A comparative study of South African and Portuguese amyotrophic lateral sclerosis cohorts

Abstract

Objective: Data on the epidemiological and clinical aspects of ALS originate from a few world regions, and very little is known about ALS in low and middle-income countries, in particular Sub-Saharan Africa. This brief report attempts to provide preliminary perspectives on the clinical features and management of ALS in Sub-Saharan Africa by comparing two cohorts from South Africa (SA) and Portugal.

Methods: The study was performed at ALS clinics at Tygerberg Hospital, Cape Town, South Africa, and Centro Hospitalar Universitário Lisboa-Norte, Portugal. We included all patients diagnosed over a four-year period, and collected demographic and clinical data at diagnosis, longitudinal data on disease progression and management over 12 months, and mortality rates at 12 and 24 months.

Results: SA patients were younger and had a higher rate of spinal-onset disease than their Portuguese counterparts. During the 12-month follow-up, NIV was introduced in half of Portuguese patients, but only a quarter of SA patients. Parenteral nutrition was introduced in less than 10% of patients in both groups. No SA patients used riluzole, while 100% of Portuguese patients did. Mortality rates were significantly higher in the SA cohort at both 12 months (35% vs 16%; p < .0001) and 24 months (63% vs 39%; p < .0001).

Conclusions: Although SA patients were younger and more likely to have spinal-onset disease, mortality was higher in this cohort. There was a significant difference in utilisation of NIV and riluzole between the two cohorts, both of which may influence survival.

Keywords: Amyotrophic lateral sclerosis; Disease progression; Epidemiology; Risk; Survival.