[The moya-moya syndrome].
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Angiomatosis↗
Biomedical subjects
M Weber
Publications and source records attributed to M Weber.
[Electroencephalographic aspects of vascular hemiplegia in the aged subject. Longitudinal study and prognostic elements apropos of 156 cases].
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Aged↗
[Detection of cerebral tumors: value of the EEG].
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Adolescent↗
[Electro-clinical features of short-term anaesthesia (author's transl)].
Short-term anaesthesia is defined in terms of duration (allowing brief but what might be painful surgery), rapid recovery, metabolism and mode of administration. After a brief review of barbiturate narcoses, the authors study the electro-clinical features of anaesthesia under Althesin, Epontol and ketamine. For the first two, although there are some clinical differences, the E.E.G. effects are fairly similar with rapid onset of burst suppression. Recovery is rapid and its study (clinically, with psychomotor tests and E.E.G.) indicates that these drugs can safely be used with out-patients. Ketamine causes very specific alterations, both clinical (dissociative anaesthesia) and E.E.G. (diffuse and continuous theta). This drug is used particularly in painful operations; its use with out-patients would seem awkward.
Adolescent↗
[Electro-clinical aspects of leucinosis].
Maple syrup urine disease, or leucinosis usually presents between the 4th and 10th day of life with neurological and gastro-intestinal symptoms. A distinctive odour of maple syrup on the child's skin or of his urine enables diagnosis to be made clinically, confirmation coming from amino-acide chromatography which reveals increased levels of the branched amino acids, leucine, valine and isoleucin in the blood and urine. The disease, untreated, is fatal, death occurring rapidly. With early diagnosis and treatment with a diet deficient in branched amino acids and purification methods the prognosis is quite good. E.E.G. appearances are clearly, therefore, of considerable interest: --burst suppression or "pseudo burst suppression" in the acute phase, suggesting severe cerebral insult and warranting amino acid chromatography. --rolandic "picket fence" waves seen between the 2nd and 4th weeks of life, which are strongly suggestive of the disease. --good correlation between clinical, biochemical and E.E.G. parameters, improvement of the last two indicating a good prognosis. --E.E.G. observation at regular intervals is justified after the acute phase to aid forecasts concerning the eventual outcome.
Cerebral Cortex↗
[Clinical and electrophysiological aspects of the gangliosidoses (author's transl)].
The gangliosidoses belong to the family of diseases known as the lipidoses and are due to an excess of ganglioside I (GM1) or II (GM2). The illness described by Landing belongs to Group I, whilst Tay-Sachs and Sandhoff's disease are type 2. This study was particularly concerned with the electro-clinical aspects of group 2, and 4 stages have been differentiated: --the first occurs between 4-10 months: the child is apathetic, hypotonic and has occasional audiogenic seizures; fundoscopy revealing the classical cherry red spot on the macula. The diagnosis can be confirmed by biopsy. The EEG is irregular but abnormalities are minor. --the second stage (10 months-2 years) the child spastic and amaurotic, often unresponsive is suffering from frequent seizures. The EEG is of high voltage, with slow and sharp waves. Auditory stimulation does not produce EEG changes. --in the third and 4th stages (after 2 years) the child is in a vegetative state with a progressive reduction in EEG voltage and sharp waves until death aged 3 or 4. Although there is a good correlation between clinical signs and EEG this is of no diagnostic value.
Brain↗
[Contribution of electromyography to the study of ulnar nerve lesions in the hand. Compression syndrome of the motor branch of the ulnar nerve (author's transl)].
Standard electromyographic investigations: detection and stimulodetection; segmental motor nerve conduction rate, distal motor latencies (interphalangeal V and I short abductor muscles), and distal sensory (antidromic) conduction time, were used to explore seven cases of distal paralysis of the ulnar nerve. Results enabled differentiation of elective lesions of the deep motor branch from those of the ulnar nerve in Guyon's canal. These two types of lesion correspond to precise anatomical features: the channel between the pisiform and unciform bones on the one hand and Guyon's canal on the other. The electroclinical syndrome of the deep branch should be considered as a separate true canalicular syndrome. Treatment is by surgery in most cases.
Electromyography↗
Flow, diffusion, and thermal convection in percolation clusters: NMR experiments and numerical FEM/FVM simulations.
