頚髄症における上肢筋力の術後変化（定量評価）

Quantitative Assessment Reveals Frequent Changes in Upper Limb Muscle Strength in Operated Patients with Cervical Myelopathy

　圧迫性頚髄症に対して椎弓形成術を施行した79例158肢(男性58例，女性21例，64.3歳)を対象にhand-held dynamometerを用いて三角筋，上腕二頭筋，上腕三頭筋の筋力と握力を術前および術後2週間で計測し前向きに検討した．いわゆる術後上肢麻痺(MMT1段階以上低下)は5例(6％)であったが，hand-held dynamometerでは筋力低下は19例(24％)に認め，これはいわゆる術後上肢麻痺の軽症例と考えられた．一方，除圧術後，各筋別に調べた術後筋力の改善は9～18％に認められた．術前MRIにおいてC3/4最大圧迫症例では他の高位に最大圧迫を有する例と比較して三角筋，上腕二頭筋，握力が有意に改善していた．

　The subjects consisted of 79 consecutive patients (58 men and 21 women；mean age, 64.3 y) who underwent laminoplasty for cervical myelopathy.　We prospectively assessed the strength of their deltoid, biceps, and triceps brachii muscles and their grip strength with a hand-held dynamometer and grip dynamometer before and 2weeks after surgery and their preoperative MRI findings.　Five patients (6%) had postoperative upper limb palsy, defined as a one or more grade reduction on the MMT.　In addition, a total of 19 patients (24%) developed weakness of one or more muscles when assessed with the dynamometer, and they were assumed to have a mild type of upper limb palsy.　The results of this study showed a 9% to 18% improvement in muscle strength postoperatively.　The patients who were found to have spinal cord compression predominantly at C3-C4 on MRI scans had significant improvement in the strength of the deltoid and biceps brachii muscles and in their grip strength.