Neuropsychological and psychiatric complications in endoscopic third ventriculostomy.

We read with interest the recent paper by Benabarre et al of the first reported case of endoscopic third ventriculostomy followed by severe psychiatric complications. In our department, we also had a patient who developed severe psychiatric symptoms after an endoscopic third ventriculostomy (ETV). A 45 year old woman with an aqueductal stenosis underwent an EVT because of progressive gait and visual disturbances. In November 1997 she underwent an ETV through a right side precoronal burr hole using a rigid neuroendoscope. The third ventricular floor was perforated with a 4 French Fogarty catheter, the perforation being enlarged with the inflatable balloon. No problems were encountered during the procedure, although we noted an incomplete septum pellucidum. After ETV her gait and visual disturbances gradually resolved. However, after the procedure the patient was nervous and agonised, and she complained of a crepitating sound in her head and behaved aggressively towards her spouse. Because her complaints and behaviour worsened a psychiatric evaluation was performed. Psychotic depression was diagnosed and three weeks after the EVT she was admitted to the department of psychiatry. For several months she was treated with antipsychotic and antidepressant drugs and her psychotic depression partially resolved. She is still being treated for mild depression. Postoperative magnetic resonance imaging six weeks, three months, and one year after the EVT showed no normalisation of the ventricular system, but no other abnormalities were seen. Signs and symptoms were abrupt and probably organic because of the apparently strong relation between the procedure and the start of the psychotic depressive episode. Previously, the patient had no psychiatric complaints and had undergone other invasive procedures under general anaesthesia and admittance to the hospital. It is not clear how this psychotic depression after EVT can be explained. Sometimes when ETV is performed, injury of the fornix is seen. The fornix constitutes the sole efferent system from the hippocampus and both are involved in the limbic system. The limbic system has an important role in mood and emotional behaviour. We hypothesize that in this patient a combination of incomplete septum pellucidum and an injury of the fornix may have caused an organic personality syndrome after EVT. We agree with Benabarre et al that clinicians should be aware of and take into account this potential serious complication of EVT in this so called minimally invasive procedure.