MRI Patterns Distinguish AQP4 Antibody Positive Neuromyelitis Optica Spectrum Disorder From Multiple Sclerosis

Neuromyelitis optica spectrum disorder (NMOSD) and multiple sclerosis (MS) are inflammatory diseases of the CNS. Overlap in the clinical and MRI features of NMOSD and MS means that distinguishing these conditions can be difficult. With the aim of evaluating the diagnostic utility of MRI features in distinguishing NMOSD from MS, we have conducted a cross-sectional analysis of imaging data and developed predictive models to distinguish the two conditions. NMOSD and MS MRI lesions were identified and defined through a literature search. Aquaporin-4 (AQP4) antibody positive NMOSD cases and age- and sex-matched MS cases were collected. MRI of orbits, brain and spine were reported by at least two blinded reviewers. MRI brain or spine was available for 166/168 (99%) of cases. Longitudinally extensive (OR = 203), "bright spotty" (OR = 93.8), whole (axial; OR = 57.8) or gadolinium (Gd) enhancing (OR = 28.6) spinal cord lesions, bilateral (OR = 31.3) or Gd-enhancing (OR = 15.4) optic nerve lesions, and nucleus tractus solitarius (OR = 19.2), periaqueductal (OR = 16.8) or hypothalamic (OR = 7.2) brain lesions were associated with NMOSD. Ovoid (OR = 0.029), Dawson's fingers (OR = 0.031), pyramidal corpus callosum (OR = 0.058), periventricular (OR = 0.136), temporal lobe (OR = 0.137) and T1 black holes (OR = 0.154) brain lesions were associated with MS. A score-based algorithm and a decision tree determined by machine learning accurately predicted more than 85% of both diagnoses using first available imaging alone. We have confirmed NMOSD and MS specific MRI features and combined these in predictive models that can accurately identify more than 85% of cases as either AQP4 seropositive NMOSD or MS.

Magnetic resonance imaging in neuromyelitis optica spectrum disorder

Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory disease of the central nervous system (CNS) associated with antibodies to aquaporin-4 (AQP4), which has distinct clinical, radiological and pathological features, but also has some overlap with multiple sclerosis and myelin oligodendrocyte glycoprotein (MOG) antibody associated disease. Early recognition of NMOSD is important because of differing responses to both acute and preventive therapy. Magnetic resonance (MR) imaging has proved essential in this process. Key MR imaging clues to the diagnosis of NMOSD are longitudinally extensive lesions of the optic nerve (more than half the length) and spinal cord (three or more vertebral segments), bilateral optic nerve lesions and lesions of the optic chiasm, area postrema, floor of the IV ventricle, periaqueductal grey matter, hypothalamus and walls of the III ventricle. Other NMOSD-specific lesions are denoted by their unique morphology: heterogeneous lesions of the corpus callosum, 'cloud-like' gadolinium (Gd)-enhancing white matter lesions and 'bright spotty' lesions of the spinal cord. Other lesions described in NMOSD, including linear periventricular peri-ependymal lesions and patch subcortical white matter lesions, may be less specific. The use of advanced MR imaging techniques is yielding further useful information regarding focal degeneration of the thalamus and optic radiation in NMOSD and suggests that paramagnetic rim patterns and changes in normal appearing white matter are specific to MS. MR imaging is crucial in the early recognition of NMOSD and in directing testing for AQP4 antibodies and guiding immediate acute treatment decisions. Increasingly, MR imaging is playing a role in diagnosing seronegative cases of NMOSD.

Clinical characteristics of very late-onset neuromyelitis optica spectrum disorder

BACKGROUND

The typical age at onset of neuromyelitis optica spectrum disorder (NMOSD) is between 30 and 40 years. A growing awareness about the disease and advances in diagnostic techniques have led to an increase in the number of patients being diagnosed with very late-onset (VLO) NMOSD. This study compared the clinical characteristics, treatments, and prognoses between patients with VLO-NMOSD or late-onset (LO) NMOSD.

METHODS

Patients in our study were assigned to two groups based on age at onset of the disease: LO-NMOSD (50-70 years old at onset) and VLO-NMOSD (> 70 years old at onset). We compared clinical characteristics, magnetic resonance imaging of lesions, prognosis, and treatments between the two groups.

