ADVANTAGES AND LIMITS OF AURICULAR DIAGNOSIS WITH ESRT

The advantage of using an electronic device is essentially to be able to explore the auricle systematically without the collaboration of the patient, needed for example in PPT for identifying those points most tender at pressure. Also, a beginner can easily identify the points, mark them with ink and transcribe their location onto the Sectogram.

The limit of ESRT is the fact that commercial devices are able to measure only one point at a time. This makes the procedure time-consuming as several points have to be tested within the area representing the suffering part of the body; moreover commercial devices usually do not store data which could be accessed over time, for example during a therapeutic course or in the follow-up period.

There are at least two further time-consuming factors which need to be borne in mind:

1. As illustrated in Chapter 6, the ESR is a time-dependent factor and the practitioner has to wait several seconds before ESR values stabilize. It should be noted that in some cases this stabilization does not occur at all and the resistance value goes down practically to zero if enough time elapses. This is why we chose to average the ESR value over a reasonable period of time (10 seconds).

2. The necessity to attribute hierarchical importance to the identified points is also time-consuming, supposing, as mentioned above, that points with the lowest ESR are also those with higher therapeutic value. As proposed by some manufacturers, each point should be measured in respect to baseline, readjusting it each time against a so-called ‘zero’ value of a part of the ear believed to be free of acupuncture points.¹ This strategy may be misleading, however, as no part of the ear, in my opinion, can with any safety be considered free of somatotopic representations.

REASONS FOR CHOOSING AGISCOP AND ADOPTING A FIXED ESR THRESHOLD IN THE VALIDATION PROCESS

The first problem I had to face when I started with my project of validation of auricular diagnosis was the choice of the most reliable electric device. As there had been no report in the literature comparing the characteristics of the devices commercially available, I chose the French Agiscop manufactured by Sedatelec, for which I declare the absence of any conflict of interest.

The ancestor of Agiscop was the Punctoscope, developed in the 1960s by Nogier himself on the basis of the pioneering research of Niboyet who dedicated his doctoral thesis in 1963 to the issue of the lower ESR of acupuncture points and meridians.²

As Agiscop is sold without an adequate technical description, we decided with F. Puglisi to carry out research aimed at answering the following basic questions:

1. Are the values obtained with this device to be referred to absolute levels of ESR or to differences of resistance between neighboring tissues or points?

2. Which are the values of ESR measured corresponding to the different positions (1 to 6) of the ‘sensitivity knob’? (See Fig. A2.3.)

3. What is the significance of the knob changing − to the + position?

To answer these questions it was necessary first to create an instrument which could measure ESR according to the basic principles of electrology aside from its clinical applications. The device developed and its characteristics have been described in Chapter 6.

We compared Agiscop with our device measuring the skin resistance of a number of points under controlled conditions (see the section on Clinical validation in Ch. 6). The results show that Agiscop has the best intra- and inter-reliability performance when the ESR threshold is about 2 MΩ, corresponding to position 3 of the above mentioned knob.

From the empirical point of view the threshold of 1 MΩ, corresponding to position 4 of the knob, seems more convenient for the majority of the examined subjects allowing the identification of a sufficient number of points for diagnosis. This threshold was maintained constantly throughout the whole validation process on 506 patients.

As shown in Chapter 6, the choice of 1 or 2 MΩ does not invalidate the classification of points in two categories, one with high and the other with low ESR values, since the former includes points with ESR 2 ÷ 100 MΩ and the latter includes points with ESR 0÷2 MΩ.

All patients were measured with the − polarity of the knob which corresponds to a difference of ESR due to a lower resistance of the surrounding coaxial electrode with respect to the central electrode (see Fig. A2.1). This modality was chosen because the average number of points identified with the − polarity was 2.3 times greater than the + polarity; indeed this difference allowed a higher diagnostic success of the first modality (see Table 9.3).

