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 9.0 months (2–35 months) in the ‘LL-first’ group, which was shorter than that in the control group (12 months [1–60 months], 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.