Pathology of spinal cord lesions caused by ossification of the posterior longitudinal ligament

Abstract

Introduction Ossification of the posterior longitudinal ligament (OPLL) causing spinal cord compression was fi rst reported in 1838 by Key [1]; this was followed by only two reports [2,3] in the fi rst part of this century. Ossification of the posterior longitudinal ligament was not recognized as defi nite clinical entity until 1960. In Japan, Tsukimoto [4] fi rst described this pathological condition following autopsy fi ndings in 1960. Since then, a number of reports have appeared [5-8]. Increased recognition of OPLL led the Ministry of Public Health and Welfare of Japan to appoint a special study group, the Investigation Committee on OPLL, in 1974, and extensive studies ranging from basic research to clinical investigations have been conducted. Although OPLL is rare among Caucasians, it is a signifi cant cause of myelopathy in middle-aged and older Japanese adults. The patients initially suffer from numbness and pain in the upper extremities and the neck. The disease progresses gradually and results in gait disturbance, spastic paralysis, and bladder disturbance. OPLL-induced myelopathy can be said to be characterized by a chronic, gradually enhanced, persistent compression of the spinal cord. Detailed pathological investigations of the spinal cord in OPLL are limited [4,9-13]. This chapter is concerned with the pathological changes of the spinal cord as observed in autopsied cases. © Springer 2006.