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PubMed2004

Pre- and postoperative assessment of left ventricular function by magnetic resonance imaging and 2-D-echocardiography in patients undergoing left ventricular aneurysmectomy.

BACKGROUND: Left ventricular (LV) aneurysms may complicate myocardial infarctions. Reliable quantification of LV functional parameters is mandatory to predict clinical outcome in patients undergoing LV aneurysmectomy. We compared global LV function measured by magnetic resonance (MR) and 2-D-echocardiography in patients before and after aneurysmectomy. METHODS: 31 patients (23 male), mean age 64 (range 35 - 85) years with an LV aneurysm (25/31 anterior MI, 5/31 inferior MI, 1/31 both) were enrolled. MR and echocardiography were performed directly before and 3 - 65 (median 8) days after surgery. MR studies were performed on a 1.5 Tesla scanner. End-diastolic and end-systolic volumes and diameters (EDV/ESV, EDD/ESD), ejection fraction (EF) and stroke volume (SV) were determined. Echocardiography was performed to determine EF, EDD and ESD. NYHA class was assessed before and 3 months after surgery. RESULTS: After aneurysmectomy MR analysis showed a decrease in EDV (255 +/- 68 ml to 202 +/- 59 ml) ( p < 0.001) and ESV (186 +/- 71 ml to 134 +/- 53 ml; p < 0.001); EF increased (28 +/- 10 % to 35 +/- 12 %; p < 0.001); EDD/ESD decreased ( p < 0.01). Compared to echocardiography, a low correlation was found in EF before/after surgery r = 0.76/r = 0.69 and ESD r = 0.43/r = 0.60, respectively. In EDD a good correlation was found before surgery (r = 0.81), and a lower correlation after surgery (r = 0.72). NYHA class improved from 3.0 +/- 0.5 before to 1.8 +/- 0.8 after operation ( p < 0.001). CONCLUSION: Resection of an LV aneurysm results in a mean improvement of 25 % in LV function, and improved clinical outcome. In asymmetric ventricles with aneurysms MR proved to be superior as a sensitive and non-invasive tool compared to conventional 2-D-echocardiography.

Adult↗

PubMed2004

Mining functional modules in genetic networks with decomposable graphical models.

In recent years, graphical models have become an increasingly important tool for the structural analysis of genome-wide expression profiles at the systems level. Here we present a new graphical modelling technique, which is based on decomposable graphical models, and apply it to a set of gene expression profiles from acute lymphoblastic leukemia (ALL). The new method explains probabilistic dependencies of expression levels in terms of the concerted action of underlying genetic functional modules, which are represented as so-called "cliques" in the graph. In addition, the method uses continuous-valued (instead of discretized) expression levels, and makes no particular assumption about their probability distribution. We show that the method successfully groups members of known functional modules to cliques. Our method allows the evaluation of the importance of genes for global cellular functions based on both link count and the clique membership count.

Gene Expression Profiling↗

PubMed2005

Global gene expression as a function of germline genetic variation.

Common, functional, germline genetic polymorphisms have been associated with clinical cancer outcomes. Little attention has been paid to the potential phenotypic consequences of germline genetic variation on downstream genes. We determined the germline status of 16 well-characterized functional polymorphisms in 126 children with newly diagnosed acute lymphoblastic leukemia (ALL). We assessed whether global gene expression profiles of diagnostic ALL blasts from the same patients differed by these germline polymorphic genotypes. Gene expression values were adjusted for ALL-subtype-specific patterns. Of the 16 loci, only the UGT1A1 promoter repeat polymorphism [A(TA)nTAA] (UGT1A1*28) and GSTM1 deletion were significant predictors of global gene expression in a supervised approach, which divided patients based on their germline genotypes [UGT1A1: 124 probe sets, false discovery rate (FDR)=13%, P< or =0.0031; GSTM1: 112 probe sets, FDR=42.5%, P< or =0.0084]. Genes whose expression distinguished the UGT1A1 (TA) 7/7 genotype from the other UGT1A1 genotypes included HDAC1, RELA and SLC2A1; those that distinguished the GSTM1 null genotype from non-null genotype included NBS1 and PRKR. In an unsupervised approach, the gene expression profiles using the entire array delineated two major clusters of patients. The only germline genotype frequency that differed between the two clusters was UGT1A1 (P=0.002; Fisher's exact test). Although their expression is limited to specific tissues, both GSTM1 and UGT1A1 are involved in the conjugation (and thus transport, excretion and lipophilicity) of a broad range of endobiotics and xenobiotics, which could plausibly have consequences for gene expression in different tissues.

