磁気センサータッピング装置を用いた頚髄症の手指運動解析

Finger-tapping Motion Analysis in Cervical Myelopathy by Magnetic Detection System

　軽量の磁気センサーを指に装着し，30秒間タッピング運動(最大努力での母指示指間反復対立運動)を行わせ新しい装置を用いて定量記録した．頚髄症(30例)では対照(30例)に比して有意にタッピング回数，総移動距離が少なく，リズム不整が強かった．またこれらの指標とJOAスコアには有意な相関関係があった．さらに全指の握り開き運動と同様に疲労現象，すくみ現象も認められた．磁気センサーを示指ではなく，環指や小指に装着することで頚髄症における麻痺をさらに詳しく定量評価できる可能性があり，本装置の応用が期待される．

　Although finger motion is well known to be impaired in cervical myelopathy, no reliable devices have been available to precisely evaluate the finger paralysis.　In this study we used a new magnetic detection system in which one oscillation coil and one detection coil, each weighing 1.5g, are attached to the surface of the nail of the thumb and index finger to measure finger motion in 30 cervical myelopathy patients and 30 healthy controls.　The subjects and controls were asked to tap their index finger against their thumb as rapidly as possible for 30 seconds, and output signals were stored in a personal computer that automatically calculated several indices.　The results showed that tapping counts and the sum of all tapping amplitudes were significantly smaller and the tapping intervals were significantly more scattered in the myelopathy group than in the control group.　The new magnetic detection system we used proved to be a useful means of assessing cervical myelopathy quantitatively and precisely.