EEG studies on patients with chronic obsessive-compulsive neurosis before and after psychosurgery (stereotaxic bilateral anterior capsulotomy).

In 35 patients with chronic severe obsessive-compulsive neurosis the EEG was studied before, shortly after (10 days) and 1--2 years after a psychosurgical intervention (stereotaxic bilateral anterior capsulotomy). The preoperative EEG was completely normal or borderline in most of the patients (94%). After surgery EEG changes appeared in 90% of the patients. In most of them (75%) these consisted in bilaterally synchronous bursts of rhythmic slow waves with a maximum in the frontal regions. No consistent change of the alpha activity could be found. At the follow-up examinations most of the EEGs (79%) showed the same pattern as at the preoperative control. No focal or epileptiform abnormalities were observed, either at the immediate postoperative or at the follow-up examination.