1331 - Lance Adams Syndrome after a traumatic brain and spinal cord injury

Chronic post hypoxic myoclonus (Lance Adams Syndrome)

Case Description:

A 34-year-old male was in a motor vehicle accident that resulted in a Glasgow coma scale of 3 with a C4D spinal cord injury and acute hypoxic respiratory failure. Brain computed tomography showed no abnormalities. He was placed on levetiracetam for seizure prophylaxis due to diffuse axonal injury. He was later noted to have stimulus-induced twitching movements with an electroencephalogram correlate and was started on valproic acid. He was transferred to inpatient rehabilitation 55 days after his accident, where he regained strength and presented with new action-dependent abnormal movements in his right lower extremity. The movements were suppressible and nonrhythmic, eventually spreading to his contralateral leg, which limited his gait, functional independence, and participation in therapy. Repeat electroencephalogram showed spikes consistent with Lance Adams Syndrome, (LAS) for which his levetiracetam was doubled, and he was started on clonazepam, resulting in decreased intensity of his myoclonus and, therefore, improved therapy participation.

Discussions:

LAS is rare, with less than 150 cases reported, and usually presents as action-dependent myoclonus > 24 hours after a post-hypoxic event. It can occur in the absence of cardiac arrest with cases after post-hypoxic COVID-19 and myocarditis. We report a case of LAS due to diffuse axonal brain and respiratory failure without cardiopulmonary arrest. It is essential to delineate this syndrome from other brain and spinal cord injury movement disorders, given their distinct impact on function, prognosis, and treatment. There is no guideline-directed treatment for LAS, but it involves several anti-epileptics with standard regimens, including a combination of levetiracetam, clonazepam, and valproate.

Conclusions:

LAS is a rare movement disorder that can present in patients with spinal cord injury, given their frequent traumatic etiology and concurrent hypoxic respiratory failure

LAS and its impact on function can improve with medications