[Motor impersistance of the eyelids. Study of 93 cases and a discussion of pathogenic mechanisms].

In a prospective study, 252 subjects were investigated for motor impersistence of the eyelids (MIE) by means of a protocol that evaluated its intensity and detected associated signs, notably other phenomena of motor impersistence. MIE was frequent, being found in 93 subjects. It was usually observed in diffuse brain lesions, then in lesions of the right hemisphere, particularly in the posterior and deep cortex. In right hemisphere lesions, MIE was significantly associated with constructional apraxia, visual neglect and Anton-Babinski syndrome. In diffuse cerebral lesions, MIE was accompanied by other phenomena of motor impersistence on a background of dementia. In these cases the P 300 wave latency was significantly prolonged. Three main mechanisms may be regarded as responsible for the occurrence of MIE: apraxia, disturbance of the interhemispheric balance (notably in lesions of the right hemisphere) and disorders of attention (predominant in diffuse lesions). Actually, in every case MIE should be inserted in a continuum the extremities of which are represented by the above mentioned mechanisms.