Lance-Adams syndrome (LAS) is a rare condition in which posthypoxic myoclonus occurs days or weeks after successful cardiopulmonary resuscitation. To date, less than 150 cases have been described in the medical literature. Myoclonus in LAS is typically triggered by intentional actions or external stimuli, is relieved during sleep or rest, and has no reliable correlation with EEG. The pathophysiology of LAS is poorly understood, though literature suggests that posthypoxic myoclonus originates from subcortical and/or cortical structures.

It is important to differentiate LAS from acute posthypoxic seizures, in which patients remain in a comatose or vegetative state.

LAS often results in significant morbidity as it can predispose patients to frequent falls and can result in dependence on a wheelchair.

Although LAS is a nonepileptic syndrome, the antiepileptic medications levetiracetam, zonisamide, clonazepam and valproate have been identified as relatively effective treatments.

January 31, 2019 e-Pearl of the Week: Lance-Adams syndrome | Neurology