La neuromyélite optique au Maroc

Neuromyelitis Optica Spectrum Disorders in Africa: A Systematic Review

BACKGROUND AND OBJECTIVES

Neuromyelitis optica (NMO) is a CNS inflammatory disease that predominantly affects the optic nerves and the spinal cord. It is more frequent in Asian and African populations than in European ones. Data on epidemiology, clinical presentation, additional investigations, and treatment in the African continent are scarce. We aim to (1) collect and analyze published data on neuromyelitis optica spectrum disorder (NMOSD), (2) indicate challenges in the diagnosis and management, and (3) discuss opportunities for future research, education, and policy making, specifically on the African continent.

METHODS

A systematic review was performed in January 2021 with the search terms "Neuromyelitis optica and Africa," "Devic Disease and Africa," and "NMOSD and Africa." We included all study types except case reports, correspondence, or conference abstracts on NMO or NMOSD. Extracted data included study design, country, study period, demographic and clinical characteristics, results of paraclinical investigations, and outcome. Data analysis was performed with descriptive statistics.

RESULTS

We retrieved a total of 79 records, of which 19 were included. Ten of 54 African countries reported a total of 410 cases. Almost half of them were from North African countries. The mean age at diagnosis was 33 years (range 7-88 years), and 75% were female. Transverse myelitis followed by optic neuritis were the most frequent symptoms at the time of presentation. One hundred nineteen patients experienced at least 1 previous relapse, and 106 had a relapsing course after diagnosis. Relapses were treated with IV methylprednisolone. Azathioprine and steroids were used most often as maintenance treatments. Outcomes were rarely described.

DISCUSSION

The majority of studies on NMOSD from the African continent are retrospective, and most countries do not report any data. Our systemic review shows that data derived from patients living in Africa correspond well to what has been previously published in meta-analyses on patients of African ancestry with NMOSD who live outside of Africa, except for a younger age at onset and a lower proportion of females. We advocate for systematic data collection to adequately capture and monitor the burden of NMOSD, for expansion of research efforts and facilities to perform fundamental and clinical research, and for improved access to health care including diagnostics, treatments, and rehabilitation services for people affected by NMOSD in the African continent.

Neuromyelitis optica spectrum disorder in Africa: What is the current state of knowledge?

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is a chronic autoimmune inflammatory disease of the central nervous system, usually involving the optic nerve, brain, and spinal cord. While the disease is believed to be more common among individuals of African descent, the disease landscape across the continent has not been systematically explored. In this study, we carried out a systematic scoping review by synthesizing original studies on NMOSD from Africa.

METHODS

A comprehensive literature search of PubMed (MEDLINE), Scopus, Embase, and Web of Science databases with the search terms 'neuromyelitis optica' and 'Africa' was performed on June 17, 2020. Synthesis of the result was done using narrative analysis.

RESULT

Of the total 133 identified records, 14 eligible studies from Africa were included. Most of the studies were from North African countries (n = 8; 57%); predominantly retrospective descriptive (n = 8; 57%), or case series (n = 3; 21%); and published within the last two decades (n = 13; 93%). The total number of cases in the studies is 332, with a reported female to male ratio of 4:1 and an age range of 12-88 years at disease onset (average of <40 years in 50% of reports). Aquaporin-4 antibodies was tested in 214 cases and found in 61.7%. Three cases had Myelin Oligodendrocyte Glycoprotein antibody test with one of the cases testing positive and was associated with severe optic neuritis. Autoimmune disorders were reported in 23 out of 93 cases from three studies, while a few studies reported infectious disease associations. IV methylprednisolone was the rule during acute attacks from all the studies, while the choice of medication for maintenance varies, possibly depending on availability and cost.

CONCLUSION

The research landscape on NMOSD in Africa, though limited, provides significant insight into the epidemiology, etiology, and clinical characteristics of the disease. Gaps still exist in the knowledge of disease management. Further research focusing on the African context is needed to provide customized evidence-based care to patients with NMOSD.

An update on epidemiology, diagnosis & management of NMO-SD in the tertiary neurology department of Marrakech (Morocco)

INTRODUCTION

Neuromyelitis optica (NMO) and NMO spectrum disorders (NMO-SD) are inflammatory demyelinating diseases of the central nervous system. There are few epidemiological studies devoted to NMO, especially in Africa and the Middle East, but individual cases and series have been reported from many countries across the African continent.

OBJECTIVES

To describe the epidemiology, diagnosis, and management of NMO patients followed at the Mohammed VI University Hospital of Marrakech.

PATIENTS AND METHODS

This was a hospital-based retrospective study of 52 patients with NMO diagnosed and followed at the Neurology department of the University Hospital of Marrakech from 2004 to July 2019. The 2006 diagnostic criteria of NMOSD were used for patients admitted before 2015 for inflammatory disease of the central nervous system and the 2015 diagnostic criteria of NMO-SD for all patients thereafter. Collected data were analysed using SPSS software.

