[Neuropsychological disorders in amyotrophic lateral sclerosis. Don't they exist or do they just go undetected?].

AIMS The aims of this paper is to demonstrate the existence of neuropsychological disorders in amyotrophic lateral sclerosis (ALS) and to perform an in depth study of the cognitive functioning of the prefrontal lobes. PATIENTS AND METHODS A neuropsychological study of 14 patients with ALS was conducted using an extensive battery of tests and were compared with a group of 14 healthy controls. Both groups were homogeneous as regards age, sex, education and manual dominance. In this clinical and research study, as well as the neuropsychological variables (subtest of the Barcelona PIEN Test neuropsychological battery), we also took the evolution of the disease, the age and neurological clinical features of the patients suffering from ALS into account. RESULTS We found neuropsychological disorders in the ALS patients that were centred, either directly or indirectly, on functions of the prefrontal lobe, and in particular of the dorsolateral and premotor cortices, which had already been observed in other research work. No memory disorders were found, something which is usually mentioned in studies about neuropsychological disorders in this type of patients. CONCLUSIONS Apart from the primary motor zones affected in ALS, there appears to be a degenerative process in most of the frontal lobe, and there is a need for longitudinal studies of the possible progressive disorders of the frontal lobe in these patients. This is difficult, since these patients end up with serious neurological alterations which prevent a correct neuropsychological exploration from being carried out cognitively, and hence no conclusions can be drawn either