[The diagnostic course in patients with hereditary ataxias and hereditary spastic paraparesis].

A postal questionnaire was sent to all patients affected by hereditary ataxias and hereditary spastic paraparesis resident in the province of Turin (Italy) to study their diagnostic process. A 61% response rate was obtained. The mean time interval between onset and diagnosis was 6 years (1 to 32 years). The percentage of late diagnoses dropped from 59% before 1959 to 19% after 1970, mostly because a reduction of the interval between symptom onset and the first contact with the general practitioner. The onset with dysarthria and ataxia led to earlier neurologic consultation, but the whole time requested for the diagnosis was not modified. A reduction of the time needed for the diagnostic process may be important to address the family to an early genetic counselling.