Abstracts

Rationale: After ischemic stroke and intracerebral hemorrhage, CNS tumor is the most common underlying etiology for new onset seizures in the elderly. However in this age group the diagnosis of cancer is not uncommon. We sought to study underlying etiologies of this phenomenon of neoplasm in elderly patients with epilepsy. We specifically sought to explore this in our patients with new onset geriatric onset epilepsy (GOE; age of onset 55 years or older) by comparing their oncologic disease state to those elderly patients with longstanding epilepsy (non-GOE; age of onset less than 55 years).Methods: Upon IRB approval, we retrospectively reviewed all patients aged 65 years or older at our institution between January 2012-July 2014 with the probable diagnosis of seizure and epilepsy utilizing ICD-codes 345/780. 431 patients were identified and screened for eligibility. Patients with unconfirmed diagnosis of epilepsy, psychogenic non-epileptic seizures, and who had a follow-up period less than 30 days were excluded. Age of onset of seizures was identified, and 236 eligible patients were stratified into GOE and non-GOE groups. Of these patients, 86 were identified to have clinically relevant neoplasms and are the subject of the current study. Detailed clinicopathologic information regarding primary tumor site as well as extent of disease was captured and evaluated (including CNS involvement, if present).Results: Of the 236 patients with geriatric epilepsy, 86 (36.4%) were noted to have a neoplasm. Of these, 40 patients (17.0%) had either a CNS primary neoplasm or nonCNS primary which was metastatic to the CNS. In addition, 46 patients (19.5%) harbored neoplasm of nonCNS primary without brain involvement. Interestingly, patients with GOE (new onset) were significantly more likely to harbor neoplasm in comparison to those of similar age with longstanding epilepsy (non-GOE) (39.7% vs 23.2%; p=0.026). Furthermore, patients with GOE were more likely to harbor disseminated neoplasm over those with non-GOE (31.0% vs 7.7%; p=0.1 nonsignificant).Conclusions: These data demonstrate the importance of careful surveillance for underlying neoplasm in patients new onset GOE, which is has special prediliction for both CNS and non-CNS involvement.