGs showed significant differences between each of the therapeutic agents compared-lithium, carbamazepine, and lithium combined with carbamazepine, haloperidol or risperidone. Nonresponders at baseline had significantly more diffuse theta activity than responders. During pharmacotherapy nonresponders had higher amplitudes in the left temporoparietal areas.

Clinical EEG findings confirmed previous reports but did not contain original observations. Applications of qEEG were limited by requirements for patient cooperation.