Combination of preoperative cerebral blood flow and 123I-iomazenil SPECT imaging predicts postoperative cognitive improvement in patients undergoing uncomplicated endarterectomy for unilateral carotid stenosis.
OBJECTIVE
The purpose of the present study was to determine whether preoperative cerebral blood flow (CBF) or cortical central benzodiazepine receptor binding potential as measured by brain perfusion or (123)I-iomazenil (IMZ) single-photon emission computed tomography (SPECT) imaging, respectively, can predict cognitive improvement after uncomplicated carotid endarterectomy (CEA).


METHODS
Neuropsychological testing was performed preoperatively and after 1 month postoperatively in 140 patients who underwent CEA for unilateral internal carotid artery (ICA) stenosis (≥ 70%). Brain perfusion SPECT using N-isopropyl-p-[(123)I]-iodoamphetamine and IMZ SPECT was also performed before surgery. SPECT data were analyzed using a 3-dimensional stereotaxic region-of-interest template.


RESULTS
Fourteen patients (10%) showed improved cognitive function postoperatively. Logistic regression analysis demonstrated that, among the variables tested, low relative CBF in the cerebral hemisphere ipsilateral to surgery was significantly associated with postoperative cognitive improvement (95% confidence interval: 0.623-0.868; P = 0.0003). The combination of reduced relative CBF and moderately reduced relative uptake of IMZ identified development of postoperative cognitive improvement with 100.0% sensitivity, 84.9% specificity, a positive predictive value of 42.4%, and a negative predictive value of 100%. Further, in a subgroup of patients with reduced relative CBF and moderately reduced relative uptake of IMZ, the difference between these 2 values was significantly greater in patients with postoperative cognitive improvement than in those without (P < 0.0001).


CONCLUSIONS
The combination of preoperative CBF and cortical central benzodiazepine receptor binding potential as determined by SPECT can predict cognitive improvement after CEA.
Department of Neurosurgery and Cyclotron Research Center, Iwate Medical University, Morioka, Japan.
Takeshi
T
Yamashita
Kuniaki
K
Ogasawara
Hiroki
H
Kuroda
Taro
T
Suzuki
Kohei
K
Chida
Masakazu
M
Kobayashi
Kenji
K
Yoshida
Yoshitaka
Y
Kubo
Akira
A
Ogawa
D000328:Adult; D000368:Aged; D016893:Carotid Stenosis / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D003071:Cognition / Q000502:physiology*; D003131:Combined Modality Therapy; D016894:Endarterectomy, Carotid; D005260:Female; D005442:Flumazenil / Q000031:analogs & derivatives*; D006801:Humans; D007457:Iodine Radioisotopes; D008297:Male; D008875:Middle Aged; D011182:Postoperative Care; D011300:Preoperative Care; D013238:Stereotaxic Techniques; D015899:Tomography, Emission-Computed, Single-Photon
D007457:Iodine Radioisotopes; D005442:Flumazenil; C063038:iomazenil