Regional intravenous sympathetic nerve blocks.

The assessment of the possible efficacy of regional intravenous blocks or sympathetic blocks, in general, raises a number of questions that may be answered after studying the techniques of regional pharmacologic segmental blocks and their effects on the sympathetic system. The authors present an original clinical study evaluating the capacity of regional intravenous guanethidine to induce a sympathetic blockade compared with other techniques.

[Vasomotor disorders of the hand and carpal tunnel syndrome]. / Troubles vasomoteurs des mains et syndrome du canal carpien.

Clinical electrophysiological and chronothermodynamic examinations were performed on 71 patients with paresthesiae and pain of the hands. In 35 patients, the electromyographic examination confirmed the diagnosis of carpal tunnel syndrome on the basis of clear signs of chronic compression of the median nerve at the carpal tunnel. In the other 36 patients, the electro-physiological findings were normal. Twenty-nine patients with bilateral (n = 24) or unilateral (n = 5) carpal tunnel syndrome, and 29 patients without, this syndrome had chronothermodynamic abnormalities demonstrating the vascular origin of the disorders of the hands; in 18 patients, a Raynaud's syndrome was suspected on the basis of severe dysthermia. In 7 patients, the origin of pain and paresthesiae remained unknown. This study shows that (i) vascular disorders of the hand are very frequent in patients with paresthesiae and pain of the hands and may mimic a carpal tunnel syndrome, and (ii) clinical examination is insufficient to assess the diagnosis of carpal tunnel syndrome. Before deciding on any kind of therapy, this diagnosis has to be assessed on electrophysiological and chronothermodynamic examinations performed according to precise protocols.

Clinical studies of the vibration syndrome using a cold stress test measuring finger temperature.

Since nine years multicentre, transversal and longitudinal clinical studies on hand-arm, vibration-exposed patients are being performed in cooperation with French occupational medicine centers and social security institutions. These studies are based upon current clinical assessment and standardized, temperature-measuring cooling tests. Data acquisition uses a portable, 10-channel, micro-processor-based temperature recorder and miniature thermal sensors. Temperature is monitored at the ten finger tips continuously, before, during and after a cold stress performed in strictly controlled conditions. Data from examinations performed at outlying sites are transferred through the telephonic network to a central processing unit. Data analysis uses a specific, expert-type software procedure based upon previous clinical studies on (i) 238 "normal" subjects, and (ii) 3,046 patients with vascular disturbances of the upper extremities of various etiologies. This procedure includes a staging process which assigns each finger a class representing the degree of severity of the abnormalities of response to cold ("dysthermia") related to vascular disorders. All data processing is fully automatic and results in a printed examination report. To date, over 1,623 vibration-exposed forestry, building and mechanical workers were examined. Sixty-three per cent of patients had received high dose of vibration (daily use of chain saws, air hammers, ballast tampers over many years). Typical white finger attacks or only neurological symptoms were found in 36% and 23% of patients respectively. The rate of sever dysthermia was much higher in patients with white finger attacks (83%) than in patients without (32%). In 90% of the vibration-exposed patients, the severity of dysthermia has differed greatly from one finger to another and between hands, while in non-exposed patients with primary Raynaud syndrome the dysthermia are generally similar for all fingers but the thumbs. Of 208 forestry workers who were asymptomatic but had dysthermia on a first examination, 31% have developed vascular or neural symptoms within subsequent follow-up. Of 223 symptomatic patients with more or less severe dysthermia at a first examination performed in winter, 17% had the same abnormalities in summer and microvascular lesions at capillaroscopy, while the other 83% had reversible dysthermia and only functional capillaroscopic abnormalities. These studies suggest that temperature-measuring cooling tests performed under well-defined, standard conditions provide significant data for grading the severity and assessing the reversibility of Raynaud phenomena, and for detecting subclinical vasomotor disorders in asymptomatic patients.

[Carpal tunnel syndrome. Can it still be a controversial topic?]. / Le canal carpien. Peut-il être encore sujet de controverse?

The authors studied two aspects of the carpal tunnel syndrome. As far as the diagnosis is concerned, clinical signs and provocative manoeuvres compared to the accepted standard of electrophysiological studies proved to be insufficient to settle a surgical indication in 85 carpal tunnel syndromes. When surgery is needed, post-operative course is frequently bothered by pillar pain and decreased strength postponing return to manual activities. The authors performed a prospective randomized study of 3 techniques in 251 carpal tunnel releases: classical technique, Agee endoscopic technique and anterior ligamentoplasty. Strength was only improved by the last technique. The only advantage for the endoscopic technique was greater post-operative comfort.

Computerized chronothermodynamic breast examinations under ambulatory conditions.

