Demyelinating lesions in the cervical cord in multiple sclerosis 10 years after onset of the disease. Correlation between MRI parameters and clinical course.

BACKGROUND AND PURPOSE

Demyelinating lesions in spinal cord in multiple sclerosis (MS) are found in magnetic resonance imaging (MRI) in 47-90% of patients; spinal cord atrophy, however, which is a measure of axonal loss and correlates with disability, is found in 13-41% of patients. Presence and character of lesions depend on the duration and progression of the disease. The aim of this study was to estimate the presence, character and location of lesions and cervical cord atrophy in MRI performed 10 years after the onset of MS in relation to the clinical course.

MATERIAL AND METHODS

60 patients (41 females and 19 males) with definite MS according to McDonald's criteria were studied. The age of patients ranged from 29 to 62 years and disease duration ranged from 11 to 40 years. The MS group comprised 20 patients with secondary progressive MS (SPMS), 20 patients with primary progressive MS (PPMS) and 20 patients with benign form of MS (BMS). Spinal cord MRI was performed in conventional T1 and T2-weighted sequences.

RESULTS

Demyelinating lesions were found in 62% of patients (50% of patients with BMS, 60% with PPMS and 75% with SPMS). 42 intrinsic focal lesions were identified in 18 patients and diffuse lesions of spinal cord were noted in 19 patients. Focal lesions were seen in patients with BMS, whereas SPMS patients had diffuse cervical cord abnormalities, and PPMS patients exhibited both forms of changes. 60% of intrinsic focal lesions were located at C3-C5 levels. Medium-sized lesions prevailed in BMS form; in PPMS form small and medium-size lesions, and in SPMS form large lesions (>10 mm) were more frequent. The spinal cord was atrophic in 8% of patients (10% of patients with PPMS and 15% with SPMS). In BMS no atrophy of the cervical cord was observed. We did not find focal demyelinating lesions in the cervical segment of patients with spinal cord atrophy.

CONCLUSIONS

Presence and character of demyelinating lesions in cervical cord ten years after onset of MS is significantly related to the clinical form of the disease. The mid-cervical region of the spinal cord appeared to be the commonest location of the focal lesions. Cervical cord atrophy was more frequent in patients with PPMS and SPMS, but it was not accompanied with intrinsic focal cord lesions.