How long does it take to diagnose patients with neuromyelitis optica (NMO) using the 2006 diagnostic criteria?

Worldwide prevalence of neuromyelitis optica spectrum disorder (NMOSD) and neuromyelitis optica (NMO): a systematic review and meta-analysis

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is a progressive demyelinating disease of the central nervous system that has overlapping symptoms with multiple sclerosis (MS) but differs from it in a variety of ways. Previous studies have reported conflicting results trying to estimate the number of individuals affected by them which is why we designed this systematic review and meta-analysis to estimate the worldwide prevalence and incidence of NMOSD/NMO based on current evidence.

METHODS

We searched PubMed, Scopus, EMBASE, Web of Science, and gray literature including references from the identified studies, review studies, and conference abstracts which were published up to February 1, 2022. We used all MeSH terms pertaining to "NMOSD," "NMO," and all the terms on "prevalence," "incidence," and "epidemiology" to identify the search components. Pooled effect sizes were measured using random-effect model by DerSimonian-Laird.

RESULTS

The prevalence and incidence rates of NMOSD/NMO ranged from 0.07 to 10 and 0.029 to 0.880 per 100,000 population, respectively. The overall pooled prevalence of NMO per 100,000 population was 1.54 (I²: 98.4%, 95% CI: 1.13-1.96, P< 0.001) based on the 2006 criteria, 1.51 (I²: 99.4%, 95% CI: 1.21-1.81, P < 0.001) based on the 2015 criteria and 2.16 (I²: 89.4%, 95% CI: 1.46-2.86, P < 0.001) based on the 2006/2015 criteria. The overall annual incidence of NMO per 100,000 population was 0.155 (I²: 95%, 95% CI: 0.115-0.195, P < 0.001) based on the 2006 criteria and 0.278 (I²: 100%, 95% CI: 0.135-0.420, P < 0.001) based on the 2015 criteria. The prevalence rates were highest in French West Indies and South Korea, and lowest in Cuba and Australia, based on the 2006 and 2015 criteria, respectively. Also, the highest annual incidence rates were obtained for Sweden and Slovak republic and the lowest for Cuba and Australia based on the 2006 and 2015 criteria, respectively. All estimated rates were higher among females compared to males.

CONCLUSION

Although rare, NMOSD/NMO impact affected individuals in devastating ways. Several large-scale prospective studies are required to reach a comprehension of the epidemiological aspects of these notorious demyelinating conditions.

The current situation of diagnosis and treatment of neuromyelitis optica spectrum disorder: Experience with 461 cases from a single centre in South China

In this study, we included 461 NMOSD patients at our hospital from January 2016 to June 2019 and got some results. Eight (1.9%) originally AQP4-IgG-seronegative patients were retested as seropositive. 221 patients (47.9%) did not receive immunosuppressive treatment within 3 month. The adult/child distribution was significantly different (p = 0.001). Thirty-three patients (7.2%) had relapses after drug withdrawal, and fifteen of them had used drugs ≥3 years. The conclusion is that decision to treat with immunosuppression was made less often in children than in adults. Patients who took medication for a long time still need to be cautious of stopping using immunosuppression.

The 2015 IPND Criteria Increases the Yield in Diagnosis of Neuromyelitis Optica Spectrum Disorder in Thai Patients Compared to the 2006 Diagnostic Criteria

BACKGROUND

The 2015 International Panel for Neuromyelitis Optica (NMO) Diagnosis (IPND) criteria was revised using systematic literature reviews and consensus from the experts. It facilitates NMOSD diagnosis and is applicable in an Asian population.

OBJECTIVE

To compare the utility of the 2015 IPND criteria and the 2006 NMO diagnostic criteria for the diagnosis of NMO/SD.

METHODS

We retrospectively reviewed the electronic medical records 5 of patients with NMOSD who attended Multiple Sclerosis and Related Disorders Clinic between January 2010 and December 2016. Two independent investigators applied the 2006 revised diagnostic criteria for NMO in patients who fulfilled the 2015 IPND criteria.

