Gabapentin shows effective in patients with locked-in syndrome, opsoclonus-myoclonus syndrome

For patients with quadriplegia, mutism and lower cranial nerve paralysis (locked-in syndrome), their only means of interacting with others is through vertical gaze and upper eyelid movements, using eye-coded communication strategies.

In the June issue of Mayo Clinic Proceedings, researchers from Italy describe four patients with locked-in syndrome who also had dancing eye syndrome (opsoclonus-myoclonus syndrome). Because these patients' eyes spontaneously and continuously oscillated in a variety of directions beyond their control, they could no longer interact with family members, physicians or other people.

The lead author, Francesca Pistoia, M.D., University of L'Aquila, Italy, reports that a decision was made to treat these patients with daily continuous gabapentin therapy based on a previous successful experience. Gabapentin was started as a single 300 mg dose on the first day followed by 600 milligrams per day in divided doses on the second day. In two of the patients, this dosage reduced ocular symptoms, and communication and quality of life improved. For the other two patients, the dose was further increased, with the best response achieved with a daily 1,200 mg dose.

In all four patients, attempts to stop treatment resulted in recurrence of dancing eye symptoms six hours after the last dose. Thus, gabapentin use was promptly resumed. Researchers found none of the patients experienced adverse effects from the treatment.

In an accompanying editorial, Joseph Sirven, M.D., Mayo Clinic neurologist, discusses the off-label use of gabapentin, which was approved by the U.S. Food and Drug Administration in 1994 for use as an adjunctive medication to control partial seizures. Dr. Sirven writes, "Ironically, despite the fact that the drug was invented and synthesized for its use in seizure prevention, its smallest market today is epilepsy and seizures."

"The study by Pistoia and colleagues has a potential profound impact for treatment of patients with locked-in syndrome and opsoclonus-myoclonus syndrome," writes Dr. Sirven. "Because this neurologic condition is so rare, small observational studies serve as the main source of clinical evidence and could be the cornerstone for clinical practice with no other evidence."