Do intracarotid barbiturate injections offer a way to investigate hemispheric models of anosognosia?

In a sample of 83 patients counterbalanced for side of temporal-lobe seizure focus, we examined unawareness of hemiplegia upon clearing of the deficit after bilateral sodium amobarbital injections. Unawareness occurred commonly (66%) and with equal frequency following left and right injections. These findings were not moderated by speech dominance, handedness, sex, or side of seizure focus. Unawareness occurred more frequently after injections contralateral to than ipsilateral to the major seizure focus and was related to objective memory performance after contralateral, but not after ipsilateral, injections. Unawareness of drug-induced hemiplegia was related to the functional status of the temporal lobe independently of hemispheric laterality or degree of frontal lobe inactivation as measured by filling of the anterior cerebral arteries.