Percolation objects were fabricated based on computer-generated, two- or three-dimensional templates. Random-site, semi-continuous swiss cheese, and semi-continuous inverse swiss-cheese percolation models above the percolation threshold were considered. The water-filled pore space was investigated by NMR imaging and, in the presence of a pressure gradient, NMR velocity mapping. The fractal dimension, the correlation length, and the percolation probability were evaluated both from the computer-generated templates and the corresponding NMR spin density maps. Based on velocity maps, the percolation backbones were determined. The fractal dimension of the backbones turned out to be smaller than that of the complete cluster. As a further relation of interest, the volume-averaged velocity was calculated as a function of the probe volume radius. In a certain scaling window, the resulting dependence can be represented by a power law the exponent of which was not yet considered in the theoretical literature. The experimental results favorably compare to computer simulations based on the finite-element method (FEM) or the finite-volume method (FVM). Percolation theory suggests a relationship between the anomalous diffusion exponent and the fractal dimension of the cluster, i.e., between a dynamic and a structural parameter. We examined interdiffusion between two compartments initially filled with H2O and D2O, respectively, by proton imaging. The results confirm the theoretical expectation. As a third transport mechanism, thermal convection in percolation clusters of different porosities was studied with the aid of NMR velocity mapping. The velocity distribution is related to the convection roll size distribution. Corresponding histograms consist of a power law part representing localized rolls, and a high-velocity cut-off for cluster-spanning rolls. The maximum velocity as a function of the porosity clearly visualizes the percolation transition.
Computer Simulation↗
[Damage to the glenoid labrum and expert assessment].
AIM: Development of criteria for the medical-legal interpretation of different patterns of labral lesions according to the labrum pathology and mechanism of injury. METHODS: A metaanalysis of the literature concerning injuries and diseases of the shoulder involving the glenoid labrum was performed. RESULTS: Lesions of the superior, anterior and posterior labrum are rare and of different severity. Arthroscopically they are divided into distinct types. They develop either spontaneously together with intraarticular diseases, due to chronic fatigue or by injury. In this field the stability of the shoulder joint and the tension of the long head of the biceps tendon play an important role. There is no correlation between the type of lesion and mechanism of injury. With respect to medical-legal interpretation, the currently used classification of labral lesions is not very helpful or is even confusing. We therefore propose a new classification according to the meniscus pathology which shows a striking similarity to labral pathology. There are two types of labral lesions: Type one shows degenerative defects, which may be influenced by mechanical loading; type two follows from shoulder instability. CONCLUSIONS: Medical-legal interpretation of labral lesions should follow the same principles that were shown to be useful in knee joint instability and meniscal tears. Only traumatic luxations of the shoulder joint may lead to labral tears without any other alterations.
Cartilage, Articular↗
[Effect of femoral intramedullary irrigation on periprosthetic cement distribution: jet lavage versus syringe lavage].
INTRODUCTION: The purpose of this experimental study was to determine quantitatively the cement penetration into periprosthetic femoral bone by Icomparing the use of jet-lavage with the conventional syringe irrigation. METHODS: 10 pairs of fresh-frozen human cadaver femora were used for cemented stem implantation, The left femora were irrigated with a syringe device, the right femora with a jet-lavage system. After implantation, all femora were cut into 5-mm slices from proximal to distal with a diamond saw. The scanned slices were analysed using an image processing system which provided a discrimination between implant, cement, and bone as well as an exact determination of the cement area. RESULTS: In all 10 femora, a recognizable improvement of the cement penetration into the periprosthetic bone was demonstrated using the jet-lavage. In the proximal part, the mean cement penetration was 8.6% higher in the jet-lavage group than in the syringe device group. An equivalent tendency towards the jet-lavage pretreated femora was seen in the middle part with 8.7% on average mean and in the distal part with 6.4% on average. Also, when subdividing the periprosthetic area into 4 quadrants, a significant improvement of the cement penetration was found with the exception of the ventro-medial region. CONCLUSION: Cement distribution and penetration is improved using the jet-lavage technique for cleaning the medullary canal of the femur. Therefore, the jet-lavage should be used as a standard procedure in clinical cementing techniques.
Arthroplasty, Replacement, Hip↗
[Is lumbar disk disease an occupational disease? Scientific background, radiological findings, and medical legal interpretations].
AIM: It should be cleared whether or not the interpretation of lumbar disk disease as an occupational disease is justifiable. Which disc changes follow whole-body vibration and can they be distinguished from those which occur constitutionally while aging? METHOD: Orthopedic meta-analysis of epidemiological and occupational studies concerning the influence of whole- body vibration. RESULTS: Reliable studies are rare. Severe methodological problems limit the interpretation of difficult relationships. The role of age when working influences begin as well as the stress and behaviour of exposed persons away from the work-place before and while working with whole-body vibration is not known. There is no study which could be called exact according orthopedic criteria. It is therefore not evident that whole-body vibration causes lumbar disc disease. CONCLUSIONS: After whole-body vibration similar to long term heavy lifting an earlier beginning of disk degeneration in X-ray-studies can be observed. This leads to prevalence differences, which diminish with increasing age. Deviation to the left of the prevalence curve lasts for five to ten years. Whole-body vibration leads to a topographic modification of disk degeneration of the lumbar spine. After long duration exposition an increased amount of spondylotic changes at the thoracolumbar junction and the middle half of lumbar spine can be observed (up to the upper plate of the fourth vertebral body). This can be explained by biomechanic means: whole-body vibration caused by tractor driving and similar long-term exposures leads to traction of the disks of the lower thoracic spine and the upper and middle parts of lumbar spine.
