TEACHING POINTS
■ Reflex seizures may be precipitated by various external stimuli: hot water; flashing lights; specific visual patterns, such as stripes; higher-level thought processes, such as those used to do arithmetic or draw; typing; rapid speech or stuttering; eating; or being startled or touched in specific trigger zones on the skin.
■ The treatment of reflex seizures depends on the cause and whether the patient also has spontaneous seizures.
■ During EEG, the patient should be exposed to the external stimulus suspected of evoking the seizure.
■ Treatment includes avoidance of the provoking external stimuli and an antiepileptic medication, if needed.
CASE
An 18-month-old male was brought to the emergency department (ED) by his family. The mother reported that for the past 5 nights, the child had had "falling out" episodes, during which he became limp and developed periorbital and lip cyanosis when placed in bathwater. No convulsions, loss of bladder/bowel control, emesis, tongue biting, eye blinking, or lip smacking was noted. Two days prior to this presentation, the child had been hospitalized for evaluation of the cyanotic episodes. The cyanosis would resolve after the child was removed from the bathtub, but he would appear very sleepy. When he awoke, he would be back to his usual self.
The child had had no recent illness and was taking no medications. There was no indication of developmental or neurologic delay to date. He had not had any problems with bathing or swimming in the past. Born at full term following a spontaneous vaginal delivery without complications, the child was otherwise healthy. There was no family history of seizures. The patient's laboratory results and findings of a neurologic examination were normal during his stay in the hospital.
Physical examination The child was a well-nourished, well-hydrated, 18-month-old male. He appeared developmentally age-appropriate and was in no acute distress. His weight was 25 lb, and he was afebrile. His skin was warm, pink, dry, and without rashes. The oral mucosa was pink and moist. On examination of his head, eyes, ears, nose, and throat, he was found to be normocephalic and without any signs of trauma. Pupils were equal, round, and reactive to light. Tympanic membranes were pearly gray. The throat appeared normal, and the neck was supple. On auscultation, his heart rate was slightly tachycardic at 110 beats per minute; no murmurs, rubs, or gallops were heard. Lungs were clear bilaterally. The abdomen was soft, nondistended, and without masses, pulsations, rebounding, or guarding. Pulses in the extremities were normal. Capillary refill was less than 3 seconds. Strength and sensation were intact distally. Neurologic examination demonstrated normal tone.
Reproducing the seizures No attempt had yet been made to induce symptoms. After we obtained parental consent, the room was prepped with a clean trash bag lining the sink, heart monitor, suction, and oxygen. The mother was asked to set the water temperature as she would at home. When first placed in the water, the child began to play. He was subsequently removed from the sink, and more hot water was added until the temperature was similar to the bathwater used at home. Within 15 to 30 seconds of being placed back into the water, the child reached for the side of the sink, developed a fixed gaze and lip smacking, and became unresponsive. His skin was pale and warm. The heart monitor showed sinus tachycardia at a rate of 160 beats per minute and no ectopy. After being removed from the water, dried, and placed on a bed, the child developed central cyanosis. Administration of blow-by oxygen via mask quickly resolved the cyanosis. The child then became postictal and slept for 1 hour. His vital signs remained stable. When he awoke, he was back to his baseline appearance.