A patient-specific computer model to predict outcomes of the balloon occlusion test

OBJECT: Balloon occlusion tests (BOTs) are performed to identify patients who are at risk for ischemia and stroke following permanent internal carotid artery (ICA) occlusion. The object of this work was to determine whether patient-specific blood flow modeling can be used to identify patients in whom the BOT would not be tolerated. METHODS: The test was performed in 16 patients who underwent BOT with continuous neurological and electroencephalographic monitoring, followed by a hypotensive challenge. During hypotension a tracer was injected so that single-photon emission tomography (SPECT) scans could be obtained. Each individual brain circulation was modeled using information gained from phase-contrast magnetic resonance (MR) angiography and digital subtraction (DS) angiography, and the predicted effect of the BOT was evaluated. Six patients did not tolerate the BOT; in these patients, decreases in middle cerebral artery (M1 segment) blood flow of 41 +/- 27% (mean +/- standard deviation), anterior cerebral artery (A3 segment) flow of 56 +/- 33%, and posterior cerebral artery (P2 segment) flow of 4 +/- 13% ipsilateral to the site of occlusion were found with modeling; these changes were significantly greater than the percentage of changes measured in the contralateral hemisphere (p < 0.05). Ten patients who tolerated the BOT well had calculated decreases in ipsilateral flows of only 9 +/- 6% for the M1 segment, 12 +/- 40% for the A3 segment, and 17 +/- 21% for the P2 segment during BOT modeling. CONCLUSIONS: A decrease in blood flow in both the ipsilateral M1 and A3 segments that was greater than 20%, calculated by flow modeling of the BOT, was 100% sensitive and 100% specific in identifying patients who could not tolerate the BOT. Blood flow modeling, coupled with DS angiography and noninvasive phase-contrast MR angiography measurements to make calculations patient specific, can be used to identify patients who have an elevated risk of ischemia during the BOT.     

Effect of eplerenone,a selective aldosterone blocker,on blood pressure,serum and macrophage oxidative stress,and atherosclerosis in apolipoprotein E-deficient mice

Oxidative stress is involved in the pathogenesis of atherosclerosis, and angiotensin II (AT-II) induces oxidative stress and enhances atherogenesis. Aldosterone, which has an important role in the pathology of heart failure, has recently been implicated as a mediator of AT-II biologic activities. In this study, we analyzed whether administration of the selective aldosterone blocker eplerenone to atherosclerotic apolipoprotein E-deficient (E0) mice would affect their oxidative status and atherogenesis. Apolipoprotein E-deficient mice were administered chow containing eplerenone (200 mg/kg/day) for 3 months. Blood pressure, serum and macrophage oxidative status, and aortic atherosclerotic lesion area were evaluated in mice treated with eplerenone compared with untreated mice. Eplerenone administration significantly decreased systolic and diastolic blood pressure by 12% and 11%, respectively, compared with untreated mice. Serum susceptibility to lipid peroxidation decreased by as much as 26%, and serum paraoxonase activity increased by 28% in eplerenone-treated mice compared with untreated mice. Peritoneal macrophages from eplerenone-treated mice contained reduced levels of lipid peroxides, and their macrophage oxidation of low-density lipoprotein (LDL) and superoxide ion release were significantly reduced (by 17% and 43%, respectively), compared to untreated mice. Daily injections of AT-II (0.1 mL, 10(-)7M) during the final 3 weeks of the study in eplerenone-treated mice substantially attenuated the eplerenone-mediated reduction in macrophage superoxide release and LDL oxidation. Finally, the atherosclerotic lesion area in aortas of eplerenone-treated mice was significantly reduced (by 35%) versus untreated mice, and this effect was reversed by AT-II. Administration of the selective aldosterone blocker eplerenone significantly reduced oxidative stress and atherosclerosis progression in E0 mice. These data suggest that aldosterone could have a significant pro-oxidative role in the pathogenesis of atherosclerosis.     

