Case Report
Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Mar 6, 2020; 8(5): 922-927
Published online Mar 6, 2020. doi: 10.12998/wjcc.v8.i5.922
Oxcarbazepine for trigeminal neuralgia may induce lower extremity weakness: A case report
Hyun-Gul Song, Francis Sahngun Nahm
Hyun-Gul Song, Department of Anesthesiology and Pain Medicine, Seoul Metropolitan Government-Seoul National University Boramae Medical Center, Seoul 07061, South Korea
Francis Sahngun Nahm, Department of Anesthesiology and Pain Medicine, Seoul National University Bundang Hospital, Seongnam 13620, South Korea
Author contributions: Song HG contributed to Conceptualization/Original draft; Nahm FS contributed to Supervision/Review and editing.
Informed consent statement: Written informed consent was obtained from the patient for publication. This case report was approved by the Institutional Review Board of the SMG-SNU Boramae Medical Center.
Conflict-of-interest statement: The authors declare no conflicts of interest.
CARE Checklist (2016) statement: The authors have read the CARE Checklist (2016), and the manuscript was prepared and revised according to the CARE Checklist (2016).
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Francis Sahngun Nahm, MD, PhD, Associate Professor, Department of Anesthesiology and Pain Medicine, Seoul National University Bundang Hospital, 82 Gumi-ro 173 Beon-gil, Bundang-gu, Seongnam 13620, South Korea. hiitsme@hanmail.net
Received: December 3, 2019
Peer-review started: December 3, 2019
First decision: January 7, 2020
Revised: February 4, 2020
Accepted: February 12, 2020
Article in press: February 12, 2020
Published online: March 6, 2020
Processing time: 93 Days and 20.8 Hours
Abstract
BACKGROUND

Although few studies have reported hyponatremia due to carbamazepine or oxcarbazepine in patients with epilepsy, no study has investigated cases of carbamazepine- or oxcarbazepine-induced hyponatremia or unsteady gait in patients with neuropathic pain. Herein, we report a case of oxcarbazepine-induced lower leg weakness in a patient with trigeminal neuralgia and summarize the diagnosis, treatment, and changes of clinical symptoms.

CASE SUMMARY

A 78-year-old male with a history of lumbar spinal stenosis was admitted to the hospital after he experienced lancinating pain around his right cheek, eyes, and lip, and was diagnosed with trigeminal neuralgia at the right maxillary and mandibular branch. He was prescribed oxcarbazepine (600 mg/d), milnacipran (25 mg/d), and oxycodone/naloxone (20 mg/10 mg/d) for four years. Four years later, the patient experienced symptoms associated with spinal stenosis, including pain in the lower extremities and unsteady gait. His serum sodium level was 127 mmol/L. Assuming oxcarbazepine to be the cause of the hyponatremia, oxcarbazepine administration was put on hold and the patient was switched to topiramate. At subsequent visit, the patient’s serum sodium level had normalized to 143 mmol/L and his unsteady gait had improved.

CONCLUSION

Oxcarbazepine-induced hyponatremia may cause lower extremity weakness and unsteady gait, which should be differentiated from those caused by spinal stenosis.

Keywords: Case report; Drug-related side effects and adverse reactions; Hyponatremia; Oxcarbazepine; Spinal stenosis; Trigeminal neuralgia

Core tip: Unsteady gait is a rare complication of oxcarbazepine; only few cases have been reported and most patients reported in case reports have epilepsy, not neuropathic pain. Oxcarbazepine, along with carbamazepine, is a commonly used drug for the first-line treatment for trigeminal neuralgia. Herein, we report the case of a patient with spinal stenosis who was on long-term oxcarbazepine therapy for trigeminal neuralgia, and manifested symptoms of lower leg weakness as a complication to medication rather than spinal stenosis.