Cognitive impairments in patients with cerebrovascular risk factors: A comparison of Mini Mental Status Exam and Montreal Cognitive Assessment

Objective and background

Recent evidence suggests that cerebrovascular risk factors are contributing factors, not only to vascular cognitive decline, but also for Alzheimer's disease. The study aim was to compare Montreal Cognitive Assessment (MoCA) and MMSE tests in subjects with cerebrovascular risk factors.

Patients and methods

Fifty patients with cerebrovascular risk factors were administrated the MMSE and MoCA tests. Data collected for all subjects and the results were compared.

Results

Cognitive impairments revealed on both tests were more frequent in females, and correlated with the level of education (for MoCA r = 0.75, p = 0.001 and for MMSE r = 0.662, p = 0.001). Mean values of MoCA score were significantly lower in patients with two or more cerebrovascular risk factors compared with those with only one risk factor (19.92 ± 5.99 versus 23.81 ± 4.06; p = 0.049), a finding that was not evidenced by MMSE.

Conclusions

The most frequent impaired domain in MMSE (for scores both less and more than 26) was attention; but in MoCA the most frequent impaired domains were delayed recall (for scores above 26), and visuo-executive (for scores ≤26), which is a common domain involved in vascular cognitive decline. MoCA may be superior to MMSE in early detection of cognitive decline in patients with vascular risk factors.     

Non-invasive assessment of right ventricular function in the late follow-up of the Senning procedure

Deteriorating ventricular function is a major concern after the Senning operation. A Doppler-derived non-geometric measurement, the so-called myocardial performance index, has been described for use in adults and children. We aimed to assess the utility of this index as a method for quantification of right ventricular function in patients in the late follow-up of the Senning procedure, and to correlate the right ventricular ejection fraction and the first derivative of right ventricular pressure as derived using echocardiography with the ejection fraction determined using magnetic resonance imaging. We studied 44 patients within a mean postoperative period of 15.3 years. We calculated the right ventricular myocardial performance index by pulsed wave Doppler interrogation of tricuspid inflow and aortic outflow, the ejection fraction by Simpson's rule, and the first derivative of right ventricular pressure by continuous wave Doppler from tricuspid regurgitation. Mean values of right ventricular myocardial performance index, ejection fraction, and the first derivative of right ventricular pressure were 0.50, 39 percent and 1,398 millimetres of mercury per second, respectively. A cut-off value of 0.47 for the right ventricle myocardial performance index was determined, with a sensitivity of 75 percent and a specificity of 62.5 percent. We found no correlation between ejection fraction and the first derivative of right ventricular pressure as estimated by echocardiography and the ejection fraction as shown by magnetic resonance imaging (r2 equal to 0.29 and 0.04 respectively). We concluded, first, that patients with preserved right ventricular function had values for the right ventricular myocardial performance index lower than 0.47, and second, that ejection fraction and the first derivative of right ventricular pressure as determined echocardiographically did not correlate with values derived using magnetic resonance imaging.     

Opioid Receptor Blockade Improves Mesenteric Responsiveness in Biliary Cirrhosis

Arterial vasodilation with concomitant hyperdynamic circulation is a common finding in cirrhotic subjects. Elevated levels of plasma endogenous opioid peptides have been reported in cholestasis and cirrhosis. Increased opioid peptides contribute to different manifestations of chronic liver disease such as pruritis, ascitis, and hepatic encephalopathy. In this study the potential role of opioid system in cirrhosis-induced vascular hyporesponsiveness was investigated. Bile duct ligated and sham operated animals received daily subcutaneous administration of naltrexone, an opioid receptor antagonist (20 mg/kg/day), or saline for 28 days. After 4 weeks the superior mesenteric artery was cannulated and was perfused according to McGregor method and then phenylephrine vasoconstrictor response of mesenteric vessels (10⁻¹⁰ to 10⁻⁶ mol) was examined. In order to evaluate the effects of acute opioid receptor blockade, additional groups of animals were treated by acute single intraperitoneal naltrexone injection (20 mg/kg). Plasma level of nitrite/nitrate as an indicator for nitric oxide production was measured. Biliary cirrhosis was accompanied with a decrease in baseline perfusion pressure in mesenteric vascular bed (P < 0.01). Chronic opioid receptor blockade significantly increased this parameter (P < 0.01). The maximum pressure response to phenylephrine was decreased significantly in cirrhosis while chronic naltrexone treatment completely improved it (P < 0.01). Acute single injection of naltrexone could not influence the understudied homodynamic parameters. Chronic opioid receptor blockade did not modulate the increased nitrite/nitrate levels following cholestasis. This study provided evidence on the contribution of endogenous opioid system to vascular hyporesponsiveness in cirrhosis which is not directly correlated to high plasma NO levels.     

Rabies virus in insectivorous bats: Implications of the diversity of the nucleoprotein and glycoprotein genes for molecular epidemiology

Insectivorous bats are the main reservoirs of rabies virus (RABV) in various regions of the world. The aims of this study were to (a) establish genealogies for RABV strains from different species of Brazilian insectivorous bats based on the nucleoprotein (N) and glycoprotein (G) genes, (b) investigate specific RABV lineages associated with certain genera of bats and (c) identify molecular markers that can distinguish between these lineages. The genealogic analysis of N and G from 57 RABV strains revealed seven genus-specific clusters related to the insectivorous bats Myotis, Eptesicus, Nyctinomops, Molossus, Tadarida, Histiotus and Lasiurus. Molecular markers in the amino acid sequences were identified which were specific to the seven clusters. These results, which constitute a novel finding for this pathogen, show that there are at least seven independent epidemiological rabies cycles maintained by seven genera of insectivorous bats in Brazil.     

Effects of mood stabilizers on hippocampus and amygdala BDNF levels in an animal model of mania induced by ouabain

There is a body of evidence suggesting that BDNF is involved in bipolar disorder (BD) pathogenesis. Intracerebroventricular (ICV) injection of ouabain (OUA), a specific Na⁺/K⁺ ATPase inhibitor, induces hyperlocomotion in rats, and has been used as an animal model of mania. The present study aims to investigate the effects of the lithium (Li) and valproate (VPT) in an animal model of mania induced by ouabain. In the reversal model, animals received a single ICV injection of OUA or cerebrospinal fluid (aCSF). From the day following the ICV injection, the rats were treated for 6 days with intraperitoneal (IP) injections of saline (SAL), Li or VPT twice a day. In the maintenance treatment (prevention model), the rats received IP injections of Li, VPT, or SAL twice a day for 12 days. In the 7th day of treatment the animals received a single ICV injection of either OUA or aCSF. After the ICV injection, the treatment with the mood stabilizers continued for more 6 days. Locomotor activity was measured using the open-field test and BDNF levels were measured in rat hippocampus and amygdala by sandwich-ELISA. Li and VPT reversed OUA-related hyperactive behavior in the open-field test in both experiments. OUA decreased BDNF levels in first and second experiments in hippocampus and amygdala and Li treatment, but not VPT reversed and prevented the impairment in BDNF expression after OUA administration in these cerebral areas. Our results suggest that the present model fulfills adequate face, construct and predictive validity as an animal model of mania.