Myoclonus is an involuntary contraction of a group of muscles or whole body muscles, usually both antagonist and active muscles at the same time. Myoclonus can be divided into physiological myoclonus and pathological myoclonus. Patients with physiological myoclonus present with sleep myoclonus and erratic contractions. Pathological myoclonus includes epileptic myoclonus, non-epileptic myoclonus. The clinical manifestations are different depending on the intensity and scope of seizures, and can be divided into axial myoclonus and wandering myoclonus. Axial myoclonus manifests as sudden head nodding, or sudden head tilting back, sometimes the whole body muscle shaking or hand shaking. Wandering myoclonus manifests as involuntary shaking of the end of the limb, sometimes the left limb, sometimes the right limb. If it is myoclonus of both lower limbs, sometimes it can be manifested as unstable walking.