Impact of obstructive sleep apnea on cardiac organ damage in patients with acute ischemic stroke.

BACKGROUND AND PURPOSE: Both obstructive sleep apnea (OSA) and cardiac organ damage have a crucial role in acute ischemic stroke. Our aim is to explore the relationship between OSA and cardiac organ damage in acute stroke patients. METHODS: A total of 130 consecutive patients with acute ischemic stroke were enrolled. Patients underwent full multichannel 24-h polysomnography for evaluation of OSA and echocardiography to evaluate left ventricle (LV) mass index (LV mass/BSA, LV mass/height), thickness of interventricular septum (IVS) and posterior wall (LVPW), LV ejection fraction and left atrium enlargement. Information on occurrence of arterial hypertension and its treatment before stroke was obtained from patients' history. RESULTS: 61.9% (70) of patients, mostly men (67.1%), with acute stroke had OSA (AHI > 10). Patients with acute stroke and OSA showed a significant increase (P < 0.05) of LV mass index, IVS and LVPW thickness and a significant left atrial enlargement as compared with patients without OSA. LV ejection fraction was not significantly different in stroke patients with and without OSA and was within normal limits. No relationship was found among cardiac alterations, occurrence of OSA and history of hypertension. CONCLUSION: Acute stroke patients with OSA had higher LV mass and showed greater left atrial enlargement than patients without OSA. This study confirms the high prevalence of OSA in stroke patients, suggesting also an association between OSA and cardiac target organ damage. Our finding of structural LV abnormalities in acute stroke patients with OSA suggests a potential role of OSA as contributing factor in determining both cerebrovascular and cardiac damage, even in absence of clear link with a history of blood pressure elevation.

Validation of a Neuro Virtual Reality-based version of the Multiple Errands Test for the assessment of executive functions.

The purpose of this study was to establish ecological validity and initial construct validity of the Virtual Reality (VR) version of the Multiple Errands Test (MET) (Shallice & Burgess, 1991; Fortin et al., 2003) based on the NeuroVR software as an assessment tool for executive functions. In particular, the MET is an assessment of executive functions in daily life, which consists of tasks that abide by certain rules and is performed in a shopping mall-like setting where items need to be bought and information needs to be obtained. The study population included three groups: post-stroke participants (n = 5), healthy, young participants (n = 5), and healthy, older participants (n = 5). Specific objectives were (1) to examine the relationships between the performance of three groups of participants in the Virtual Multiple Errands Test (VMET) and at the traditional neuropsychological tests employed to assess executive functions and (2) to compare the performance of post-stroke participants to those of healthy, young controls and older controls in the VMET and at the traditional neuropsychological tests employed to assess executive functions.

Implementation of the multiple errands test in a NeuroVR-supermarket: a possible approach.

Our goal was to develop a tool for the assessment of executive functions by customizing a virtual reality (VR) version of the Multiple Errands Test (MET) [Shallice & Burgess, 1991; Fortin et al., 2003]. The MET is an assessment of executive functions in daily life which consists of tasks that abide by certain rules. It is performed in an actual shopping mall-like setting where there are items to be bought and information to be obtained. The specific goal of this study was to conduct a pilot study using the virtual version of MET (VMET) with both control subjects and patients with cognitive impairment derived from stroke.

A NeuroVR based tool for cognitive assessment and rehabilitation of post-stroke patients: two case studies.

Neuropsychological disorders are common in stroke patients, ranging from an isolated impairment to impairment in multiple cognitive functions. The cognitive domains affected are in particular executive functions. These comprise planning, organising, conducting, assessing and controlling actions. Dual task abilities, that is the ability to perform successive or simultaneous tasks, are not easy to be evaluated and recovered by traditional paper and pencil methods, due to their ecological and contextual nature. NeuroVR 1.5 is a cost-free virtual reality platform based on open-source software, allowing professionals to easily modify a virtual world, to best suit the needs of the clinical setting.The present study was designed to develop and test a NeuroVR based tool for the rehabilitation of shifting of attention and action planning functions using tasks reminiscent of daily life tasks. We present the virtual environment and the cognitive procedure we developed, discussing two stroke patients case studies, which underwent an integrated neuropsychological and VR assessment.

Candidate gene analysis of IP-10 gene in patients with Alzheimer's disease.

Interferon-gamma-inducible Protein-10 (IP-10) is supposed to play a role in Alzheimer's disease (AD) development, as demonstrated by increased levels in cerebrospinal fluid from patients with AD. A mutation scanning of IP-10 exonic region was carried out in 10 patients with AD and 10 age-matched controls, demonstrating the presence of two previously reported single nucleotide polymorphisms (SNPs) in exon 4 (G-->C and T-->C) as well as a novel SNP in exon 2 (C-->T). Exon 4 G-->C and T-->C allelic variants were next evaluated in a population of 279 AD patients and 251 controls, in order to determine whether their presence could influence the susceptibility towards the development of the disease. These two SNPs were in complete linkage disequilibrium. No differences in haplotype frequencies were found in AD patients as compared with controls, even stratifying according to the presence of Apolipoprotein E varepsilon4 allele, gender or age at onset. A new protocol was developed to easily determine the C-->T SNP in exon 2. A preliminary analysis revealed a very low frequency of this allelic variant (1%). Therefore, the complete association study was not carried out because the size of our population was not sufficient to draw reliable conclusions. According to these results, IP-10 does not seem to be a risk factor for AD. However, a novel rare polymorphism has been identified, which could exert a role in AD susceptibility. Thus, further studies on larger populations are needed before confidently excluding IP-10 as a susceptibility gene for AD.

Serum MCP-1 levels are increased in mild cognitive impairment and mild Alzheimer's disease.

Upregulation of a number of chemokines, including monocyte chemotactic protein-1 (MCP-1), is associated with Alzheimer's disease (AD) pathological changes. Emerging evidence suggests that inflammatory events precede the clinical development of AD, as cytokine disregulation has been observed also in patients with mild cognitive impairment (MCI). MCP-1 levels were evaluated in serum samples from 48 subjects with MCI, 94 AD patients and 24 age-matched controls. Significantly increased MCP-1 levels were found in MCI and mild AD, but not in severe AD patients as compared with controls. mRNA levels in peripheral blood mononuclear cells (PBMC), evaluated by quantitative RT-PCR analysis, paralleled serum MCP-1 levels. Moreover, a progressive MCP-1 decrease was observed over a 1-year follow up in a subgroup of MCI subjects converted to AD. MCP-1 upregulation is likely to be a very early event in AD pathogenesis, by far preceding the clinical onset of the disease. Nevertheless, as MCP-1 is likely to play a role in several pathologies with an inflammatory component, a possible usefulness as an early AD biomarker would be possible only in combination with other molecules.