Biomedical subjects

H-E Schaller

Publications and source records attributed to H-E Schaller.

6 recordsLinked to original sources

PubMed2006

[Memantine and Complex Regional Pain Syndrome (CRPS): effects of treatment and cortical reorganisation].

BACKGROUND: In recent studies a central nervous system involvement in the pathogenesis of Complex Regional Pain Syndrome (CRPS) was suggested, stimulating the introduction of central acting drugs. Animal studies have demonstrated an increased expression of the N-methyl-D-aspartate (NMDA) receptors in experimental neuropathic pain. PURPOSE: The aim of this study was to investigate the relationship between NMDA receptor blockers and CRPS. METHOD: Three patients suffering from CRPS of one upper extremity where treated with oral NMDA antagonist Memantine for eight weeks. Patients expressed their pain levels with a visual analog scale ranging from zero to ten at rest and after fist clenching. Furthermore, the range of movement of the fingers and the wrist were documented. To assess force, a pinchmeter and a dynamometer were used. Cortical reorganisation was studied with functional Magnetic Resonance Imaging (fMRI) and Magnetoencephalography (MEG). RESULTS: Six months after treatment with Memantine no rest pain was present in any of the patients. Furthermore, an increase in finger movement was observed after six-month follow-up with no deficits and free movement ranges. Additionally, wrist movement was improved and an increase of force was measured after six months with the dynamometer and the pinchmeter. Moreover the functional impairment, cortical reorganisation was observed in all patients before treatment. These changes returned to a normal pattern after eight weeks of treatment with Memantine. CONCLUSION: These first results demonstrate central nervous system involvement in the development and maintenance of CRPS. The results (functional, pain, fMRI, MEG) after treatment with Memantine indicate the importance of the NMDA receptor system in neuropathic pain syndromes and provide a promising approach for the treatment of CRPS.

Administration, Oral↗

PubMed2006

[Tissue engineering of peripheral nerves].

BACKGROUND: In spite of considerable progress in microsurgical techniques, the treatment of long distance defects in peripheral nerves remains challenging for the surgeon. Autologous nerve grafting has been the only applicable procedure to overcome such defects in the past. Due to the known disadvantages of this procedure (neuroma formation and sensory deficits at the donor-site, limited availability of donor-material, etc.) and impaired regenerative results, different tubulisation techniques are discussed more frequently as alternatives to the autologous nerve grafts. AIM OF THE STUDY: In this work, the authors summarise their experiences and results with different synthetically developed materials, cellular and acellular tubes and venous conduits for the reconstruction of peripheral nerve defects. MATERIAL AND METHODS: To analyse peripheral nerve regeneration, we utilised a median nerve model in rats. In these studies nerve gaps up to 40 mm were induced. Guiding tubes of various materials (trimethylene carbonate-epsilon-caprolactone, polyethylene, veins, and collagen) were employed. Furthermore, we introduced Schwann cells as cellular elements into some of the trimethylene carbonate-epsilon-caprolactone tubes. The longest postoperative observation period was nine months. RESULTS: The results demonstrated that only in the case of cellular filled tubes (syngenic Schwann cells) did regeneration occur across the 20 mm gap. This regeneration was comparable to that induced after autologous grafting. Across a 40 mm gap the autologous graft demonstrated the best results.

Animals↗

PubMed2005

[Soft-tissue coverage of the hand using the posterior interosseous artery flap].

UNLABELLED: Significant trauma, severe bacterial infections and tumour resections of the hand are often complicated by primary or secondary soft-tissue defects. The Posterior Interosseous Artery Flap (PIA), described by Zancolli and Angrigiani in 1985 offers one possibility for soft-tissue coverage. In this abstract, we present the results of 35 patients who were treated with distally based PIA flap reconstructions during the years 1998 to 2003. 24 patients were available for one-year follow-up and beyond. RESULTS: Long-term follow-up demonstrates excellent colour and texture match with reliable soft-tissue coverage. Two of the 33 flaps were lost because of ischemic necrosis. The incidence of distal local ischemia was predictable when the flaps were extended to the level of the PIP joint or beyond. CONCLUSION: The PIA flap affords a very durable and aesthetic option for soft-tissue coverage of the dorsum of the hand. The flap donor site can usually be closed primarily with little to no morbidity. In comparison to other local and distally based flaps such as the radial forearm flap, major blood vessels are spared. In summary, the PIA flap should be considered as a reliable and judicious alternative to free microvascular transfer procedures for soft-tissue defects of the hand proximal to the level of the PIP joint.

Adolescent↗

PubMed2005

[Peroneal nerve palsy caused by a recurrent proximal tibiofibular joint ganglion--a case report and review of the literature].

PURPOSE/BACKGROUND: Compression of peripheral nerves is a well known complication of articular synovial cysts. The peroneal nerve is the most common site of intraneural ganglia (pseudocysts) originating from the proximal tibiofibular joint. The neurological deficit associated with these cysts is often severe due to delayed diagnostic and surgical treatment. Therefore, recurrence is very often seen and recovery is incomplete. MATERIAL AND METHODS: We report a case of a 60-year-old man with peroneal nerve palsy caused by recurrent proximal tibiofibular joint ganglion. RESULTS: Within the context of the current literature, clinical symptoms, diagnostics, differential diagnosis with regard to imaging methods, neurology, pathology and the broader spectrum of operative and non-operative treatment are discussed. The cyst was completely resected, but a recurrent cyst developed eight years later. At reoperation, a communication of the cyst with the tibiofibular joint was demonstrated. Despite complete resection of the cyst and ligation of the ganglion stem, a routine postoperative MRI disclosed a second recurrence of the cyst nine months later. On the last clinical examination, twelve years after onset of the symptoms, a complete paresis of the peroneal nerve was seen. CONCLUSION: This entity needs careful, prompt preoperative evaluation to avoid neurological damage. Surgical treatment includes microsurgical decompression and complete resection of the cyst and also ligation of the ganglion stem. Early diagnosis and treatment is required to ensure recovery.

Diagnosis, Differential↗

PubMed2004

[Clinical importance of CMV-infection in German-speaking burn centers].

Due to immunosuppression, burn patients are at risk for CMV-infection. By means of a retrospective questionnaire we evaluated the clinical rating and management of CMV-infection in German-speaking burn centers. 41 % of the participating burn centers considered the role of CMV-infection of overall minor importance, 41 % of importance only in intensive care burn patients, 18 % of overall great importance. 70 % of the participating burn centers do not perform CMV-screening at admission. More than 50 % of the participating burn centers consider application of CMV-negative human blood-derived products in CMV-seronegative individuals as essential. At present clinical importance of CMV-infection in burn patients can not be clearly determined. But further prospective studies utilizing recently developed diagnostics seem warranted to the potential influence of CMV-infection on morbidity and mortality in burn patients.

Austria↗

PubMed2002

Dominances in finger arteries.

We studied the patterns of dominance in the palmar digital arteries of the fingers in 39 fresh cadaver arms which had been injected with coloured latex solution. We also performed photoplethysmographic studies in 20 hands. The ulnar digital artery in the index finger and the radial digital artery of the little finger were usually dominant, and their counterparts were slim and often hypoplastic. The findings are relevant to digit revascularization and might influence the planning of digital island-flaps or toe transfers.

Fingers↗