Abstract Details

Title Gabapentin-Induced Myokymia: A Case Report

Topic General Neurology

Presentation(s) General Neurology Posters (7:00 AM-5:00 PM)

Poster/Presentation
Number 074

Objective We present the clinical course of a patient presenting with known symptoms suggestive of gabapentin toxicity along with a newly associated adverse effect: focal segmental myokymia. We also discuss successful management of gabapentin toxicity with a brief period of abstinence.

Background Gabapentin is a commonly used medication for neuropathic pain and epilepsy that is prescribed by a wide range of medical specialties. Although uncommon, its toxicity in the form of asterixis and myoclonus has been reported in patients with chronic kidney disease.

Design/Methods A 69-year-old man with history of TBI, peripheral neuropathy, amnesia, and PTSD presented to the hospital with acute onset stimulus-sensitive muscle spasms in all extremities, diffuse action tremors and tongue tremors, and myokymia in his bilateral calves. His spasms were disabling, limiting his ability to walk and causing falls, and thus prompted hospitalization.

Results Initial workup, including metabolic panel, non-contrast CT, CT angiography of the head, EEG and MRI of the brain, was insignificant. Gabapentin toxicity was suspected, and a Gabapentin holiday was initiated with improvement of myokymia by hospital day 3. The patient was found to have high gabapentin level (25.8 mcg/mL, reference range 2.0-20.0 mcg/mL) measured the morning following hospital presentation. He reported taking a total daily dose of 9600 mg of gabapentin, as prescribed by his primary care provider. After restarting on a lower dose of gabapentin with multimodal pain control, the patient continued to improve with diminution of his myoclonus, tremors, and gait instability.

Conclusions Myokymia is a newly described motor symptom associated with gabapentin use. The mechanism of gabapentin-associated myokymia is currently unknown. A brief medication holiday resulted in resolution of motor symptoms without significant withdrawal symptoms. Knowledge of this newly reported adverse manifestation can aid physicians in diagnosis of gabapentin toxicity and prompt treatment, as gabapentin levels are not widely or immediately available.

Authors/Disclosures
Aimalohi Esechie, MD, PhD (SLUH) PRESENTER	Dr. Esechie has nothing to disclose.
Bhanu Gogia, MBBS (home)	Dr. Gogia has nothing to disclose.
Elena Shanina, MD, FAAN (University of Texas Medical Branch, Neurology Department)	Dr. Shanina has nothing to disclose.

��ɫ��

��ɫ��