An exploration of the genetics of the mutant Huntingtin (mHtt) gene in a cohort of patients with chorea from different ethnic groups in sub-Saharan Africa.

BACKGROUND: Africans are underrepresented in Huntington's disease (HD) research. A European ancestor was postulated to have introduced the mutant Huntingtin (mHtt) gene to the continent; however, recent work has shown the existence of a unique Htt haplotype in South-Africa specific to indigenous Africans. OBJECTIVE: We aimed to investigate the CAG trinucleotide repeats expansion in the Htt gene in a geographically diverse cohort of patients with chorea and unaffected controls from sub-Saharan Africa. METHODS: We evaluated 99 participants: 43 patients with chorea, 21 asymptomatic first-degree relatives of subjects with chorea, and 35 healthy controls for the presence of the mHtt. Participants were recruited from 5 African countries. Additional data were collected from patients positive for the mHtt gene; these included demographics, the presence of psychiatric and (or) cognitive symptoms, family history, spoken languages, and ethnic origin. Additionally, their pedigrees were examined to estimate the number of people at risk of developing HD and to trace back the earliest account of the disease in each region. RESULTS: HD cases were identified in all countries. Overall, 53.4% of patients with chorea were carriers for the mHTT; median tract size was 45 CAG repeats. Of the asymptomatic relatives, 28.6% (6/21) were carriers for the mHTT; median tract size was 40 CAG. No homozygous carries were identified. Median CAG tract size in controls was 17 CAG repeats. Men and women were equally affected by HD. All patients with HD-bar three who were juvenile onset of <21 years-were defined as adult onset (median age of onset was 40 years). HD transmission followed an autosomal dominant pattern in 84.2% (16/19) of HD families. In familial cases, maternal transmission was higher 52.6% (10/19) than paternal transmission 36.8% (7/19). The number of asymptomatic individuals at risk of developing HD was estimated at ten times more than the symptomatic patients. HD could be traced back to the early 1900s in most African sites. HD cases spread over seven ethnic groups belonging to two distinct linguistic lineages separated from each other approximately 54-16 kya ago: Nilo-Sahara and Niger-Congo. CONCLUSION: This is the first study examining HD in multiple sites in sub-Saharan Africa. We demonstrated that HD is found in multiple ethnic groups residing in five sub-Saharan African countries including the first genetically confirmed HD cases from Guinea and Kenya. The prevalence of HD in the African continent, its associated socio-economic impact, and genetic origins need further exploration and reappraisal.

Surveillance of Viral Encephalitis in the Context of COVID-19: A One-Year Observational Study among Hospitalized Patients in Dakar, Senegal.

The burden of encephalitis and its associated viral etiology is poorly described in Africa. Moreover, neurological manifestations of COVID-19 are increasingly reported in many countries, but less so in Africa. Our prospective study aimed to characterize the main viral etiologies of patients hospitalized for encephalitis in two hospitals in Dakar. From January to December 2021, all adult patients that met the inclusion criteria for clinical infectious encephalitis were enrolled. Cerebrospinal fluids, blood, and nasopharyngeal swabs were taken and tested for 27 viruses. During the study period, 122 patients were enrolled. Viral etiology was confirmed or probable in 27 patients (22.1%), with SARS-CoV-2 (n = 8), HSV-1 (n = 7), HHV-7 (n = 5), and EBV (n = 4) being the most detected viruses. Age groups 40-49 was more likely to be positive for at least one virus with an odds ratio of 7.7. The mortality was high among infected patients, with 11 (41%) deaths notified during hospitalization. Interestingly, SARS-CoV-2 was the most prevalent virus in hospitalized patients presenting with encephalitis. Our results reveal the crucial need to establish a country-wide surveillance of encephalitis in Senegal to estimate the burden of this disease in our population and implement strategies to improve care and reduce mortality.

Spectrum of movement disorders: Experience of a one and half year of existence of the first specialized center in Senegal.

