title: Myoclonus in the critically ill: Diagnosis, management, and clinical impact.
abstract: Myoclonus is the second most common involuntary non-epileptic movement in intensive care units following tremor-like gestures. Although there are several types of myoclonus, they remain underappreciated, and their diagnostic and prognostic associations are largely ignored. This review discusses clinical, electrophysiological, neuroanatomical, and neuroimaging characteristics of different types of myoclonus in critically ill adults along with their prognostic impact and treatment options. Myoclonus is characterized by a sudden, brief, and sometimes repetitive muscle contraction of body parts, or a brief and sudden cessation of tonic muscle innervation followed by a rapid recovery of tonus. Myoclonus can resemble physiologic and other pathologic involuntary movements. Neurologic injuries, anesthetics, and muscle relaxants interfere with the typical appearance of myoclonus. Identifying "real myoclonus" and determining the neuroanatomical origin are important, as treatment responses depend on the involved neuroanatomical structures. The identification of the type of myoclonus, the involved neuroanatomical structures, and the associated illnesses is essential to direct treatment. In conclusion, the combined clinical, electrophysiological, and neuroradiological examination reliably uncovers the neuroanatomical sources and the pathophysiology of myoclonus. Recognizing cortical myoclonus is critical, as it is treatable and may progress to generalized convulsive seizures or status epilepticus.
authors.affiliation: Clinic for Intensive Care Medicine, University Hospital Basel, Basel, Switzerland; Division of Clinical Neurophysiology, Department of Neurology, University Hospital Basel, Basel, Switzerland. Electronic address: Raoul.Sutter@usb.ch.
authors.forename: Raoul
authors.initials: R
authors.lastname: Sutter
authors.affiliation: Clinic for Intensive Care Medicine, University Hospital Basel, Basel, Switzerland.
authors.forename: Anette
authors.initials: A
authors.lastname: Ristic
authors.affiliation: Division of Clinical Neurophysiology, Department of Neurology, University Hospital Basel, Basel, Switzerland.
authors.forename: Stephan
authors.initials: S
authors.lastname: Rüegg
authors.affiliation: Division of Clinical Neurophysiology, Department of Neurology, University Hospital Basel, Basel, Switzerland.
authors.forename: Peter
authors.initials: P
authors.lastname: Fuhr
mesh_terms: D003422:Critical Care / Q000379:methods*; D004569:Electroencephalography; D004576:Electromyography; D006801:Humans; D008279:Magnetic Resonance Imaging; D009207:Myoclonus / Q000175:diagnosis* / Q000209:etiology / Q000628:therapy
keywords: Critical illness; Diagnosis; Myoclonus; Neurocritical care; Prognosis; Treatment