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 the patient and normal groups were detectable in the slower beta frequencies: Normal subjects showed a power increase, whereas OCD patients showed no modification or a 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.