Startle epilepsy, characterized by startle-provoked epileptic seizures, was historically recognized as one of the reflex epilepsies but currently lacks classification as a specific epileptic syndrome because of insufficient characterization. This study presents an institutional experience and review of relevant literature focusing on the neurophysiologic and anatomical aspects of startle epilepsy. We describe a pediatric patient with an underlying structural etiology of left frontal encephalomalacia who continued to experience disabling seizures despite multiple antiseizure medications and previous palliative surgery. A comprehensive presurgical evaluation using SEEG led to the resection of the left supplementary motor area and adjacent middle cingulate cortex, resulting in successful seizure remission. A literature review on the surgical treatment of startle epilepsy revealed consistent reports of successful seizure remission through neocortical resection of the supplementary motor area and/or cingulate region. This case study and literature review highlights startle epilepsy as a distinct form of epilepsy with identifiable neurophysiologic and anatomical characteristics. Our observations emphasize the potential of resective surgery as a viable treatment option for startle epilepsy and underscore the importance of neurophysiologic monitoring in guiding surgical interventions.

Startle-induced seizure is a rare type of reflex seizure triggered by unexpected sensory stimuli that often occurs in children with early acquired cerebral lesions or brain malformations. We report a unique case of adult-onset epilepsy with startle-induced seizures. A 24-year-old woman had suffered high fever and focal to bilateral tonic-clonic seizures. A diagnosis of febrile infection-related epilepsy syndrome (FIRES) was made based on the febrile infection occurring 7 days to 24 h before the onset of status epilepticus, which met all criteria for cryptogenic new-onset refractory status epilepticus (NORSE) according to the cryptogenic NORSE score. Immunotherapy and several antiseizure medications resulted in transient resolution of the seizures. Four months later, she experienced startle-induced seizures triggered by unexpected stimuli, such as auditory, visual, or unexpected events, and manifesting as initial tachycardia followed by right ear deafness, right hemifacial dysesthesia, eye deviation to the right, and tonic-clonic convulsions. Ictal electroencephalography revealed left temporal initial rhythmic delta activity, followed by rhythmic theta activity. The patient was diagnosed with startle epilepsy associated with FIRES and continued to receive anti-seizure medications. Claustrum-insular-operculum lesions may have been the epileptic focus in this case, in contrast to previous cases of epilepsy with startle-induced seizures originating in a frontoparietal network. This case indicates a new category of adult-onset post-FIRES epilepsy with startle-induced seizures.

Herein, we present the case of a 21-year-old man with a history of generalized tonic seizures since the age of 4 years. These seizures occurred either spontaneously or could be provoked by auditory stimuli such as the sounds of a vacuum cleaner or an electric shaver. Despite trials with 10 different anti-seizure medications, his seizures remained refractory. Interictal electroencephalography (EEG) revealed generalized epileptiform activity, whereas ictal EEG showed a generalized attenuation pattern. Magnetic resonance imaging revealed extensive chronic infarctions, predominantly in the bilateral cerebral watershed areas. At the age of 17, the patient underwent a one-stage complete callosotomy, which only achieved remission of auditory-provoked seizures. Based on this experience and published reports, we propose that the posterior corpus callosum, particularly the isthmus and anterior splenium, may be involved in seizures caused by unexpected sound stimuli.