Incidence of amyotrophic lateral sclerosis in Chile.

OBJECTIVE: This study aimed to estimate amyotrophic lateral sclerosis (ALS) incidence and survival rates in the Metropolitan region of Chile. METHODS: We conducted a cohort study of ALS cases in the Metropolitan Region from 2016 to 2019. A total of 219 ALS patients were recruited from Corporación ELA-Chile registry, in collaboration with neurologists from Sociedad de Neurología, Psiquiatría y Neurocirugía de Chile. We calculated incidence rates by sex and age and determined median survival from onset and diagnosis. Survival analysis used the Kaplan-Meier statistic, estimating hazard ratios for age, sex, time from symptom onset and from diagnosis using a Weibull regression model. All analyses were done using R 4.1.0. RESULTS: Overall, ALS diagnosis incidence was 0.97 cases per 100,000 inhabitants, peaking in the 70-79 age group and declining thereafter. The male-to-female ratio was 1.23. The median time to death from diagnosis was 2.3 years (95% confidence interval [CI]: 1.9-2.5), and from the first symptom, it was 3.1 years (95% CI: 2.8-3.5). CONCLUSIONS: This is the first population-based study reporting ALS incidence and survival rates in Chile's Metropolitan region. Incidence resembled other Latin American studies. Median survival from diagnosis and from the first symptom were in line with previous findings. Our results corroborated lower ALS rates in Latin America, consistent with prior research.

LAENALS: epidemiological and clinical features of amyotrophic lateral sclerosis in Latin America.

OBJECTIVE: The Latin American Epidemiologic study of ALS (LAENALS) aims to gather data on ALS epidemiology, phenotype, and risk factors in Cuba, Chile, and Uruguay, to understand the impact of genetic and environmental factors on ALS. METHODS: A harmonized data collection protocol was generated, and a Latin-American Spanish language Register was constructed. Patient data were collected in Uruguay in 2018, in Chile from 2017 to 2019, and in Cuba between 2017 and 2018. Statistical analysis was performed using SPSS 25.0.0 software. Crude cumulative incidence, standardized incidence, and prevalence were calculated in the population aged 15 years and older. RESULTS: During 2017-2019, 90 people with ALS from Uruguay (55.6% men), 219 from Chile (54.6% men), and 49 from Cuba (55.1% men) were included. The cumulative crude incidence in 2018 was 1.73/100,000 persons in Uruguay, 1.08 in Chile and 0.195 in Cuba. Crude prevalence in 2018 was 2.19 per 100,000 persons in Uruguay, 1.39 in Chile and 0.55 in Cuba. Mean age at onset was 61.8 ± 11.96 SD years in Uruguay, 61.9 ± 10.4 SD years in Chile, and 60.21 ± 12.45 SD years in Cuba (p = 0.75). Median survival from onset was 32.43 months (21.93 - 42.36) in Uruguay, 24 months (13.5 - 33.5) in Chile, and 29 months (15 - 42.5) in Cuba (p = 0.006). CONCLUSIONS: These preliminary data from LAENALS confirm the lower incidence and prevalence of ALS in counties with admixed populations. The LAENALS database is now open to other Latin American countries for harmonized prospective data collection.

Enfermedad de Creutzfeldt-Jakob: experiencia de 5 años en un hospital terciario de Chile / Creutzfeldt-Jakob disease, experience in 17 patients

Background: Creutzfeldt-Jakob disease (CJD) is a prion affection that typically produces a rapidly progressive dementia with different neurologic and extra-neurologic manifestations. Aim: To characterize clinical, imaging and electroencephalography findings in patients with a probable CJD. Patients and Methods: A case series study of patients admitted in the Neurology department at a public hospital, between 2014 and 2019. Demographic, clinical, imaging, and electroencephalographic data of patients with probable CJD were analyzed. Results: Seventeen patients aged 63 ± 11 years (53% women) with a probable CJD were gathered. The incidence was 4.7 cases/year per million inhabitants. Twenty four percent of patients had a family history of CJD. The median time between the onset of symptoms and the hospital admission was three months with a survival of four months. The most common clinical manifestations were an amnesic syndrome in 88%, myoclonus in 76%, frontal syndrome and ataxia in 71%. Brain MRI was abnormal in all patients. The preponderant finding was the involvement of the caudate nucleus in 82% of cases. In the EEG, 94% of patients had abnormalities. All had a theta-delta slowing as a base rhythm. The pseudo-periodic pattern was observed in the 29% and status epilepticus in 18%. Conclusions: In this group of patients we observed the heterogeneity of the clinical manifestations of the disease, the frequent imaging and electroencephalographic alterations and the short evolution time leading to death.

[Creutzfeldt-Jakob disease, experience in 17 patients]. / Enfermedad de Creutzfeldt-Jakob: experiencia de 5 años en un hospital terciario de Chile.

BACKGROUND: Creutzfeldt-Jakob disease (CJD) is a prion affection that typically produces a rapidly progressive dementia with different neurologic and extra-neurologic manifestations. AIM: To characterize clinical, imaging and electroencephalography findings in patients with a probable CJD. PATIENTS AND METHODS: A case series study of patients admitted in the Neurology department at a public hospital, between 2014 and 2019. Demographic, clinical, imaging, and electroencephalographic data of patients with probable CJD were analyzed. RESULTS: Seventeen patients aged 63 ± 11 years (53% women) with a probable CJD were gathered. The incidence was 4.7 cases/year per million inhabitants. Twenty four percent of patients had a family history of CJD. The median time between the onset of symptoms and the hospital admission was three months with a survival of four months. The most common clinical manifestations were an amnesic syndrome in 88%, myoclonus in 76%, frontal syndrome and ataxia in 71%. Brain MRI was abnormal in all patients. The preponderant finding was the involvement of the caudate nucleus in 82% of cases. In the EEG, 94% of patients had abnormalities. All had a theta-delta slowing as a base rhythm. The pseudo-periodic pattern was observed in the 29% and status epilepticus in 18%. CONCLUSIONS: In this group of patients we observed the heterogeneity of the clinical manifestations of the disease, the frequent imaging and electroencephalographic alterations and the short evolution time leading to death.