Itch sensation through transient receptor potential channels: a systematic review and relevance to manual therapy.

OBJECTIVE: Patients may present with a complaint of "itchiness" or an "odd sensation" that can be relieved by manual therapy treatment options, which demonstrates the relevance of transient receptor potential (TRP) channels. There are studies that identify the role of various TRP channels as modulators of the itch sensation; however, discrepancies in the literature exist with respect to the overall neural pathway of the itch sensation, musculoskeletal implications, and decisive therapeutic implications. The purpose of this study was to review the literature and rate the quality of published articles regarding the role of TRP channels in the itch sensation. METHODS: A systematic search of relevant literature that was published in English by a peer-reviewed journal between January 2000 and June 2012 was performed in PubMed. Studies that met the predetermined inclusion criteria regarding the relationship between TRP channels and itch were identified and then evaluated for methodological quality by the Downs and Black Quality Index score system and were summarized. RESULTS: Nine studies were identified that met the inclusion criteria, all of which had fair methodological quality from the perspective of the modified Downs and Black Quality Index. TRPA1, TRPM8, and TRPV1-4 were indicated as key channels responsible for the transmission of the itch sensation. TRPV1 channels convey histamine-dependent itch, and TRPA1 channels convey histamine-independent itch. Temperature, nerve growth factor, and substance-P were also described as important itch modulators. There are similarities between the neural pathways responsible for itch, pain, and temperature, which explain the ability of noxious temperature to suppress the desire to scratch. Although transcutaneous electrical nerve stimulation, innocuous vibration, and cutaneous field stimulation have demonstrated relatively weak attenuation of itch, the use of topical capsaicin, noxious heat, and noxious cold have been demonstrated as effective therapies. CONCLUSIONS: The findings of this review show that studies have assessed the function of TRP channels and itch, rather than identifying the relationship between itch and effective noninvasive treatment options. Therefore, TRP channels could serve as important, complex clinical targets for manual therapists.

A comparative analysis of sonographic interpretation of peripheral nerves in the anterior compartment of the forearm between an experienced and novice interpreter.

PURPOSE: This article describes a pilot study that compares the ability of a novice interpreter and an experienced interpreter to interpret ultrasound images of peripheral nerves in the anterior compartment of the forearm. METHODS: Twenty subjects between 18 and 50 years of age were included. A student was taken through tutorials in which she was guided through identification of the peripheral nerves of the anterior forearm. After the tutorials, the experienced interpreter traced the subjects' ulnar nerve and artery neurovascular bundle proximally in the anterior compartment of the forearm until just before it separated into the artery and nerve. Here the distance between the median and ulnar nerve was measured by the investigators. The Bland and Altman design and paired t tests were used to compare the agreement between the results of the two investigators. RESULTS: The Bland and Altman analysis reveals that the difference between two sets of measurements (experienced investigator vs. student) is calculated to be 0.08 mm ± 0.22 mm for the left arm and 0.16 mm ± 0.43 mm for the right arm. A paired t test revealed that there is no significant difference in the measurements obtained by the two investigators (left arm: p = .12; right arm: p = .10). These results suggest that the measurements of the two investigators may be interchangeable. CONCLUSIONS: This pilot study shows that after tutorials combining dissection and sonographic interpretation, the ability of a novice interpreter to identify ultrasonographic images of peripheral nerves in the anterior compartment of the forearm is comparable to that of an experienced interpreter.

Back to the debate: sternalis muscle / Volver al debate: músculo esternal

The sternalis muscle (SM) is an anatomical variant found in the anterior thoracic wall. While the attachment sites of SM are generally agreed upon, the innervation and function of this muscle are not well established. Cadaveric and surgical explorations to date report that SM is innervated by either the pectoral nerves or the anterior branches of the intercostal nerves, or a combination of both. Knowledge of SM is relevant to health care providers specialising in imaging and/or surgery of the anterior thoracic wall. This paper aims to raise awareness in the medical community of the clinical relevance of SM through two case reports and a brief literature review.

El músculo esternal (ME) es una variante anatómica en la pared torácica anterior. Mientras que los sitios de fijación del ME estan acordados, la inervación y la función de este músculo no están bien establecida. Exploraciones cadavéricas y quirúrgicas han informado que el ME está inervado por los nervios pectorales o ramos anteriores de los nervios intercostales, o una combinación de ambos. El conocimiento del SE es relevante para los proveedores de atención de salud especializada de imágenes y/o cirugía de la pared torácica anterior. Este documento tiene como objetivo crear conciencia en la comunidad médica de la relevancia clínica de ME a través de dos reportes de caso y una breve revisión bibliográfica.