A new approach to the assessment of breast health was developed based upon continuous ambulatory recording of breast temperature for 24 hrs. A new data acquisition system consisting of a portable, multi-channel, microprocessor-based recorder worn on a belt was developed to record temperatures. Dramatic thermal fluctuations were noted during the recordings in response to multiple stimuli (physiological, behavioral, environmental). Specific algorithms and software programs were developed to process the thermobiologic and chronobiologic information. Data processing was fully automatic and included an examination report indicating a score and a chronothermodynamic class for each of the five areas examined on each breast. The preliminary clinical studies have concerned more than 450 patients with healthy or diseased breasts.

Thermovascular changes associated with in situ and minimal breast cancers. Results of an ongoing prospective study after four years.

A four-year prospective study was conducted on more than 25,000 women, both asymptomatic (59%) and symptomatic (41%), with a view to investigating the thermal and vascular disorders associated with early stages of breast malignancy. All the patients underwent thermographic, mammographic and physical examinations performed under standard conditions and, when indicated, complementary radiographic (spot/magnified pictures), ultrasound and cytologic tests. Of the 294 in situ, microinvasive and nonpalpable cancers diagnosed in this study, 60-70% generated significant thermal anomalies that, in most cases, consisted of distorted thermovascular patterns. A tentative explanation for these clinical observations was formed from intramammary measurements of temperature and blood flow performed on seven patients and was based on recent experimental data on the origin of vascular reactions associated with cancer growth. This study clearly showed that thermography may contribute to the early detection of breast cancer and to the identification of women at high risk of developing breast cancer. Two hundred four (21.3%) of the 958 patients who, on their first visit, had an abnormal thermogram but no findings at physical examination or mammography developed cancer within the next three years (length of follow-up, 4-41 months).

[Thermobiologic evaluation of benign and malignant breast diseases]. / Thermobiologische Beurteilung benigner und maligner Brusterkrankungen.

This paper is a review of the recent technical and clinical advances in the area of breast thermography. Emphasis is placed upon thermal imaging using liquid crystal films, and computer-assisted analysis of breast thermograms. New data are presented concerning the value of thermography for the identification of women at high risk of developing breast cancer, the early detection of mammary carcinomas, and the detection of cancer in fibrocystic breasts.

Active microwave tomographic imaging of isolated, perfused animal organs.

The relative transparency of biological materials to high-frequency electromagnetic waves has encouraged the development of new systems for imaging. This report describes experiments of microwave tomography conducted on a prototype. The object to be analyzed is submerged in water and is illuminated by a plane wave. The total electric field is analyzed by a microwave camera. The recorded data are then processed numerically in order to reconstruct the image that corresponds to the distribution of equivalent currents in a defined plane of a section. Experiments have been conducted on isolated kidneys with and without perfusion. The influence of the perfusing solution temperature has also been studied. These experiments show the potential of this system, especially through the correlation between microwave images and the biological structures. They also confirm previous results concerning spatial resolution and depth of exploration. Finally, the results demonstrate the influence of temperature and support the applicability of this imaging system in non-invasive thermometry, especially for clinical hyperthermia.

Thermobiological assessment of benign and malignant breast diseases.

The recent technical and clinical advances in breast thermography are reviewed in this article. Emphasis is placed upon liquid crystal thermal imaging and computer-assisted analysis of breast thermograms. New data are presented concerning the value of thermography for the early detection of mammary carcinomas, the identification of women at high risk of developing breast cancer, and the detection of cancer in fibrocystic breasts.

[The future of women with isolated abnormal infrared thermogram of the breast (author's transl)]. / Avenir des femmes á thermogramme infra-rough mammaire anormal isolé.

Abnormal infra-red thermograms of the breast are called "isolated" when they are not accompanied by other clinical or paraclinical abnormalities. They occur in asymptomatic women systematically examined or in women consulting for mammary symptoms other than palpable nodules. Their incidence is about 10-15%. They are usually considered as "false-positive" findings, but when these women are regularly followed up breast cancers are found to occur with a frequency ranging from 5% to 38%. "False-positive" thermograms therefore imply a high risk of breast cancer. Extremely prolonged clinical surveillance with periodical radiothermic tests and, if necessary, guided biopsies are required for early detection of small-size or even impalpable mammary carcinomas.

[Microwave hyperthermia: influence of blood flow and thermoregulation processes (author's transl)]. / Hyperthermie micro-ondes: influence du flux sanguin et des phénomènes thermorégulateurs.

Various problems are encountered during production of local, deep-seated microwave hyperthermia, involving the technology of the irradiating system, and the complexity of heat transfer in living tissues. Before starting investigations on patients, preliminary studies were conducted on different models. Taking the influence of the blood flow into account, the thermal effects of microwaves were simulated on a numerical model, and a perfused phantom. These studies were completed by investigations in animals. The analysis of findings demonstrates that, in given conditions of irradiation, the temperature distribution is strongly dependent on blood flow. This means that the phantom models are only useful to evaluate the influence of the irradiation parameters and to develop and compare the generator-applicator systems, and that accurate planning of therapeutic trials requires in vivo studies on animals as well as on patients.