The clinical case report of a patient who underwent an endoscopic third ventriculostomy for the treatment of a slit ventricle syndrome is presented. After surgery the patient developed a severe complication consisting of an organic personality disorder, characterised by impulsiveness, physical heteroaggressiveness, binge eating, hypersomnia and impairment of memory, and frontal-executive functions. A frontal lobe lesion may explain some of the symptoms presented, such as the uncontrolled impulses, the aggressive behaviour, and even the binge eating. However, a longitudinal neuropsychological evaluation showed a severe deficit in immediate memory and difficulties in planning and consolidation of newly learned information, which may be best related to damage in the frontal basal structures of the brain: the fornix and its connection to the hippocampus and the mamillary bodies. Postoperative MR images confirmed the clinical hypothesis. The emergence of such a severe organic personality disorder and cognitive dis turbances as a psychiatric complication of an endoscopic third ventriculostomy has not, it seems, been previously reported elsewhere. Clinicians should take these possible complications into account when recommending this so-called minimally invasive neuroendoscopic procedure. (J Neural Neurosurg Psychiatry 2001;71:268-271)
Keywords: third ventriculostomy; neuropsychological complications; neuroendoscopy
Changes in personality defined as organic personality disorders, which may occur after the administration of noxious organic agents, account for 2%-5% of all personality disorders. These disorders should be categorised as "disorders of the personality or behaviour owing to illness, cerebral damage or dysfunction" (CIE-l0),  or "change of personality owing to... --specifying the nosologic agent responsible" (DSM-IV). 
The clinical picture of such a disorder generally starts with a marked change in lifestyle and the emergence of traits of an unadjusted personality, after the necessary previous presence of an organic causal factor and, always, with a previously normal behaviour pattern.
There are many causes that could lead to organic personality disorders. The most frequent is head injury, but also many cases have been reported in the literature related to stroke, brain tumours--especially those affecting frontal or temporal lobes--epilepsy, Huntington's disease, multiple sclerosis, toxic drugs, neurosyphilis, HIV infection, and also surgery. 
Our patient was a 20 year old man diagnosed with a slit ventricle syndrome. At the age of 8 months, he underwent shunt surgery for a …