Incidence and prevalence of amyotrophic lateral sclerosis in Uruguay: a population-based study.

OBJECTIVE: To determine the incidence and prevalence of amyotrophic lateral sclerosis (ALS) in the Republic of Uruguay. METHODS: The study was performed in Uruguay (3,241,003 inhabitants) during a 2-year period (2002-2003). To ensure complete case ascertainment, multiple sources of information were used, including all the neurologists, other medical specialties, general physicians, neurophysiology laboratories, hospital medical records and death certificates. ALS diagnosis was based on El Escorial criteria. Although all patients with motor neuron disease were enrolled in the follow-up, only probable and definite cases are included in the study. RESULTS: Between January 1st, 2002, and December 31st, 2003, 89 new patients were diagnosed with probable or definite ALS. The mean annual incidence rate was 1.37 per 100,000 persons. The incidence was higher for men (1.95) than for women (0.84) with a male to female ratio of 2:1. For both, the incidence increased throughout the years showing a peak in the 65-74 age group among men and the 55-64 age group among women. Mean age at onset of ALS disease was 58.7 years. The estimated mean annual incidence for ALS calculated by the capture recapture method was 1.42 (95% CI, 1.13-1.72). On December 31st, 2002, the crude prevalence was 1.9 per 100,000 inhabitants. CONCLUSIONS: ALS incidence is within a narrow range across countries despite the genetic, environmental and socioeconomic differences when similar prospective design, diagnosis criteria and data analyses are applied.

Differences in the dynamics of frontal sharp transients in normal and hypoglycemic newborns.

OBJECTIVE: This study focuses on the characteristics of frontal sharp transients (FST), a normal variant of neonatal EEG, in newborns with hypoglycemia. METHODS: The EEG from 20 newborns with symptomatic hypoglycemia were compared with a control group of normal newborns matched by conceptional age. The dynamics of these transients were evaluated concerning sleep stages. The density, type and bilateral synchrony of FST were also calculated. The results were compared in the two groups by Student's t test. RESULTS: When compared with controls, hypoglycemic newborns have increased density of frontal sharp transients in all sleep stages but less bilateral synchrony (P<0.05). FST density was even higher in small for gestational age newborns. CONCLUSIONS: The data suggests that normal patterns of neonatal EEG as FST can be influenced by systemic disturbances.