Alvaro Reyes

The effect of multidisciplinary rehabilitation on brain structure and cognition in Huntington's disease: An exploratory study

There is a wealth of evidence detailing gray matter degeneration and loss of cognitive function over time in individuals with Huntingtons disease (HD). Efforts to attenuate disease‐related brain and cognitive changes have been unsuccessful to date. Multidisciplinary rehabilitation, comprising motor and cognitive intervention, has been shown to positively impact on functional capacity, depression, quality of life and some aspects of cognition in individuals with HD. This exploratory study aimed to evaluate, for the first time, whether multidisciplinary rehabilitation can slow further deterioration of disease‐related brain changes and related cognitive deficits in individuals with manifest HD.

Effects of prenatal stress and exercise on dentate granule cells maturation and spatial memory in adolescent mice

Exposure to prenatal stress (PS) increases the risk of developing neurobehavioral disturbances later in life. Previous work has shown that exercise can exert beneficial effects on brain damage; however, it is unknown whether voluntary wheel running (VWR) can ameliorate the neurobehavioral impairments induced by PS in adolescent offspring. Pregnant CF‐1 mice were randomly assigned to control (n = 5) or stressed (n = 5) groups. Pregnant dams were subjected to restraint stress between gestational days 14 and 21 (G14–21), whereas controls remained undisturbed in their home cages. On postnatal day 21 (P21), male pups were randomly assigned to the following experimental groups: control (n = 5), stressed (n = 5), and stressed mice + daily submitted to VWR (n = 4). At P52, all groups were behaviorally evaluated in the Morris water maze. Animals were then sacrificed, and Golgi‐impregnated granule cells were morphometrically analyzed. The results indicate that PS produced significant behavioral and neuronal impairments in adolescent offspring and that VWR significantly offset these deleterious effects.

Respiratory Muscle Training for Respiratory Deficits in Neurodegenerative Disorders: A Systematic Review

BACKGROUND Studies of the impact of respiratory muscle training (RMT) on central neurodegenerative pathologies have been aimed at improving pulmonary function. However, there is no certainty about the effectiveness of RMT in patients affected by these groups of disorders. The purpose of this review was to assess the evidence regarding the efficacy of inspiratory muscle training (IMT) and expiratory muscle training (EMT) on respiratory function in patients with neurodegenerative disorders of the CNS. METHODS A comprehensive search from 1990 to September 2012 on MEDLINE, Physiotherapy Evidence Database (PEDro), PubMed, Cochrane Library, and Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases was made. Studies reporting on IMT and EMT in patients with neurodegenerative diseases were included. The selected studies were abstracted using a standardized data collection instrument and were assessed by a quality checklist created and adapted from CONSORT (Consolidated Standards for Reporting Trials) and TREND (Transparent Reporting of Evaluation with Nonrandomized Designs). RESULTS Twenty-four studies were identified by the search strategy. Only 19 studies met the criteria for full review. Ten studies met all the inclusion criteria and were included in the final analysis. Of the 16 parameters present in the quality assessment checklist, only six were achieved for the studies analyzed. CONCLUSIONS There is some evidence that RMT improves a number of respiratory function parameters in patients with Parkinson disease and multiple sclerosis; however, the number of studies and their quality are not sufficient to conclude whether IMT or EMT is effective in improving respiratory function in patients with neurodegenerative disorders of the CNS.

Prognosis of Cryptogenic Ischemic Stroke: A Prospective Single-Center Study in Chile

