Abstracts

Rationale: In a recent systematic review about psychosis in temporal lobe epilepsy(TLE), Irwin & Fortune (2014) documented the lack of studies on this issue, showing that only 27 articles were suitable for analysis. One possible reason for this paucity of studies is the frequency of psychosis in TLE caused by hippocampal sclerosis (MTLE-HS) that although higher than in average population is not as frequent as mood disorders. In the current study, we evaluated 22 patients with MTLE-HS and psychosis in order to determine possible risk factors. Methods: We reviewed the database of patients with MTLE-HS referred to our center for epilepsy surgery in the last 5 years. Patients included in this analysis had unequivocal MTLE-HS.Psychosis was defined by the presence of delusions and hallucinations, the absence of negative symptoms, better premorbid day-to-day function, and rare deterioration of the patient's personality (revision in Kanner & Palac,2002). Clinical variables evaluated were: age; age of onset; duration of epilepsy; seizure types and their frequency; presence of status epilepticus; history of febrile seizures;number of AEDs used; presence of psychiatric disorders; use of psychoactive drugs; family history of epilepsy and psychiatric disorders; presence or not of epileptiform activity restricted to temporal lobes in previous EEGs and; side of the lesion on MRI. Statistical analysis was performed using ANOVA and Fisher test. All variables with p-value < 0.1 were analyzed with a linear regression model. In this study, a Classification and Regression Tree (CART) was also used for predicting dependent variables regression and categorical predictors variables. Results: 88 patients with MTLE-HS were evaluated. 22 (25 %) with MTLE-HS had psychosis. The mean age of these patients was 41.5 years (SD + 11.34); 59.1% were male. 16 (72.7%) had a left MTLE-HS; 3 (13.6 %) had a right MTLE-HS and 3 (13.6 %) a bilateral MTLE-HS. Left and bilateral MTLE-HS was associated with psychosis (p 0.019).Using Classification and Regression Tree, left and bilateral MTLE-HS was predictive of psychosis in 68.2% and right MTLE-HS was predictive of mood disorders in 67.5%. Other clinical variables were not associated with the occurrence of psychosis. Conclusions: This study corroborates the notion that left MTLE-HS is a risk factor for psychosis. However, we could not corroborate the concept that early age of onset and history of status epilepticus are also predictive factors for psychosis. Some strengths of the current study is that post-ictal psychosis was not included and patients were diagnosed with consistent clinical findings. A major limitation remains the number of patients in our series and its retrospective nature, although a standard protocol was used for all patients. Larger series are necessary to corroborate these findings. Irwin LG, Fortune DG. Risk factors for psychosis secondary to temporal lobe epilepsy: a systematic review. J Neuropsychiatry Clin Neurosci. 2014 Winter;26(1):5-23. Kanner AM, Palac S. Neuropsychiatric complications of epilepsy. Curr Neurol Neurosci Rep. 2002 Jul;2(4):365-72.