RESULTS

The study concerned 52 patients, 18 males and 34 females. Median age at disease onset was 32.5 years (range 7-55). Mean time between symptom onset and diagnosis of NMO was nine months 18 days (range 7 days to 4 years). In most patients, manifestations included visual acuity, tetraparesis, and sensorial disorders. Refractory vomiting and hiccup were noted in the first attack in 19% of patients. Two patients had hypersomnia and polyphagia, and one had been treated for depression ten months before the development of severe tetraplegia. Magnetic resonance imaging did not show any brain lesions in 29% of patients. Cervical myelitis extending to more than three vertebrae was found in 60% of patients. AQP4-antibody assay was performed only in 57.7% of patients, and was positive in 38.4%; anti-MOG was positive in four anti-AQP4 seronegative patients. Management strategies for NMO-SD included methylprednisolone pulses (70% of patients), plasmapheresis (25%), and rituximab (since 2017) for 46%. Outcome was favourable in 40% of patients and has remained stable in 50% of them.

CONCLUSION

Anti-NMO assays, made available during the last five years with the help of The Guthy-Jackson Charitable Foundation, have led to a clear jump in the number of cases diagnosed. Major advances in the field of epidemiology, imaging, and pathophysiology of NMO-SD have led to improved patient care and outcome.

EFNS guidelines on diagnosis and management of neuromyelitis optica

BACKGROUND AND PURPOSE

Neuromyelitis optica (NMO) or Devic's disease is a rare inflammatory and demyelinating autoimmune disorder of the central nervous system (CNS) characterized by recurrent attacks of optic neuritis (ON) and longitudinally extensive transverse myelitis (LETM), which is distinct from multiple sclerosis (MS). The guidelines are designed to provide guidance for best clinical practice based on the current state of clinical and scientific knowledge.

SEARCH STRATEGY

Evidence for this guideline was collected by searches for original articles, case reports and meta-analyses in the MEDLINE and Cochrane databases. In addition, clinical practice guidelines of professional neurological and rheumatological organizations were studied.

RESULTS

Different diagnostic criteria for NMO diagnosis [Wingerchuk et al. Revised NMO criteria, 2006 and Miller et al. National Multiple Sclerosis Society (NMSS) task force criteria, 2008] and features potentially indicative of NMO facilitate the diagnosis. In addition, guidance for the work-up and diagnosis of spatially limited NMO spectrum disorders is provided by the task force. Due to lack of studies fulfilling requirement for the highest levels of evidence, the task force suggests concepts for treatment of acute exacerbations and attack prevention based on expert opinion.

CONCLUSIONS

Studies on diagnosis and management of NMO fulfilling requirements for the highest levels of evidence (class I-III rating) are limited, and diagnostic and therapeutic concepts based on expert opinion and consensus of the task force members were assembled for this guideline.

An epidemiological study of neuromyelitis optica in Cuba

INTRODUCTION

Two population-based studies of neuromyelitis optica (NMO) in non-white populations provided prevalence rates of 0.32 and 3.1 per 100,000 population.

OBJECTIVE

To estimate NMO prevalence in the multiethnic Cuban population by nation-wide case ascertainment.

METHODS

The study was conducted from October 1, 2003 to November 30, 2004. Ninety percent of general practitioners and all neurologists responded positively to the request for information on cases suspected of optic neuritis (ON), transverse myelitis (TM), multiple sclerosis, or NMO. Among the population of 11,177,743 there were 798 suspected cases, including 89 with possible NMO, relapsing ON (RON) and TM. Of the 89, 87 were examined by two of us (Cabrera JA, Lara R) who selected the NMO cases according to the 1999 Mayo Clinic criteria as well as those with relapsing TM and RON.

RESULTS

58 cases provided a prevalence rate of 0.52 per 100,000 (95% CI 0.39-0.67). The 7 males and 51 females gave rates of 0.13 (CI 0.05-0.26) and 0.91 (CI 0.68-1.20). The estimated average annual incidence rate was 0.053 per 100,000 (CI 0.040-0.068). Prevalence rates did not differ significantly among the three ethnic groups. Black NMO cases were significantly older, with more relapses and motor deficit, as well as more abnormalities in brainstem evoked potentials and in brain MRI (not meeting MS criteria). The predominant clinical form was relapsing over monophasic.

CONCLUSIONS

This Cuban multiethnic population had a prevalence of NMO of 0.52 per 100,000 and an estimated average annual incidence rate of 0.053 per 100,000 with no differences by ethnicity. Black patients were older, with more relapses and motor impairment.