It is well known that the diagnostic process in amyotrophic lateral scleros
is (ALS) may be excessively prolonged, with negative consequences for the p
atients and their families. The ISIS study assessed the diagnostic process
in 201 patients affected by ALS from 6 different countries (Argentina, Braz
il, Germany, Italy, Spain and USA). The median time from onset to diagnosis
ranged from 12 months in Spain to 17 months in Italy. The median time: for
patients to have a first consultation with a physician was 2 months (range
: 1-1.5 months) and with a neurologist was 6-9 months. The median time need
ed for the neurologist to confirm the diagnosis was 3-6 months. Electromyog
raphy was performed on more than 90% of patients in all countries, and was
requested in most cases by the neurologist. False-negative diagnoses were q
uite frequent (45% of cases with at least one other diagnosis evoked at any
time before the ALS diagnosis) and were made by neurologists in 28% of cas
es, by general practitioners in 29% of cases, by orthopaedic surgeons in 26
% of cases and by other specialists in 18% of cases. The reasons for misdia
gnoses were: presence of other diseases to which the symptomatology was att
ributed, misinterpretation of examinations, and lack of familiarity with AL
S.