A Metabolomic Signature of Ischemic Stroke Showing Acute Oxidative and Energetic Stress.

Metabolomics is a powerful data-driven tool for in-depth biological phenotyping that could help identify the specific metabolic profile of cryptogenic strokes, for which no precise cause has been identified. We performed a targeted quantitative metabolomics study in West African patients who had recently suffered an ischemic stroke, which was either cryptogenic (n = 40) or had a clearly identified cause (n = 39), compared to a healthy control group (n = 40). Four hundred fifty-six metabolites were accurately measured. Multivariate analyses failed to reveal any metabolic profile discriminating between cryptogenic ischemic strokes and those with an identified cause but did show superimposable metabolic profiles in both groups, which were clearly distinct from those of healthy controls. The blood concentrations of 234 metabolites were significantly affected in stroke patients compared to controls after the Benjamini-Hochberg correction. Increased methionine sulfoxide and homocysteine concentrations, as well as an overall increase in saturation of fatty acids, were indicative of acute oxidative stress. This signature also showed alterations in energetic metabolism, cell membrane integrity, monocarbon metabolism, and neurotransmission, with reduced concentrations of several metabolites known to be neuroprotective. Overall, our results show that cryptogenic strokes are not pathophysiologically distinct from ischemic strokes of established origin, and that stroke leads to intense metabolic remodeling with marked oxidative and energetic stresses.

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.

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.