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

Abstract

The pathologic changes in the spinal cord of three autopsied cases associated with ossification of the posterior longitudinal ligament ( OPLL ) are reported. Compression of the spinal cord was marked at the level of the intervertebral disc, and the spinal cord was strikingly flattened antero-posteriorly. Intensive damage was seen in the gray matter as compared to the white matter. The white matter showed demyelination and axon loss with status spongiosus, which was more marked in the postero-lateral than in the anterior columns. The most seriously damaged parts of the spinal cord showed tissue necrosis and cavity formation which extended from the central parts of the gray matter to the ventral parts of the posterior columns. Adventitial fibrous thickening of the vein, hyaline degeneration of the walls of the arterioles, and compression of the anterior spinal vein were observed in the damaged regions. It was evident that secondary circulatory disturbance due to the compression produced by the ossification was of significance in the pathogenesis of the spinal cord damage. A tangle of peripheral nerves, ectopic and reactive, with Schwann cell proliferation was present in the posterior median fissure and the postero-lateral columns in one case. The spinal nerve roots that showed marked demyelination and axon loss were damaged by ossification at the places where the anterior nerve roots emerged from the spinal cord and where the roots penetrate the dura. There was ossification of the dura mater in all cases examined.

Invited. Ossification of posterior longitudinal ligaments: Evaluation with MRI

“…Autopsy studies frequently show an anteriorly concave, very thin, crescent-shaped cord (12-1 4). Hashizume et a1 (13) reported that the most profound spinal medullary changes were found in the gray matter rather than the white matter. The most marked damage was observed in the central gray matter and neighboring ventral fibers of the posterior columns.…”

“…Secondary vascular disturbances seem to affect the spinal cord significantly (13). According to Hashizume et a1 (13). the most serious pathologic changes in the central gray matter and ventral fibers of the posterior columns were in the area of the terminal supply of the anterior spinal artery.…”

“…The spinal cord damage has been attributed to direct effects of chronic compression (12.13) and to secondary circulatory disturbances of the anterior spinal artery (13). Autopsy studies frequently show an anteriorly concave, very thin, crescent-shaped cord (12-1 4).…”

“…Secondary vascular disturbances seem to affect the spinal cord significantly (13). According to Hashizume et a1 (13).…”

Surgical treatment for cervical myelopathy

“…35 Since Stookey's report, there have been many studies presenting patients with similar symptoms. [36][37][38][39][40] The cause of cervical myelopathy is chronic compression of the cervical spinal cord. This compression has been shown to be a result of many different factors including herniated discs, osteophytes, or ossified posterior longitudinal ligament.…”