Incidence of amyotrophic lateral sclerosis in Sicily: A population based study.

Our objective was to investigate incidence of amyotrophic lateral sclerosis (ALS) in Sicily, southern Italy, by means of a population based study. We included people with ALS resident in five Sicilian provinces, whose onset occurred in the two-year period 2005-2006 (population at 31 December 2006: 3,481,096 inhabitants). A multisource case-finding procedure was adopted and patients were classified as affected by ALS according to revised El Escorial criteria. During the two-year surveillance period, 97 patients meeting eligibility criteria included 57 males (58.8%) and 40 females (41.2%). Crude annual incidence rate was 1.4/100,000 person years (95% CI 1.33-1.47). The incidence rate was higher in males (1.71/100,000; CI 1.61-1.81) than in females (1.11/100,000; CI 1.01-1.21). Standardized incidence rate for the total population in the 45-74-years-old age group was 3.22 (CI 3.11-3.33). Prevalence rate was 6.0/100,000 (CI 5.97-6.03), higher in males (7.1/100,000; CI 7.02-7.18) than females (4.9/100,000; CI 4.86-4.94). In conclusion, ALS rates observed in the present study are higher in males than females, with a peak of incidence at 70 years of age in both genders. These findings are consistent with those of other population based European studies.

Factors affecting the diagnostic delay in amyotrophic lateral sclerosis.

BACKGROUND: Although amyotrophic lateral sclerosis (ALS) is a relentlessly progressive disorder, early diagnosis allows a prompt start with the specific drug riluzole and an accurate palliative care planning. ALS at onset may however mimic several disorders, some of them treatable (e.g., multifocal motor neuropathy) or epidemiologically more frequent (e.g., cervical myelopathy). OBJECTIVE: To study the delay from onset to diagnosis in a cohort of ALS patients and to the variables that may affect it. METHODS: We performed a retrospective analysis of the diagnostic delays in a cohort of 260 patients affected by ALS (M/F = 1.32) followed at our tertiary referral ALS Center between 2000 and 2007. RESULTS: The median time from onset to diagnosis was 11 months (range: 6-21) for the whole ALS cohort, 10 months (range: 6-15) in bulbar-onset (n = 65) and 12 months (range: 7-23) in spinal-onset (n = 195) patients (p = 0.3). 31.1% of patients received other diagnoses before ALS and this led to a significant delay of the correct diagnosis in this group (other diagnoses before ALS, n = 81: median delay, 15 months [9.75-24.25] vs ALS, n = 179, median delay, 9 months [6-15.25], p < 0.001). CONCLUSIONS: The diagnostic delay in ALS is about one year, besides the growing number of tertiary centres and the spread of information about the disease through media and internet. Cognitive errors based on an incorrect use of heuristics might represent an important contributing factor. Furthermore, the length of the differential diagnosis from other disorders and delays in referral to the neurologist seems to be positively associated with the delay in diagnosis.