Nelly Campo

Cerebral Fat Microembolism and Cognitive Decline After Hip and Knee Replacement

Background and Purpose— Intra-operative cerebral microembolism may be a factor in the etiology of cognitive decline after orthopedic surgery. We here examine the impact of intra-operative microembolism on cognitive dysfunction after hip and knee replacement surgery. Methods— We enrolled 24 patients, at least 65 years old, requiring elective knee or hip replacement surgery. A transcranial Doppler shunt study was done to determine study eligibility so that the final study population consisted of 12 consecutive patients with and 12 consecutive patients without a venous-arterial shunt. A standard neuropsychological test battery was administered before surgery, at hospital discharge and 3 months after surgery. All patients were monitored intra-operatively for microemboli. Quality of life data were assessed at 1 year. Results— The mean age of patients was 74 years. All patients had intra-operative microemboli. The mean number of emboli was 9.9±18. Cognitive decline was present in 18/22 (75%) at discharge and in 10/22 (45%) at 3 months, despite improved quality of life measures. There was no correlation between cognitive decline and intra-operative microembolism. Conclusion— Cognitive decline was seen frequently after hip and knee surgery. Intra-operative microembolism occurred universally but did not significantly influence postoperative cognition. Quality of life and functional outcome demonstrated improvement in all cases in spite of cognitive dysfunction.

High-Dose Atorvastatin Enhances Impaired Cerebral Vasomotor Reactivity

The influence of statin therapy on cerebral vasomotor function has not been fully characterized. We report the effects of high-dose atorvastatin therapy on cerebral vasomotor reactivity (VMR) in patients with controlled hypertension and dyslipidemia. We prospectively enrolled 36 patients with controlled hypertension and a low-density lipoprotein (LDL) cholesterol concentration >100 mg/dL. Atorvastatin 80 mg was given daily for 6 months and then discontinued. VMR was assessed by hypercapnic and hypocapnic transcranial Doppler challenge in both the right and left middle cerebral artery (MCA) at baseline, and after 3 and 6 months of therapy. Forty-five days after statin cessation, a repeat VMR was performed. VMR impairment was defined as ≤70%. Blood pressure, lipid levels, liver function, and creatine kinase level were monitored. Mean patient age was 60 years, 16 were men, and 13 had a previous history of subcortical infarction. Mean LDL cholesterol level before treatment was 154 ± 30 mg/dL. Atorvastatin lowered LDL by 53% at 3 months and by 46% at 6 months. Baseline VMR was 71% ± 21% in the right MCA and 70% ± 19% in the left MCA. No significant effect of atorvastatin on VMR was seen at 3 months and 6 months in the study population as a whole. In the subgroup of patients with baseline VMR impairment, atorvastatin therapy was associated with significantly improved VMR at both 3 and 6 months. This effect persisted for at least 45 days after discontinuation of therapy. Our findings indicate that high-dose atorvastatin therapy can significantly improve impaired cerebral VMR, and that the effects of atorvastatin on VMR persist for 1.5 months after discontinuation of therapy. We found no benefit of atorvastatin therapy in patients with preserved baseline vasoreactivity.

MR Imaging after Hip and Knee Replacement

Diffusion‐weighted (DW) imaging abnormalities often develop in patients after invasive procedures associated with cerebral microembolism. Cerebral microembolism has recently been shown during orthopedic surgery. We here examine the effects of intraoperative microembolism on acute magnetic resonance(MR) imaging in patients undergoing hip and knee replacement.

Moderate correlation between breath-holding and CO(2) inhalation/hyperventilation methods for transcranial doppler evaluation of cerebral vasoreactivity.

Both CO2 inhalation followed by hyperventilation and breath‐holding have been utilized to measure cerebral vasomotor reactivity (VMR) but their correlation has been poorly studied and understood.

Topography of Vertebral Artery Origin Plaques: Characteristics and Determinants: Vertebral Artery Plaque Topography

Atherosclerotic plaques located at the vertebral artery ostium (VAo) are a mechanism for posterior circulation stroke, but little is known about VAo plaque topography and formation. In this study, we describe the topography of atherosclerotic plaques involving the origin of the vertebral artery (VA).

B-Flow and B-Mode Ultrasound Imaging in Carotid Fibromuscular Dysplasia: B-Flow Imaging in FMD

Previous ultrasound studies in fibromuscular dysplasia (FMD) have largely reported on color flow imaging, power Doppler, and Doppler flow augmentation. We here report on arterial wall imaging findings by B‐flow and B‐mode in patients with carotid FMD.