Bilateral internuclear ophthalmoplegia reversed by naloxone

Area of Science:

• Neuroscience
• Toxicology
• Ophthalmology

Background:

• Internuclear ophthalmoplegia (INO) is a rare condition affecting eye movement coordination.
• Patient presented with stupor, history of narcotic and benzodiazepine use, and phenytoin sodium for seizures.

Observation:

• The patient exhibited apparent bilateral internuclear ophthalmoplegia (INO).
• INO symptoms were rapidly reversed upon administration of naloxone, a narcotic antagonist.

Findings:

• The rapid reversal of INO by naloxone suggests a direct toxic effect of narcotics on ocular motor control.
• The exact mechanism remains unclear, as opiate receptors are not definitively located in the medial longitudinal fasciculus.

Implications:

• This case highlights a potential, previously unrecognized neurotoxic effect of narcotics.
• Further research is needed to elucidate the neuroanatomical pathways and receptor interactions involved in narcotic-induced INO.
• Understanding these mechanisms could inform treatment strategies for drug-induced neurological deficits.