Unawareness of deficits after right hemisphere stroke: double-dissociations of anosognosias

Objectives - The aim was to study whether anosognosia for hemiparesis, anos ognosia for neglect and general unawareness of illness double-dissociate, i ndicating that anosognosias are specific and independent impairments of awa reness. On the other hand, anosognosias may be associated with one another and with general cognitive dysfunction, which decreases awareness of defici ts. The persistence and predictive value of anosognosias was examined durin g a 1-year follow-up. Patients ann methods - Fifty-seven consecutive patien ts with acute right hemisphere infarction underwent neurological and neuror adiological examinations, neuropsychological testing and an interview 10 da ys, 3 months and I year after onset. Results - Anosognosia for neglect and anosognosia for hemiparesis double-dissociated, as did unawareness of illne ss and anosognosia for neglect. Patients showing unawareness of illness or anosognosia for neglect and anosognosia for hemiparesis had poorer orientat ion and verbal memory than patients who were aware of these defects. Unawar eness of illness and anosognosia for hemiparesis disappeared during 3-month follow-up. Conclusion - Double-dissociations demonstrate that anosognosias for different defects are independent and specific impairments of awarenes s, although general cognitive disorder may also reduce awareness of defects . Unawareness of illness and anosognosia for hemiparesis disappear rapidly and can hardly be direct causes of poor long-term recovery. However, transi ent anosognosia may be associated with persistent disorders which result in poor outcome.