Guillain-Barré syndrome in South-West Stockholm, 1973-1991, 3. Clinicoepidemiological subgroups.

Using hierarchical cluster analysis, applied to 47 cases of Guillain-Barré Syndrome (GBS) incident in South-West Stockholm (SWS) during the period from January 1973 to June 1992, we identified three major clinicoepidemiological subgroups. The first subgroup, 25.5% of the cases (26.7 +/- 6.7 years), recorded a peak incidence at ages 20-29 years and presented significant differences from other subgroups, a high proportion of cases with onset at low age preceded by respiratory infection (83.3%) and with normal motor conduction velocity (50.0%). Also found, were less affected biological parameters, a rapidly progressive course and independence in gait at one month after onset. A second subgroup, 27.7% of cases, was severely affected, clinically and functionally. It consisted predominantly of young individuals (22.7 +/- 11.1 years), with a high incidence (69.2% of cases) in autumn. A third subgroup, comprising 40.4% of cases, was older (61.1 +/- 11.0 years) and, in general, also severely affected. The incidence of this form appeared to be invariant with time.