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.

Diagnosis and classification of optic neuritis.

There is no consensus regarding the classification of optic neuritis, and precise diagnostic criteria are not available. This reality means that the diagnosis of disorders that have optic neuritis as the first manifestation can be challenging. Accurate diagnosis of optic neuritis at presentation can facilitate the timely treatment of individuals with multiple sclerosis, neuromyelitis optica spectrum disorder, or myelin oligodendrocyte glycoprotein antibody-associated disease. Epidemiological data show that, cumulatively, optic neuritis is most frequently caused by many conditions other than multiple sclerosis. Worldwide, the cause and management of optic neuritis varies with geographical location, treatment availability, and ethnic background. We have developed diagnostic criteria for optic neuritis and a classification of optic neuritis subgroups. Our diagnostic criteria are based on clinical features that permit a diagnosis of possible optic neuritis; further paraclinical tests, utilising brain, orbital, and retinal imaging, together with antibody and other protein biomarker data, can lead to a diagnosis of definite optic neuritis. Paraclinical tests can also be applied retrospectively on stored samples and historical brain or retinal scans, which will be useful for future validation studies. Our criteria have the potential to reduce the risk of misdiagnosis, provide information on optic neuritis disease course that can guide future treatment trial design, and enable physicians to judge the likelihood of a need for long-term pharmacological management, which might differ according to optic neuritis subgroups.

Multiple sclerosis in Kenya: Demographic and clinical characteristics of a registry cohort.

BACKGROUND: Multiple Sclerosis (MS) is the leading cause of non-traumatic neurological disability in young adults. There is limited literature regarding the burden of MS in sub-Saharan Africa (SSA). OBJECTIVE: To describe the demographic and clinical characteristics of patients with MS (PwMS) presenting to a tertiary referral hospital in Nairobi. METHODS: We conducted a retrospective descriptive study for PwMS presenting to Aga Khan University Hospital, Nairobi from 2008-2018. RESULTS: 99 cases met the diagnostic criteria for MS with a male to female ratio of 1:4. Majority (68.7%) of PwMS were indigenous Africans with a mean age of onset of 30.7 years. Mean duration from symptom onset to first neuro-imaging was 5.04 years. Only 33% of patients had sensory symptoms at onset whereas 54.5% had vitamin D deficiency/insufficiency. Majority (79.5%) had relapsing remitting MS (RRMS) and 56.6% were initiated on disease modifying therapy (DMT). Only 21.2% of patients on DMT were non-compliant. Patients with RRMS were more likely to be initiated on DMT at our hospital (p < 0.001). CONCLUSION: Clinical characteristics of these patients largely resemble those of other SSA cohorts and African American patients. There was a delay between symptom onset and neuroimaging. There were also issues with DMT compliance.

"Old people problems", uncertainty and legitimacy: Challenges with diagnosing Parkinson's disease in Kenya.

Very little is known about the experience of people living with Parkinson's disease (PD) in low- and middle-income countries, such as those in sub-Saharan Africa. The number of specialists in the region is low and awareness is limited among the population and healthcare professionals. Drawing on ten months of ethnographic fieldwork in urban and rural Kenya with 55 people living with PD (PwP), 23 family members and 22 healthcare professionals from public and private clinics, we set out to understand the experience of diagnosis among PwP in Kenya. The diagnostic journeys of our study participants were typically long, convoluted and confusing. Lack of relevant information, combined with comorbidities and expectations about 'normal' ageing, often conspired to delay interactions with health services for many. There often followed an extended period of diagnostic uncertainty, misdiagnosis and even 'undiagnosis', where a diagnostic decision was reversed. Following diagnosis, patients continued to lack information about their condition and prognosis, making it difficult for friends, family members and others to understand what was happening to them. We suggest that awareness of PD and its symptoms needs to improve among the general population and healthcare professionals. However, diagnosis is only the first step, and needs to be accompanied by better access to information, affordable treatment and support.

Cases of neuromyelitis optica spectrum disorder from the East Africa region, highlighting challenges in diagnostics and healthcare access.

BACKGROUND: Neuromyelitis optica spectrum disorder (NMOSD) is an auto-immune disease of the central nervous system (CNS) associated with the IgG-antibody against aquaporin-4 (AQP4-IgG). There is little published epidemiology of NMOSD from sub-Saharan Africa (SSA). METHODS: We retrospectively collated NMOSD cases admitted to our tertiary regional neurology centre. RESULTS: We identified 11 cases (10 female, average age 30 years). 64% (7/11) were seropositive for AQP4-IgG, measured using indirect immunofluorescence. The remaining cases could either not afford tests, or had pathognomonic radiological features. 57% (4/7) of seropositive cases had concurrent/recent CNS infection. All patients were treated with high-dose intravenous methylprednisolone (IVMP), and 36% (4/11) also had plasma exchange. Only 55% (6/11) of the patients were seen by a neurologist at presentation: they had less relapses (1.3 vs 2.4), less diagnostic delay (2.3 vs 7.4 months), and were less disabled at the end of our review period. 10 cases were immunosuppressed long-term: 60% on mycophenolate, 30% azathioprine, and one on rituximab. CONCLUSION: Our study is the largest case series of NMOSD from the East Africa region. Patients faced challenges of access to appropriate and affordable testing, and timely availability of a neurologist at onset, which had impacts on their functional outcomes. The majority of the seropositive cases had recent/concurrent CNS infections, suggesting triggered auto-immunity.

