Post hypoxic myoclonus: A tale of two minds

Area of Science:

• Neurology
• Critical Care Medicine

Background:

• Post-hypoxic myoclonus (PHM) is a significant neurological complication following cardiac arrest.
• Traditional classification categorizes PHM as acute or chronic (Lance-Adams Syndrome) based on onset.
• Accurate prognostication may require differentiation based on clinical and EEG findings.

Observation:

• A 33-year-old female developed generalized, stimulus-sensitive myoclonus 12 hours post-cardiac arrest, consistent with acute PHM.
• Later, she exhibited resting and intention myoclonus with dysarthria, indicative of Lance-Adams Syndrome.
• Brain and cervical spine MRI were initially unremarkable.

Findings:

• The patient's myoclonus improved with clonazepam and later baclofen.
• The case demonstrates distinct clinical trajectories within PHM.
• Successful management involved medication adjustments for different symptom presentations.

Implications:

• This case underscores the heterogeneity of PHM presentations and outcomes.
• A nuanced understanding of PHM subtypes is essential for clinical decision-making.
• Avoiding premature withdrawal of care is vital, given the potential for varied recovery patterns.