Neurologic Manifestations of Atlanto-axial Subluxation in the Patients with Rheumatoid Arthritis

ABSTRACT

BACKGROUND: Atlanto-axial dislocation (AAD) is a common complication of rheumatoid arthritis (RA). Diverse or different patterns of neurological manifestations including brainstem signs, myelopathy, vertebrobasilar insufficiency, and radiculopathy are expected in each type of AAD. This study is designed for the evaluation of neurological manifes-tations of AAD in RA, and for the comparison of clinical profiles with radiological findings. METHODS: Thirty patients compatible with radiological criteria of AAD were selected. The age, sex, symptom duration, and neurological signs were evaluated in the clinical profiles. Based on the neurological signs, the patients were classified into three groups. Radiological classifications of AAD were done according to the direction of AAD (anterior, vertical, lateral, mixed) and degrees of dislocation (grade I, II, III). Correlational analysis was performed as a measure of association with the clinical profiles and radiological findings. RESULTS: Neurological manifestations were present/found in 50% of the patients. Each types of AAD were distributed into the following groups:; anterior - 76.7%, mixed - 13.3%, lateral -10%, pure vertical - 0% in our study. The various groups determined by the neurological signs may be correlated with the severity of AAD, especially in the anterior type (> 8mm) and mixed type. Neurological signs were not noted in the pure lateral type. Vascular signs such as vertebrobasilar insufficiency (VBI) were more common in the anterior-AAD, but myelopathic or brainstem signs were more common in the mixed type. CONCLUSIONS: Diverse neurological findings exist in AAD. Different and characteristic manifestations are also noted in each type of AAD. Critical neurological signs including myelopathic, brainstem signs and VBI are prominent in severe anterior-AAD or mixed type.