Cervical spine involvement in ankylosing spondylitis

Our objective was to study cervical spine involvement in a Moroccan population of ankylosing spondylitis (AS) patients and evaluate correlations with disease symptomatic and structural severity. Patients were prospectively enrolled for a 1-year period. Clinical, biological, and radiological data were collected. The risk of cervical spine involvement was estimated using the Kaplan-Maier method. Sixty-one patients were enrolled: 38 males (62.2%) and 23 females of mean (SD) age 35.1 years [11] (range 17-66). The mean disease duration was 10.6 years [7] (0.5-30). Forty-three patients (70.4%) had a history of neck pain. Radiological involvement was present in 33 cases (54%). The concordance between clinical and radiological involvement was statistically significant (kappa=0.49; P<10(-6)). The risk of cervical spine involvement with regard to disease duration showed that 19.6% of patients had radiological involvement after 5 years, 29.9% after 10 years, 45.1% after 15 years and 70.0% after 20 years. Comparison between patients with and without cervical spine radiological involvement showed no difference in age of onset or sex. There was statistical difference in symptomatic severity parameters (Schöber, chest expansion, BASMI, BASFI, BASDI, BASG) and structural severity parameters (lumbar syndesmophytes score, BASRI). Our study confirms the greater severity of AS in North African countries. Cervical spine involvement increases with age and disease duration in AS and is more frequent in symptomatic and structural severe forms of the disease.