Anosognosia during Wada testing

Anosognosia, the verbally explicit denial of hemiplegia, is more often reported after right- than left-hemisphere lesions. However, this asymmetric incidence of anosognosia may be artifactual and related to the aphasia that often accompanies left-hemisphere lesions. Anosognosia has been attributed to psychological denial and the emotional changes associated with hemispheric dysfunction. Eight consecutive patients undergoing intracarotid barbiturate (methohexital) injections as part of their presurgical evaluations for intractable epilepsy were assessed for anosognosia after their hemiplegia and aphasia had cleared. After their left-hemisphere anesthesia, all subjects recalled both their motor and language deficits. However, after right-hemisphere anesthesia, none of the eight patients recalled their hemiplegia. These results suggest that anosognosia is more often associated with right- rather than left-hemisphere dysfunction and that it cannot be attributed to either psychological denial or the emotional changes associated with hemispheric dysfunction.