510 - Myoclonic Epilepsy with superimposed Lance-Adams Syndrome

Thursday, February 19, 2026

5:00 PM - 6:30 PM AST

Presenting Author(s)

AA

Arin T. Amin, DO

Resident Physician
University of Louisville PM&R Program
Wolverine Lake, Michigan, United States

Co-Author(s)

AN

Anish Nimmagadda, BS

Medical Student
Michigan State College of Osteopathic Medicine
East Lansing, Michigan, United States

Submitter(s)

AA

Arin T. Amin, DO

Resident Physician
University of Louisville PM&R Program
Wolverine Lake, Michigan, United States

Case Diagnosis: The diagnosis of Lance-Adams syndrome (chronic post-hypoxic myoclonus) was made after the patient's symptoms failed to resolve with anti-epileptic therapy. A repeat EEG after initiation of AEDs demonstrated intermittent focal delta slowing over the left temporal region without epileptiform correlates to the myoclonus, suggesting a superimposed intention myoclonus. The persistence of action myoclonus refractory to AEDs, coupled with these subsequent EEG findings, confirmed the diagnosis of LAS.

Case Description: The patient is a 60-year-old male with a medical history notable for recent cardiac arrest who presented to the hospital with “tremors.” Seventeen days earlier, he had been discharged from a separate hospital following cardiac arrest with at least 9 minutes of downtime. After being discharged home, the patient developed new “tremors” that were worsening in severity. On examination, he demonstrated severe, intention-based myoclonic jerks of all four limbs, which were absent at rest. An initial EEG showed right frontocentral epileptiform discharges correlating to the myoclonus, consistent with myoclonic epilepsy. Anti-epileptic drugs (AEDs) were initiated; however, the debilitating action myoclonus persisted with minimal improvement.

Discussions:
This case highlights the diagnostic challenge of Lance-Adams syndrome (LAS), an extremely rare sequela of anoxic brain injury. The patient's intention myoclonus was initially attributed to myoclonic epilepsy, a more common finding. However, the persistence of myoclonus despite anti-epileptic therapy, and subsequent EEG findings lacking epileptiform correlation, were crucial in differentiating LAS.
LAS is often refractory to standard anti-epileptics. Due to its rarity, no standardized treatment guidelines exist. However, some patients have been treated with a combination of clonazepam, valproate, and piracetam.

Conclusions: Lance-Adams syndrome is a rare and profoundly disabling complication of hypoxic-anoxic brain injury that can be mistaken for post-hypoxic myoclonic epilepsy. Early physiatry involvement is crucial for initiating a comprehensive, multidisciplinary rehabilitation program aimed at improving function and mitigating the severe disability associated with this condition.