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Updated: Jul 4, 2026

The Ex vivo Preparation of Spinal Cord Slice for the Whole-Cell Patch-Clamp Recording in Motor Neurons During Spinal Cord Stimulation
Published on: September 8, 2023
Decremental responses following repetitive nerve stimulation in spinal and bulbar muscular atrophy
Keisuke Tachiyama1, Masahiro Nakamori1, Yuki Fujii2
1Department of Clinical Neuroscience and Therapeutics, Hiroshima University Graduate School of Biomedical and Health Sciences, Japan.
Objective:
The presence of decremental responses following repetitive nerve stimulation (RNS) in amyotrophic lateral sclerosis (ALS) is well established. However, in spinal and bulbar muscular atrophy (SBMA), a rare X-linked recessive lower motor neuron disease, the incidence and distribution of decremental responses across different muscles have not been thoroughly investigated.
Methods:
Patients with SBMA were retrospectively identified in our database. RNS at a frequency of 3 Hz was performed on five muscles: the abductor pollicis brevis (APB), abductor digiti minimi (ADM), upper trapezius, deltoid, and facial muscles (frontalis or nasalis).
Results:
A total of forty patients were identified. A significant (> 5%) decremental response in at least one muscle was observed in all patients. It was observed more frequently in proximal muscles than in distal muscles: deltoid (86%), trapezius (70%), facial muscles (44%), APB (37%) and ADM (25%). The magnitude of the decremental response in the deltoid was significantly higher than that in the other muscles.
Conclusions:
Our results demonstrated that decremental responses were frequently observed in patients with SBMA, with a distribution pattern similar to that in ALS. The fact that the decremental responses are observed in SBMA having an extremely chronic course would be relevant for the pathophysiological mechanism of the decremental response.
Significance:
The RNS findings provide valuable insights into the pathological mechanisms of SBMA and may contribute to the development of future treatments.
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