RESULTS

We collected data from 12 VLO-NMOSD patients with a median age at onset of 74.0 years (interquartile range, 72.6-75.9 years) and 104 LO-NMOSD patients with a median age at onset of 56.0 years (55.8-57.9 years). There were a high proportion of female patients in both the VLO-NMOSD group (9, 75.0%) and the LO-NMOSD group (91, 87.5%). Our study indicated that VLO-NMOSD patients had significantly higher expanded disability status scale (EDSS) scores (8.5 vs 4.0, p = 0.01), higher motor disability rates (41.7% vs 9.6%, p = 0.002), and higher mortality rates (25.0 vs 4.8%, p = 0.044) at last follow-up. However, patients with VLO-NMOSD had lower rates of immunosuppressant usage (50.0% vs 76.9%, p = 0.044). Age at onset was positively correlated with EDSS score at remission (r = 0.49, p < 0.001).

CONCLUSION

VLO-NMOSD was associated with higher EDSS score at remission, higher rates of mortality and motor disability, but lower rates of immunosuppressive treatment usage than LO-NMOSD. Future studies are needed to understand the effects of NMOSD on older patients, and to seek suitable treatment to improve their prognosis.

Blood Brain Barrier Permeability Could Be a Biomarker to Predict Severity of Neuromyelitis Optica Spectrum Disorders: A Retrospective Analysis

Background: Blood-brain barrier (BBB) pathology exists in neuromyelitis optica spectrum disorders (NMOSD). However, the clinical use of BBB permeability, such as predicting disease severity of NMOSD, has rarely been studied in a large cohort of patients.

Objectives: The current study explored the association between BBB permeability and clinical parameters in order to assess if BBB permeability could be a biomarker to predict disease severity and clinical characteristics of NMOSD.

Methods: Among 69 enrolled NMOSD patients, 47 with albumin index over 5 × 10⁻³ were assigned to the increased BBB permeability group, and the remaining 22 were to the normal BBB permeability group. Disease severity was assessed using the Expanded Disability Status Scale (EDSS).

Results: Patients in the increased BBB permeability group had significantly higher EDSS scores, anti-aquporin-4 immunoglobulin G titers, more dense cerebrospinal fluid protein concentrations, white blood cell counts, myelin basic protein levels and more dense complement 3 concentrations than found in the comparative normal BBB permeability group. The albumin index was positively correlated to the length of lesions in spinal cord.

Conclusions: BBB permeability was associated with clinical features, laboratory results and radiological data of NMOSD patients, and may be a potential biomarker to predict disease severity and clinical characteristics of NMOSD.

Analysis of brain and spinal cord lesions to occult brain damage in seropositive and seronegative neuromyelitis optica

OBJECTIVES

According to aquaporin-4 antibody (AQP4-Ab), neuromyelitis optica (NMO) can be divided into seropositive and seronegative subgroups. The purpose of this study was to a) compare the distribution of spinal cord and brain magnetic resonance imaging (MRI) lesions between seropositive and seronegative NMO patients; b) explore occult brain damage in seropositive and seronegative NMO patients; and c) explore the contribution of visible lesions to occult grey and white matter damage in seropositive and seronegative NMO patients.

MATERIALS AND METHODS

Twenty-two AQP4-Ab seropositive and 14 seronegative NMO patients and 30 healthy controls were included in the study. Two neuroradiologists independently measured the brain lesion volume (BLV) and the length of spinal cord lesion (LSCL) and recorded the region of brain lesions. The normal-appearing grey matter volume (NAGM-GMV) and white matter fractional anisotropy (NAWM-FA) were calculated for each subject to evaluate occult brain damage.

RESULTS

The seropositive patients displayed more extensive damage in the spinal cord than the seronegative patients, and the seronegative group had a higher proportion of patients with brainstem lesions (28.57%) than the seropositive group (4.55%, P=0.064). Both NMO subgroups exhibited reduced NAGM-GMV and NAWM-FA compared with the healthy controls. NAGM-GMV was negatively correlated with LSCL in the seropositive group (r_s=-0.444, P=0.044) and with BLV in the seronegative group (r_s=-0.768, P=0.002). NAWM-FA was also negatively correlated with BLV in the seropositive group (r_s=-0.682, P<0.001).

CONCLUSION

Our findings suggest that the occult brain damage in these two NMO subgroups may be due to different mechanisms, which need to be further clarified.

Distinctive characteristics of early-onset and late-onset neuromyelitis optica spectrum disorders

OBJECTIVES

Little is known about patients with neuromyelitis optica spectrum disorders (NMOSD) as defined by onset age. This study aimed to analyze the different demographic, clinical, laboratory, and magnetic resonance imaging (MRI) characteristics in early-onset (≤50 years) NMOSD (EONMOSD) and late-onset (>50 years) NMOSD (LONMOSD).

MATERIALS AND METHODS

We enrolled 142 patients with NMOSD from Tianjin Medical University General Hospital, Tianjin, China, and categorized them into two groups according to the age of onset: EONMOSD and LONMOSD. Demographic, clinical, laboratory, and MRI characteristics were collected and compared between the two groups. Serum aquaporin-4 (AQP4) antibody levels were determined by cell-based assay and fluorescence immunoprecipitation assays.

