Related Experiment Video
Updated: Mar 11, 2026
Induction of Paralysis and Visual System Injury in Mice by T Cells Specific for Neuromyelitis Optica Autoantigen Aquaporin-4
Published on: August 21, 2017
Ring-enhancing spinal cord lesions in neuromyelitis optica spectrum disorders
Nicholas L Zalewski1, Padraig P Morris2, Brian G Weinshenker1
1Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA.
Objective:
We assessed the frequency and characteristics of ring-enhancing spinal cord lesions in neuromyelitis optica spectrum disorder (NMOSD) myelitis and myelitis of other cause.
Methods:
We reviewed spinal cord MRIs for ring-enhancing lesions from 284 aquaporin-4 (AQP4)-IgG seropositive patients at Mayo Clinic from 1996 to 2014. Inclusion criteria were as follows: (1) AQP4-IgG seropositivity, (2) myelitis attack and (3) MRI spinal cord demonstrating ring-enhancement. We identified two groups of control patients with: (1) longitudinally extensive myelopathy of other cause (n=66) and (2) myelitis in the context of a concurrent or subsequent diagnosis of multiple sclerosis (MS) from a population-based cohort (n=30).
Results:
Ring-enhancement was detected in 50 of 156 (32%) myelitis episodes in 41 patients (83% single; 17% multiple attacks). Ring-enhancement was noted on sagittal and axial images in 36 of 43 (84%) ring enhancing myelitis episodes and extended a median of two vertebral segments (range, 1-12); in 21 of 48 (44%) ring enhancing myelitis episodes, the ring extended greater than or equal to three vertebrae. Ring-enhancement was accompanied by longitudinally extensive (greater than or equal to three vertebral segments) T2-hyperintensity in 44 of 50 (88%) ring enhancing myelitis episodes. One case of a spinal cord biopsy during ring-enhancing myelitis revealed tissue vacuolation and loss of AQP4 immunoreactivity with preserved axons. The clinical characteristics of ring-enhancing myelitis episodes did not differ from non-ring-enhancing episodes. Ring-enhancing spinal cord lesions were more common in NMOSD than other causes of longitudinally extensive myelopathy (50/156 (32%) vs 0/66 (0%); p≤0.001) but did not differ between NMOSD and MS (50/156 (32%) vs 6/30 (20%); p=0.20).
Conclusions:
Spinal cord ring-enhancement accompanies one-third of NMOSD myelitis episodes and distinguishes NMOSD from other causes of longitudinally extensive myelopathies but not from MS.
Insights
Ring-enhancing spinal cord lesions are found in one-third of neuromyelitis optica spectrum disorder (NMOSD) myelitis episodes. This finding helps differentiate NMOSD from other causes of myelopathy but not from multiple sclerosis (MS).
Area of Science:
- Neurology
- Radiology
- Immunology
Background:
- Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune disease targeting the central nervous system.
- Spinal cord lesions are a hallmark of NMOSD, but their specific imaging characteristics require further elucidation.
- Ring-enhancing lesions on MRI can indicate active inflammation in the spinal cord.
Purpose of the Study:
- To determine the frequency and characteristics of ring-enhancing spinal cord lesions in NMOSD.
- To compare the occurrence of these lesions in NMOSD versus other causes of myelitis, including multiple sclerosis (MS).
Main Methods:
- Retrospective review of spinal cord MRIs from 284 aquaporin-4 (AQP4)-IgG seropositive patients with myelitis.
- Inclusion criteria: AQP4-IgG seropositivity, myelitis attack, and MRI evidence of spinal cord ring-enhancement.
- Comparison with control groups: 66 patients with longitudinally extensive myelopathy of other causes and 30 patients with MS-associated myelitis.
Main Results:
- Ring-enhancement was observed in 32% of NMOSD myelitis episodes (50/156) across 41 patients.
- These lesions often extended longitudinally (≥3 vertebral segments) and were associated with T2-hyperintensity.
- Ring-enhancing lesions were significantly more common in NMOSD than in other myelopathies (32% vs 0%, p≤0.001) but not significantly different from MS (32% vs 20%, p=0.20).
Conclusions:
- Spinal cord ring-enhancement occurs in approximately one-third of NMOSD myelitis episodes.
- The presence of ring-enhancing lesions helps distinguish NMOSD from other longitudinally extensive myelopathies.
- Ring-enhancement does not differentiate NMOSD from multiple sclerosis based on this study's findings.
