How to define level of evidence for tinnitus treatment by acupuncture?

© Longhua Chinese Medicine. All rights reserved. Longhua Chin Med 2021 | http://dx.doi.org/10.21037/lcm-21-17 In order to answer this question, the authors of the article “Efficacy of acupuncture for tinnitus: an umbrella review” analyzed systematic reviews published until mid2020, but unfortunately it has not yet been possible to confirm the effect of this therapy (1). Not because of the lack of effectiveness of acupuncture as a therapeutic tool, but because of difficulties in analyzing the data, also described on published papers, such as low quality of studies, type of intervention (manual or electrical stimuli), among others (2,3). In order to understand these findings, some points must be identified and analyzed. Most of medical knowledge was obtained from observing the phenomena related to the pathologic process, the natural history of disease. Thousands of years ago, only the enviable ability to identify and interpret these phenomena combined in the so-called patterns of disharmony was able to constitute one of the fundamental pillars of Traditional Chinese Medicine (TCM). For the description of patterns of disharmony used for diagnosis, TCM considers sometimes vague and nonspecific symptoms not valued by the Cartesian point of view of Western Medicine. Perhaps one of the biggest challenges for ENT doctors is dealing with tinnitus, a sensation of sound in the absence of external sound stimulus with many possible causes. Even the classic concept of tinnitus—“auditory phantom sensation”—emphasizes the difficulty to explain the symptom and to identify causes besides hearing loss. Due to these characteristics and similarities of its pathophysiological mechanism, tinnitus has often been compared to chronic pain or phantom limbs (4). Previous studies have demonstrated that central nervous system structures related to emotions (limbic system) and reaction to sound (autonomic nervous system) play a fundamental role in determining the degree of discomfort (5) and can be modulated by acupuncture with evidence by functional image exams (6). Many drugs and therapies are used in common (7). The good results obtained with the use of acupuncture for pain treatment justify its application in patients with tinnitus (4,6,7). The study of TCM organs physiology (Zang Fu) makes it possible to identify two main causes of tinnitus with very different characteristics: the Kidney (Shen) Deficiency syndrome and the Liver (Gan) Excess. The clinical characteristics of Kidney (Shen) deficiency tinnitus are lowfrequency tinnitus with a history of insidious, gradual onset, memory difficulties, low back pain, dizziness and hearing loss in older patients. Tinnitus due to the Liver (Gan) excess has a sudden high frequency onset, in younger individuals and related to emotional tension, irritability and headache (8). These psychoacoustic characteristics of tinnitus have been ignored for a long time by otorhinolaryngologists, but recent studies indicate that in some patients they may be related to their handicap and prognosis (9). Editorial