Levetiracetam suppresses long-loop reflexes at the cortical level

Area of Science:

• Neuroscience
• Clinical Neurology

Background:

• Posthypoxic coma can lead to persistent neurological deficits, including cortical and brainstem hyperexcitability.
• Understanding the neurophysiological underpinnings is crucial for effective treatment strategies.

Observation:

• A 47-year-old male presented with severe posthypoxic cerebral dysfunction 5 months after resuscitation.
• Neurophysiological tests showed increased long-loop reflexes (cortical hyperexcitability) and exaggerated startle responses (brainstem disinhibition).

Findings:

• Levetiracetam administration dose-dependently suppressed transcortical long-loop reflexes.
• The drug did not suppress spinal H-reflexes, indicating a selective cortical effect.
• A mild attenuation of the exaggerated startle response was observed.

Implications:

• Levetiracetam demonstrates a suppressive effect on cortical neurons, distinct from spinal reflex pathways.
• These findings support the therapeutic potential of levetiracetam for managing cortical hyperexcitability in posthypoxic brain injury.
• Further research may elucidate levetiracetam's role in improving outcomes for patients with posthypoxic neurological sequelae.