Introduction

The concept for the ElectroDermal screening devices, EDS, was the creation of Dr. Reinhardt Voll[1¹], who discovered that the electrical resistance of the human body is not homogenous and that meridians exist over the body which have been demonstrated as electrical fields[2²]. Voll found the body had 1000 points on the skin which followed the 12 lines of the classical Chinese meridians. Working with Fritz Werner, Voll created an instrument to measure the skin resistance at each of the acupuncture points, patterned after Galvanic Skin Resistance (GSR) technique. During the 1950s, many investigators[3]³ studied the electrical conductance of the skin. Elasticity, resistance, permeability, and chemistry of the skin was evaluated and found that there was a much lower skin resistance at specific points on the skin. Normally, the skin has a resistance of 2-4 million Ohms but over the specific conductance points, the resistance of only 100,000 Ohms is found in normal healthy persons. These points corresponded to classical acupuncture points.

These acupuncture points were investigated and the assumption was made that the health status of an organ will affect the concentrations of the ions at the measurement points along the meridian. It was considered that inflammation of an organ may cause increase ion concentration and the increase of ions enhances the flow of electrons causing resistance to decrease while the conductance may increase. Conversely, a degeneration of an organ may cause decease in ion concentration that hinders the flow of electrons, so as the resistance increases conductance decreases.

During the procedure of ElectroDermal screening the body becomes an integral part of a closed circuit. The conductance circuit touches two areas on the body being tested. For the first point of contact, the ground electrode is held in the palm of the opposite hand to be tested. For the second contact the test probe touches the acupuncture point on the skin. After completing this closed circuit, a known amount of electric current is emitted from the instrument through the probe. The instrument then measures the conductance from baseline to peak and return to baseline through the conductance point that is being tested by the probe. This represents a dynamic conductance value.

Assessment of Thyroid Status

Because hypothyroidism is a relatively common disorder and its symptoms may be subtle, laboratory tests are usually required to assess thyroid dysfunction. The transition from the euthyroid to the hypothyroid state may first be manifested as a slightly increased TSH level in the presence of normal levels of T₄ and T₃. This is because as thyroid hormone levels begin to decrease, a compensatory increase in TSH secretion occurs, thus maintaining normal levels of T₃ and T₄. As thyroid failure progresses, levels of thyroid hormones continue to decrease despite further increases in TSH. In general, a TSH level below the normal range suggests high thyroid hormone activity at the tissue level. Conversely, a higher-than-normal TSH suggests that cells are receiving inadequate stimulation by thyroid hormone. Levels of TSH are correlated with serum free T₄ rather than T₃ because T₄ is the principal hormone produced by the thyroid gland in response to TSH stimulation.^[5] However, these levels do not correlate to adequate free T3 levels. Some healthy individuals may have normal TSH levels despite having low free T₃ values, suggesting that there are individual variations in the threshold for TSH inhibition.^[116] Of course, the presence of a pituitary tumor or disease should be excluded when the TSH is low relative to the levels of T₄.

The measurement of TSH as an initial step in the diagnosis of hypothyroidism is appropriate because, in most patients, the amount of thyroid hormone reaching the pituitary is comparable to that reaching the peripheral tissues. Furthermore, almost no other disease increases serum TSH levels, and individuals with primary hypothyroidism may have high TSH levels even when serum thyroid hormones are in the normal range. The assessment of both TSH and free T₃ is required to achieve a definitive diagnosis and to develop an appropriate treatment approach. It has been suggested that in rare instances, thyroid hormones, and not TSH, are the most relevant and appropriate indicators of thyroid status, but this approach is not yet widely accepted.^[9,159] The utility of using TSH for screening purposes depends on the presence of a normal pituitary gland.

Primary hypothyroidism is the most common cause of elevated TSH. Serum T₄ is decreased early in the disease, whereas T₃ remains normal until a substantial deterioration of thyroid function occurs.

Subclinical Hypothyroidism

In subclinical hypothyroidism, although the patient is usually asymptomatic and clinically euthyroid with apparently normal free T_4.TSH is higher than the upper limit of normal, free T₃ is below 4.0 and thyroid peroxidase and thyroglobulin antibodies are frequently present.^{[133,134,135,136,160]}

The prevalence of subclinical hypothyroidism is approximately 47% in women.^[133] There is a much higher prevalence in those over 60 years of age.^[137,138] Parle and colleagues^[139] observed that approximately 17% of patients over 60 years of age with subclinical hypothyroidism progressed to overt hypothyroidism over a 12-month period. The number of patients progressing to overt hypothyroidism may be higher over a more prolonged period of time. The causes of subclinical hypothyroidism are similar to those that cause overt hypothyroidism. Most patients have Hashimoto's thyroiditis, as defined by positive titers of thyroid peroxidase antibodies. A previous history of ablative therapy for the thyrotoxicosis of Graves' disease is another major cause. Drugs such as lithium or iodine-containing medications such as amiodarone, as well as external radiation to the neck, may also cause subclinical hypothyroidism.

