Abstract Details Title Eating Epilepsy, Redefining the Semiology Topic Epilepsy Presentation(s) P07 - (-) Poster/Presentation Number 173 Objective Background BACKGROUND: Eating epilepsy is a rare form of reflex epilepsy. Various postulates exist on the origin of eating epilepsy but semiology and pathophysiology remain obscure. Design/Methods DESIGN/METHODS: We studied three cases of eating epilepsy with detailed history, interictal EEG and ictal video-EEG recording, MR imaging with epilepsy protocol and interictal ECD-Tech SPECT scanning. We searched literature on seizures originating from operculum and insula- the cortical areas associated with initiation and motor control of eating. Based on the common features in semiology in these cases and data from literature, we propose a definitive semiology for this obscure syndrome. Based on the EEG and imaging data from these cases and review of literature, we propose a new hypothesis for the origin of the epileptic syndrome. Results RESULTS: All three patients strikingly had complex partial seizures followed by tonic/atonic/truncal myoclonic seizures. All three had normal MRI brain. Ictal EEG and interictal SPECT showed lateralization to each hemisphere in one case each and lack of lateralization in the third. Literature search revealed that seizures of the opercula and insular cortex induce mastication, salivation, swallowing and gustatory hallucinations*. We hypothesize that, as a corollary, the normal physiology of mastication, salivation, swallowing and gustation while eating induce hypersynchrony of firing in the hyperexcitable epileptogenic zones of opercula (including insular cortex) resulting in reflex eating epilepsy.*Ref: PMID 2502382. Conclusions CONCLUSIONS: A combination of CPS and atonic/tonic/truncal myoclonic seizures is the defining semiology in reflex eating epilepsy. We hypothesise that hyperexcitable epileptogenic zones of opercula including insular cortex, result in reflex eating epilepsy irrespective of the side of epileptogenic focus. Distinct semiology suggests origin in insular cortex and spread to midline structures resulting in tone and postural changes. Authors/Disclosures Andreas Lysandropoulos (Parexel) Andreas Lysandropoulos has nothing to disclose.