[Towards a question of formation mechanisms of hand muscular dystonia].

Review researches on a problem of muscular dystonia mechanisms formation on an example of a writer's cramp (WC) was presented. WC is a movement disorder, task-specific dystonia, characterised by involuntary excessive muscle contractions producing abnormal postures during selective motor activities that often involve highly skilled, repetitive movements. The precise pathophysiology remains unclear, increasing evidence suggests reduced inhibition at different levels of the sensorimotor system. There has also been a greater understanding of the causes ofdystonic movements, from the study of genetics, neurophysiology (TMS, EMP), and functional imaging (fMRI, PET). Last investigation of hand motor skill by a method of the three-dimensional kinematics analysis has shown that at WC there is an inconsistency of processes of planning of movement.