Abstracts

Rationale: Dravet syndrome (DS) or severe myoclonic epilepsy in infancy, is a catastrophic pediatric epilepsy syndrome related to abnormalities in the SCNA1 gene. This disorder has a well known association with seizure triggers related to temperature variation. As seizures may be triggered by environmental, body, or emotional temperature changes, we hypothesized these children have alterations in autonomic control. Methods: In a pediatric neurology clinic, we administered a survey based on parental report of signs reflective of autonomic abnormalities; it was offered on-line to the parents of children with DS. In addition to queries about autonomic signs, data collected included age, gender, diagnosis, and medications. A motor screen (sit/walk alone) and a feeding screen (self feed/with assist/gastrostomy tube fed) were also included. The survey focused on readily observable signs: body temperature regulation, hand/feet red or bluish in color, alterations in sweating, large pupils, slow emptying of the stomach, and episodes of tachycardia or facial/chest flushing with out associated exercise or identified cause. Clusters of events of at least 4 symptoms occurring for at least 15 min were reported. Frequency of events was noted. A comparison group (CG) of 92 children with other neurologic diagnoses was utilized to establish a baseline rate of dysautonomic signs. Children with cerebral palsy as a primary diagnosis, as well as those with poorly controlled epilepsy, were excluded from the comparison group, as we hypothesize they may have significant signs of dysautonomia also. Results: Surveys of 47 DS and 92 CG children were analyzed. Age range for DS was 14 mo - 14 years; for the CG it was 2 - 17 years. There were 31 girls and 17 boys (1 not available) in the DS group; 44 girls and 48 boys in the CG. The DS group had a mean of 2.71 signs on a weekly or more frequent basis. Children in the CG had a mean of 0.93 signs. This is a notable difference. Regulation of distal extremity temperature, tendency to overheat, and decreased sweating were markedly increased in the DS group, as were facial/chest flushing and slow gastric emptying. Three children with DS experienced recurring clusters of autonomic events. Survey results are delineated in the table below. Conclusions: This survey shows children with Dravet Syndrome have significantly higher rates of events related to autonomic control than a comparison group. Formal studies of autonomic function in these children, as well as children with other forms of catastrophic epilepsy are needed. The clinical significance, particularly in the child with DS who is exquisitely temperature/emotional state sensitive needs further determination. Greater understanding of autonomic disturbances in these children may lead to additional therapeutic approaches.