Absence of correlation between amobarbital distribution as assessed with spect brain perfusion imaging and behavioral manifestations during the intracarotid amobarbital procedure (wada test)

Intracarotid amobarbital disrupts synchronous and nested oscillatory activity ipsilateral to injection

“…This suggests that the unilateral inactivation model for amobarbital action cannot adequately explain the unilateral deficits observed during the procedure. Other authors have speculated that amobarbital may function in this setting by, “deafferentation,” from cortical and subcortical structures [6] ; however, this description does not clarify the physiologic mechanism for this deafferentation.…”

“…For example, EEG changes are frequently bilateral, rather than merely ipsilateral to the injection side on scalp EEG [3] , [4] and intracranial EEG [5] . Although this could possibly be attributed to crossing of the drug to the contralateral hemisphere via the circle of Willis, nuclear medicine studies show that the drug passes to the other hemisphere a very small proportion of the time [6] . This suggests that the unilateral inactivation model for amobarbital action cannot adequately explain the unilateral deficits observed during the procedure.…”