Child↗

PubMed1989

Nitrous oxide does not induce myocardial ischemia in patients with ischemic heart disease and poor ventricular function.

Despite evidence from animal experiments to the contrary, nitrous oxide (N2O) reportedly does not induce myocardial ischemia when used as an adjunct to fentanyl anesthesia in patients with coronary artery disease who have well-preserved left ventricular (LV) function. However, the incidence of ischemia with N2O administration in similar patients with poor LV function may be different. The effects of N2O on segmental LV function, as determined by two-dimensional transesophageal echocardiography, changes in the ST-segment of the electrocardiogram were compared with the effects of an equal concentration of nitrogen (N2) (crossover design) in 70 patients who required elective coronary artery bypass grafting. Of these patients, 24% had left ventricular ejection fraction (LVEF) less than or equal to 40%. Myocardial ischemia was diagnosed in 14 patients during the study: four while awake, seven during induction of anesthesia and tracheal intubation, and four during the remainder of the study (one during N2O and three during 100% oxygen; one patient had two distinct periods of ischemia). No value for LVEF could be found that would distinguish between patients who did or did not have ischemia during the study. Patients treated with beta-adrenergic blocking drugs preoperatively were less likely to develop ischemia (P less than 0.05). Preoperative calcium channel blockers made no such differences. Onset of ischemia was not closely associated with hemodynamic changes. Thus, N2O does not induce clinically detectable myocardial ischemia in patients who have coronary artery disease, and poor LV function in situations in which the effects of deepening anesthetic depth and mild depression of global myocardial function are deemed desirable or harmless.

Adult↗

PubMed1999

Health utilities in Alzheimer's disease: a cross-sectional study of patients and caregivers.

OBJECTIVES: Although the broad impacts of Alzheimer's disease (AD) are increasingly recognized, little work has focused on the overall health-related quality of life experienced by Alzheimer's disease patients and their caregivers. The study had two main objectives: (1) to test the feasibility of measuring health utilities in Alzheimer's disease with a generic preference-weighted instrument using proxy respondents and (2) to assess the utility scores of Alzheimer's disease patients (and their caregivers) in different disease stages and care setting. METHODS: A cross-sectional study of 679 Alzheimer's disease patient/caregiver pairs was conducted at 13 sites in the United States: four academic medical centers, four managed care plans, two assisted living facilities, and three nursing homes. The Health Utilities Index Mark II (HUI:2) questionnaire was administered to caregivers of patients who responded both as proxies for patients and for themselves. Responses to the questionnaire were converted into a global utility score, between 0 and 1, using the HUI:2 multi-attribute utility function. RESULTS: Global utility scores varied considerably across patients' Alzheimer's disease stage: for the six stages assessed (questionable, mild, moderate, severe, profound, and terminal), mean utility scores were 0.73, 0.69, 0.53, 0.38, 0.27, and 0.14, respectively. In multiple regression analyses, Alzheimer's disease stage was a negative and significant predictor of utility scores for patients; setting did not exert an independent effect. Utility scores for the caregivers were insensitive to patients' Alzheimer's disease stage and setting. CONCLUSIONS: Patients' Alzheimer's disease stage had a substantial influence on health utilities, as measured by the HUI:2. More research is needed to assess the validity of using proxy respondents.

Activities of Daily Living↗

PubMed2005

The effect of high thoracic epidural anesthesia on systolic and diastolic left ventricular function in patients with coronary artery disease.

In patients with coronary artery disease, vasoconstriction is induced through activation of the sympathetic nervous system. Both alpha1- and alpha2-adrenergic epicardial and microvascular constriction are potent initiators of myocardial ischemia. Attenuation of ischemia has been observed when sympathetic nervous system activity is inhibited by high thoracic epidural anesthesia (HTEA). However, it is still a matter of controversy whether establishing HTEA may correspondingly translate into an improvement of left ventricular (LV) function. To clarify this issue, LV function was quantified serially before and after HTEA using a new combined systolic/diastolic variable of global LV function (myocardial performance index [MPI]) and additional variables that more specifically address systolic (e.g., fractional area change) or diastolic function (e.g., intraventricular flow propagation velocity [Vp]). High thoracic epidural catheters were inserted in 37 patients scheduled for coronary artery surgery, and HTEA was administered in the awake patients. Echocardiographic and hemodynamic measures were recorded before and after institution of HTEA. HTEA induced a significant improvement in diastolic LV function (e.g., Vp changed from 45.1 +/- 16.1 to 53.8 +/- 18.8 cm/s; P < 0.001), whereas indices of systolic function did not change. The change in the diastolic characteristics caused the MPI to improve from 0.51 +/- 0.13 to 0.35 +/- 0.13 (P < 0.001). We conclude that an improvement in cardiac function was due to improved diastolic characteristics.

