Research On The Epidemiological Characteristics Of Primary Dystonia And Primary Hemifacial Spasm In East China

Objective:Research on the epidemiological characteristics of primary dystonia and primary hemifacial spasm in east China.Methods:Collected the information of primary dystonia and primary hemifacial spasm patients voluntarily admitted by botulinum toxin clinic of east China cooperative group from 18th April 2010 to 8th October 2010, analyzed the proportion ratio, gender ratio, age of onset and other epidemiology information.Results:There were 1045 patients of primary hemifacial spasm. There was a left predominance (L:R=1.03:1),and a female predominance (M:F=1:1.81) in primary hemifacial spasm overall. Mean age of onset for all patients was 46.04 years (range, 17-86 years). The average diagnosis period was 2.93 years (range,0-28 years). There's no significant difference in terms of the age of onset between male and female patients, the average diagnosis period of female patients was longer than the one of male patients (3.21±4.09 years VS2.41±3.18 years). There were 523 patients of primary dystonia, primary focal dystonia was the most common type,followed by segmental and multifocal dystonia.Blepharospasm was the most common focal dystonia, while Meige syndrome was the most common segmental dystonia.There was a significant female predominance in primary dystonia overall (M:F=0.51:1). Mean age of onset for all patients was 47.89 years (range,10-83 years). There's no significant difference in terms of the age of onset between male and female patients. The mean age of onset for primary segmental dystonia was bigger than the one for focal dystonia (51.27±9.76 yearsVS45.14±13.52 years).There's no significant difference of primary dystonia of focal, multifocal and segmental types in terms of the age of onset between male and female patients (P＞0.05).The age of onset for blepharospasm was the latest among the types of primary focal dystonia. There's no·significant difference among the six subtypes in terms of the ages of onset between male and female patients. The average period of diagnosis for the patients of primary dystonia was 2.12 years (range,0-25 years). There's no significant difference in terms of the age of onset between male and female patients. There's no significant difference among the three types of primary focal, multifocal and segmental dystonia and between male and female patients respectively in terms of periods of diagnosis. There's no significant differences among the six subtypes of primary focal dystonia and between male and female patients respectively in terms of periods of diagnosis.Conclusions:1.Primary focal dystonia was the most common primary dystonia, which is consistent with conclusion of the study abroad.2.Blepharospasm was the most common type of primary focal dystonia,this is consistent with result of Japanese research but inconsistent with result of European and U.S. research, which is probably d ue to the unique epidemiological characteristic in Asia.3.The proportion of primary hemifacial spasm is bigger than primary dystonia, this is inconsistent with foreign documents, which is probably due to the human species and regions for the researches, this is probably one of the epidemiological characteristics of China.