[The deep linguo-mental reflex: an early sign of temporal lesions (author's transl)].

The deep linguo-mental reflex is produced by light tapping on a spatula placed on the protruding tongue one centimeter in front of the dental arch. It is positive when contraction of the chin muscles occurs. This reflex is the only early neurological sign evoking a diagnosis of temporal lesions. It is usually found on the opposite side from that of the lesion. In psychotic patients and in those with behavioral disorders having impulsive and violent tendencies, the reflex is bilateral or contralateral to the dominant hemisphere. In dysphoric emotional disorders it is contralateral to the minor hemisphere affected. This reflex is not found in normal adults or in neurological diseases without cerebral lesions.