A prospective psychometric study was conducted in 16 patients who recently developed classic sporadic amyotrophic lateral sclerosis and had no signs of anxiety or depression. Tests included PM38, MMS, Rey word and Rey image tests, span, Stroop test, verbal fluency, Wisconsin test and London Tower test coupled with 99m Tc HMPAO tomography. Results demonstrated that the patients had no intellectual degradation nor visual constructive disorders but had disturbed verbal and visual memory with a reduced verbal fluency (particular bulbar forms), perseverance errors on the Wisconsin test (half of the cases) and an increased number of movements in the London Tower test. These disorders were moderate with no clinical impact and variable (the neuropsycological examination was normal in 4/16 patients). 99m Tc HMPAO tomography was normal in 4 cases, showed slight rolandic hypoperfusion in 6 and extensive hypoperfusion outside the motor zone in 2. Visual analysis of the 99m Tc HMPAO images did not reveal any clinico-metabolic correlations.