 As originally defined by Oppenheim 5, dystonia refers to the slow, sustained, writhing, contorting movements of dystonia musculorum deformans. Dystonic movements, however, are often rapid 6 and this can be a cause for misdiagnosis. Electromyography EMG may be helpful in corroborating dystonia, but is not essential for diagnostic purposes. Nerve conduction studies, short and long loop reflexes and analysis of motor units are normal 7, 8. Ballistic movements, which are normally tri-phasic in pattern with alternating agonist-antagonist bursts, may show disrupted patterns with co-contraction of agonist and antagonist muscles and excessively long EMG bursts in dystonia 3. 