Linear lesions may assist early diagnosis of neuromyelitis optica and longitudinally extensive transverse myelitis, two subtypes of NMOSD.

PURPOSE: To investigate the relationship between linear lesions (LL) and the development of longitudinally extensive spinal cord lesions (LESCL) in Chinese patients with neuromyelitis optica or longitudinally extensive transverse myelitis.

METHOD: The clinical records of 143 patients with these conditions were reviewed. Forty-one patients with LL were divided into three groups according to the order of appearance of LL and LESCL (simultaneously [n=10], LL first [n=26], or LESCL first [n=5]). The remaining 102 patients without LL were used as a control group.

RESULTS

Patients who developed LL first demonstrated a lower annualized relapse rate than those in the simultaneous group (1.00 [0.23-10.00] vs. 4.38 [0.60-6.67], p=0.017) and the control group (1.00 [0.23-10.00] vs. 2.00 [0.24-10.00], p=0.007). Among all patients with LL, there were significantly more who developed them before LESCL than those who developed them after LESCL (p<0.001) or at the same time (p=0.008). The mean time before the appearance of LESCL was 9.0months (2-35months) in the 'LL-first' group, which was shorter than that in the control group (12months [1-60months], p=0.010). The rate of positivity for anti-aquaporin 4 IgG antibodies was higher in patients with LL compared with controls (90.24% vs. 64.71%, p=0.002).

CONCLUSION

LL may be a precursor to LESCL and assist early diagnosis of neuromyelitis optica and longitudinally extensive transverse myelitis.