Although a TRH-stimulation test is rarely necessary to confirm the diagnosis of subclinical hypothyroidism, patients may exhibit an exaggerated TSH response to TRH stimulation.^[124] It is recommended that a thorough history and physical exam be performed on all patients with subclinical hypothyroidism. The evaluation should include measurements, on at least 2 separate occasions, of TSH, free T₄, free T₃, and thyroglobulin and thyroperoxidase antibodies. Repeated measures would detect transient elevations in TSH, such as those associated with nonthyroidal illness. If there are palpable thyroid abnormalities, an ultrasonographic exam should be considered. A radionuclide scan is generally not useful for making a diagnosis. For example, radioactive iodine uptake by the thyroid gland may be inappropriately elevated in Hashimoto's thyroiditis.^[140]

There is an ongoing debate as to whether patients with subclinical hypothyroidism (eg, TSH between 5-10 mU/L and free T₃ below 4.0) should be treated with thyroid hormone replacement. Several double-blind, controlled studies indicate that patients with subclinical hypothyroidism experience improvements in symptoms, such as psychomotor functioning, after being treated with L-T₃.^{[141,142,143,144,145,159]} Most clinicians agree that individuals with a TSH level higher than 10 mU/L should undergo thyroid hormone replacement therapy, but there is some uncertainty about how to manage those with TSH levels between 5-10 mU/L. The best approach is to measure free T₄ and free T3 over several weeks or months to assess the consistency of testing and to ensure that the patient is not experiencing transient silent thyroiditis. If free T₄ and free T3 values are consistent, and especially if thyroid antibody titers are high, treatment with L-T₃ should be strongly considered. The decision to treat should be achieved jointly by the physician and patient after the potential advantages and disadvantages of therapy are discussed. If the decision is made not to treat, then thyroid function should be assessed at regular intervals.

In general, once treatment with L-T₃ is started, it usually continues indefinitely. The diagnosis of subclinical hypothyroidism has been complicated by a recent report of TSH resistance developing in some patients with elevated levels of TSH and normal circulating T₄ and T₃, thus leading to confusion as to whether subclinical hypothyroidism was actually present in these individuals.^[146] It is important to consider that resistance to TSH is considered extremely rare, and these patients would not be expected to have high titers of thyroglobulin and thyroid peroxidase antibodies. Furthermore, the presence of antibodies indicates that more overt hypothyroidism will eventually develop.^[147] Therefore, in mild hypothyroidism, if treatment with L-T₃ is not initiated, patients should have their thyroid function evaluated as often as every 6 to 12 months. Because TSH resistance is rare, the vast majority of patients with elevated TSH levels are considered to have subclinical hypothyroidism.

Study Design

This study of ElectroDermal screening was designed as blinded to the EDS operator in which 500 patients were evaluated by the EDS technique without the aid of a medical history or a physical examination or diagnosis known to the operator before the testing. The same patient was immediately evaluated by a separate rater, an MD or ND student who did a complete history and physical examination and complete laboratory test results. Following the data pooling an additional statistician evaluated and correlated the results. The construction of the study was to measure the capability of the EDS system for the purpose of evaluating sub-physiologic hypothyroidism in women and to evaluate the EDS without interview technique.

Method of Study

Each of the patients was randomly assigned to the study , from a clinic pool of 1,800 patients, after appropriate approval was granted. A complete medical and surgical history and examination was obtained at the time of the study and all of the necessary supporting laboratory data was provided to support the medical diagnosis. Each patient was evaluated, without any interview, by the EDS operator and then by an MD or ND student. A diagnosis was made on the basis of the detailed biochemical laboratory data. The laboratory for each patient was compared to the medical diagnosis and the EDS graphic recording. Control patients without sub-physiologic hypothyroid levels were also tested by the same EDS operator.