Aged↗

PubMed2004

Improved systolic ventricular function with normal myocardial mechanics in compensated cardiac hypertrophy.

There is still controversy about the relation between changes in myocardial contractile function and global left ventricular (LV) performance during stable concentric hypertrophy. To clarify this, we analyzed LV function in vivo and myocardial mechanics in vitro in rats with pressure overload-induced cardiac hypertrophy. Male Wistar rats (70 g) underwent ascending aortic stenosis for 8 weeks (group AAS, n = 9). LV performance was assessed by transthoracic echocardiography under anesthesia. Myocardial function was studied in isolated papillary muscle preparations during isometric contraction. The data were compared with age- and sex-matched sham-operated rats (group C, n = 9). LV weight-to-body weight ratio (C: 2.13 +/- 0.14 mg/g; AAS: 3.24 +/- 0.44 mg/g), LV relative wall thickness (C: 0.18 +/- 0.02; AAS: 0.33 +/- 0.09), and LV fractional shortening (C: 54 +/- 5%; AAS: 70 +/- 8%) were increased in group AAS (P < 0.05). Echocardiographic analysis also indicated a significant association (r = 0.74; P < 0.001) between the percent fractional shortening index and LV relative wall thickness. The performance of AAS isolated muscle revealed that active tension (C: 6.6 +/- 1.7 g/mm2; AAS: 6.5 +/- 1.5 g/mm2) and maximum rate of tension development (C: 69 +/- 21 g/mm2/s; AAS: 69 +/- 18 g/mm2/s) were not significantly different from group C (P > 0.05). In conclusion, compensated pressure-overload myocardial hypertrophy is associated with preserved myocardial function and increased ventricular performance. The improved LV function might be due to the ventricular remodeling characterized by an increased relative wall thickness.

Animals↗

PubMedDate not supplied

A review of the randomized controlled trials of tacrine in the treatment of Alzheimer's disease: methodologic considerations.

This review examines the features of the 16 randomized controlled trials that have been published on the use of oral tacrine for treating probable Alzheimer's disease and explores the methodologic problems associated with these studies. Patient selection using the standard National Institute of Neurological and Communicative Disorders and Stroke/Alzheimer's Disease and Related Disorders Association (NINCDS/ADRDA) criteria is now a feature of all studies; however, the specificity of the diagnosis, the severity of the dementia, the heterogeneity of the dementia with respect to disease and patient genotype, and the health status of the patients all are factors that may affect responsiveness to therapy. Most studies use crossover designs; however, because of the progressive nature of the disease and the variability in the rate of decline, parallel group studies over a length of time sufficient to produce worsening in disease severity in a placebo group appear to be most suited to detecting clinically relevant therapeutic effects. The close relation between dose, efficacy, and serious adverse events has been a problem in the tacrine trials, since many studies, titrating to maximum tolerated doses, have used clinically ineffective doses. This problem can be circumvented by the use of fixed-dose regimens. Three broad classes of outcome measures have been used to assess treatment efficacy: 1) performance-based tests of cognitive function, 2) global impressions of change on the part of the clinician or care giver, and 3) functional measures of daily living. Including a limited number of each type of measure provides strong evidence of clinically relevant therapeutic benefit; however, more widely accepted and better validated instruments need to be developed for all three areas.

Alzheimer Disease↗

PubMed1992

On the nature of global classification.

Molecular sequencing technology has brought biology into the era of global (universal) classification. Methodologically and philosophically, global classification differs significantly from traditional, local classification. The need for uniformity requires that higher level taxa be defined on the molecular level in terms of universally homologous functions. A global classification should reflect both principal dimensions of the evolutionary process: genealogical relationship and quality and extent of divergence within a group. The ultimate purpose of a global classification is not simply information storage and retrieval; such a system should also function as an heuristic representation of the evolutionary paradigm that exerts a directing influence on the course of biology. The global system envisioned allows paraphyletic taxa. To retain maximal phylogenetic information in these cases, minor notational amendments in existing taxonomic conventions should be adopted.

Biological Evolution↗

PubMed2004

Comparison between tagged MRI and standard cine MRI for evaluation of left ventricular ejection fraction.

