腰仙椎単根障害例からみた疼痛・しびれ範囲の検討

Study on the Area of Pain and Numbness in Cases with Lumbosacral Radiculopathy

Ⅰ．諸言

　神経学的診断において疼痛・しびれの領域は最も重要な要素である．過去に報告された皮膚髄節の図譜は作成方法が異なり，かなりのバリエーションがある^{1-6,11,15,16,18,19)}．今回，われわれは臨床・画像所見から腰仙椎単根障害と考えられ，手術にて圧迫を確認し，さらに除圧にて改善を確認できた症例の痛み・しびれ領域を前向きに調査し，文献的考察と併せて検討した．

　In the clinical diagnosis of lumbosacral radicular symptoms, dermatome maps are commonly used, by which the segmental location of the affected nerve can be determined. However, the diagnosis is often difficult because the pattern of sensory disturbance does not necessarily match the patterns of classical dermatomes, and there are many dermatome maps made by different methods. The author examined the area of pain and numbness in cases of lumbosacral radiculopathy.

　Clinical features of pain and numbness in consecutive seventy three cases of lumbosacral radiculopathy were investigated (L3: n＝13, L4-S1: n＝20). Patients of L3 radiculopathy showed symptoms at the upper buttock and ventral surface of the thighs, knees and upper ventral surface of the legs. Patients of L4 radiculopathy showed symptoms at the ventro-lateral surfaces of the thigh and leg. The distinctive region, defined as the region having 100% superimposition, of L4 radiculopathy was the lateral part of the shin. Patients of L5 radiculopathy showed symptoms at the lateral surfaces of the thigh and leg. The distinctive region was the upper buttock. Patients of S1 radiculopathy showed symptoms at the lower buttock, dorso-lateral part of the leg and lateral part of the foot. The distinctive region was the lateral part of the calf. It was found that the regions of pain and numbness formed a continuous band-like zone from thigh to leg in 8% of L3, 45% of L4 and L5, and 35% of S1 radiculopathy. Using a visual analogue scale, the degree of leg pain was more severe than low back pain in 68% of the patients, but in 5% of patients, low back pain was more severe.