Amyotrophic Lateral Sclerosis in Southwestern and Eastern Finland

Abstract

Introduction: The incidence of Amyotrophic lateral sclerosis (ALS) worldwide is approximately 1-2.6/1,000,000 and prevalence 5-6/100,000. ALS has been suggested to be relatively common in Finland but epidemiological information on the subject is scarce and outdated. Material and methods: Patients with ALS diagnostic codes were identified from mandatory administrative registries in the provinces of Southwestern Finland (population circa 430,000) and North Karelia (population circa 170,000) together comprising 11.7 % of the total population of Finland. The diagnoses were verified, and data extracted by reviewing the patient records. Incidence period was 2010-2018, and the prevalence date December 31, 2018. Age-standardization was performed using European Standard Population 2013 (ESP2013) Results: Overall crude incidence of ALS was 4.2/100'000 person-years in Southwestern Finland (ESP2013: 4.0/100,000) and 5.6/100,000 person-years in North Karelia (ESP2013: 4.8/100,000), while crude prevalences were 11,9/100,000 (ESP2013: 10.5/100,000) and 10,9/100'000 (ESP2013: 9.3/100,000), respectively. Mean age at diagnosis was 65.5-71.6 years in women (higher in Southwestern Finland compared to North Karelia, p=0.003) and 64.7-67.3 years in men (no difference between provinces, p=0.39). The diagnosis had been made in 50 % before the age of 70 years in Southwestern Finland and before the age of 65 years in 51 % in North Karelia. Genetic testing had been conducted in 28 % of all patients with the most common findings being SOD1 and c9orf72. After the diagnosis, mean survival was 2.0-2.7 and median survival 1.3-1.4 years. Onset phenotype (p<0.001), age at diagnosis (p<0.001) and genotype (p=0.001) predicted survival. Riluzole had been used by 25 % of patients and tracheostomy and invasive ventilation (TIV) had been performed in <1 %. Conclusions: Both incidence and prevalence of ALS in Finland are among the highest in the world but with some notable differences between the eastern and southwestern parts of the country. Low median life expectancy may be related to the advanced age of patients and the high prevalence of c9orf72 repeat expansion in Finland as well infrequent use of TIV and Riluzole.

Increased incidence of motor neuron disease in Sweden: a population-based study during 2002–2021

“…The incidence of ALS also varies greatly within Europe. Research from the last two decades has indicated an incidence rate of up to 4 to 6 per 100,000 person-years in some regions within the Nordic countries, England, and Italy, [ 7 – 11 ] whilst figures from other regions are more in line with the European estimates cited above [ 12 – 17 ]. A significant increase in the incidence rate of ALS during the latter half of the twentieth century has also been reported in various Western countries, [ 18 ] including Norway, [ 19 ] Finland, [ 20 ] Scotland, [ 21 ] and New Zeeland, [ 22 ] which is unlikely solely attributed to an ageing population.…”

“…This difference might partly be explained by better detection of MND patients due to the high-quality patient registration of the Swedish health care system but may also reflect a true higher incidence of MND in Sweden compared to other European countries. However, recent reports from some regions in other Nordic countries, England, and Italy have shown an incidence rate of ALS of 4 to 6 per 100,000 person-years [ 7 – 11 ]. An increasing south-to-north gradient in the incidence rate of MND has been shown in studies from several European countries [ 26 ].…”

Exploring amyotrophic lateral sclerosis patients’ experiences of psychological distress during the disease course in China: a qualitative study

“… 1–3 The global incidence of ALS stands at approximately 1–2.6 per 1 000 000 individuals, with a prevalence of 5–6 per 100 000. 4 5 Recent statistics indicate an annual incidence of 1.6 per 100 000 worldwide, 6 while in China, the annual incidence is reported at 1.24 per 100 000. 7 Despite being a rare disease, over 90% of ALS cases lack a family genetic history.…”

Mitochondrial Dysfunction in Sporadic Amyotrophic Lateral Sclerosis Patients: Insights from High-Resolution Respirometry

“…The disease is characterized by the progressive neurodegeneration of motor neurons in the brain and spinal cord at all levels of the motor system. The prevalence of this disease is approximately 6/100,000 persons [ 2 ]. Even nowadays, there is no evidence to fully elucidate the pathophysiology of this severe disease.…”