What is the recommended management for Lance Adams syndrome?

Management of Lance-Adams Syndrome

Levetiracetam is the recommended first-line treatment for Lance-Adams syndrome, with valproic acid as an effective alternative, often requiring combination therapy with benzodiazepines for optimal symptom control. 1

Clinical Overview

Lance-Adams syndrome (LAS) is a rare neurological complication characterized by action myoclonus that develops days to weeks after successful cardiopulmonary resuscitation following hypoxic brain injury. Unlike post-hypoxic status myoclonus (which carries a poor prognosis), LAS is compatible with good neurological recovery when properly managed 2.

Diagnostic Approach

Early recognition of LAS is critical for appropriate management:

• Key clinical features: Action myoclonus (triggered by voluntary movements) that develops after the patient regains consciousness following cardiac arrest
• Distinguishing from status myoclonus: Preserved brainstem reflexes, reactive EEG (though may be epileptiform), and localization to pain within 72 hours after cardiac arrest 3
• Warning: LAS may be misdiagnosed as poor-prognosis status myoclonus, potentially leading to inappropriate withdrawal of care 2

Treatment Algorithm

First-Line Therapy:

1. Levetiracetam (1000-3000 mg/day)

   • Most commonly used initial treatment (67% of patients) 1
   • High efficacy rate with 85% of patients showing improvement 1
   • Can be started early in the acute phase 4

2. Valproic acid

   • Effective alternative first-line option
   • 100% of patients showed improvement in the largest case series 1

Second-Line/Combination Therapy:

Most patients (72%) require multiple medications for adequate symptom control 1:

1. Benzodiazepines (most common second-line agents - 48% of cases)

   • Clonazepam is frequently used 3
   • May be required at high doses initially

2. Additional options:

   • Perampanel (emerging evidence for efficacy in acute phase) 5
   • Lacosamide 5
   • In severe cases requiring ICU management: propofol or midazolam may be temporarily needed 3

Treatment Considerations

• Dosing approach: "Start low, go slow" but titrate to effective doses
• Duration: Long-term treatment is typically required; only 46% of patients who attempted medication withdrawal were successful 1
• Monitoring: Assess for functional improvement in activities of daily living rather than complete resolution of myoclonus

Expected Outcomes

• Symptom improvement: 85% of patients show improvement over time 1
• Symptom control: 77% achieve control (defined as minimal/no myoclonus causing functional impairment) 1
• Time to control: Median 70 days for patients diagnosed during initial hospitalization 1
• Functional outcomes: At 6 months, 53% achieve favorable outcomes (CPC 1-2) 1
• Return to awareness: Can be delayed (3-23 days, median 11.8 days) 3

Important Caveats

• Avoid premature prognostication: Delayed awakening is common in LAS patients but does not necessarily indicate poor outcome 3
• Distinguish from status myoclonus: LAS is compatible with good recovery, unlike status myoclonus which typically indicates severe brain injury 2
• Medication side effects: Monitor for sedation, cognitive impairment, and other adverse effects of antiepileptic medications
• Rehabilitation: Early rehabilitation program implementation is associated with improved functional outcomes 6

The evidence supports an aggressive pharmacological approach with combination therapy as needed, recognizing that most patients will show improvement over time with appropriate treatment.