Cross-Sectional Studies↗
[Filling of osteochondral donor site defects. Experimental study with tricalcium phosphate cement and BMP-2].
AIM: Osteochondral grafting procedures have developed into one of the preferred methods of treatment for focal osteochondral lesions, although the management of the donor site remains problematic. In this animal study, an attempt at sealing the donor site with a fully-resorbable tricalcium phosphate bone cement was evaluated. METHOD: Autologous osteochondral transplantation of the medial and lateral condyle was performed on the ovine knee using a standard operative protocol. The ensuing defect was filled with the original beta-TCP cement laterally, while medially the cement was augmented with 50 micro g BMP-2. Two groups, consisting of 10 sheep each, were evaluated after three and 6 months, respectively. RESULTS: The clinical evaluation of the specimens revealed an improved reconstruction of the joint surface following the application of the augmented biomaterial. Macroscopically, the superficial border of the original donor site could easily be outlined at both time periods in both groups. Solid osteointegration of the bone cement could be documented radiographically as early as three months following implantation. CONCLUSION: The beta-TCP bone cement represents a promising resorbable filler for osteochondral defects. The augmentation with BMP-2 seems to expedite the remodelling process and improve the surface reconstruction.
Animals↗
[Posteromedial bowing of the lower leg and neuroblastoma with possible neurofibromatosis type I: a case report and literature review].
BACKGROUND: The posteromedial bowing of the tibia is a rare condition that is not yet known to be related to neurofibromatosis. The case of a three month-old boy with the tentative diagnosis of neurofibromatosis is described. He developed paraplegia due to an abdominal neuroblastoma at the age of 9 months. This led us to a review of the literature. METHOD: 122 cases of posteromedial bowing of the tibia in 20 publications of the years 1949 - 2000 were analysed under special respect to gender, side of affection, shortening of the lower leg, treatment and possible cause. RESULTS: The posteromedial bowing of the lower leg seems to affect more boys as well as the left side. As far as described in all but one case it was the first delivery. Regularly, a limb shortening and pes calcaneovalgus is to be found. 99 children were treated conservatively, 21 got an operation of the affected side. In 19 performed osteotomies no pseudarthrosis occurred. One case of a fracture due to an adequate trauma without healing problems is described.
Abdominal Neoplasms↗
[Is the implantation of titanium stems in hip prostheses really obsolete?].
AIM: Due to several bad results of studies, titanium is no longer used as an implant material in cemented total hip arthroplasty. This study attempts figure out by means of a meta-analysis if the material titanium itself was responsible for the bad results of some studies or if specific implant characteristics contributed to implant failure, independent of titanium. METHOD: Studies between 1960 and July 2002 were analysed concerning failure rates of cemented titanium total hip arthroplasties regarding their specific implant characteristics. RESULTS: Specific implant characteristics such as roughness of the surface and geometrical features led to significantly different failure rates. Stems of titanium with a dull surface and a wide proximal geometry could achieve such good results as those of the cobalt-chromium stems published in the study results of Malchau. CONCLUSION: Titanium is justified as a cementable material in total hip arthroplasty. By respecting specific implant characteristics, very good failure rates can be achieved. The high failure rates, published in several studies, are based upon implant characteristics which are not suitable for cementing techniques and not upon the implant material titanium itself.
Arthroplasty, Replacement, Hip↗
[Nation-wide registration of limb deficiencies in Germany].
AIM: A detailed registration of the frequency and the aetiology of limb deficiencies has been established for the first time in Germany. METHOD: According to the ESPED model (Documentation of rare paediatric diseases in Germany) we send out at an interval of three months a questionnaire for registration of live births, still births and their limb deficiencies to 1 073 gynaecological hospitals. In case of a positive response for a limb deficiency a second questionnaire is sent for details about pregnancy, birth and family. The limb defects are registered according to the ICD-10 classification and statistically analysed. RESULTS: Current acquisition period: 48 months (April 2000-April 2004). Total number of registered births: 1 070 541. Number of live births with limb deficiencies: 1 534 (0.14 %). Number of still births with limb deficiencies: 55 (1.7 %). Minor limb deficiencies such as polydactyly (22.4 %) are more frequent than major deficiencies of the tibia (1.0 %) or of the fibula (1.6 %). A familiar disposition is found in 9.7 %. A correlation to the profession of parents or their age (mother: 29, father: 33), or nicotine abuse could not be detected. The numbers of special features during pregnancy (amniocentesis in 3.3 %, oligohydramnion in 0.5 %, polyhydramnion in 0.3 %, etc.) and during delivery (relation between normal delivery and caesarean section = 59.5 %/29 %, etc.) were similar to the frequencies in the normal population. CONCLUSIONS: Our register represents the largest study world-wide in respect to the birth rate and the most accurate record of limb deficiencies. In the current acquisition period no correlation of the registered limb deficiencies to environmental effects, individual misbehaviour, exposed professional group and peculiarities during pregnancy and parturition could be found. The continuation of our register is essential for further detection of the incidence and aetiology of limb defects.
