慢性咳嗽と機序

Chronic Cough in CANVAS

CANVAS（Cerebellar ataxia with neuropathy and vestibular areflexia syndrome）に代表される，RFC1遺伝子関連スペクトラム障害の患者の少なくとも6割以上に，発作性の乾性咳嗽が認められることが判明し，慢性咳嗽は本疾患の診断のキーポイントとなる重要な所見として認識されるようになった。咳嗽は初発症状となることが多く，症例によっては失調症状や感覚障害などの神経症状に30年以上先行する。病態機序は不明な点も多いが，咳嗽反射の求心路である迷走神経の障害，あるいは小脳障害が咳嗽発症に寄与している可能性がある。

Abstract

Among patients with RFC1 spectrum disorders represented by the phenotype of cerebellar ataxia with neuropathy and vestibular areflexia syndrome (CANVAS), at least 60% are known to manifest chronic, paroxysmal, and spasmodic dry cough. Chronic cough is a key diagnostic feature of RFC1-related diseases. It is often the first symptom and, in some cases, precedes neurological symptoms such as ataxia and sensory disturbance for more than 30 years. Although the pathogenesis of the cough remains unclear, it is possible that impairment of the vagus nerve, which includes an afferent pathway of the cough reflex, or the cerebellum would have contributed to the generation of the cough.