Approximately 25%-40% of ischemic strokes are considered of unknown cause (ie, cryptogenic). The available information on associated risk factors, functional outcome, and recurrence of this subtype of stroke is limited, especially for the Chilean population. We conducted a prospective cohort study of 380 patients aged ≥ 18 years admitted consecutively to a stroke unit with demonstrated ischemic stroke. The stroke subtypes were classified according to the Trial of Org 10172 in Acute Stroke Treatment criteria. The modified Rankin Scale score and Barthel Index were used to assess functional outcome. The Kaplan-Meier product-limit method and Cox proportional hazards regression analysis were used to identify predictors of recurrent stroke during the follow-up period (mean, 2.1 years). Cryptogenic stroke (CS) was diagnosed in 76 patients (20%), 55.2% of them male, with a mean age of 62 ± 17 years. CS was the third most common stroke subtype after the large-artery disease (29%) and cardioembolic (24.4%) subtypes. After adjustment for age and sex, no vascular risk factors or laboratory parameters assessed at the time of admission were found to be predictive of CS. The CS subtype had the lowest rate of stroke recurrence at the end of the follow-up period (n = 4; 2.5% per year; odds ratio, 0.32; 95% confidence interval, 0.11-0.91; P = .022), a favorable functional outcome (mean modified Rankin Scale score, 2; mean Barthel Index, 77), and no increase in mortality risk (odds ratio, 0.73; 95% confidence interval, 0.29-1.77; P = .48). Our findings demonstrate that patients with no definite etiology identified after an extensive workup are at lower risk of recurrence and more likely to have a favorable outcome. No risk factors distinguish CS from other stroke subtypes in our study population.

Propuesta de índices de gestión de servicios médico-quirúrgicos hospitalarios mediante técnicas estadísticas multivariantes

Data on admissions to a University Hospital during 2003 were analyzed. Number ofdischarges, lethality rate, re-admission rate, number of outpatient consultations, length ofhospital stay and surgical complexity index were analyzed, using information obtained by theOperations Management Department. The Principal Components Analysis (PCA) technique wasapplied and the R correlation matrix was used.

Surface electromyograph activity of submental muscles during swallowing and expiratory muscle training tasks in Huntington's disease patients

INTRODUCTION Huntingtons disease (HD) patients have difficulty in swallowing, leading to aspiration pneumonia, which is a major cause of death. It seems possible that submental muscles that are crucial for preventing an escape of a bolus into the airway, are affected by HD, but no previous studies have investigated this. OBJECTIVE To assess surface electromyograph (sEMG) activity of submental muscles during swallowing and expiratory muscle training (EMT) tasks in HD patients in comparison to healthy volunteers. METHODS sEMG activities of submental muscles during saliva, water swallowing, EMT tasks performed at 25% and 75% of maximum expiratory pressure were recorded and normalised by the sEMG activity during an effortful swallow in 17 early to mid stage HD patients and 17 healthy volunteers. RESULTS sEMG activity was greater (p<0.05) during EMT tasks than saliva and water swallowing, but was not significantly different between groups for saliva, water swallowing and EMT at 25%. HD patients had lower sEMG activity for EMT at 75% (p<0.05). CONCLUSION Decreases in submental muscle activity were not evident in HD patients except during EMT at 75%. This suggests that relative submental muscle weakness is observed only during a high intensity task in early to mid stage HD patients.

Melatonin ameliorates neocortical neuronal dendritic impairment induced by toluene inhalation in the rat

The present study investigated the effects of toluene inhalation and the restorative effects of melatonin on branching and basal dendritic outgrowth of superficial pyramidal neurons in rats frontal, parietal, and occipital cortices. At postnatal day 21 (P21), Sprague-Dawley male rats were randomly assigned to either an air-only group or a toluene group. From P22 to P32 the animals were exposed to either clean air or toluene vapors (5000-6000 ppm) for 10 min/day. This strategy simulated common toluene abuse in humans, which consists of 15-20 rapid inhalations of highly concentrated solvent. Once the inhalation period was over (P32), toluene exposed animals were randomly reassigned to one of following experimental groups: (i) air-control/saline; (ii) toluene/saline; (iii) toluene/melatonin 0.5mg/kg; (iv) toluene/melatonin 1.0mg/kg; (v) toluene/melatonin 5.0mg/kg; and (vi) toluene/melatonin 10mg/kg. Seven days after the last inhalation (P39), all the animals were sacrificed under deep anesthesia; brains were dissected out and stained according to the Golgi-Cox-Sholl procedure. Layer II/III pyramidal neurons were morphologically analyzed by measuring their basilar dendritic length and the number of branches. The results obtained revealed that (i) toluene inhalation significantly reduced dendritic outgrowth and branching in all cortical areas studied, and (ii) intraperitoneal administration of melatonin (0.5-10mg/kg) was able to restore the dendritic impairment induced by toluene exposure.

