Differential distribution of epilepsy in patients with different types of dementia: a single-centre, retrospective study

Aim: the risk of epilepsy in patients with Alzheimer Disease (AD) is 5-10 fold increased as compared to age matched controls (Amatnick et al, 2006). the present study was aimed at investigating possible differences in epilepsy co-morbility among patients with different types of dementia. Patients: Patients attending the dementia and Neuropsychology Centre of the Unit of Neurology and Neuromuscolar Disorders of the University of Messina were investigated through an analysis of their charts from 2000 to 2010. Methods: The study was retrospective. The charts of 1893 demented patients were reviewed and only those patients with a well documented type of dementia and a firm siagnosis of epilepsy chronically treated with AEDs were considered. The charts of 639 non demented patients matched for age and sex were reviewed and served as a control group. Standard statistical methods were used to analyse our results. Results: 12 patients (1.9%) were suffering from epilepsy in the population of non demented patients (p<0.001 vs demented population) 201 patients in the demented population had epilepsy, but 38 of these were excluded because of insufficient information regarding their epilepsy and/or type of dementia. The remaining 163 patients with epilepsy and dementia co-morbility were analyzed. The epilepsy distribution was the following: 5,3% in patients with AD (n=31/590), 7,5% vascular dementia (n=38/509); 11,5% frontotemporal dementia (n=33/286) 12,7% mixed dementia (n=61/479) Poropotion test showed that dementia-epilepsy co-morbility was more frequent in mixed and in fronto-temporal dementia as compared to the remaining two forms (all p values<0.0001) a trend of significance was also seen for vascular dementia in comparison with AD (p=0.06). Discussion Previous studies have shown that 8-20% of patients with AD have at least one unprovoked seizure (Amatniek et al 2006, Rao et al. 2009, Bernardi et al.2010) our results agree with those of literature and additionally indicate that the risk of epilepsy is different in various types of dementia. Patients with both the neurodegenerative and the vascular disorders exhibit the highest risk of epilepsy. Conclusion: A percentage of 5% of patients with AD has epileptic seizures. Patients with other forms of dementia exhibit a higher risk of developing epilepsy. Conclusion: A percentage of 5% of patients with AD has epileptic seizures. Patients with other forms of dementia exhibit a higher risk of developing epilepsy, the highest value being observed in patients with mixed dementia. Further larger multicentre studies are required to archieve conclusive results and to explore the risk of epilepsy in other forms of dementia, like for example cortico-basal degeneration and Lewy body dementia