HOLLYWOOD, FLA. — Carotid artery stenting produced sustained and significant improvements in neurocognitive function in a study with 37 patients who were followed for a year.
The finding was unexpected because half of the patients were classified as asymptomatic at the time that they underwent CAS, suggesting that their initial carotid stenosis had a physiologic impact that went unnoticed, Dr. Rodney Raabe said at the 19th International Symposium on Endovascular Therapy.
It's been generally assumed that the circle of Willis and collateral circulation provides enough brain perfusion to prevent ischemia and reduced brain function in patients with carotid stenosis who lack the conventional symptoms of stroke or transient ischemic attack. But if future results continue to dispute this, then improved brain function may become a new goal for CAS or endarterectomy, said Dr. Raabe, chief of radiology at Sacred Heart Medical Center in Spokane, Wash.
The study enrolled 62 patients who were divided evenly between symptomatic and asymptomatic. The patients were assessed by a panel of 12 neurocognitive tests at baseline and during follow-up by a neuropsychologist and psychometrician. The patients at baseline served as their own controls. Symptomatic patients had a minimum of 70% carotid stenosis; asymptomatic patients had at least 80% stenosis. All patients were treated with an Acculink stent and distal protection device.
So far, 37 of the patients were assessed 1 year after stenting and they showed, on average, statistically significant improvements in several neurocognitive parameters, including memory and intelligence. When assessed individually, 16 of the 37 had improvements in their dementia-rating score that were more than a half standard deviation better than their baseline levels, and another 20 patients had stable scores. Only one patient had a substantial decline in cognition.
Improvements in neurocognitive scores began appearing 3 months after CAS, and by 6 months the differences had widened and become significant, Dr. Raabe said.