Equipment and Use

ElectroDermal Screening (using the Asyra EDS) consists of obtaining conductance measurements at different (acupressure) locations on the skin, storing these baseline measurements and displaying these readings on a monitor. The normal flow of electrical energy is briefly inhibited by a micro current and the conductance was again measured. While the subject is the ground for a closed system, the instrument functions as a micro-Ohm meter. The technique is non-invasive and has no-risk to the subject. The instrument is calibrated to read the resistance on a scale of 0 (lowest conductance) to 100 (highest conductance). The higher conductance has been associated with inflammation while the lower conductance is associated with degeneration. Each of these acupuncture points become part of one or more channels or meridians and generally follow the Chinese Meridian lines. Ordinarily, the normal individual will register about 50 plus or minus 5-10 on this scale for each point. In general, it is thought that the point of higher conductance represents an imbalance with higher energy while a lower conductance represent an imbalance with lower energy. However, this does not imply that a EDS disturbance (higher or lower conductance) corresponds to pathological changes in an organ that is named as a specific acupuncture point or meridian.

Analysis of Data

The patient population ranged in age from 35 to 65 with a mean age of 46.6, pregnancies 4.3 and live births 3.6 . There were 600 females in the study as compared to 0 males. The diagnostic categories were:

Each of these symptomatic patients were associated with sub-physiologic Free T-3 levels, fatigue, headaches, short term memory loss, weight gain and cold extremities.

Each of the patients/means of the data was statistically analyzed for rise/fall and peak in each of acupressure points. Furthermore, each patient was screened for history of medical illness and clinical features of disease.

Deviations of more than 1 standard deviation from the mean for each acupressure (testing point) were calculated and the statistical mean was plotted for each patient and group. Statistical difference of the means was then developed and calculated using the ANOVA method.

Results

The acupressure points/meridians used for this study were thyroid, metabolic, female and hormonal. The mean data points with 1 SD variance for the 500 patients with sub-physiologic (sub-clinical) free T₃[¹⁵⁹] were consistently found in endocrine abnormalities included 97% incidence of measurable symptomatic thyroiditis and multiple estrogen/progesterone abnormalities.

Utilizing this technique, the statistical variation for each mean acupressure point was calculated for the purpose of defining the appropriate diagnosis / remedy for therapy for sub-physiologic hypothyroid. It was noted that the variance of the means in the sub free T₃ group demonstrates significantly less variation than the control patients.

The EDS disturbances consistently found in the sub-physiologic hypothyroid patients but not in the controls:

A. Thyroid meridian - Lower conductance (under active imbalance) - Degeneration

T4, free T3

B. Metabolic meridian - Lower conductance (under active imbalance) - Degeneration

Thyroid

C. Female meridian - Lower conductance (under active imbalance) - Degeneration

Estrogen, HGH, Progesterone

D. Hormonal meridian - Lower conductance (under active imbalance) - Degeneration

DHEA, Testosterone

Conclusion

Because the majority of the effects of hypothyroidism can be prevented or reversed by thyroid hormone replacement, the clinician must be able to identify those patients who are most at risk for developing hypothyroidism and recognize the subtle clinical signs and symptoms of the disease. It is important to consider that there may be a wide variation in the clinical presentation. Routine screening programs identify hypothyroid neonates, so that treatment can be started shortly after birth. Hypothyroidism should be suspected when there is evidence of underlying thyroid, pituitary, or hypothalamic disease or when the patient has been previously exposed to any treatment that may disrupt the function of the hypothalamic-pituitary-thyroid axis. Laboratory assessment after an EDS assessment of thyroid function is the optimal approach to confirm the diagnosis. However, thyroid function tests may not accurately reflect thyroid status in individuals with nonthyroidal illness, conditions that affect thyroid binding to plasma proteins, and thyroid hormone resistance. Consequently, the clinician must integrate clinical observations, EDS findings and laboratory data to properly diagnose and manage the hypothyroid patient. The goals of thyroid hormone replacement are to relieve symptoms. Many decades of experience show the efficacy of treating hypothyroidism with L-T₃ alone.

This study has demonstrated the effectiveness of ElectroDermal screening with both the clinical and laboratory diagnosis in 500 patients with sub-physiologic hypothyroid have been compared to 100 normal age adjusted control subjects. The correlation between the EDS measured abnormalities, using standard deviation (SDI) criteria and patients with sub-physiologic hypothyroid state was statistically significant at 99.5% with a P< 0.005. Thus EDS has demonstrated its effectiveness as a valuable tool for the analysis and diagnoses of sub-physiologic hypothyroid levels.