Objective:

Highlight resolution of palilalia and bruxism with amantadine in post-anoxic encephalopathy.

Background:

Prolonged encephalopathy after anoxic brain injury lacks proven therapeutic management. Palilalia and bruxism are rare neurobehavioral and motor features of anoxic encephalopathy. Amantadine, an NMDA receptor antagonist with dopaminergic effects, aids recovery after traumatic brain injury, but its role in post-anoxic palilalia and bruxism is unclear.

Design/Methods:

Single patient retrospective chart review.

Results:

A 63-year-old woman was found unresponsive at home with respiratory depression and severe hypoxemia near a prescription bottle of alprazolam used for anxiety. She was admitted to the intensive care unit with acute altered mental status, palilalia, and bruxism. Continuous video-EEG monitoring showed no electrographic seizures; paroxysmal events recorded were artifacts secondary to bruxism. Brain MRI with and without contrast demonstrated diffuse cortical and basal ganglia signal abnormalities consistent with hypoxic ischemic injury, favoring post-anoxic encephalopathy. With minimal improvement in the patient medical course, a trial of amantadine was started by the neurology team. Amantadine was started at 100 mg twice daily with nightly melatonin 6 mg to regulate sleep wake cycle. Within days, palilalia and bruxism resolved, and cognition improved substantially, permitting recovery to the patient's baseline.

Conclusions:

This case supports a possible role for amantadine in post-anoxic encephalopathy presenting with palilalia and bruxism. Amantadine may enhance dopaminergic signaling and attenuate glutamatergic activity, potentially stabilizing basal ganglia–thalamocortical and frontal–subcortical circuits implicated in speech initiation and oromotor control. Reports of improvement in palilalia or bruxism after anoxia are rare; post-anoxic bruxism has been treated with botulinum toxin in case reports, and palilalia after anoxic injury is described but uncommon. A monitored amantadine trial may be reasonable in similar cases; systematic study is warranted.