RESULTS

Of all 70 cases who had an NMOSD diagnosis according to 2015 criteria, 56 cases (80.0%) were positive for aquaporin-4 immunoglobulin (AQP4-IgG). Nineteen patients (27.1%) fulfilled the 2006 NMO diagnostic criteria. The 2015 IPND criteria identified 51 more NMOSD cases, increasing the diagnostic yield by 268%, compared to the 2006 criteria. The median time from onset to diagnosis by using the 2015 IPND criteria was shorter than those identified by the 2006 criteria (128 vs. 547 days, p=0.002). The 2015 IPND also provides for lesser attacks occurring before achieving diagnosis (1.7 vs. 2.7, p<0.001). In the absence of known AQP4-IgG serostatus, the 2015 criteria still indicated NMOSD patients by a 124% increase in detection rate (p<0.001); however, time to diagnosis was not statistically significant between the two criteria (258 vs. 604 days, p=0.081).

CONCLUSIONS

Compared to the 2006 criteria, the 2015 IPND criteria increased diagnostic yield for NMOSD regardless of AQP4-IgG status and shortened the time from onset to diagnosis in patients with NMOSD with known AQP4-IgG serostatus.

Clinical characteristics and long-term visual outcome of optic neuritis in neuromyelitis optica spectrum disorder: A comparison between Thai and American-Caucasian cohorts

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) occurs more commonly in Asian than Caucasian populations. Few studies have examined the clinical features and visual outcome of optic neuritis (ON) within NMOSD in different racial populations. The objective of this study was to compare the clinical characteristics and long-term visual outcome of a Thai and an American-Caucasian cohort with NMOSD-related ON.

METHODS

Medical records including brain and orbital magnetic resonance imaging (MRI) of 16 consecutive subjects who developed visual loss due to ON as part of NMOSD evaluated at a single American tertiary referral center between 2006 and 2015 were reviewed and compared to those of 16 consecutive similar subjects evaluated at a single Thai tertiary referral center between 2010 and 2016. These cohorts represented the total number of NMOSD-related ON subjects seen during that time at those institutions. Statistical analyses were used for continuous and categorical data sets, and multiple regression analysis was used to adjust for differences in duration of follow-up and number of episodes of ON in each affected eye.

RESULTS

All subjects within the Thai cohort were Asian, while the American cohort initially consisted of 14 Caucasian, 1 Asian and 1 African-American subject, but the latter two were excluded from analysis. In the Thai cohort, ON occurred in 21 eyes, with a total of 19 episodes, while in the American-Caucasian cohort ON occurred in 22 eyes, with a total of 21 episodes. Aquaporin 4 (AQP4)-antibody was positive in all subjects except for one American-Caucasian subject. The mean follow-up time was 17.8 (± 16.0) and 52.8 (± 51.9) months for the Thai and American-Caucasian populations, respectively. There was no difference between the two cohorts with respect to gender, age of NMOSD and NMOSD-related ON onset, initial clinical presentation of NMOSD, initial visual acuity and automated visual fields, prevalence of swollen optic disc in the acute phase, presence of pain on the affected side, mean time of onset of ON symptoms to MRI examination, distribution of segmental involvement of the anterior visual pathway abnormalities based on MRI findings, mean time of onset of ON symptoms to treatment, final visual acuity and automated visual fields. However, a higher proportion of Thai affected eyes were found to have an initial visual acuity of 20/200 or worse compared with the American-Caucasian cohort. Azathioprine was the most common maintenance treatment (75%) used among Thai subjects in contrast to rituximab (78.6%) among American-Caucasian subjects.

CONCLUSION

Despite the different prevalence among Thai and American-Caucasian populations, the clinical characteristics of ON in the NMOSD were very similar across these two populations, other than for more severe visual loss initially among Thai subjects. Notably, long-term visual outcome did not differ between these cohorts despite significant difference in the maintenance treatment regimen. This study did not assess neurological status or outcome.