Global left ventricular function is a prognostic indicator and is used to evaluate therapeutical interventions in patients with heart failure. Regional left ventricular function can be determined with tagged MRI. Assessment of global left ventricular function using the tagging data may have additional clinical value without incurring extra scanning time, which is currently a limiting factor in cardiac imaging. Direct determination of end-diastolic volume is not possible with conventional tagged MRI. However, end-systolic volume can be directly measured because myocardium-blood contrast improves through a tagged image series. We investigated the potential of tagged MRI using frequency-domain analysis software to retrospectively track end-diastolic contour from end-systolic contour and subsequently calculate the ejection fraction. Tagged MRI was compared with the standard bright-blood cine MRI in healthy volunteers ( n=20) and patients with previous myocardial infarction ( n=8). Left ventricular ejection fraction derived from tagged MRI is linearly correlated to left ventricular ejection fraction obtained by standard cardiac cine MRI ( y=1.0 x+1.31, r>0.98, p=0.014). In addition, the inter-observer and intra-observer coefficient of variation for left ventricular ejection fraction measurements was low (CV(intra)=0.4%, CV(inter)=1.3%). With tagged MRI, only end-systolic volume needs to be manually determined, and accurate estimation of left ventricular ejection fraction is obtained because end-diastolic and end-systolic volumes are determined using identical anatomical points. Our data indicate that tagged MRI can be used to quantitatively assess both regional and global left ventricular function. Therefore, tagged MRI may be a valuable clinical tool for determining the prognosis and evaluating the effect of therapeutical intervention using a single imaging session in patients with left ventricular dysfunction.

Humans↗

PubMed2003

Evolutionary trace of G protein-coupled receptors reveals clusters of residues that determine global and class-specific functions.

G protein-coupled receptor (GPCR) activation mediated by ligand-induced structural reorganization of its helices is poorly understood. To determine the universal elements of this conformational switch, we used evolutionary tracing (ET) to identify residue positions commonly important in diverse GPCRs. When mapped onto the rhodopsin structure, these trace residues cluster into a network of contacts from the retinal binding site to the G protein-coupling loops. Their roles in a generic transduction mechanism were verified by 211 of 239 published mutations that caused functional defects. When grouped according to the nature of the defects, these residues sub-divided into three striking sub-clusters: a trigger region, where mutations mostly affect ligand binding, a coupling region near the cytoplasmic interface to the G protein, where mutations affect G protein activation, and a linking core in between where mutations cause constitutive activity and other defects. Differential ET analysis of the opsin family revealed an additional set of opsin-specific residues, several of which form part of the retinal binding pocket, and are known to cause functional defects upon mutation. To test the predictive power of ET, we introduced novel mutations in bovine rhodopsin at a globally important position, Leu-79, and at an opsin-specific position, Trp-175. Both were functionally critical, causing constitutive G protein activation of the mutants and rapid loss of regeneration after photobleaching. These results define in GPCRs a canonical signal transduction mechanism where ligand binding induces conformational changes propagated through adjacent trigger, linking core, and coupling regions.

Amino Acid Sequence↗

PubMed2003

Passive ventricular constraint to improve left ventricular function and mechanics in an ovine model of heart failure secondary to acute myocardial infarction.

OBJECTIVE: This study investigated the effects on global cardiac function and myocardial energetics of limiting progressive dilatation after infarction by means of a woven polyester jacket cardiac support device. We hypothesized that placement of the cardiac support device results in a decrease in myocardial wall stress and improvement in cardiac function and myocardial energetics. METHODS: To investigate the effect of passive constraint on left ventricular function and mechanics, a total of 10 sheep were studied with pressure-volume analysis and magnetic resonance imaging. A baseline study was followed by the creation of an anterior infarct. After 1 week, the animals underwent a second study. The cardiac support device was then placed over the epicardium in 5 sheep; the remaining animals served as controls. A terminal study was performed at 2 months after the infarct. RESULTS: The cardiac support device group at the terminal study exhibited a decrease in end-diastolic volume (control 110.3 +/- 19.8 mL vs cardiac support device 67.6 +/- 4.7 mL, P =.006) and an improved ejection fraction (control 15.5% +/- 5.7% vs cardiac support device 29.46% +/- 4.42%, P =.008) relative to the control group. Myocardial energetics were also enhanced in the cardiac support device group, as evidenced by the significant improvements in potential energy (control 2015 +/- 503 mL. mm Hg/beat vs cardiac support device 885 +/- 220 mL. mm Hg/beat, P =.006), efficiency (control 39.4% +/- 13.6% vs cardiac support device 59.8% +/- 8.5%, P =.044), and oxygen consumption (control 0.072 +/- 0.013 mL O(2)/beat vs cardiac support device 0.052 +/- 0.007 mL O(2)/beat, P =.034). CONCLUSION: Passive constraint with the cardiac support device after infarct prevents further remodeling and may stimulate reverse remodeling in heart failure secondary to acute myocardial infarction. These results suggest that in human beings placement of the cardiac support device after a large anterior myocardial infarction may be effective in halting the remodeling process that often leads to end-stage heart failure. If proved effective, placement of a cardiac support device after large heart attacks has the potential to decrease the incidence of heart failure that results after large myocardial infarctions.

