neurologic disorders
Myoclonus
Symptoms and Signs of Myoclonus
Myoclonus can vary in amplitude, frequency, and distribution. Muscle jerks may occur spontaneously or be induced by a stimulus (eg, sudden noise, movement, light, visual threat). Myoclonus that occurs when patients are suddenly startled (startle myoclonus) may be an early symptom of Creutzfeldt-Jakob Disease (CJD) None Myoclonus due to severe closed head trauma or hypoxic-ischemic brain damage may worsen with purposeful movements (action myoclonus) or may occur spontaneously when movement is limited because of injury. Myoclonus due to metabolic disturbances may be multifocal, asymmetric, and stimulus-induced; it usually involves facial or proximal limb muscles. If the disturbance persists, generalized myoclonic jerks and, ultimately, seizures may occur. 