Treatment of myofascial trigger points in common shoulder disorders by physical therapy: A randomized controlled trial [ISRCTN75722066]

Background  

Shoulder disorders are a common health problem in western societies. Several treatment protocols have been developed for the clinical management of persons with shoulder pain. However available evidence does not support any protocol as being superior over others. Systematic reviews provide some evidence that certain physical therapy interventions (i.e. supervised exercises and mobilisation) are effective in particular shoulder disorders (i.e. rotator cuff disorders, mixed shoulder disorders and adhesive capsulitis), but there is an ongoing need for high quality trials of physical therapy interventions. Usually, physical therapy consists of active exercises intended to strengthen the shoulder muscles as stabilizers of the glenohumeral joint or perform mobilisations to improve restricted mobility of the glenohumeral or adjacent joints (shoulder girdle). It is generally accepted that a-traumatic shoulder problems are the result of impingement of the subacromial structures, such as the bursa or rotator cuff tendons. Myofascial trigger points (MTrPs) in shoulder muscles may also lead to a complex of symptoms that are often seen in patients diagnosed with subacromial impingement or rotator cuff tendinopathy. Little is known about the treatment of MTrPs in patients with shoulder disorders.     

Early diagnosis of n-hexane–caused neuropathy

n-Hexane neuropathy was studied in 20 workers exposed for prolonged periods to this solvent, and with urinary 2, 5-hexanedione concentrations exceeding the biological exposure index recommended by the American Conference of Governmental Industrial Hygienists (5 mg/L) with a mean of 11.02 mg/L (range 5.3—24.2 mg/L). Although neurological examination did not detect significant anomalies in any of the patients, and the conduction velocity and F waves of all the nerves tested were normal, neurographic studies revealed significant differences in the amplitude of sensory nerve action potentials (SNAP) recorded from the sural (mean 14.0 μV), median (mean 17.3 μV), and ulnar (mean 7.9 μV) nerves when compared with normal values from healthy adults of the same age range, examined under identical conditions. The amplitude of the SNAP in sural and median nerves correlated significantly with the number of years worked. The notable decrease in mean amplitude of the SNAP appeared to reflect the primary neurotoxic effects of 2,5-hexanedione. © 1994 John Wiley & Sons, Inc.     

Thyroid function studies in patients with cancer of the larynx: preliminary evaluation

OBJECTIVE: Our goal was to evaluate thyroid function before and after surgery only or radiotherapy plus surgery for laryngeal neoplasms. STUDY DESIGN AND SETTING: The study group consisted of a total of 30 patients with laryngeal cancer (22 treated with surgery only and 8 treated with surgery plus radiotherapy) who were evaluated by ultrasensitive thyroid-stimulating hormone, free T4, and antithyroid antibodies both preoperatively and at 6 and 12 months after surgery. RESULTS: All patients had normal thyroid function before treatment (1 patient had elevated antithyroid autoantibodies); after 1 year, 4 (13.34%) patients were hypothyroid. In 3 patients, it was subclinical (ie, elevated thyroid-stimulating hormone with normal free T4), and in 1 patient, it was symptomatic. CONCLUSION: Our preliminary data suggest that hypothyroidism occurs in a small but substantial proportion of patients undergoing surgery with or without adjuvant radiotherapy for laryngeal cancer. SIGNIFICANCE: Thyroid hormone dosing should be routinely included in the assessment of patients with laryngeal cancer, because it is simple and inexpensive and may allow the early diagnosis and management of hypothyroidism.     

Importance of spatiotemporal heterogeneity of cellular restitution in mechanism of arrhythmogenic discordant alternans

BACKGROUND: Spatially discordant cellular alternans form a substrate for development of unidirectional block and ventricular fibrillation. However, the mechanisms responsible for discordant alternans remain poorly understood. Previous work suggests electrical restitution is critical to the development of alternans in single cells. OBJECTIVES: The purpose of this study was to investigate the hypothesis that spatial and temporal heterogeneities of restitution underlie the mechanism eliciting discordant alternans. METHODS: Steady-state pacing was used to elicit concordant cellular alternans in nine Langendorff-perfused guinea pig hearts. A single extrastimulus (S2) was applied every 51st beat following either the even or the odd beat of alternans. The cellular response to S2 was determined using optical mapping to generate action potential duration (APD) restitution curves from 256 ventricular sites for both the even and the odd beats. RESULTS: Restitution kinetics were temporally heterogeneous during alternans, as restitution curves between the even and the odd beats differed significantly. Temporal heterogeneity was quantified by the average separation of restitution between the two curves, or Delta-restitution. Delta-Restitution was spatially heterogeneous and proportional to the amount of alternans at a given ventricular site. A computer simulation based on the experimental results showed the mechanism of discordant alternans was dependent on both spatial and temporal heterogeneities of restitution. CONCLUSION: Both temporal and spatial heterogeneities of restitution exist during cellular alternans in the intact heart. Temporal heterogeneities of restitution, quantified by Delta-restitution, are proportional to the magnitude of cellular alternans. The combination of spatial and temporal heterogeneities of restitution may underlie the genesis of discordant alternans.