Objective: To highlight that timing of post-anoxic myoclonus following initial anoxic injury can result in markedly different outcomes.

Background: Post-anoxic myoclonus is typically considered a poor prognostic sign. However, there is a rare form of delayed myoclonus called Lance-Adams Syndrome that can present days to weeks after the initial anoxic insult.

Methods: Case reports.

Results: Patient AD is a 32 year old man without any significant past medical history who suffered respiratory distress secondary to choking from his seatbelt during a motor vehicle accident. He was emergently intubated at the scene and was noted to be taking spontaneous breaths during transport. Shortly after arrival to the hospital, he developed whole-body myoclonic jerks. EEG did not show evidence of cortical myoclonic status epilepticus. He was trialed on multiple medications for his persistent myoclonus; including clonazepam, gabapentin, baclofen, levetiracetam, and topiramate; without notable improvement. He was discharged on comfort care measures given his persistent comatose state, and died within a week. Patient MC is a 59 year old man with a past medical history significant for polysubstance abuse, cardiomyopathy, COPD, and hepatitis C, who was found unconscious outside a bar in ventricular fibrillation with his inhaler in hand. He received approximately 20 minutes of ACLS with recovery of spontaneous circulation and was then intubated in the field. He was cooled upon arrival to the hospital, and subsequently rewarmed per protocol. He regained consciousness and was successfully extubated. About a week after his initial cardiac arrest, he developed whole-body myoclonic jerks. EEG did not show evidence of cortical myoclonic status epilepticus. He was started on valproic acid followed by levetiracetam with marked improvement of his myoclonus. He was discharged to a skilled nursing facility for rehabilitation. Currently, he is still alive a year after his cardiac arrest.

Conclusions: Lance-Adams Syndrome was first described in the 1960s, and thus far less than 150 cases have been reported. As illustrated in this case comparison, patients with Lance-Adams Syndrome develop myoclonus in a consciousness state days to weeks after initial anoxic insult, and tend to respond well to anti-epileptic medications, carrying overall a better prognosis. Therefore, timing of myoclonus onset post-anoxic brain injury should be taken into consideration when determining treatment options and prognostication.

« Back to 2016 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/post-anoxic-myoclonus-timing-matters/