ANOSOGNOSIA FOR HEMIPLEGIA - TEST OF THE PERSONAL NEGLECT HYPOTHESIS

Objective. To test the personal neglect hypothesis of anosognosia for hemiplegia (AHP) using selective anesthesia of the right hemisphere. B ackground: Although AHP most commonly follows right-hemisphere injury, the mechanism responsible for this hemispheric asymmetry has not been entirely elucidated. Because denial of ownership of parts on the cont ralesional side of one's body (personal neglect) also more commonly fo llows right-hemisphere damage, personal neglect might account for AHP. Design/Methods: AHP and personal neglect were assessed in 20 patients during right intracarotid barbiturate infusion. With vision restricte d to the central field, patients were randomly presented with either t heir own hands or those of examiners matched for size, gender, and rac e. Patients were asked to read numbers placed on the hands to establis h that hemianopia did not confound hand recognition. Results: All subj ects correctly read the numbers on all trials. Only 4 of 20 subjects m isidentified their hands and denied awareness of left hemiplegia. All errors occurred for the left hand, indicating personal neglect. Howeve r, the 16 subjects without personal neglect also demonstrated AHP. Con clusion: Because AHP and personal neglect are dissociable, personal ne glect cannot completely account for AHP.