The aims of this study were to verify the incidence of hypohidrosis and to determine the predictive value of noninvasive indicator test (Neurocheck™) for sweating after administration of topiramate in newly diagnosed pediatric epileptic patients.

A total of 46 epileptic patients (22 boys; 24 girls) on topiramate treatment were evaluated in this study at the Department of Pediatrics, Chonbuk National University Hospital, from October 2004 to July 2005. We measured sweating functions using a noninvasive sweating test (Neurocheck™) before topiramate medication, and after 3 months when topiramate reached its target dosage. We performed a direct questionnaire survey for the hypohidrosis related symptoms during topiramate treatment.

The mean age was 7.8±3.2 year. The mean dosage of topiramate was 4.5±0.8 mg/kg/day. Among the patients, there were 40 complex partial seizures, one simple partial seizure, two partial seizures with secondarily generalization, two generalized seizures, and one Lennox-Gastaut syndrome case. Of the 46 epileptic patients, 17 patients (37.0 percent) experienced hypohidrosis and hypohidrosis related symptoms, 12 (26.1 percent) had facial flushing, four (8.7 percent) had heat intolerance, one(2.2 percent) had lethargy, but no one had anhidrosis. Among the 17 patients, the mild group numbered 12 and the severe group totalled five. Hypohidrosis by Neurocheck™ was diagnosed in 16 patients. The overall measures of agreement between Neurocheck™ and the survey was 76.5 percent. The specificity of this test was 89.7 percent. Patients who showed a time delay after medication, especially over 3 minutes, were seen only in the severe group.

Neurocheck™ could be clinically useful to detect and predict topiramate induced hypohidrosis in pediatric epileptic patients. We recommend that patients who show a delay over 3 minutes in Neurocheck™ test after topiramate initiation should be monitored for hypohydrosis.