NEW YORK (Reuters Health) – Patients with chronic internal carotid artery occlusion who successfully undergo carotid artery stenting show improvement in global cognitive function, Taiwanese researchers report in an August 11th on-line paper in Stroke.

“Confirmation of the benefit on neurocognitive functions in patients with carotid artery stenosis,” Dr. Hsien-Li Kao told Reuters Health by email, “will expand significantly the current indications for carotid revascularization.”

Dr. Kao of National Taiwan University Hospital, Taipei and colleagues note that chronic cerebral hypoperfusion due to chronic coronary artery occlusion may lead to impairment in neurocognitive performance. The situation is unclear although it appears that restoration of cerebral circulation may lead to cognitive improvement.

To investigate further, the team prospectively enrolled 20 such patients with objective ipsilateral hemisphere ischemia, in whom carotid artery stenting was attempted. Recanalization was successful in 12. One patient had intracranial hemorrhage during the procedure and was excluded from the analysis.

Ten of the 12 patients in the successful group had improvement in ipsilateral brain perfusion after the procedure, compared to none in the unsuccessful group.

At 3 months, compared to baseline, the successful group showed significant score improvement in the Alzheimer Disease Assessment Scale–Cognitive Subtest, the Mini-Mental State Examination and in Color Trail Making A. There were no such improvements in the unsuccessful group.

The researchers caution that “Despite the significant overall improvement in the successful group, there were still variations in individual patients and individual tests.”

These preliminary results are promising, but they conclude that “Higher patient enrollment and longer follow-up duration accompanied by functional evaluation are mandatory to evaluate the clinical value of cognitive improvement after carotid revascularization.”

Stroke 2011.