Diffuse idiopathic skeletal hyperostosisに伴った頸椎前縦靱帯骨化症による嚥下障害を来たした2例

Dysphagia Caused by Ossification of the Anterior Longitudinal Ligament Associated with Diffuse Idiopathic Skeletal Hyperostosis : report of 2 cases

I．はじめに

　1950年ForestierとRotes-Querol^5）が脊椎の強直を来たす特殊な病態として，強直性脊椎骨肥厚症（ankylosing hyperostosis of the spine）を報告した．本疾患は前縦靱帯の高度の石灰化または骨化を特徴とし，変形性脊椎症に伴った椎体前面に形成された骨棘や強直性脊椎炎との鑑別が重要である．1970年代Resnickら^12-14）は脊椎以外の骨格系にもこの骨化素因が脊椎病変と合併したり，また単独に存在し，骨化を生じることを確認し，diffuse idiopathic skeletal hyperostosis（DISH）として命名した．この臨床病理学的概念は現在でも用いられており，数椎体におよぶ椎体前面の石灰化または骨化，病変部位の椎間板腔の比較的良好な保持，仙陽関節部の異所性骨化等が代表的なレントゲン学的特徴として定義づけられている．

　今回われわれはDISHの頸椎前縦靱帯骨化により嚥下困難を来たした患者に対し外科的に治療し，良好な結果を得られたので文献的考察を加えて報告する．

Two cases of ossification of the anterior longitudinal ligament (OALL) associated with diffuse idiopathicskeletal hyperostosis (DISH) presenting as dysphagia are reported. DISH has long been regarded as aradiological entity manifesting flowing ossification adjacent to the anterior and lateral borders of at leastfour contiguous vertebral bodies, maintenance of disc spaces, and a dearth of bony ankylosis and erosionof the apophyseal and sacroiliac joints. In the majority of cases, this entity shows an innocuous clinicalcourse, but the dysphagia shown in our cases has also been documented in previous literature. Case 1 wasa 63-year-old male developing progressive dysphagia and rhinolalia. Cervical X-rays and CT showed flow-ing OALL in the entire cervical spine. MRI demonstrated displacement of the trachea and esophagus bythis mass. There was OALL in the thoracic and lumbar spine. Case 2 was a 62-year-old male who hadundergone removal of ossification of the posterior longitudinal ligament (OPLL) from C2 to C5. He deve-loped dysphagia and myelopathy. Cervical X-rays and CT demonstrated projection of OALL as well asposterior osteophytes at C5/6. MRI suggested that OALL, had caused dysphagia, and osteophytes deterio-rated myelopathy. Removal of OALL was carried out in these two cases. In case 2, removal of the osteo-phytes and herniated disc was carried out at the same time. Postoperative course was unremarkable withimprovement of symptoms. Treatment of dysphagia due to OALL is considered to be conservative.However, surgical decompression should be considered in cases of marked projection of OALL obstructingthe esophagus as shown in our cases.