1
|
Yamada S, Hashizume A, Hijikata Y, Inagaki T, Ito D, Kishimoto Y, Kinoshita F, Hirakawa A, Shimizu S, Nakamura T, Katsuno M. Mexiletine in spinal and bulbar muscular atrophy: a randomized controlled trial. Ann Clin Transl Neurol 2022; 9:1702-1714. [PMID: 36208052 PMCID: PMC9639628 DOI: 10.1002/acn3.51667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Revised: 09/09/2022] [Accepted: 09/12/2022] [Indexed: 11/22/2022] Open
Abstract
Objective Patients with spinal and bulbar muscular atrophy (SBMA) often experience muscular weakness under cold exposure. Methods In our previously conducted observational study, we assessed nerve conduction and grip strength to examine the effect of cold exposure on motor function, based on which we conducted a randomized controlled trial to evaluate the efficacy and safety of mexiletine hydrochloride in SBMA (MEXPRESS). Results In the observational study, 51 consecutive patients with SBMA and 18 healthy controls (HCs) were enrolled. Of the patients with SBMA, 88.0% experienced cold paresis. Patients with SBMA exhibited greater prolongation of ulnar nerve distal latency under cold (SBMA, 5.6 ± 1.1 msec; HC, 4.3 ± 0.6 msec; p <0.001); the change in the distal latencies between room temperature and cold exposure conditions correlated with the change in grip power. In the MEXPRESS trial, 20 participants took mexiletine or lactose, three times a day for 4 weeks with a crossover design. There was no difference in distal latencies at room temperature and under cold exposure between mexiletine and placebo groups as the primary endpoint. However, tongue pressure and 10‐sec grip and release test under cold exposure were improved in the mexiletine group. There were no serious adverse events throughout the study period. Interpretation Cold paresis is common and associated with prolongation of distal latency in SBMA. The results of the phase II clinical trial revealed that mexiletine showed short‐term safety, but it did not restore cold exposure‐induced prolongation of distal latency.
Collapse
Affiliation(s)
- Shinichiro Yamada
- Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Atsushi Hashizume
- Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan.,Department of Clinical Research Education, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Yasuhiro Hijikata
- Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Tomonori Inagaki
- Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Daisuke Ito
- Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Yoshiyuki Kishimoto
- Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Fumie Kinoshita
- Department of Advanced Medicine, Nagoya University Hospital, Nagoya, Japan
| | - Akihiro Hirakawa
- Department of Clinical Biostatistics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Shinobu Shimizu
- Department of Advanced Medicine, Nagoya University Hospital, Nagoya, Japan
| | - Tomohiko Nakamura
- First Department of Medicine, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Masahisa Katsuno
- Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan.,Department of Clinical Research Education, Nagoya University Graduate School of Medicine, Nagoya, Japan
| |
Collapse
|