National Survey of Segawa Disease In Japan

Aims: Since Segawa disease (SD) was discovered in 1970, clinical variations of SD have been reported. Methods: We conducted an online national survey of SD requested from Japanese Society of Child Neurology, Movement Disorder Society of Japan. This study was approved by our Ethics Committee (SMNCC22-03R2). Results: In the primary survey, 56 neurologists consented to a secondary survey and 20 responded. In the secondary survey 118 patients (men;27,women;91) were examined. Median age of onset was 6 (1–34) years. Seventy-four patients (63%) were familial. Of the 110 patients who underwent GCH-1 gene examination, 97 (88%) had mutations. Symptoms at onset were focal dystonia in 113 (two with tremor, four with writer’s cramp, one with musician’s dystonia). One hundred eight patients (91%) had diurnal fluctuation. The left lower limb was common onset in 103 patients (87%). Some had late diagnoses because of misdiagnoses with cerebral polyphasic paraplegia, neuromuscular disease, and psychogenic. Seventy-one patients (60%) consulted orthopedists and 12 had unnecessary surgery. Twenty-seven patients had decreased neopterin and biopterin in cerebral spinal fluid. Initial treatment was plain levodopa in 86 (72.8%) and levodopa with decarboxylase inhibitor (DCI) in 27 (22.8%). Currently, the age ranges from 4–88 years (median; 29). Eighty-six patients (72.8%) had no symptoms with DCI or plain levodopa. Non-motor symptoms were anxiety/depression in 18, sleep disorder in five, and neurodevelopmental disorders.　Fifteen (17%) had menstrual aggravation. Thirteen (40.6%) out of 32 had dystonia exacerbation during pregnancy. Conclusion: We revealed the clinical features SD in Japan and a database is necessary eventually.