Survival rate of patients with amyotrophic lateral sclerosis in Wakayama Prefecture, Japan, 1966 to 2005.

To investigate longitudinal changes in the survival rate of patients with amyotrophic lateral sclerosis in Wakayama Prefecture, Japan, we made a retrospective hospital-based study of 454 patients diagnosed with motor neuron disease (MND) at Wakayama Medical University (WMU) Hospital between 1966 and 2005. Of the 454 patients, 240 who were born and who lived in Wakayama Prefecture were diagnosed with definite or probable ALS during this period, according to the El Escorial criteria. The clinical data of the 240 patients, including sex, birth date, birthplace, address, age at onset, initial symptoms, date when respiratory support was applied (tracheostomy, noninvasive positive pressure ventilation, or mandatory artificial ventilation), and date of death were reviewed retrospectively.