Dominique Mortel1, Sarah Braun2, Lorraine Chishimba2, Mashina Chomba2, Frighton Mutete2, Naluca Mwendaweli2, Coolwe Namangala2, Stanley Zimba2, Deanna Saylor3
1Clinical Neurophysiology, Brown University Neurology Department, 2University Teaching Hospital, 3Johns Hopkins Hospital
Objective:
Describe demographic and clinical characteristics of Zambian adults with MS and neuromyelitis optica (NMO).
Background:
MS and other demyelinating diseases are reportedly rare in sub-Saharan Africa and remain understudied.
Design/Methods:
Adults diagnosed with either MS, NMO, NMO spectrum disorder (NMOSD), or clinically isolated syndrome (CIS) at the only neurology outpatient clinic in Zambia were eligible to participate from October 2019 to February 2022. An MS-trained nurse administered structured questionnaires regarding sociodemographic characteristics, and each participant also underwent a comprehensive neurological history and examination by a neurologist. Finally, plasma 25-hydroxyvitamin D levels were obtained. For analysis, the cohort was dichotimized into a MS/CIS disease group and NMO/NMOSD disease group. Descriptive statistics of the cohort are presented and compared between both groups.
Results:
Amongst the 34 participants, mean age was 36 + 9 years, 65% (n=22) were female, 90% were Black-African, 10% were of Southeast Asian decent, 50% had MS/CIS, and 50% had NMO/NMOSD. The average age was 34 + 11 years in the MS/CIS group and 37 + 7 years in the NMO/NMOSD group (p=0.28). Females constituted 65% (n=11) of both disease groups. Median time to diagnosis was 242 days (interquartile range IQR: 91-974) and did not differ significantly between the groups. The majority (82%) of the NMO/NMOSD group presented with bilateral optic neuritis. Among the MS/CIS group, median EDSS was 4 (IQR: 2.25-4.25), median Disease Steps were 2 (IQR: 1-2), and 59% (n=10) had an abnormal gait at enrollment. Median 25-hydroxyvitamin D level was 29 (IQR: 24-46) ng/mL in the overall cohort but did not differ by disease group or supplementation status.
Conclusions:
In this sub-Saharan African cohort of adults with demyelinating diseases, MS and NMO were equally prevalent. Delays in diagnosis resulted in high levels of disability in both groups.