A clinico-pathological study of cervical myelopathy in rheumatoid arthritis: post-mortem analysis of two cases

Spinal cord

We first present a brief historic review of developments in the understanding of spinal cord clinical neuroanatomy and neurophysiology over the past 200 years. We then discuss the technical aspects that apply to the examination of the human spinal cord giving details on the interrelations between the spinal cord and the overlying structures, including the meninges and vertebrae. The subsequent discussion focuses on diseases of the spinal cord. Diseases that affect the spinal cord are vascular disease, diseases of spinal column, trauma, developmental abnormalities, central nervous system degenerative disease, inflammatory disease, metabolic and nutritional myelopathies, and tumors. We summarize our knowledge regarding general reactions of spinal cord tissue to disease, in particular Wallerian degeneration of descending/ascending tracts and axonal reaction. Two categories of disease will be covered in depth: vascular disease of the spinal cord, including a review of normal vascular anatomy, and diseases of the vertebral column that can affect the cord secondarily.

The anatomical basis for disease localisation in seronegative spondyloarthropathy at entheses and related sites

The 2 major categories of idiopathic inflammatory arthritis are rheumatoid arthritis and the seronegative spondyloarthropathies. Whilst the synovium is the primary site of joint disease in the former, the primary site in the latter is less well defined. However, it has recently been proposed that enthesitis-associated changes in the spondyloarthropathies are primary and that all other joint manifestations are secondary. Nevertheless, some of the sites of disease localisation have not been adequately explained in terms of enthesitis. This article summarises current knowledge of the structure, function, blood supply, innervation, molecular composition and histopathology of the classic enthesis (i.e. the bony attachment of a tendon or ligament) and introduces the concept of 'functional' and articular 'fibrocartilaginous' entheses. The former are regions where tendons or ligaments wrap-around bony pulleys, but are not attached to them, and the latter are synovial joints that are lined by fibrocartilage rather than hyaline cartilage. We describe how these 3 types of entheses relate to other, and how all are prone to pathological changes in spondyloarthropathy. We propose that the inflammatory responses characteristic of spondyloarthropathies are triggered at these seemingly diverse sites, in genetically susceptible individuals, by a combination of anatomical factors which lead to higher levels of tissue microtrauma, and the deposition of microbes.

Fibrocartilage in the transverse ligament of the human atlas

STUDY DESIGN

Immunohistochemical investigation.

OBJECTIVE

To determine whether molecules typical of articular cartilage are present in the transverse ligament and whether the ligament may be a target for an autoimmune response in rheumatoid arthritis.

SUMMARY OF BACKGROUND DATA

In chronic rheumatoid arthritis there is often a marked instability of the atlantoaxial complex, and the transverse ligament can show degenerative changes that compromise its mechanical function. In some rheumatoid patients there can be an autoimmune response to cartilage link protein, aggrecan, and Type II collagen.

METHODS

Transverse ligaments were removed from 13 cadavers and fixed in 90% methanol. Cryosections were immunolabeled with antibodies against proteoglycans (aggrecan, link protein, and versican), glycosaminoglycans (chondroitin-4-sulfate, chondroitin-6-sulfate, dermatan sulfate, and keratan sulfate), and collagens (Types I, II, III, and VI).

RESULTS

Labeling for aggrecan and link protein was characteristic of the fibrocartilages, but versican was only detected in the fibrous regions. Equally, Types I, III, and VI collagens and keratan, dermatan, and chondroitin-4-sulfates were found throughout the ligament, but labeling for Type II collagen and chondroitin-6-sulfate was restricted to the fibrocartilages.

CONCLUSION

The presence of molecules typical of articular cartilage (aggrecan, link protein, and Type II collagen) in the transverse ligament explains why it can be a target for destruction in rheumatoid arthritis and also suggests that it is subject to constant compression against the dens rather than only at the extremes of movement.

A long-term follow-up study of cervical lesions in rheumatoid arthritis

To determine the natural history of cervical lesions in rheumatoid arthritis, 161 patients who had been followed for a minimum of 5 years were enrolled in this study. The average follow-up period was 10.2 years (range, 5 to 20 years). The severity of the rheumatoid arthritis was classified into three types based on the multiplicity of peripheral joint rheumatoid involvement: a least erosive subset, a more erosive subset, and a mutilating disease subset. Ninety-two patients (57%) had upper cervical involvement, which progressed in the order of anterior atlantoaxial subluxation, anterior atlantoaxial subluxation combined with vertical subluxation, and vertical subluxation alone. Subaxial subluxation was found in 18 patients (11%). In 17 of these 18 patients, upper cervical lesions were also noted. The incidence of cervical involvement in each disease subset was 39% in the least erosive group, 83% in the more erosive group, and 100% in the mutilating disease group. Fifty percent of the patients with cervical involvement had neck pain, and the remaining patients were asymptomatic. Neural involvement occurred in 10 patients. In 7 of these 10 patients, vertical subluxation of the atlas was responsible for the neural deficit. Six patients required surgical intervention because of progressive myelopathy.