Amyotrophic lateral sclerosis in Lancashire and South Cumbria, England, 1976-1986. A geographical study
J. D. Mitchell, H. N. Gibson and A. Gatrell
Department of Neurology, Royal Preston Hospital, England.
An attempt was made to identify all patients presenting with amyotrophic
lateral sclerosis (ALS) during a 10-year period in Lancashire and South
Cumbria, England. An analysis of their place of residence was made using
the postal code. This was used to allocate each patient to an electoral
ward. Using such small areal units, it was found that more cases of ALS had
arisen than would have been expected by chance in several wards during the
study period. Although the actual number of wards showing this effect was
probably not increased, the significance levels suggest that the disease
may not show a random geographical distribution. No evidence of clustering
of year of birth was found. These findings indicate the need for further
work seeking geographical clusters of ALS and are discussed in relation to
current etiological hypotheses of the disease.