Background and aims: Symptomatic carotid stenosis is associated with an increased risk of early stroke recurrence. Post-stroke vascular cognitive impairment is highly prevalent with significant functional consequences. However, reliable biomarkers for early prediction of cognitive decline are not well established. We postulated that regional hypoperfusion due to carotid stenosis would impair cognitive performance. Hence, we evaluated the cognitive parameters at baseline and their natural course during 90-days of follow up.
Methods: This ongoing prospective study included consecutive patients within 30-days of recent stroke and ipsilateral carotid stenosis (≥50%). Data regarding demographics and vascular risk factors were recorded. Cognitive parameters were assessed with the 30-point mini-mental scale (MMSE) and Montreal Cognitive Assessment (MoCA). All patients underwent carotid duplex sonography and 18-fluorodeoxyglucose (FDG) Positron Emission Tomography (PET) of carotid arteries. Embolic potential of the carotid plaque is estimated by presence of spontaneous microembolic signals (MES) on extended transcranial Doppler monitoring of the middle cerebral arteries. Patients are followed prospectively for change in cognitive parameters.
Results: Of the 33 patients included in this study, 7 (21%) demonstrated deterioration of their cognitive parameters (MMSE in 4, MOCA in 5 and both in 6) during 90-day follow up. Only high Standard Uptake Value (SUV) on PET (3.62g/ml in cognitive-deterioration group versus 1.72g/ml in the unaffected group; p=0.01) and presence of concomitant intracranial stenosis (p=0.01) were associated with cognitive deterioration. Of the 7 cases who underwent carotid revascularization, 5 (71%) demonstrated improved cognitive performance at day-90.
Conclusions: Early cognitive decline is common among patients with symptomatic stenosis of the extracranial carotid artery, especially when associated with concomitant intracranial stenosis and plaque inflammation.