Occlusive Patch Therapy for Reduction of Seizures in Dravet Syndrome

A 2-year-old Caucasian male presented with a history of nystagmoid eye movements. He also had a history of seizures that were poorly controlled with medications. The parents felt the seizures were exacerbated by exposure to light as they were worse on waking up from a nap. The patient was born at 38 weeks gestational age with a birth weight of 8 lbs 13 oz and birth height of 20.25 inches. His gestational history was complicated only by preeclampsia, for which his mother underwent induction of labor. At 9 months of age, he had his first febrile seizure leading to status epilepticus. His past medical history until that time was only significant for recurrent acute otitis media, for which he had been on amoxicillin treatment at the time of his seizure. He was evaluated by neurology, underwent an electroencephalogram (EEG), and was diagnosed with generalized epilepsy of unknown origin. His parents were given a prescription for diazepam by rectal suppository to be given at the onset of a seizure. The patient continued to have seizures and was placed on multiple anti-epileptic medications, including topiramate (Topamax), levetiracetam (Keppra), clonazepam (Klonopin), and lamotrigine (Lamictal). These were all ineffective and he was finally started on valproic acid (Depakene), which was changed to divalproex sodium (Depakote), which partially controlled his seizures. Around 15 to 18 months of age, the patient began regressing developmentally. Although he had been walking previously, he resorted back to crawling and could no longer verbally communicate with his parents with wellformed words. His receptive language skills surpassed those of expressive language. The parents continued to notice that the seizures appeared to be triggered by exposure to bright light and began to keep him in totally dark environments and made him wear sunglasses constantly. Given the intractable seizures and photosensitivity, genetic testing was performed, which revealed that the patient had a severe-type mutation in the SCN1A gene. Both parents tested negative for the same SCN1A gene mutation indicating a de novo mutation. The patient was diagnosed with Dravet syndrome previously known as severe myoclonic epilepsy of infancy. At his first consultation with ophthalmology, a complete examination could not be performed because of seizure activity with exposure to light when attempting a Hirschberg examination. It was noted that he had jerky nystagmoid movements of the eyes and that his eyes crossed. A trial of alternating monocular patching was initiated where each eye was patched for 6 hours in an alternating pattern. The patient’s parents noted a dramatic improvement in his seizure activity after a few months of starting the patching. The number of seizures decreased from 20 seizures in 2007 to 12 seizures in 2008, the year he was being patched. All these seizures occurred while he was not wearing the eye patch. In addition, his tolerance for dim, low-wattage light had also improved. He returned for another eye examination in 2008 and had been seizure-free for 5 months prior to the examination, which was a marked improvement. At this examination his vision was estimated to be 20/80 in the right eye (9.8 cy/cm at 38 cm) and 20/150 in the left eye (4.8 cy/cm at 38 cm) using Teller acuity cards. At a subsequent examination, 3 months later, his vision had improved to 20/50 (9.8 cy/cm at 55 cm) in each eye. He could also tolerate a full eye examination without seizure activity with each eye evaluated separately and the other eye patched.