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Biomedical subjects

H M Mayer

Publications and source records attributed to H M Mayer.

47 records · Page 3Linked to original sources

[Neurinoma of the L3 spinal nerve root as a cause of stress-induced lumbo-ischialgias].

Degenerative diseases of the lumbar vertebral discs or the vertebral joints are the main causes of low back pain and sciatica following overstraining during sports activities. However, they are rarely seen in sportsmen engaged in competitive sports because these persons are mostly young and well-trained. Other neurological diseases are even rarer as possible causes of sciatica. That is why we report on a young athletic who is a short-distance hurdler (110m hurdle race) and has been suffering from a neurinoma of the spinal nerve root L3 with sciatica and pain in the knee as initial symptoms. Attention is drawn to the importance of neurological examinations as part of medical examinations conducted by sports physicians for the purpose of obtaining an overall guiding picture of the subjects' health status.

Adult↗

Skin testing for chymopapain allergy in chemonucleolysis.

Chemonucleolysis with chymopapain (Chymodiactin, Discase) bears the risk of unpredictable anaphylactic reactions. The rate of anaphylaxis is reported to be between 0.35% and 1.5%. Serological in vitro tests such as RAST (radio-allergo-sorbent test) or ChymoFAST (fluorescent allergo-sorbent test) are used to determine increased specific immunoglobulin E antibody titers against chymopapain in patients submitted to chemonucleolysis. Alternatively, skin prick tests have also been applied in clinical trials. A skin prick test including Discase, Chymodiactin, and Solutrast 250 M, which is a radiopaque dye, has been performed in a total of 257 patients; 222 patients were tested before, and 35 patients were tested after chemonucleolysis with chymopapain. From the group tested before chemonucleolysis, 2.3%-3.3% had positive skin tests. After chemonucleolysis, the overall allergy rate to chymopapain increased to 42.9%. Positive skin reactions seem to be time-dependent--between the 3rd and 12th weeks after chemonucleolysis, more than 70% of the patients had positive skin tests. There was no correlation between a history of previous allergy and the skin test result. Patients with positive skin tests should be excluded from chemonucleolysis. This procedure increases the safety for patients submitted to chemonucleolysis. No anaphylactic reaction has been observed hitherto in more than 350 patients who were treated with the intradiskal injection of chymopapain after a negative skin prick test.

Anaphylaxis↗

[Incidence and prevention of allergic reactions following chemonucleolysis with chymopapain].

Allergic reaction following chemonucleolysis with chymopapain is responsible for half of all known complications of this treatment. Although the incidence of allergic reactions is comparatively low one should not underestimate the danger involved. If chemonucleolysis is performed under local anaesthesia, the risk of an anaphylactic reaction is reduced. If no pre-operative test methods are available, the patient risk can be considerably lessened by suitable premedication and by keeping anti-allergics within easy reach during intradiscal therapy. Exclusion of patients who have a previous history of allergy from chemonucleolysis will not result in additional safety. The specificity of the serological tests is very high, but their sensitivity and reliability in respect of prediction of an allergic reaction with positive or negative test result is comparatively low. They take up a lot of time (24 hours) and require skilled personnel trained in laboratory chemistry. The chymopapain prick test is simple to perform and the result of the test rapidly available (15 minutes). The danger of allergic reactions to the prick test itself is negligibly small, as experience has shown. At the present time no comparative tests are available between serological tests and skin tests in a large group of patients, so that we can say something about the reliability only on the basis of empirical data. Of the 352 test-negative patients investigated so far, none had an allergic immediate reaction to chymopapain. Even if we take the possibility of false positive skin tests into consideration, we believe that it would not be appropriate with a positive skin test to perform chemonucleolysis.

Anaphylaxis↗

[Cerebral hemodynamics in chronic hypoxic hypoxia].

The effects of chronic-hypoxic hypoxia on cerebral blood flow and its regulating mechanisms were investigated by means of intracardiac injection of radioactively labelled microspheres. In a gas chamber designed and constructed for the purpose, adult cats were exposed to stepwise decreasing inspiratory oxygen concentrations (for 4.5 months with a final O2 concentration of 8 vol%). Using animals adapted to hypoxic hypoxia, responsiveness of cerebral blood flow either to alterations in systemic arterial pressure (SAP) or to alterations in arterial blood oxygen tension (PaO2) were assessed. Flow measurement was done under three different conditions: normoxic normotension (PaO2 greater than 100 mmHg; SAP greater than 100 mmHg), hypoxic normotension (PaO2 = 30 mmHg; SAP greater than 100 mmHg), or normoxic hypotension (PaO2 greater than 100 mmHg; SAP = 60 mmHg). Hematocrit values continuously increased to 56% during the process of adaptation to hypoxia. There was also a remarkable increase in cardiac output of hypoxia-adapted animals subjected to hypoxia and to normoxia. Chronic-hypoxic hypoxia led to increased cerebral blood flow, which persisted even when animals were returned to normoxia. Under hemorrhagic hypotension, cerebral blood flow fell significantly in animals adapted to chronic-hypoxic hypoxia but did not fall short of the absolute values in controls. The relative reduction in cerebral blood flow might be attributable to the decrease in cardiac output and to altered blood viscosity. This implied that, even in animals subjected to long-standing graded hypoxic hypoxia, autoregulatory capacity might be partly preserved.

Adaptation, Physiological↗

[Chymopapain allergy. Diagnostic value of a skin test before and after chemonucleolysis].