RESULTS

Among the patients studied, 83 had early onset (≤50 years) and 59 had late onset (>50 years) of NMOSD. As compared with LONMOSD, EONMOSD patients had more severe visual disability according to functional scores in clinical parameters, significantly lower C3 and C4 serum levels, more frequent cervical lesions, and more lesions around the fourth ventricle, but fewer lesions in hemispheric white matter. LONMOSD patients suffered more motor and sensory disability than EONMOSD patients.

CONCLUSIONS

In NMOSD, the clinical, laboratory, and MRI features differ according to age of onset, suggesting that differences in pathogenesis and treatment should be further investigated.

Clinical manifestations of neuromyelitis optica in male and female patients

Neuromyelitis optica (NMO) is a severe, idiopathic, immuno-mediated, inflammatory demyelinating disease of the central nervous system. We examined the clinical features between male and female NMO patients, for which not much data exist. One hundred and eight Chinese Han patients with NMO were analysed retrospectively, all had been detected for the aquaporin-4 (AQP4) antibody using a cell-based assay. Of 108 NMO patients, 92 were female and 16 were male (female/male = 5.75). Ninety-four (87%) were positive for the AQP4 antibody in their serum and/or cerebral spinal fluid. Aquaporin-4 antibody-positive NMO patients had a higher female/male ratio than the negative group (P = 0.001). Female NMO patients had a higher positive rate of the AQP4 antibody than male NMO patients (92.4 vs 56.3%, P = 0.001). All NMO male patients were divided according to their AQP4 antibody status. 77.8% (7/9) of patients in the seropositive group had initial optic neuritis, while only one patient (14.3%, 1/7) in the negative group had optic neuritis (P = 0.041). Limb paraesthesia was reported in only one patient in the negative group (11.1%), but it was reported in all patients in the positive group (100%) (P = 0.001). The mean length of vertebral segments of the spinal cord lesions was 3.6 ± 1.3 in the positive group, while it was 6.6 ± 2.6 in the negative group (P < 0.0001). The involvement of the cervical spinal cord was found in 88.9% (8/9) of the positive members, but only 11.1% in the negative group (P = 0.009). However, the involvement of the thoracic spinal cord was found in 22.2% of patients in the positive group and 85.7% of patients in the negative members (P = 0.041). In conclusion, male NMO is rare and has a low positive rate of AQP4 antibody.

The frequency of anti-aquaporin-4 Ig g antibody in neuromyelitis optica and its spectrum disorders at a single tertiary referral center in malaysia

Background. In the past the occurrence of neuromyelitis optica in Malaysia was thought to be uncommon and the frequency of anti-aquaporin-4 Ig G antibody was unknown. Objective. To evaluate the frequency of anti-aquaporin-4 Ig G antibody (Anti-AQP4 antibody) amongst patients with neuromyelitis optica (NMO) and its spectrum disorders (NMOSD) and the differences between the seropositive and seronegative groups. Methods. Retrospectively, 96 patients with NMO/high risk syndromes for NMOSD (HRS-NMOSD) were identified out of 266 patients with idiopathic inflammatory demyelinating disease from a single center hospital based registry. Anti-AQP4 seropositivity was found in 38/48 (79.2%) with NMO, 12/21 (57.1%) with brain involvement at high risk for NMOSD, 12/15 (80%) with transverse myelitis (i.e., 11/15 with relapsing transverse myelitis and one with monophasic transverse myelitis), and 3/7 (42.8%) with relapsing optic neuritis. Sixty-five out of 96 patients, that is, 67.7%, with NMO/HRS for NMOSD were seropositive. Seropositivity was significantly associated with female gender, a higher number of mean relapses, that is, 5.15 ± 4.42 versus 2.10 ± 1.68, longer length of spinal cord lesions, that is, 6.6 ± 4.9 versus 2.9 ± 2.5, vertebral bodies, higher EDSS, 4.5 ± 2.4 versus 2.4 ± 2.6, presence of paroxysmal tonic spasms, and blindness (unilateral/bilateral); P < 0.001. Longitudinally extensive cord lesions (contiguous or linear), presence of lesions in the cervical and thoracic regions, and involvement of the central gray matter or holocord regions on axial scans, were also significantly associated with seropositivity; P < 0.001. Conclusion. NMO and HRS for NMOSD are present in larger numbers than previously thought in Malaysia. More than 2/3rds are seropositive. Seropositive and seronegative NMO/NMOSD have differences that are useful in clinical practice.