Myoclonus is a brief, shock-like, involuntary jerk of a muscle or a group of muscles. Contractions are called positive myoclonus; relaxations are called negative myoclonus. Myoclonic jerks may occur alone or in sequence. They may occur infrequently or many times each minute.
Anatomically, myoclonus may originate from lesions of the cortex, subcortex, or spinal cord. Myoclonus may be related to seizures, neoplasm, and neurodegenerative disorders, as a result of toxin exposure, medication side effect, or as a result of renal or hepatic impairment. It may be seen with hypoxic ischemic events, lipid storage diseases, and spinal cord injury. It may be seen at rest or provoked by movement or sound.
Myoclonus is a common movement disorder often seen in hospitalized patients related to toxic and metabolic issues.
Myoclonus related to a metabolic or medication issue may resolve completely when the underlying issue is...
References and Readings
- Obeso, J. A., & Zamarbide, I. (2004). Classification, clinical features, and treatment of myoclonus. In R. L. Watts & W. C. Koller (Eds.), Movement disorders (2nd ed., pp. 659–670). New York: McGraw-Hill.Google Scholar