Abnormalities, Multiple↗
[Cemented total knee arthroplasties].
INTRODUCTION: The aseptic loosening of cemented total knee arthroplasties is still an unsolved problem. In this regard, the hydrolysis resistance in the metal-to-bone cement interface is of major importance. MATERIAL AND METHODS: Cemented pre-treated tibia components coated by means of a silica/silane interlayer system of the model "Columbus PS" were dynamically loaded with the help of a knee-simulator similar to DIN ISO 14243. After loading, the components were microscopically analysed concerning debonding in the metal-to-bone cement interface as well as with regard to cement mantle defects. These data were matched with uncoated "Columbus PS" components. Unloaded coated and uncoated tibia components acted as a control. RESULTS: In comparison with uncoated tibia components, the pre-treated and coated ones yielded a highly significant reduction of cement defects (p < 0.01) as well as a significant reduction of debonding in the metal-to-bone cement interface (p < 0.05). CONCLUSION: By means of the silica/silane interlayer system for cemented tibia components, a hydrolytic debonding in the metal-to-bone cement interface with subsequent mechanical loosening and consecutive early cement mantle failure can be significantly reduced. This could lead to an increased long-term stability of the metal-to-bone cement compound with decreased aseptic loosening in clinical use.
Adhesiveness↗
[Effect of risk factors and therapy on intermediate-term hip deformity in Perthes disease].
UNLABELLED: The prognostication of risk factors for the outcome of LCPD was examined. The radiographic results of conservative treatment with Thomas splint and operative treatment with intertrochanteric derotational varus osteotomy (DVO) were compared using the Index of Deformity (D). METHOD: Radiographs of 153 patients with unilateral LCPD were evaluated retrospectively 1.5-3 years and 3-7 years after diagnosis using the Index of Deformity and Index of Direction. We investigated the radiographic changes in relation to acetabular or metaphyseal reaction, Waldenström classification or limited range of motion at diagnosis and in dependence of therapy. RESULTS: There was a significant better acetabulum-head-index of deformity after DVO. Children with metaphyseal or acetabular reaction had bigger deformities. Patients with metaphyseal reaction had smaller deformities after DVO compared with conservative treatment. Free range of motion (ROM) was prerequisite for good results after DVO. Waldenström classification at diagnosis did not have any influence on morphologic changes after 3-7 years. CONCLUSION: DVO leads to a better containment than conservative treatment with Thomas splint, metaphyseal reaction should be an indication for operative treatment. Prerequisite for DVO is a free ROM. Because Waldenström class at diagnosis does not influence the outcome, free ROM before starting the treatment is more important than an immediate start of therapy.
Adolescent↗
[Primary correction of scoliosis with the Wilmington corset].
QUESTION: As part of our study, the effectiveness and patient's acceptance of the Wilmington-brace is to be evaluated. The effectiveness can be documented with the help of the primary correction achieved, especially in light of the fact, that the primary correction and the long-term results are directly dependant upon one another. MATERIAL AND METHOD: We examined a total of 52 patients with an idiopathic scoliosis treated in a thermoplast brace. The group consisted of 38 female and 14 male patients (average age 11.6 years). The angulation was measured with the help of the Cobb-angle and the rotation with the method described by Nash and Moe. The skeletal age was classified according to Risser's-sign. The angle determinations were carried out at three separate points in time--at first presentation, prior to bracing and four to six weeks following bracing. RESULTS: The patients presented with an average angulation of 31 degrees. The average correction achieved in the Wilmington-brace was 41%. This corresponds to a correction of 13 degrees. The best primary correction (45%) was obtained in the thoracolumbar spine. Those patients with the smallest deformity at the onset of treatment showed the best results. The scoliosis with a large primary deformity and a marked rotation of the vertebral bodies responded poorly to correction. Advanced age or skeletal maturity were also limiting factors. Physical therapy had a positive influence on the amount of primary correction obtained. CLINICAL RELEVANCE: The Wilmington-brace (thermoplast) allows for a good primary correction of idiopathic scoliosis. The simplicity of application and the low production costs are also positive attributes.
Adolescent↗