Article révisé par les pairs
Résumé : Starting with 8 neuropsychological detailed observations, the author has studied mental deterioration resulting from normal pressure hydrocephaly and the short term evolution of mental troubles after spinal fluid derivation. The presurgical mental troubles are characterized essentially by short term memory troubles, by behavioral troubles relating to the 2 poles of the frontal syndrome and by disturbances in writing and calculus. The modification of the state of consciousness, the visual constructive troubles, attention and concentration troubles, verbal language troubles and psychomotor retardation are also frequent. Aphasia and alexia are rare. Generally, postsurgical evolution is immediate and global; the troubles of consciousness, mental deterioration and behavior disorders are also reduced. Three out of 4 troubles disappear. Memory troubles and difficulties in concentrating, although improving, are still maintained 6 mth after ventricular drainage.