Respiratory muscle training on pulmonary and swallowing function in patients with Huntington’s disease: a pilot randomised controlled trial

Objective: To examine the effects of 4-month of respiratory muscle training on pulmonary and swallowing function, exercise capacity and dyspnoea in manifest patients with Huntington’s disease. Design: A pilot randomised controlled trial. Setting: Home based training program. Participants: Eighteen manifest Huntington’s disease patients with a positive genetic test and clinically verified disease expression, were randomly assigned to control group (n=9) and training group (n=9). Intervention: Both groups received home-based inspiratory (5 sets of 5 repetitions) and expiratory (5 sets of 5 repetitions) muscle training 6 times a week for 4 months. The control group used a fixed resistance of 9 centimeters of water, and the training group used a progressively increased resistance from 30% to 75% of each patient’s maximum respiratory pressure. Main measures: Spirometric indices, maximum inspiratory pressure, maximum expiratory pressure, six minutes walk test, dyspnoea, water-swallowing test and swallow quality of life questionnaire were assessed before, at 2 and 4 months after training. Results: The magnitude of increases in maximum inspiratory (d=2.9) and expiratory pressures (d=1.5), forced vital capacity (d=0.8), forced expiratory volume in 1 second (d=0.9) and peak expiratory flow (d=0.8) was substantially greater for the training group in comparison to the control group. Changes in swallowing function, dyspnoea and exercise capacity were small (d≤0.5) for both groups without substantial differences between groups. Conclusions: A home-based respiratory muscle training program appeared to be beneficial to improve pulmonary function in manifest Huntington’s disease patients but provided small effects on swallowing function, dyspnoea and exercise capacity.

A dynamic evaluation of how kick point location influences swing parameters and related launch conditions

In golf, many parameters of the driver can be modified to maximise hitting distance. The main objective of this study was to determine whether drivers fitted with shafts having high and low kick points would alter selected swing parameters and related launch conditions. In total, 12 elite male golfers (handicap score = 1.2 ± 1.8) had three shots analysed for two drivers fitted with ‘stiff’ shafts with differing kick point location. Stiffness profiles of these shafts were also measured. Five swing and related launch parameters were measured using a real-time launch monitor. The locations of the low and high kick points on each shaft during the golf swing (the dynamic kick points) were confirmed via motion analysis. The driver fitted with the shaft containing the high kick point displayed a more negative (steeper) angle of attack (p < 0.01), a lower launch angle (p < 0.01) and an increased spin rate (p < 0.01) when compared to a driver fitted with a low kick point shaft. It is possible that the attack angle differed between drivers due to the greater amount of shaft bending found late in the downswing (80% of the downswing and just before impact). Future work is needed in this under-researched area to determine why these differences occurred.

Estudio de variables asociadas al cáncer de piel en Chile mediante análisis de componentes principales

Resumen Fundamento La incidencia de cancer de piel en Chile ha aumentado en los ultimos anos. Objetivo Asociar variables al cancer de piel en Chile a traves de indices generados mediante tecnicas estadisticas descriptivas multivariantes. Material y metodo Durante el mes de mayo de 2004 se recopilo informacion de datos demograficos, meteorologicos y clinicos de Chile, correspondientes al ejercicio 2001, ultima informacion completa y oficial disponible para la totalidad de los Servicios de Salud del pais. Se estudiaron las variables confeccionadas por el Instituto Nacional de Estadistica (INE), el Ministerio de Salud (MINSAL), el Ministerio de Planificacion y Cooperacion (MIDEPLAN), el Fondo Nacional de Salud (FONASA), la Direccion Meteorologica de Chile, la Universidad Tecnica Federico Santa Maria y la Direccion General de Aguas. Se aplico a los datos obtenidos un analisis de components principales (ACP). Resultados Se seleccionaron las tres primeras components principales, con un porcentaje acumulado de variabilidad explicada de 54,48 %. La primera componente principal explica el 24,92 % de la variabilidad y tiene relacion con variables del orden climatico y geografico. La segunda componente principal explica el 15,77 % de la variabilidad y se relaciona principalmente con la poblacion beneficiaria de FONASA y el indice de pobreza. En ella se opone de manera importante la tasa de letalidad por cancer cutaneo. La tercera componente principal explica el 13,79% de la variabilidad y se relaciona con caracteristicas poblacionales como poblacion total asignada, poblacion femenina y poblacion urbana. Conclusion La aplicacion del ACP es util para el estudio de los factores asociados con el cancer de piel.