EEG power modifications in obsessive-compulsive disorder during olfactory stimulation.

Temporal lobe electroencephalogram (EEG) activity was quantitatively analyzed in obsessive-compulsive disorder (OCD) when subjects are at rest and during a temporal lobe activating procedure, i.e., olfactory stimulation. At rest with eyes closed, delta-1 and alpha-2 power differences were evident in OCD patients as compared with normal controls. During olfactory stimulation, differences between patients and normal groups were detectable in the slower beta frequencies: Normal subjects showed a power increase, whereas OCD patients showed no modification or slight decrease. Our results support previous findings of temporal lobe EEG abnormalities in OCD patients with an abnormal pattern of response to a temporal lobe activating procedure.