ABSTRACT
Involuntary movements are widely originated from different parts of the nervous system. The character of movements depends upon its site and pathological changes. The presence of more than one type of involuntary movements in a patient can cause confusion and difficulty about proper classification of movement disorders which then leads to problems in the differential diagnosis and appropriate treatment. This work was planned to have a view about the prevalence and aetiological factors of chorea, dystonia, athetosis and hemiballismus in Assiut [a representative of Upper Egyptian population]. This study was carried out on 7000 families [42,000 subjects] representing different types of communities [2,000 families from urban, 2000 families from suburban and 3000 families from rural communities]. All members of these samples were interviwed at home personally. Full clinical assessment and special investigations required for the diagnosis of different types of chorea, dystonia and athetosis were carried out in Assiut University Hospital. The prevalence rate for rheumatic chorea was 62/100,000 population and it is significantly higher [P<0.01] among rural than, urban and suburban population, whereas Huntington's chorea had prevalence rate 21/100,000 with no significant difference between different studied areas [urban, suburban and rural]. The other two common types of chorea were reported in prevalence rates, 12/100,000 for encephalitic type and 17/100,000 for atherosclerotic type. No single case of generalized dystonia was recorded and all cases were of focal type of dystonia with a prevalence rate of 26/100,000 population and no significant differences were recorded between the different studied areas [urban, suburban and rural]. Idiopathic form and drug induced form were the most prevalent types of focal dystonia [10/100,000]. The prevalence rate of athetotic cases [all of which are post encephalitic] in our study was 12/100,000 with no significant difference between different studied areas: [urban, suburban and rural]