Overnight response to levetiracetam in Lance–Adams syndrome presenting 3 years after cardiac arrest

Background: Lance–Adams syndrome (LAS), also known as chronic post-hypoxic myoclonus manifests as myoclonic movements of the face, limbs, or trunk following hypoxic brain injury, which may occur during respiratory failure or cardiac arrest. Case presentation: We present a case and provide a video of a patient who developed LAS 3 years after experiencing cardiac arrest, presenting with action-induced generalized myoclonus upon standing. The patient exhibited a significant response to levetiracetam. To the best of our knowledge, this is the first reported case of LAS with such a delayed onset following the initial hypoxic event. Conclusion: It is crucial for clinicians to be aware of this treatable condition and recognize that its onset may be delayed, occurring years after a hypoxic brain insult. This improved understanding will facilitate prompt diagnosis and effective management of LAS, ultimately enhancing patient outcomes.