Epiphyseal involvement of simple bone cysts

Epiphyseal involvement of a simple bone cyst (SBC) is uncommon. Eight patients are reported in whom an SBC was found to cross the growth plate, involving the epiphysis in seven patients and the apophysis in one. All patients had more than two pathologic fractures. In seven patients growth disturbance was found. Functional impairment did not develop in any patient. Radiographically, all lesions presented a characteristic involvement of the epiphysis and metaphysis in various proportions. Only one of four cysts treated with methylprednisolone acetate injections showed incomplete healing; the others failed to respond. After percutaneous grafting of autologous bone marrow, three of seven cysts healed and the others attained incomplete healing. Epiphyseal involvement of SBC should be considered a more aggressive form of an active lesion.     

Regression of left ventricular hypertrophy with moexipril, an angiotensin-converting enzyme inhibitor, in hypertensive patients

Left ventricular hypertrophy (LVH) is a common complication of essential hypertension and an independent risk factor for the development of cardiovascular disease. Therefore, antihypertensive treatment should decrease blood pressure (BP) and reverse LVH. However, antihypertensive drugs have been shown to have different effects on LVH despite similar effects on BP reduction. Although lowering BP produces a beneficial effect on LVH per se, meta-analyses of clinical trials have indicated that angiotensin-converting enzyme (ACE) inhibitors decrease left ventricular mass (LVM) to a greater extent than do some other antihypertensives. The aim of this study was to evaluate the effect of a 24-week treatment with the ACE inhibitor moexipril (15 mg once daily) on the regression of LVH in hypertensive patients. This was a multicenter, international, single-blind, single-group, nonrandomized study. After a wash-out placebo period of 2 weeks, 15 mg moexipril once daily was administered for 24 weeks followed by a 2-week follow-up placebo period. Subjects with mild to moderate essential hypertension were screened; those with LVH [defined as an LVM indexed for body surface area (LVMIs) >111 g/m in men and LVMIs >106 g/m in women] were eligible to participate in this study. Echocardiograms were recorded on videotape and sent to a centralized laboratory for reading by 2 independent experts blinded for treatment, center, and visit; the mean values of these readings were calculated and used for analysis. Valid echocardiographic data were obtained from 72 patients (50 males, 22 females) with a mean age of 49 +/- 11 years. Analysis showed significant decrease of LVMIs (121 +/- 20 versus 103 +/- 17 g/m; P < 0.001) and BP (152 +/- 12/96 +/- 9 versus 140 +/- 13/86 +/- 9 mm Hg; P < 0.001) with moexipril. For patients who met LVMI inclusion criteria after centralized, blinded readings, the decrease from baseline in LVMIs was 23.4 g/m. The decrease in LVMIs was independent from the regression to the mean phenomenon as observed from the follow-up placebo period. Moexipril 15 mg once daily administered for 24 weeks resulted in a significant reversal of LVH in patients with essential hypertension. The result compares favorably with results previously obtained in trials of similar duration with other ACE inhibitors.     

Parameters for predicting favorable responses to botulinum toxin in children with cerebral palsy

We sought markers for predicting a favorable outcome of botulinum toxin A injected to the lower-extremity muscles of 26 children with hemiplegic or diplegic cerebral palsy. Clinical assessment preceding and 1 month following injection included gross motor function measure, a modified Ashworth scale, and evaluation of range of motion of knee extension and ankle dorsiflexion. Response to treatment was classified based on a parent questionnaire. The 19 children (73%) considered by their parents as being good responders were compared to the 7 (27%) considered as being poor responders. In the good responders, the preinjection Ashworth scale (spasticity) was significantly higher (P < .05) and gross motor function measure scores (function) were lower (P < .05). Sixty-eight percent of the good responders were nonindependent walkers compared to 14% of the poor responders (P < .05). There were no differences in age, type of cerebral palsy, and dose of injection. An Ashworth scale indicating increased muscle tone, lower gross motor function measure scores, and nonindependent ambulatory status were predictive for a favorable response to botulinum toxin A injections and can guide patient selection and expectations of treatment outcome.