Description
A 62-year-old man was resuscitated after an in-hospital pulseless electrical activity (PEA) cardiac arrest. He awakened after 24 hours but after another 24-hour interval, he had worsening action and stimulus-induced myoclonus.1–3 He was able to relax fully without movement but any volitional movement initiated a burst of appendicular arrhythmic jerks (video 1). The disabling myoclonus was significantly muted with levetiracetam and valproate. No cerebellar lesions were found on CT or MRI.
video 1.
Action myoclonus is exceptionally rare (less than 0.5% in a series of patients who have a cardiac arrest) and is potentially confused with myoclonus status in a comatose patient, yet the examination, imaging, degree of disability, time of onset and prognosis are very divergent.4 Typically, there is no electroencephalogram (EEG) seizure correlate.3 The symptoms can improve or persist chronically, and many remain with significant disability from myoclonus. Medication treatment options include levetiracetam, valproic acid and other anti-epileptic drugs (AEDs).
Learning points.
Myoclonus occurring after hypoxic brain injury from cardiac arrest, characterised by abrupt irregular muscle contractions. (1) Acute: starting within 48 hours after the arrest (when isolated, sometimes terms acute Lance-Adams syndrome). (2) Chronic: Lance-Adams syndrome, which may start from days to weeks after arrest and progressively worsen, with or without other neurological symptoms.
Potentially confused with myoclonus status in a comatose patient, yet the examination, imaging, degree of disability and prognosis are very divergent.
Typically, no EEG seizure correlates.
Footnotes
Twitter: @chrismarcellino
Contributors: CM: draft of the manuscript, clinical care of the patient, video recording and editing. EFMW: revised the manuscript for intellectual content, clinical care of the patient. EFMW is also a current BMJ fellowship subscriber.
Funding: The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests: None declared.
Patient consent for publication: Next of kin consent obtained.
Provenance and peer review: Not commissioned; externally peer reviewed.
References
- 1.Lance JW, Adams RD. The syndrome of intention or action myoclonus as a sequel to hypoxic encephalopathy. Brain 1963;86:111–36. 10.1093/brain/86.1.111 [DOI] [PubMed] [Google Scholar]
- 2.Aicua Rapun I, Novy J, Solari D, et al. Early Lance-Adams syndrome after cardiac arrest: prevalence, time to return to awareness, and outcome in a large cohort. Resuscitation 2017;115:169–72. 10.1016/j.resuscitation.2017.03.020 [DOI] [PubMed] [Google Scholar]
- 3.Lee HL, Lee JK, syndrome L-A. Lance-Adams syndrome. Ann Rehabil Med 2011;35:939. 10.5535/arm.2011.35.6.939 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Wijdicks EFM, Hijdra A, Young GB, et al. Practice parameter: prediction of outcome in comatose survivors after cardiopulmonary resuscitation (an evidence-based review): report of the Quality Standards Subcommittee of the American Academy of Neurology. Neurology 2006;67:203–10. 10.1212/01.wnl.0000227183.21314.cd [DOI] [PubMed] [Google Scholar]