Correlates of arterial-filling patterns in the intracarotid amobarbital procedure
K. Perrine, O. Devinsky, D. J. Luciano, I. S. Choi and P. K. Nelson
Department of Neurology, Hospital for Joint Diseases, New York (NY) University School of Medicine, USA.
OBJECTIVE: To determine behavioral correlates of anterior cerebral artery
(ACA) and posterior cerebral artery (PCA) perfusion patterns in the
intracarotid amobarbital sodium procedure. DESIGN: Multivariate analysis of
covariance and partial correlations of behavioral measures to ACA crossflow
and PCA filling. SETTING: Angiography and the intracarotid amobarbital
procedure at a comprehensive epilepsy center. SUBJECTS: Forty-two patients
with intractable epilepsy (right-hemisphere seizure focus [n-23];
left-hemisphere seizure focus [n = 19]). MEASUREMENTS: Internal carotid
angiography was performed both at a standard injection rate (8 mL of
contrast per second) and at 1 mL/s, which matched the rate 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 measures. RESULTS: The
ACA crossflow did not correlate significantly with that of any measure. The
degree of PCA-filling pattern correlated significantly only with the level
of consciousness (r = .31, P < .004), but it was not significant after
accounting for the effects of seizure laterality, injection side, and
amobarbital dosage. Neither ACA crossflow nor PCA filling correlated
significantly with memory. The degree of ACA and PCA filling was
overestimated at standard angiography (8 mL of contrast medium per second)
injection rates. CONCLUSIONS: Although the degree of PCA filling correlates
mildly with the level of consciousness postinjection, possibly by perfusion
of thalamic or mesencephalic branches, it is not reliably predictive and is
less contributory than the injection side and seizure laterality. The PCA
filling is not required to produce valid memory assessment in the
intracarotid amobarbital procedure, and ACA crossflow is not predictive of
behavioral responses.