PREVALENCE OF CHOREA, DYSTONIA AND ATHETOSIS IN ASSIUT, EGYPT - A CLINICAL AND EPIDEMIOLOGIC-STUDY

Involuntary movements originate from different parts of the nervous sy stem. The character of movements depends upon the site of the lesion a nd the type of pathological change. The presence of more than one type of involuntary movement in a patient can cause confusion and difficul ty in the proper classification of movement disorders, which then lead s to problems in the differential diagnosis and appropriate treatment. This work was planned to estimate the prevalence and to study the aet iological factors of chorea, dystonia, athetosis and hemiballismus in Assiut, a representative community of Upper Egypt. This study was carr ied out on 7,000 families (42,000 subjects) representing different typ es of communities (2,000 families from urban, 2,000 families from subu rban and 3,000 families from rural communities). All members of these samples were personally interviewed at home. Full clinical assessment and special investigations required for the diagnosis of different typ es of chorea, dystonia and athetosis were carried out in Assiut Univer sity Hospital. The prevalence rate for rheumatic chorea was 62/100,000 population and it was significantly higher (p < 0.01) among rural tha n urban and suburban populations, whereas Huntington's chorea had a pr evalence rate of 21/100,000 with no significant difference between dif ferent areas studied (urban, suburban and rural). The other two common types of chorea were reported with prevalence rates of 12/100,000 for the encephalitic type and 17/100,000 for the atherosclerotic type. No single case of generalized dystonia was recorded and all cases were o f the focal type of dystonia with a prevalence rate of 26/100,000 popu lation. No significant differences were recorded between the different areas studied (urban, suburban and rural). Idiopathic form and drug-i nduced form were the most prevalent types of focal dystonia (10/100,00 0). The prevalence rate of athetotic cases (all of which are postencep halitic) in our study was 12/100,000 with no significant difference be tween different areas studied (urban, suburban and rural).