Biomedical subjects
Publications and source records attributed to M Brock.
A case of arteriovenous malformation of the left cerebellopontine angle causing symptoms of ipsilateral trigeminal neuralgia is reported. Pain relief followed microsurgical removal of the malformation. The authors review the literature on the subject.
Surgical treatment for protrusion of intervertebral disks in the lumbar region has been considerably optimised. Progress in imaging techniques has enabled representation and recording of intervertebral disk disorders at various pathogenetic stages. Backache has become endemic in industrial countries, in the course of time, and is often accompanied by pseudoradicular ischialgia. It is quite often uncritically attributed to intervertebral disk damage on the basis of findings recorded from computed tomography. With patients increasingly suffering pain, this has in many cases led to rash surgical decisions. -Principles of differential diagnosis by which the complexity of morphological findings underlying clinical symptoms is taken into due consideration are absolutely necessary to counter the above developments. Indications for neurosurgical differential therapy for protrusion of intervertebral disks at lumbar level should be individually established with due consideration of therapeutic procedures available and of the severity of complaints. The percutaneous and microsurgical techniques described in this paper are likely to suggest that procedures, such as hemilaminectomy and laminectomy are no longer justified unless exceptional cases are to be handled.
The mechanism by which precursor and pre-B cells undergo differentiation is unclear; however, it is known that growth factors play an important role in this maturation process. The lymphokine, IL-4 has been shown to increase expression of class II Ag on B cells and induce B cell proliferation. In the murine system, IL-4 induced differentiation of precursor B cells into pre-B cells. In order to analyze growth factors on B cell development we have established an in vitro culture system for human bone marrow cells. We found that in the presence of IL-4, normal human precursor and pre-B cells can be induced to differentiate in the absence of cell proliferation with four days of culture. Furthermore, IL-4 depressed proliferation induced by supernatant from a T cell line. The differentiation was measured by an increase in both the number of cytoplasmic mu and surface IgM-positive cells. The effect of IL-4 on precursor and pre-B cell differentiation was detected as soon as 14 h of exposure to the lymphokine in the absence of an adherent feeder layer. These data suggest that IL-4 directly affects the differentiation process of normal human precursor and pre-B cells, and may antagonistically affect cell proliferation.
41 patients with brain stem gliomas are presented and analyzed. Optimal therapy as well as outcome depend on the histological identity of the tumours. Histological examination cannot be replaced by CT, angiography and NMR. Therefore stereotactic biopsies are recommended in all cases with brain stem gliomas.
Regeneration of both median nerves was studied in the rat in three different experimental models of centrocentral anastomosis through an interposed segment of pre-degenerated tibial nerve after denervation by spinal root transection. Different patterns of regeneration were observed in the anastomoses. These patterns suggest a bio-electrical polarity related to neuronal function. The present experimental model appears to offer a new opportunity to study neuronal regeneration under the influence of defined bioelectrical conditions.
Both brachial plexuses of Wistar rats were deafferented or deefferented by disrupting their dorsal or ventral roots. At the same time, the ulnar nerves were transected and sutured. A sham group and another group in which the upper (C-5) and lower (T-1) spinal nerves were transected on both sides were included as control groups. Clear differences in the ulnar nerve regeneration rate were found between the deafferented and the deefferented animals. Ultrastructural studies disclosed signs of transient axonopathy in the nontransected fibers of the proximal segment of the ulnar nerve. The possible role of bioelectricity in the genesis of these changes is discussed.
Intervertebral lumbar disk herniation in children and adolescents is rare. The incidence varies between 0.8% and 3.8% of all disks treated surgically. The uncertainty concerning operative or conservative treatment of this rare clinical entity has led to considering the use of atraumatic techniques, such as chemonucleolysis or percutaneous diskectomy. We report the unusual case of an 11-year-old girl with herniated disk at the L4-5 level treated by percutaneous diskectomy. This is, to our knowledge, the first case of a child treated by this technique. The technical simplicity, the minimal trauma it causes, and the excellent clinical result show that percutaneous diskectomy is a reasonable therapeutic alternative in the treatment of juvenile disks.
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.
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The history of five patients, having developed intraventricular bleeding following head injury, was reviewed. Only two patients survived, one of whom eventually lapsed into a persistent vegetative state. The only patient showing good recovery was an 8-year-old girl. Primary traumatic intraventricular hemorrhage should be considered a rare, but serious entity with a very poor prognosis.
Axonal ensheathment and myelination, one form of axon-sheath cell interaction, was studied under normal earth magnetism, in the absence of terrestrial magnetic field, and under a 5 G (0.0005 T) magnetic field. Results indicate that the geomagnetic field is necessary for the fundamental biological activity of axonal ensheathment and myelination. The exact mechanism of action remains obscure.
In 1985 and 1986 the Department of Neurosurgery of the University of Berlin treated two cases of arachnoid cysts of third ventricle, both of which were successfully dealt with surgically. They are reported in this paper. Arachnoid cysts from ventricular system and cisterns are rare. Up to now 46 cases have been reported in the specialized literature. The computerized tomography and magnetic resonance make diagnosis easier, as shown through the cases reported.
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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.
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A method is shown for fractionated afterloading therapy of inoperable cerebral tumors. A 3 mm thick, tube-form applicator of noble metal which is closed at the front side is implanted into the tumor by a stereotaxic technique and firmly screwed together with the osseous calotte. It remains there up to two weeks, giving full mobility to the patient. The afterloading therapy with a moving iridium source is performed one or two times per day with individual doses of 2 Gray. Thus, the chronological and--to a certain extent--also the spatial dose distribution is variable when applying this method.
A prospective randomized study has been conducted since 1978 to judge the value of combined radio- and chemotherapy (CCNU) in the postoperative treatment of grade III and IV supratentorial gliomas. Inoperable or recurrent tumors were excluded from these series, but evaluated in addition. Increase in median survival time (18 months) for the entire series (62.2% glioblastomas) was only small compared to other series mentioned in literature, but there was a significant prolongation of the recurrence-free interval (16.5 months) and in the total survival time from the onset of symptoms in 46.4% of cases living more than 18 months. If 'useful recovery' is the major goal of present treatment of cancer, the recurrence-free interval and the fraction of long-term survivors may be more important statistical parameters than median survival time. To improve the 'quality of life' in a number of patients (so-called long-term survivors) and the length of recurrence-free intervals should be the therapeutic goal, even if overall survival time remains essentially unaffected. We conclude that combined therapy, including radio- and chemotherapy, following surgical resection is of value in most cases of malignant glioma.