The Effect of Methylprednisolone Acetate Injection at Cervical Trigger Points in both Chronic and Drug Resistant Headache

Introduction & Objective: Most adults have surely once experienced a headache. A high percentage of these headaches are the referred pain from cervical structures, such as neck muscles, known as cervicogenic headaches. This study aimed to assess the efficacy of injection of methylprednisolone acetate at the Gallbladder-20 acupuncture points in muscle originated chronic and drug resistant headaches. Materials & Methods: In this randomized clinical trial study conducted at Shiraz University of Medical Sciences in 2009-2010, 25 patients with both chronic and drug resistant cervicogenic headaches, who had cervical muscle tender points, underwent methylprednisolone acetate injection. To evaluate the severity of these patients' headache, VAS (Visual Analogue Scale) was used. The collected data was analyzed using the SPSS software and Wilcoxon test. Results: The Mean headache intensity on the visual scale of these people before the injection was 3 .2 ± 76.7. This value was 2.60±2.9, 3 days after injection. The values at 1 and 3 months post procedure were 3.52±3.3, and 3.48±3.5, respectively. In other words, a statistically significant loss of pain score (P<0.001) was observed. The frequency of headache attacks 1 and 3 months after injection decreased 72% and 76% among patients, respectively. Average duration of headache attacks, one month and three months after injection, was decreased in 72 percent of patients. Conclusion: Injection of methylprednisolone acetate at the GB-20acu points in muscle originated cervicogenic headache could be used as an appropriate therapy that has significant therapeutic efficacies only when injected once

FRACTURE TOUGHNESS MEASUREMENTS AND FAILURE MECHANISMS OF METAL MATRIX COMPOSITES

Abstract— This paper compares the fracture toughness values obtained from two different specimen geometries, i.e. pre‐cracked compact tension and chevron‐notched short rod. The former is in widespread use, however, the latter has significant advantages in that no pre‐cracking is required resulting in more economical use of material and reduced machining. Four 6061‐aluminium‐matrix composites reinforced with discontinuous alumina particles were investigated. Good agreement in fracture toughness values from the two specimen geometries was obtained for all the materials and all the heat treatments examined. Detailed analyses of the fracture surfaces were used to identify the fracture mechanisms. The effects of specimen geometry, volume fraction of reinforcement and ageing treatment on fracture toughness are discussed. Copyright © 1994, Wiley Blackwell. All rights reserve