Background and Purpose-Although cerebral hyperperfusion after carotid endarterectomy (CEA) often impairs cognitive function, MRI does not always demonstrate structural brain damage associated with postoperative cognitive impairment. The purpose of the present study was to determine whether postoperative cortical neural loss, which can be detected by 123 I-iomazenil single-photon emission CT, is associated with cerebral hyperperfusion after CEA and whether it correlates with postoperative cognitive impairment. Methods-In 60 patients undergoing CEA for ipsilateral internal carotid artery stenosis (Ͼ70%), cerebral blood flow was measured using N-isopropyl-p-[ 123 I]-iodoamphetamine single-photon emission CT before and immediately after CEA and on the third postoperative day. The distribution of benzodiazepine receptor binding potential in the cerebral cortex was assessed using 123 I-iomazenil single-photon emission CT before and 1 month after surgery and was analyzed using 3-dimensional stereotactic surface projection. Neuropsychological testing was also performed preoperatively and at the first postoperative month. Results-Post-CEA hyperperfusion and postoperative cognitive impairment were observed in 9 patients (15%) and 8 patients (13%), respectively. Post-CEA hyperperfusion was significantly associated with postoperative hemispheric reduction of benzodiazepine receptor binding potential (95%

Background: The purpose of the present study was to investigate whether resolution of crossed cerebellar hypoperfusion (CCH) and increase in ¹²³I-iomazenil (IMZ) uptake in the ipsilateral cerebral cortex after carotid endarterectomy (CEA) are associated with postoperative improvement of cognitive function. Methods: Neuropsychological testing was performed preoperatively and after 1 postoperative month in 79 patients undergoing CEA for ipsilateral internal carotid artery stenosis (≧70%). Brain perfusion single photon emission computed tomography (SPECT) using N-isopropyl-p-¹²³I-iodoamphetamine and ¹²³I-IMZ SPECT were also performed before and after surgery. Data were analyzed using a three-dimensional stereotaxic region of interest template. Results: Seven patients (9%) showed improvement in postoperative cognitive function. All the 7 patients exhibited both postoperative increase in blood flow in the ipsilateral cerebral cortex and resolution of CCH. Five patients (6%) had a postoperative hemispheric increase in ¹²³I-IMZ uptake, and cognitive function improved in all of these 5 patients. Analysis by a receiver operating characteristic (ROC) curve was used to estimate the ability to discriminate between patients with and without postoperative cognitive improvement. The area under the ROC curve was significantly greater when analyzing the magnitude of postoperative resolution of CCH (0.991; 95% CI 0.984–1.001) or postoperative hemispheric increase in ¹²³I-IMZ uptake (0.981; 95% CI 0.972–0.999) when compared with the magnitude of postoperative increase in cerebral blood flow (0.929; 95% CI 0.886–0.971) (p < 0.05). Conclusions: Resolution of CCH and increase in ¹²³I-IMZ uptake in the ipsilateral cerebral cortex after CEA is associated with postoperative improvement in cognitive function. These results may indicate that cognitive impairment is related to a state of potentially reversible central benzodiazepine receptor downregulation in the cortex in response to transient ischemic attack or minor stroke.

Successful treatment for respiratory diseases relies on effective delivery of medication to the lungs using an inhalation device. Different inhalers have distinct characteristics affecting drug administration and patient adherence, which can impact clinical outcomes. We report on the development of the Respimat® soft mist inhaler (SMI) and compare key attributes with metered-dose inhalers (MDIs) and dry powder inhalers (DPIs). The Respimat SMI, a pocket-sized device generating a single-breath, inhalable aerosol, was designed to enhance drug delivery to the lungs, reduce the requirements for patient coordination and inspiratory effort, and improve the patients’ experience and ease of use. The drug deposition profile with Respimat SMI is favorable compared with MDIs and DPIs, with higher drug deposition to the lung and peripheral airways. The slow velocity and long spray duration of the Respimat SMI aerosol also aid patient coordination. Clinical equivalence has been demonstrated for maintenance treatment of chronic obstructive pulmonary disease using once-daily tiotropium between Respimat SMI (5 µg) and HandiHaler DPI (18 µg). In comparative studies, patients preferred Respimat SMI to MDIs and DPIs; they reported that Respimat SMI was easy to use and felt the inhaled dose was delivered. The Respimat SMI, designed to generate a slow-moving and fine mist, is easy to use and effectively delivers drug treatment to the lungs. The patient-centered design of Respimat SMI improved patient satisfaction, and may help to promote long-term adherence and improve clinical outcomes with asthma and chronic obstructive pulmonary disease.

Preoperative CVR to acetazolamide measured by quantitative brain perfusion SPECT predicts development of cerebral ischemic lesions on postoperative DWI that are caused by microemboli during CEA.

Although cerebral hyperperfusion syndrome after CEA sometimes results in reversible brain edema visible on MR imaging, postoperative cerebral hyperperfusion -- even when asymptomatic -- often results in impaired cognitive function without structural brain damage on MR imaging.