Animals↗

PubMed2001

Philadelphia Panel evidence-based clinical practice guidelines on selected rehabilitation interventions for neck pain.

INTRODUCTION: A structured and rigorous methodology was developed for the formulation of evidence-based clinical practice guidelines (EBCPGs), then was used to develop EBCPGs for selected rehabilitation interventions for the management of neck pain. METHODS: Evidence from randomized controlled trials (RCTs) and observational studies was identified and synthesized using methods defined by the Cochrane Collaboration that minimize bias by using a systematic approach to literature search, study selection, data extraction, and data synthesis. Meta-analysis was conducted where possible. The strength of evidence was graded as level I for RCTs or level II for nonrandomized studies. DEVELOPING RECOMMENDATIONS: An expert panel was formed by inviting stakeholder professional organizations to nominate a representative. This panel developed a set of criteria for grading the strength of both the evidence and the recommendation. The panel decided that evidence of clinically important benefit (defined as 15% greater relative to a control based on panel expertise and empiric results) in patient-important outcomes was required for a recommendation. Statistical significance was also required but was insufficient alone. Patient-important outcomes were decided by consensus as being pain, function, patient global assessment, quality of life, and return to work, providing that these outcomes were assessed with a scale for which measurement reliability and validity have been established. VALIDATING THE RECOMMENDATIONS: A feedback survey questionnaire was sent to 324 practitioners from 6 professional organizations. The response rate was 51%. RESULTS: For neck pain, therapeutic exercises were the only intervention with clinically important benefit relative to a control (grade A for pain and function, grade B for patient global assessment). There was good agreement with this recommendation from practitioners (93%). For several interventions and indications (eg, thermotherapy, therapeutic ultrasound, massage, electrical stimulation), there was a lack of evidence regarding efficacy. CONCLUSIONS: This methodology of developing EBCPGs provides a structured approach to assessing the literature and developing guidelines that incorporates clinicians' feedback and is widely acceptable to practicing clinicians. Further well-designed RCTs are warranted regarding the use of several interventions for patients with neck pain where evidence was insufficient to make recommendations.

Acute Disease↗

PubMed2006

Transcoronary transplantation of progenitor cells after myocardial infarction.

BACKGROUND: Pilot studies suggest that intracoronary transplantation of progenitor cells derived from bone marrow (BMC) or circulating blood (CPC) may improve left ventricular function after acute myocardial infarction. The effects of cell transplantation in patients with healed myocardial infarction are unknown. METHODS: After an initial pilot trial involving 17 patients, we randomly assigned, in a controlled crossover study, 75 patients with stable ischemic heart disease who had had a myocardial infarction at least 3 months previously to receive either no cell infusion (23 patients) or infusion of CPC (24 patients) or BMC (28 patients) into the patent coronary artery supplying the most dyskinetic left ventricular area. The patients in the control group were subsequently randomly assigned to receive CPC or BMC, and the patients who initially received BMC or CPC crossed over to receive CPC or BMC, respectively, at 3 months' follow-up. RESULTS: The absolute change in left ventricular ejection fraction was significantly greater among patients receiving BMC (+2.9 percentage points) than among those receiving CPC (-0.4 percentage point, P=0.003) or no infusion (-1.2 percentage points, P<0.001). The increase in global cardiac function was related to significantly enhanced regional contractility in the area targeted by intracoronary infusion of BMC. The crossover phase of the study revealed that intracoronary infusion of BMC was associated with a significant increase in global and regional left ventricular function, regardless of whether patients crossed over from control to BMC or from CPC to BMC. CONCLUSIONS: Intracoronary infusion of progenitor cells is safe and feasible in patients with healed myocardial infarction. Transplantation of BMC is associated with moderate but significant improvement in the left ventricular ejection fraction after 3 months.