One of the reasons for the higher number of points identified with the (−) modality has been explained in Appendix 2 as being due to the possible indentation of the skin under the measuring probe, causing greater contact with the coaxial rather than with the central electrode (Fig. A2.4).

It should be noted that another commercial device (Pointoselect by Schwa-medico) utilizes a similar differential technique and a similar coaxial electrode. However, it is able to recognize automatically if the coaxial electrode has a higher or lower ESR in comparison with the central one.

Whatever commercial device is chosen for auricular diagnosis, it should be underlined that the information offered to professionals by the various manufacturers is incomplete at best and in the majority of cases it is really unsatisfactory. Practitioners are apparently considered incapable of developing any knowledge whatsoever in technical matters.

In my opinion it is unethical for a practitioner to use a device on his patients when he is ignorant of its elementary functions and the meaning of the measurements.

THE GENERAL DISTRIBUTION OF POINTS WITH LOWER ESR ON THE AURICLE

If we examine the general distribution of points with lower ESR (~1 MΩ) on the outer ear in 325 patients with the − modality, we get an average of 5.24 on the right side compared to 5.98 on the left. This non-significant difference of distribution may appear to indicate a homogeneous and symmetrical distribution of points but that is not the case. If we analyze the clusters per sector we may notice that the left ear shows a higher number of sectors of high value compared to the right (Fig. 7.1). This phenomenon, similarly to what happens with PPT (see Fig. 5.5), is not easily explainable: we have to assume that the asymmetry of distribution may be intrinsic to the ear or may be the result of an asymmetrical activation of the auricles which manifests itself physiologically in the majority of patients. Our hypothesis, also expressed in Chapter 9, is that this phenomenon could be related to the asymmetrical lateralization of some functions in our brain such as language, handedness, etc.

Fig. 7.1 Sectors of high value identified by cluster analysis of points with low ESR in 325 patients.

DIFFERENCES IN THE DIAGNOSTIC PERFORMANCES OF ESRT AND PPT

Both these methods show a similar performance on the total of symptoms (32.9% for ESRT and 34.6% for PPT) but their combination provides a better outcome (52.3%), which is significantly higher compared to either ESRT or PPT considered on its own (P<0.001). However, if we compare the success rates in the identification of the symptoms of various bodily systems, we may notice that there are some significant differences. For example, PPT shows a better outcome with musculoskeletal, teeth–temporomandibular joint (TMJ) and nervous system disorders, whereas ESRT seems to be more suitable for detecting mental and gastrointestinal problems.

The reasons for these differences may be attributed to various factors, as for example the different ability in detecting points on the various parts of the auricle and/or the intrinsic specificity of each method in diagnosing symptoms belonging to different apparatus.

I tried to find an answer to these issues by first comparing the distribution of points identified with ESRT and PPT on the auricle. We can see that ESRT identified points principally on the medial surface, followed by the lower and upper concha, whereas PPT identified a higher percentage of points on the ear lobe followed by the anthelix and the medial surface (Table 7.1). However, in my opinion these slight differences may be related at least partially to the differing anatomical composition of the tissues on which diagnosis is performed. For example, the higher number of points detected by ESRT on the medial surface may depend on the reduced thickness of the skin covering this part of the auricle. For the concha (in total 25.6% to 20.3% of PPT) we may also suppose an anatomical factor represented by the particular density of sebaceous glands in this area. We are however not sure that the ducts of sebaceous glands may favor the electrical shunt as has been supposed for sweat glands; in effect sebum seems not to be an ion conducting material such as sweat.

Table 7.1 Concentration of identified points on the different zones of the ear in 325 patients. (a) % of points with low ESR; (b) % of tender points

As regards PPT and the higher number of tender points on the ear lobe, I have suggested in Chapter 5 that this higher sensitization may result from the lack of cartilaginous support leading the practitioner inadvertently to exert a higher pressure than intended on this zone. The higher number of tender points on the anthelix could nevertheless be associated with the bias, typical in the West, towards starting auricular exploration from this part, representing as it does the spine and other structures of the musculoskeletal system.