シンポジウム２８‐２ 電気生理からみたＡＬＳの病態ｕｐｄａｔｅ ＡＬＳでは運動神経軸索の膜電位変動が大きい
スポンサーリンク
概要
- 論文の詳細を見る
Amyotrophic lateral sclerosis (ALS) is characterized by increased excitability of motor neurons and early involvement of large motor fibers that have low electrical thresholds. Despite the advent of new techniques of threshold tracking, exploration of this abnormal excitability has not been straightforward, by tracking at the single target level as previous reported, because of the heterogeneous nature of the disease process among fibers that have variable thresholds. We have assessed different populations of motor axons by tracking at four different target response levels (10, 20, 40 and 60% of maximum compound muscle action potentials), and conducted multiple nerve excitability tests in 27 ALS patients and 23 control subjects. In normal controls, axons with low thresholds have the following characteristics compared to those with high thresholds: greater threshold reduction during depolarizing currents and smaller threshold increase to hyperpolarizing currents, reflecting the order of the fiber size. In contrast, ALS patients lacked these relationships, suggesting increased variability of axonal membrane potentials. Three ALS patients demonstrated changes in threshold electrotonus, consistent with overt membrane depolarization, as seen in ischemic nerves. The variability of motor nerve excitability accounts for fasciculations, confirms previously reported dysfunction of potassium channels, and suggests failure of Na+/K+pumps, possibly caused by mitochondrial dysfunctions at the early stage.
- 日本神経学会の論文
日本神経学会 | 論文
- 書字動作の神経科学 : 書字運動の計算理論モデルを中心に
- 重症筋無力症に合併した難治性バセドウ眼症の1例
- 神経サルコイドーシスの診断基準案
- 大腸癌とその転移にともなう凝固線溶系の異常により脊髄円錐部出血をきたした1例
- 垂直性共同視麻痺を呈した両側延髄内側梗塞の1例