Difference between revisions of "5° Clinical case: Spontaneous Electromyographic Activity"

In this chapter we will address another subject, much discussed but also much followed and proposed as a diagnostic test in particular in patients with Orofacial Pain (OP) and Temporomandibular Disorders (TMDs), that of electromyography in a muscle in resting conditions which causes immediately the usual Hamletic question:

Zieliński et al.<ref>Grzegorz Zieliński, Aleksandra Byś, Jacek Szkutnik, Piotr Majcher, Michał Ginszt. Electromyographic Patterns of Masticatory Muscles in Relation to Active Myofascial Trigger Points of the Upper Trapezius and Temporomandibular Disorders. Diagnostics (Basel) 2021 Apr; 11(4): 580.  Published online 2021 Mar 24. doi: 10.3390/diagnostics11040580 PMCID: PMC8063936</ref> noted that changes in electromyographic patterns of masticatory muscles may be associated with the presence of pain due to active myofascial trigger points (MTrPs)<ref>Fernández-de-Las-Peñas C., Galán-Del-Río F., Alonso-Blanco C., Jiménez-García R., Arendt-Nielsen L., Svensson P. Referred Pain from Muscle Trigger Points in the Masticatory and Neck-Shoulder Musculature in Women with Temporomandibular Disoders. J. Pain. 2010;11:1295–1304. doi: 10.1016/j. jpain.2010.03.005.</ref><ref>Peck C., Murray G., Gerzina T. How Does Pain Affect Jaw Muscle Activity? The Integrated Pain Adaptation Model. Aust. Dent. J. 2008;53:201–207. doi: 10.1111/j.1834-7819.2008.00050.x.</ref><ref>Pietropaoli D., Ortu E., Giannoni M., Cattaneo R., Mummolo A., Monaco A. Alterations in Surface Electromyography Are Associated with Subjective Masticatory Muscle Pain. Pain Res. Manag. 2019;2019:6256179. doi: 10.1155/2019/6256179. </ref><ref>Manfredini D., Cocilovo F., Favero L., Ferronato G., Tonello S., Guarda-Nardini L. Surface Electromyography of Jaw Muscles and Kinesiographic Recordings: Diagnostic Accuracy for Myofascial Pain. J. Oral Rehabil. 2011;38:791–799. doi: 10.1111/j.1365-2842.2011.02218.x. </ref><ref>Simons D.G., Travell J.G., Simons L.S. Travell & Simons’ Myofascial Pain and Dysfunction: The Trigger Point Manual. 2nd ed. Williams & Wilkins; Baltimore, MD, USA: 1999.</ref> and furthermore, during electromyography examination, significantly higher values of activity at rest within the anterior temporalis muscle were observed among MTrPs and TMDs patients compared to healthy individuals. The authors conclude that this altered pattern may be related to the presence of active MTrPs in the trapezius muscle, which, as a result of a referred pain mechanism, alters the activity of the anterior temporal (TA)   

In our opinion it would be somewhat complex and perhaps irrational to try to correlate the activity of the masticatory muscles at rest in subjects suffering from more or less severe depression because the phenomenon of electrical activity in the muscles at rest is called 'spontaneous activity' in neurophysiological jargon and it is a phenomenon with a non-trivial explanation. If this phenomenon is not at least broadly clarified, the myriad of physiopathogenetic interpretations circulating in the dental field can lead to a diagnostic error.

=== 5° Clinical case: Spontaneous Electromyographic Activity ===