H-reflex changes during static stretching and two variations of proprioceptive neuromuscular facilitation techniques

The effects of 3 stretching methods on the motor pool excitability of the soleus muscle as measured by the Hoffmann reflex have been compared with the objective of revealing central nervous system influences promoting muscle compliance to lengthening. The H-wave was reduced slightly throughout the static stretch method. The contract-relax (CR) method produced profound inhibition during the first several hundred milliseconds following contraction, but gradually increased to values similar to static stretch (SS) values 2 sec following contraction. Hoffmann reflex values for the contract-relax-antagonist-contract (CRAC) method were greatly depressed throughout the stretching phase with a slight increase after 2 sec. It was concluded that several inhibitory neural influences can have an additive effect in profoundly reducing motor pool excitability. Under the assumption that greater motor pool inhibition reduces muscle contractibility and therefore allows more muscle compliance, it is suggested that the proprioceptive neuromuscular facilitation (PNF) methods, particularly those involving reciprocal activation, provide the greatest potential for muscle lengthening. This is supported by previous studies which compared gains in range of motion using these 3 stretching methods (Holt et al. 1970; Moore and Hutton 1980; Etnyre and Abraham 1985).     

Exploration of the difference in results of economic submissions to the National Institute of Clinical Excellence by manufacturers and assessment groups

OBJECTIVES: A recent study showed that estimates of cost-effectiveness submitted to National Institute for Health and Clinical Excellence (NICE) by manufacturers had significantly lower incremental cost-effectiveness ratios (ICERs) than those submitted by university-based Assessment Groups. This study extends that analysis. METHODS: Data were abstracted from relevant NICE documentation for thirty-two of eighty-two possible appraisals. RESULTS: The results from the analysis showed that sources of the difference in ICERs appear to be the effectiveness estimates relating to the comparator technology and the cost estimates relating to the technology under evaluation. That is, manufacturers estimated lower average benefits for the comparator technology and lower costs relating to the technology under evaluation compared with estimates submitted by the Assessment Groups. CONCLUSIONS: These findings may be particularly important, given the introduction of the "Single Technology Appraisal." Considerable difficulties were encountered when undertaking this study, highlighting, above all else, the complexity of explaining why results from economic evaluations purporting to answer the same question diverge.     

Methods of H-reflex evaluation in the early stages of Parkinson's disease.

Differentiating the early stages of Parkinson's disease from the normal consequences of aging or from other common neurologic conditions can be diagnostically problematic. The purpose of this study was to compare methodologies for measuring motor neuron excitability of Parkinson's disease patients with a control group. H-reflexes were monitored in 16 patients diagnosed in the early stages of Parkinson's disease (Hoehn & Yahr stages I and II) compared with 30 subjects who were disease free. Methods of measurement included H-reflex latencies, the relative values of maximum H-reflexes to maximum direct motor responses (H-to-M ratio), the relative values of H-reflex amplitudes during vibration compared with control H-reflex amplitudes (Hv-to-Hc ratio), and double-stimulation H-reflex recovery curves using different interstimulus interval parameters. No significant differences were observed for the H-to-M or Hv-to-Hc ratios, or for the H-reflex latencies. The H-reflex recovery curves for the patients with Parkinson's disease demonstrated significantly greater ratio amplitudes than the control group during the double-stimulus responses between the 150-msec and 700-msec interstimulus intervals. Although comparisons of simple H-reflexes and H-reflexes during vibration did not differentiate the patients in the early stages of Parkinson's disease from the control group, the double-stimulation paradigm was a sensitive method for detecting early diagnoses of this disease.     

Building public trust in uses of Health Insurance Portability and Accountability Act de-identified data

Objectives

The aim of this paper is to summarize concerns with the de-identification standard and methodologies established under the Health Insurance Portability and Accountability Act (HIPAA) regulations, and report some potential policies to address those concerns that were discussed at a recent workshop attended by industry, consumer, academic and research stakeholders.

Target audience

The target audience includes researchers, industry stakeholders, policy makers and consumer advocates concerned about preserving the ability to use HIPAA de-identified data for a range of important secondary uses.

Scope

HIPAA sets forth methodologies for de-identifying health data; once such data are de-identified, they are no longer subject to HIPAA regulations and can be used for any purpose. Concerns have been raised about the sufficiency of HIPAA de-identification methodologies, the lack of legal accountability for unauthorized re-identification of de-identified data, and insufficient public transparency about de-identified data uses. Although there is little published evidence of the re-identification of properly de-identified datasets, such concerns appear to be increasing. This article discusses policy proposals intended to address de-identification concerns while maintaining de-identification as an effective tool for protecting privacy and preserving the ability to leverage health data for secondary purposes.     

Capillary leak syndrome: A rare cause of acute respiratory distress syndrome

Capillary leak syndrome (CLS) is a rare clinical syndrome associated with significant morbidity and mortality. Intensive care and supportive therapy constitute the mainstay of the treatment, along with judicious use of crystalloids and colloids such as dextran and starch during the leak phase. The advantages of proning, steroids, and intravenous immunoglobins are worth contemplating in patients with such a presentation. Extracorporeal membrane oxygenation appears to be an excellent strategy to surmount the impediments of the leak and post leak phase of CLS, especially in patients with severe or refractory hypoxemia.