The Accessibility of Parkinson's Disease Medication in Kenya: Results of a National Survey.

BACKGROUND: There is a dearth of knowledge about the availability and affordability of the different drug treatments for Parkinson's disease (PD) across sub-Saharan Africa (SSA). We aimed to determine the availability and affordability of drugs for treating PD in Kenya. METHODS: A facility-based survey was conducted in selected medicine outlets (pharmacies) in what were formerly the headquarter towns of the eight provinces of Kenya. We used the World Health Organization/Health Action International methodology to obtain data for drugs used to treat PD. Unit price for each drug was obtained. RESULTS: Forty-eight outlets were visited in total, six in each of Kenya's eight provinces. Levodopa (L-dopa) was available in only 24 (50.0%) outlets. Only one public pharmacy sold l-dopa (14 were private and nine were other types of outlet). Ergot-derived dopamine agonists (DAs) and anticholinergics were available in 37 and 35 outlets, respectively. Monoamine-oxidase inhibitors, non-ergot-derived DAs, and catechol-O-methyl transferase inhibitors were available in four, two and zero outlets, respectively. Mean cost of 100 l-dopa tablets was $48.2, though costs varied widely (range, $28.2-$82.4). Only five outlets considered l-dopa affordable, all of which sold 100 tablets for less than $31. CONCLUSION: There is a lack of availability of PD drugs in Kenya, particularly in public pharmacies, where costs are generally lower. Few pharmacists consider the drugs available to be affordable. If PD is to be effectively managed in Kenya, then strategies are needed to increase the availability and affordability of medication.

Patients with adult-onset dystonic tremor resembling parkinsonian tremor have scans without evidence of dopaminergic deficit (SWEDDs).

We present the clinical details and dopamine transporter SPECT scan results of 10 patients with arm tremor, including a rest component and reduced arm swing on the affected side, in whom the possibility of PD had been raised. All patients had signs of dystonia or components of their arm tremor that were compatible with dystonic tremor, and none had true akinesia with fatiguing or decrement, even after a mean follow-up period of 5.8 years. All patients had normal dopamine transporter SPECT scans. Clinicians should be aware that primary adult-onset dystonia can present with an asymmetric resting arm tremor, with impaired arm swing and sometimes also facial hypomimia or a jaw tremor, but without evidence of true akinesia. Given the important consequences of misdiagnosing such patients as PD, in cases with diagnostic uncertainty functional imaging should be considered. Among patients suspected of PD, dystonic tremor may be one cause of SWEDDs (Scans Without Evidence of Dopaminergic Deficit).

Progression of multiple system atrophy (MSA): a prospective natural history study by the European MSA Study Group (EMSA SG).

The disease-specific Unified Multiple System Atrophy Rating Scale (UMSARS) has been developed recently and validated for assessing disease severity in multiple system atrophy (MSA). Here, we aimed at (1) assessing rates of disease progression in MSA and (2) validating UMSARS for sensitivity to change over time. Impairment was assessed at two time points 12 months apart using UMSARS Part I (historical review), UMSARS Part II (motor examination), as well as measures of global disease severity, including UMSARS Part IV, Hoehn and Yahr (HY) Parkinson's disease staging, Schwab England Activities of Daily Living (SE ADL), and a three-point global Severity Scale (SS3). Fifty patients (male:female ratio, 1:0.9; possible MSA, 16%; probable MSA, 84%; MSA-parkinsonian, 58%; MSA-cerebellar, 42%) were assessed twice with an interval of 12.3 months. UMSARS II scores progressed by 57.3% (P<0.0001) and UMSARS I scores by 35.6% (P<0.0001) in relation to the respective baseline scores with no differences between motor subtypes, diagnostic categories and gender. Significant inverse correlations between (1) UMSARS I or UMSARS II progression and (2) baseline disability measures (i.e., the respective UMSARS or SS3 scores) and disease duration were found. Furthermore, the increases in HY staging, SE ADL and SS3 correlated significantly with UMSARS I, UMSARS II, and UMSARS IV progression. This report is the first prospective study showing rapid annual UMSARS rates of decline in MSA. Our data contribute to the ongoing validation process of UMSARS, and they facilitate the planning and implementation of future neuroprotective intervention trials.