BACKGROUND: Movement disorders have different prevalence in different regions and they are little studied in Africa. OBJECTIVES: Evaluate the prevalence and determine the spectrum of movement disorders in the first specialized center in Senegal. METHODS: It was a prospective study over on 18 months in adult outpatient clinic. Demographic, clinical, paraclinical data, including genetic test in collaboration with the Queen Square Institute of Neurology at UCL were collected. RESULTS: One hundred and thirty four patients were followed up, representing a prevalence of 4.7%. Men represented 56% for a sex ratio of 1.3. The mean age of population was 47.7 ± 18 years with limits ranging from 16 to 81 years. Eighty-one patients (60.4%) had hyperkinetic and 53 patients (39.6%) had hypokinetic movements. Twenty-nine patients (21.6%) had tremors and 18 (13.4%) had dystonic movements. Ataxia and choreic movements were respectively in 11 (8.2%) and 10 patients (7.5%). Twenty-four patients (17.9%) were from a first-degree consanguineous. A genetic test on saliva samples was done in 16 patients (11.9%) and confirmed Huntington's disease in 8 patients of 6 families. Parkinson disease was the most frequent etiology (32.8%) followed by essential tremor (12.7%) and psychogenic tremor in 7.5%. Stroke accounted for 6% of the causes of MD (tremor, ballism, dystonia, ataxia and parkinsonism) and no etiology was found in 9%. CONCLUSION: The spectrum of movement disorders is very heterogeneous with a non-negligible frequency and diverse etiologies in neurological practice in Senegal.

Neuromyelitis optica spectrum disorders (NMO-SD) in a Sub-Saharan Africa country: A preliminary study of sixteen Senegalese cases.

BACKGROUND: Neuromyelitis optica (NMO) is an autoimmune disease of the central nervous system. In Sub-Saharan Africa, publications are rare and deal with isolated cases. Our goal was to analyze the characteristics of NMO spectrum disorders in a Senegalese cohort compiled in Dakar. PATIENTS AND METHOD: This was a retrospective descriptive study conducted at the Neurology Department of Fann Teaching Hospital. We included all patients with NMO-SD according to the 2014 diagnostic criteria. RESULTS: Sixteen patients were enrolled, 4 men and 12 women with an average age of 30 years. Ten patients (62.5%) presented an acute myelopathy associated with retrobulbar optic neuritis and 5 (31.25%) had isolated spinal cord injury. Spinal MRI showed abnormal cervical (6 patients), dorsal (4 patients), bulbar-cervical (3 patients) or cervico-dorsal (2 patients) signal extended (≥3 vertebral segments) of the spinal cord. Visual evoked potentials (VEP) showed demyelinating optic nerve involvement in 8 patients. Ten patients were positive to AQP-4 IgG. Systemic corticosteroid therapy was the rule in all patients, associated with azathioprine in 10 of them. The clinical course at 3 months was predominantly favourable (10 patients). CONCLUSION: This cohort is the first one compiled in Dakar. African multicentric epidemiological studies are needed.

[Epidemiological and socio-economic support patients living with epilepsy in Dakar, Senegal]. / Profil épidémiologique et prise en charge socioéconomique des patients vivant avec l'épilepsie à Dakar, Senegal.

BACKGROUND: Epilepsy remains a major public health problem especially in developing countries where access to new therapies remains limited. OBJECTIVE: The aim of this work was to study the socio-demographic profile of patients living with epilepsy in Dakar and supported. METHODS: We conducted a cross-sectional study over a period of eight months from November 2009 to June 2010 at Fann University Hospital and Health Center Pikine through research on adherence. RESULTS: The study involved patients living with epilepsy aged over 15 years, diagnosed clinically with epilepsy and/or confirmed by an electroencephalogram and put under antiepileptic drug for more than 3 months. We recruited 411 patients aged 15-74 years with a mean age of 28.93 years. The age range was 15-24 years with 44.6 % majority. The male sex predominated with 52.3 % and the sex ratio was 1.09. Singles outnumbered with 64.7 %. The level of education was the most representative secondary with 29.4 % and patients without profession were 35.5 %. Most of the patients was from semi-urban areas with 47.7 %. Generalized seizures were more frequent with about 70 %. Most of the patients was supported either by their family or by themselves. CONCLUSION: The management should be multisectoral for epilepsy out of darkness.