CORRELATES OF ARTERIAL-FILLING PATTERNS IN THE INTRACAROTID AMOBARBITAL PROCEDURE

Objective: To determine behavioral correlates of anterior cerebral art ery (ACA) and posterior cerebral artery (PCA) perfusion patterns in th e intracarotid amobarbital sodium procedure. Design: Multivariate anal ysis of covariance and partial correlations of behavioral measures to ACA crossflow and PCA filling. Setting: Angiography and the intracarot id amobarbital procedure at a comprehensive epilepsy center. Subjects: Forty-two patients with intractable epilepsy (right-hemisphere seizur e focus [n-23]; left-hemisphere seizure fetus [n=19]). Measurements: I nternal carotid angiography was performed both at a standard injection rate (8 mL of contrast per second) and at 1 mL/s, which matched the r ate of the subsequent amobarbital injection. The degree of ipsilateral PCA and contralateral ACA filling were graded on a seven-point scale and compared with postinjection behavior, language, and memory measure s. Results: The ACA crossflow did not correlate significantly with tha t of any measure. The degree of PCA-filling pattern correlated signifi cantly only with the level of consciousness (r=.31, P<.004), but it wa s not significant after accounting for the effects of seizure laterali ty, injection side, and amobarbital dosage. Neither ACA crossflow nor PCA filling correlated significantly with memory. The degree of ACA an d PCA filling was overestimated at standard angiography (8 mL of contr ast medium per second) injection rates. Conclusions: Although the degr ee of PCA filling correlates mildly with the level of consciousness po stinjection, possibly by perfusion of thalamic or mesencephalic branch es, it is not reliably predictive and is less contributory than the in jection side and seizure laterality. The PCA filling is not required t o produce valid memory assessment in the intracarotid amobarbital proc edure, and ACA crossflow is not predictive of behavioral responses.