Abstracts

Rationale: Ictal forced mouth opening is a rare semiologic phenomenon seen in focal epilepsy. We report the mouth opening as an ictal sign in a 30-year-old woman with history of refractory epilepsy since age 8 months. At age 4 she had right frontal lesionectomy for a low-grade tumor but it did not control seizures. She had another epilepsy surgery at age 10 that too failed to control her seizures. Then at age 19 years she had third epilepsy surgery with right temporal lobectomy. She became seizure-free for ten years. She continued to take lamotrigine and topiramate. In 2017 the seizures recurred and oxcarbazepine was added but she continued to have nightly seizures. All her seizures were focal impaired awareness seizures (FIAS)  and she never had FIAS evolution to tonic clonic activity. She had failed several antiepileptic medications including ketogenic diet.  Methods: She was evaluated with video EEG monitoring. We recorded 13 typical FIAS that were characterized by left hand and face tingling, followed by grimacing, forced mouth opening, hypermotor left arm movements, and agitation. Electrographically, EEG was obscured by muscle artifact at the onset. In some seizures a semi-rhythmic slow wave activity was noted in right frontocentral region just prior to clinical onset. Her MRI showed previous resections. She underwent stereo-electroencephalography (SEEG) with eight depth electrodes placed each with ten contacts: six depth electrodes in right hemisphere and two were placed in left hemisphere.  Results: We recorded 51 FIAS with consistent ictal forced mouth opening and unresponsiveness. The ictal onset had a very focal onset in the right middle frontal gyrus region just behind the prior resection cavity. She underwent resection of right middle frontal gyrus. Postoperatively she developed supplementary motor area syndrome with left arm more than left leg weakness that needed physical therapy. Her weakness improved over next four weeks and she has remained seizure free since the surgery.  Conclusions: Ictal forced mouth opening be considered as a rare automatism seen in epileptic seizures and can be a semiologic sign of a right frontal convexity epilepsy. This rare ictal manifestation should be recognized as epileptic to avoid misdiagnosis and treatment failure.  Funding: No funding