Chemonucleolysis with Chymopapain (Chymodiactin, Disease) bears the risk of unpredictable anaphylactic reactions. The rate of anaphylaxis is reported to be between 0.35 and 1.5%. Serological in vitro tests such as RAST (Radio Allergo Sorbent Test) or ChymoFAST (Fluorescent Allergo Sorbent Test) are used to determine increased specific IgE antibody titres against chymopapain in patients submitted to chemonucleolysis for lumbar disc disease. Alternatively skin prick tests have also been applied in clinical trials. A skin prick test including Discase, Chymodiactin and Solutrast 250 M, which is a radiopaque dye used for discography, has been performed in a total of 208 patients. One-hundred and seventy-seven patients were tested before, 31 patients were tested after chemonucleolysis with chymopapain. From the group tested before chemonucleolysis, 2.3-3.5% had positive skin testes. After chemonucleolysis, the overall allergy rate to chymopapain increased to 41.9%. Positive skin reactions seem to be time-dependent: Between the 3rd and 12th week after chemonucleolysis more than 70% of the patients had positive skin tests. There was no correlation between a history of previous allergy and the skin test result. Patients with positive skin tests should be excluded from chemonucleolysis. This procedure increases the safety for patients submitted to chemonucleolysis. No anaphylactic reaction has been observed hitherto in nearly 350 patients who were treated with the intradiscal injection of chymopapain following a negative skin prick test.

Adult↗

[Anesthesiologic aspects of chemonucleolysis in local anesthesia].

After treatment of herniation of a lumbar disc by injection of the enzyme chymopapain, i. e. after chemonucleolysis, anaphylactic reactions can occur in about one per cent of the cases. In order to recognise the pattern of signs associated with such reactions, well in advance, while avoiding the additional risk of general anaesthesia, some authors propagate local anaesthesia. We report on our perioperative procedure in 102 cases of chemonucleolysis under local anaesthesia. Prick's tests were carried out before surgery to exclude sensitization to the substances to be injected. In two cases only due to a positive prick test to chymopapain chemonucleolysis had to be effected with collagenase; as a matter of fact, collagenase is not known to have caused any anaphylactic reactions, but it may be responsible for local side effects, such as destruction of adjacent tissues. The patients were kept under observation by an anaesthetist during and after surgery. No anaphylactic reaction was seen. Chemonucleolysis appears to be a suitable treatment method provided it is carried out under local anaesthesia with the same precautions as applied under regional anaesthesia by the anaesthetist.

Adult↗

Complications following chemonucleolysis with collagenase.

Lumbar disc tissue from eight patients previously submitted to unsuccessful chemonucleolysis with collagenase was studied by light and scanning electron microscopy (SEM). Similar material from eight patients subjected to primary disc surgery served as control. The control discs revealed the characteristic signs of degeneration of collagen tissue, microcystic areas, and giant chondromas. However, the anulus fibrosus and the end-plates remained intact. Following chemonucleolysis with collagenase, "digestion" of the nucleus pulposus, the anulus fibrosus, and extensive damage to the end-plates, bone, ligaments, and epidural fat were seen.

Adult↗

[The delayed OP--indications for surgery of lumbar disc herniations].

In Germany, lumbar disc herniations require surgical treatment in about 50,000 patients/year. The clinical and socio-economical results are determined by the preoperative duration of symptoms and preoperative time out of work (highly predictive). Other parameters such as severity of neurological deficits, morphology of disc herniation, age, associated diseases, type of surgery, working conditions or litigation processes are only weak predictors of outcome. Postoperative improvement of clinical symptoms as well as professional reintegration is strongly determined by the time period between onset of symptoms and surgery. Surgery performed "too early" diminishes the chance for improvement by conservative therapy. If surgery is performed "too late" the risk of a bad result is high, and the reintegration of the patient into his preoperative social and professional activities may be prevented. The duration of conservative therapy including so-called semi-invasive procedures is critical in this sense. If a therapeutic success (= professional and social reintegration) cannot be achieved by conservative measures and if there is a clear morphological correlate (= disc herniations with corresponding clinical symptoms) of the clinical symptoms an early change of the strategy towards surgical therapy is recommended.

Diskectomy↗

[Lumbar epidural lipomatosis].

Spinal epidural lipomatosis is a pathological accommodation of fat tissue in the spinal canal. It seems to be a disease entity, which, though rare, has recently been diagnosed more frequently and can be accompanied by neurological deficits. The thoracic spinal canal is the preferred localization. Eighteen cases of symptomatic lumbar epidural lipomatosis have been described in the literature. We are reporting on our experience with another 8 patients. Three of these patients presented with the typical signs of spinal nerve irritation. In these cases epidural lipomatosis was associated with a small disk herniation without direct contact to the spinal nerve. Another 5 patients showed the clinical picture of a spinal claudication. In all 5 patients, there was a concentric compression of the thecal sac by epidural fat. In one patient, the cause of the lipomatosis was assumed to be long-term steroid therapy following kidney transplantation. Four patients suffered from extreme obesity. No cause for lipomatosis could be found in 3 patients. A microdiskektomy was performed in the 3 patients with the associated disk herniation; the remaining patients were treated conservatively. In 6/8 patients (3x surgery/3x diet), an "excellent" or "good" clinical result could be achieved after 1 year. Two patients had a "satisfactory" result. Lumbar epidural lipomatosis can be treated conservatively in cases with only mild neurological dysfunctions and known cause (e.g. obesity, steroid therapy). The surgical removal of associated disk herniation proved to be sufficient in cases described in this paper.

Adult↗