1. Gabapentin-induced myoclonus: A case report Mehmet Ozmenoglu, MD 1, Sibel Gazioglu, MD 1, Vildan Altunayoglu Cakmak, MD 1, Hilal Horozoglu, MD 2 Karadeniz Technical University Medical Faculty, Department of Neurology, Trabzon, TURKEY 1 Tekirdag Goverment Hospital, Department of Neurology, Tekirdag, TURKEY 2 BACKGROUND / OBJECTIVE Myoclonus may be caused by a variety of underlying problems including epilepsy, postanoxic brain injury, metabolic encephalopathies and focal central nervous system lesions. Various drugs also have been reported to induce myoclonus. We report a case of myoclonus secondary to gabapentin use in a patient with no epilepsy or renal disease. CASE PRESENTATION Examination revealed bilateral action-induced clonus in the hands. Mental status was normal, and there was no weakness. Ankle reflexes were normal, and plantar reflexes were flexor. There was mild hypesthesia of the distal lower extremities. CONTACT INFORMATION Dr. Mehmet Ozmenoglu Dr. Sibel Gazioglu E-mail: mozmenoglu@gmail.com sibelgazioglu@hotmail.com Routine blood tests including urea, creatine, electrolytes and thyroid function tests were normal. Gabapentin levels were not determined. Gabapentin was discontinued, and his symptoms spontaneously resolved 2 days after discontinuation of gabapentin. DISCUSSION /CONCLUSION The close time relationship between gabapentin initiation and onset of myoclonus, and the rapid resolution of symptoms after withdrawal of the drug suggested that gabapentin played a causative role in our patient. Pathophysiological mechanisms of gabapentin-induced myoclonus remain poorly understood and may be related to several neurotransmitter systems. It has been suggested that the serotonin neurotransmitter system maybe involved in the pathogenesis and γ-aminobutyric acid (GABA) and glutamate likely play some role in myoclonus. Administration and dose escalation of gabapentin should be performed with caution, and gabapentin should be always considered as a potential etiology for myoclonus. REFERENCES 1- Ege F, Koçak Y, Titiz AP, Oztürk SM, Oztürk S, Ozbakir S. Gabapentin-Induced myoclonus: case report. Mov Disord. 2008 Oct 15;23(13):1947-8. 2- Cho KT, Hong SK. Myoclonus induced by the use of gabapentin. J Korean Neurosurg Soc. 2008 May;43(5):237-8. 3- Zhang C1, Glenn DG, Bell WL, O'Donovan CA. Gabapentin-induced myoclonus in end-stage renal disease. Epilepsia. 2005 Jan;46(1):156-8. 4- Asconapé J, Diedrich A, DellaBadia J. Myoclonus associated with the use of gabapentin. Epilepsia. 2000 Apr;41(4):479- 81. Gabapentin (GBP), an anticonvulsant, is commonly used for neuropathic pain in clinical practice. Besides the most common side effects of gabapentin such as somnolence, dizziness, asthenia, tremor, and peripheral edema, GBP may also induce movement disorders. Gabapentin-induced myoclonus has been reported previously, especially in cases with impaired renal function or epilepsy. 68-year-old male presented with hand tremors Tremors started 2 weeks after the initiation of 1800 mg daily gabapentin recommended for distal neuropathic pain.