On ears and Head.

The original empirical conjecture of auric-ular acupuncture (AA) consists of a claim that the entire human body is represented in a certain way on the auricle (eg, in the form of an inverted fetus, see fi gure 1A), and that the pathology of human organs leads to specifi c changes at these respective areas on the auricle. It is claimed that these changes can be identifi ed as the areas with skin discolourations, which are tender on palpation. Moreover, the stimulation of these auricular areas, which are supposed to somehow be connected to the organ with 'pathology', is believed to improve the functioning of the impaired organ or relieve the related pain. 1 The representation of the human body on the auricle is often called 'somatotopic', analogous to motor and sensory somato-tops of precentral and postcentral gyri of the cortex, as described by Penfi eld and Rasmussen on the basis of experimental research. 2 Interestingly, randomised clinical trials on the effi cacy of AA have demonstrated that stimulation of the areas of auricle according to the AA empirical conjecture was effective as complementary treatment for a variety of pain syndromes and preoperative anxiety. 3–5 However, no neuroanatomical pathways are known to connect the 'diseased' organs with the external auricle so that the observed phenomena cannot be explained by the underlying anatomy. A diagnostic approach has been frequently used for testing the hypothesis of the 'somatotopic' representation of the human body on the external auricle. Within this diagnostic approach, the correlation between known 'loci morbi/ dolendi' on patients' bodies and the zones on the external auricle, which were iden-tifi ed using inspection, palpation and electrodermal measurements, has been established in several studies. Oleson et al performed the fi rst scien-tifi c double-blind evaluation of auricu-lar diagnosis in 40 patients with painful musculoskeletal disorders. 6 The doctors, without prior knowledge of the patients' medical conditions, examined the tenderness and electrodermal characteristics of the patients' auricles, while the patients were draped to conceal any visible information. The concordance between the established medical diagnosis and the potentially corresponding auricular areas was 75%. Saku et al studied the electrical skin resistance (ESR) on the external auricles in patients with coronary artery disease and in healthy subjects. The areas of low ESR were frequently found in the centre of concha auriculae, the zone representing the heart and lung systems in the empirical model of AA. The …