Aged↗

PubMed2004

Histone deacetylase activity is required for embryonic stem cell differentiation.

Mammalian development requires commitment of cells to restricted lineages, which requires epigenetic regulation of chromatin structure. Epigenetic modifications were examined during in vitro differentiation of murine embryonic stem (ES) cells. Global histone acetylation, a euchromatin marker, declines dramatically within 1 day of differentiation induction and partially rebounds by day 2. Histone H3-Lys9 methylation, a heterochromatin marker, increases during in vitro differentiation. Conversely, the euchromatin marker H3-Lys4 methylation transiently decreases, then increases to undifferentiated levels by day 4, and decreases by day 6. Global cytosine methylation, another heterochromatin marker, increases slightly during ES cell differentiation. Chromatin structure of the Oct4 and Brachyury gene promoters is modulated in concert with their pattern of expression during ES cell differentiation. Importantly, prevention of global histone deacetylation by treatment with trichostatin A prevents ES cell differentiation. Hence, ES cells undergo functionally important global and gene-specific remodeling of chromatin structure during in vitro differentiation. genesis 38:32-38, 2004.

Acetyltransferases↗

PubMed1998

Evaluation of autosomal dominant polycystic kidney disease by DTPA renal scintigraphy.

Sixty patients with previously documented autosomal dominant polycystic kidney disease (ADPKD) were investigated using dynamic kidney scintigraphy with 99mTc-diethylenetriaminepentaacetic acid (DTPA). Patients were subdivided in respect of glomerular filtration rate (GFR) as follows: PKD I group (normal GFR), PKD II group (moderately reduced GFR), and PKD III (severely reduced GFR). Scintigraphic features, time activity curves, excretion parameters, global and individual kidney functions were analyzed. Because of GFR dependent sensitivity, in advanced renal failure being only 0.1, and low reproducibility (11% intraobserver, 22% interobserver), 99mTc-DTPA dynamic kidney scintigraphy cannot be generally recommended for the diagnosis of ADPKD, but has to become a routine method for functional evaluation of both global and individual renal functions, as well as degree of excretion disturbances in ADPKD patients.

Adult↗

PubMed2000

The effect of intracortical competition on the formation of topographic maps in models of Hebbian learning.

Correlation-based learning (CBL) models and self-organizing maps (SOM) are two classes of Hebbian models that have both been proposed to explain the activity-driven formation of cortical maps. Both models differ significantly in the way lateral cortical interactions are treated, leading to different predictions for the formation of receptive fields. The linear CBL models predict that receptive field profiles are determined by the average values and the spatial correlations of the second order of the afferent activity patterns, whereas SOM models map stimulus features. Here, we investigate a class of models which are characterized by a variable degree of lateral competition and which have the CBL and SOM models as limit cases. We show that there exists a critical value for intracortical competition below which the model exhibits CBL properties and above which feature mapping sets in. The class of models is then analyzed with respect to the formation of topographic maps between two layers of neurons. For Gaussian input stimuli we find that localized receptive fields and topographic maps emerge above the critical value for intracortical competition, and we calculate this value as a function of the size of the input stimuli and the range of the lateral interaction function. Additionally, we show that the learning rule can be derived via the optimization of a global cost function in a framework of probabilistic output neurons which represent a set of input stimuli by a sparse code.

Algorithms↗

PubMed2005

[Evaluation of the disabilities of hemiplegic patients].

OBJECTIVES: To identify and describe the most useful functional disability scales for assessing post-stroke hemiplegic patients and those used largely in clinical trials. METHODS: A literature review of Medline about the functional parameters for balance, gait and mobility, upper extremity functional abilities, and activities of daily living. The metrologic properties of the scales were specified as were their clinical use. RESULTS: Thirty-three scales were evaluated and classified into five categories: balance (6 scales), gait and mobility (4), upper limb function (11), global motricity scales (5) and independence in activities of daily living (7). DISCUSSION AND CONCLUSION: Many functional scales are useful for assessing post-stroke hemiplegic patients. To assess balance, the Postural Assessment Stroke Scale and Berg Balance Scale are the most interesting. The Functional Ambulation Classification and the Timed Up and Go Test are the most relevant to assess gait and mobility. The Action Research Arm Test is largely used to assess upper limb functional abilities. The Functional Independence Measure and the Barthel Index are largely used to assess independence in activities of daily living.

Disability Evaluation↗