Improvement of Cerebral Glucose Metabolism in Symptomatic Patients With Carotid Artery Stenosis After Stenting.

PURPOSE: Neurocognitive performance among patients with carotid artery stenosis or occlusion may deteriorate because of chronic cerebral hypoperfusion. Carotid artery stenting (CAS) has been reported to improve cerebral perfusion and neurocognitive function. The purpose of the study was to evaluate cerebral metabolism using F-fluorodeoxyglucose (FDG) positron emission tomography (PET) after CAS. METHODS: Nineteen consecutive patients (15 men, 69 ± 13 years) with carotid artery stenosis or occlusion and cerebral ischemia detected on brain perfusion computed tomography (CT) or magnetic resonance imaging (MRI) were enrolled. Four patients had bilateral lesions, and 15 subjects had previous ischemic stroke. Neurocognitive function (NCF) assessments and brain FDG PET scans were performed before and 19 ± 7 (12-31) months after the procedure. RESULTS: The procedural success rate of CAS was 70%. Two patients were excluded from the study because of procedural complications. No new cerebral ischemic events or neurologic deaths occurred during follow-up of 44 ± 11 (15-54) months. Significant improvements were observed in the Mini-Mental State Examination (before, 26.06 ± 3.32 versus after, 28.13 ± 2.8; P = 0.0016), the verbal fluency test (26.81 ± 7.82 versus 30.75 ± 9.58; P = 0.0378), and marginal upgrading in the Alzheimer Disease Assessment Scale-Cognitive Subtest (7.19 ± 7.59 versus 5.63 ± 5.90; P = 0.0523). Six of 9 patients who underwent successful CAS showed improvement of cerebral glucose metabolism. Of the 4 patients with recanalization failure, 2 exhibited decline in ipsilateral glucose metabolism. Cerebral FDG metabolism improved in patients with successful CAS (P = 0.038), although there was a weak correlation between interval change of NCF tests and brain FDG metabolism. CONCLUSIONS: Successful CAS may improve long-term cerebral glucose metabolism and neurocognitive function in patients with chronic severe carotid stenosis or occlusion.