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Biomedical subjects

W Müller-Forell

Publications and source records attributed to W Müller-Forell.

At least 37 records · Page 2Linked to original sources
PubMed1999

Neuroradiological diagnosis in thyroid-associated orbitopathy.

No renunciation can be made of modern imaging techniques in primary diagnosis as well as in the course of endocrine orbitopathy. Even in times of cost reduction of the public health and although expansive CT and MR play a constant role in the interdisciplinary challenge, concerning the treatment of these patients. Both methods show the actual objective morphological findings, MR giving additional information concerning the acuteness (T2 relaxation time) or chronicity (fatty degeneration), which is of great importance for the chosen therapy. CT and MR is mandatory for the control of the clinical course after conservative, surgical and/or radiotherapeutic therapy.

Graves Disease↗
PubMed1998

Basic principles and clinical applications of neuronavigation and intraoperative computed tomography.

Computed tomography (CT) images in combination with a navigation device enable three-dimensional (3-D) localization of intracranial lesions. Furthermore, CT scanning can be adapted for intraoperative application to actualize the image data and to check the anatomical situation during the operation. Frameless navigation was used in 100 patients. The procedure was performed in 46 cases with an optical navigation system, in 38 cases with a sensory arm, and in 16 cases with a navigated microscope. Six skin markers were used for registration. Mean fiducial registration error was 2.18 mm with a standard deviation of 1.03 mm. The indication for navigation was tumor localization and planning of the craniotomy in 81 cases, stereotactic biopsy in eight cases, and endoscopic procedures in 11 cases. Technical problems with the navigation system were observed in nine cases. In two additional cases the tumor was not found by navigation. All eight biopsy cases were successful, and histologically relevant specimens were obtained without complications. Navigation was helpful in 11 endoscopic cases for choosing an optimal trajectory through the foramen of Monro or for connecting multiple intraventricular cysts. For intraoperative CT imaging, the mobile Philips Tomoscan M was adapted to the needs of the operating environment. The mobile CT was used in 78 cases in the operating room: 16 patients who underwent a stereotactic procedure had only preoperative CT scans, 36 patients had an intraoperative CT during tumor surgery, and 26 patients during the test period of the device had only a postoperative CT investigation. In 10 cases (28%) of the intraoperative group the remaining tumor tissue could be demonstrated on the CT scans. The tumor remnants that were not visible in the microscopical surgical field were subsequently removed. According to our results, intraoperative navigation seems superior for the localization of intracranial lesions and intraoperative CT is more useful when considering the radicality of tumor removal.

Brain Neoplasms↗
PubMed1998

Differentiation of recent and old cerebral infarcts by diffusion-weighted MRI.

We performed MRI, including diffusion-weighted imaging, in 15 patients with recurrent strokes with acute ischaemia and at least one old lesion according to the clinical history and/or CT. Routine MRI showed similar signal intensity changes in both situations. Diffusion-weighted images, however, were positive in all acute or subacute infarcts. The high signal of acutely disturbed diffusion due to intracellular oedema could also be identified in small brain stem lesions. Spatial resolution was increased by applying separate gradients in each axis instead of creating anisotropy-independent trace images.

Adult↗
PubMed1997

Impaired cortico-bulbar tract function in dysarthria due to hemispheric stroke. Functional testing using transcranial magnetic stimulation.

We investigated cortico-lingual and cortico-orofacial tract function utilizing transcranial magnetic stimulation in 18 consecutive patients with dysarthria due to hemispheric stroke. Delayed responses (conduction time > mean + 2.5 SD of that of 43 controls) or absent responses were considered abnormal. In all patients, motor-cortex stimulation of the lesion side demonstrated absent (13 patients) or delayed (five patients) responses to the tongue bilaterally (17 patients) or unilaterally (one patient). In 14 patients the contralateral orofacial responses were either absent (13 patients) or delayed (one patient). According to the electrophysiological findings, all lesions revealed by CT or MRI, were located within the pyramidal tract at the lower motor cortex (n = 4), the corona radiata (n = 7), and the genu of the internal capsule (n = 3) or its posterior limb (n = 4). We conclude that interruption of the cortico-bulbar tract fibres to muscles involved in articulation is a frequent cause of dysarthria in hemispheric stroke.

Aged↗
PubMed1996

Randomized trial of intravenous immunoglobulins versus prednisolone in Graves' ophthalmopathy.

Glucocorticoids are usually given for management of Graves' ophthalmopathy (GO), but they may cause side effects. By comparison, intravenous administration of immunoglobulins resulted in clinical improvement and decreased antibody titres in a large number of autoimmune diseases. Therefore, a randomized trial was done, in which 19 patients with active GO were treated with a 20-week course of oral prednisolone (P, starting dose 100 mg/day), and 21 received 1 g immunoglobulin/kg body weight for 2 consecutive days every 3 weeks. The immunoglobulin course was repeated six times. Before and at the end (20 weeks) of immunomodulating therapy, ophthalmological investigation and quantitative magnetic resonance (MR) imaging were performed. A successful outcome was observed in 12 (63%) P- and in 13 (62%) immunoglobulin-treated patients. Overall, there were no marked differences in degree of improvement between the two groups. Responders to treatment in both groups showed improvements in proptosis (median from 24.5 to 21.5 mm; P < 0.005), visual acuity (from 0.6 to 0.85; P < 0.001), intraocular pressure (from 25 to 20 mmHg; P < 0.0001), lid aperture (from 14 to 12 mm: P < 0.01) and a decrease in eye muscle area (inferior, from 44 to 33 mm2; medial, from 43 to 34 mm2; both P < 0.0005). Among the immunoglobulin-treated patients, there was a marked decrease of thyroid antibody titres. Side effects were more frequent and severe during P than during immunoglobulin therapy. Thus, with respect to the above mentioned objective parameters, P and immunoglobulin appeared to be equally effective in treatment of active GO.

Administration, Oral↗
PubMed1996

[Microsurgical endonasal decompression in traumatic and neoplastic optic nerve compression].

UNLABELLED: The therapy of traumatic optic neuropathy remains controversial. Some authors recommend observation and others, the use of megadose corticosteroids or surgical decompression of the optic nerve. Improvements in visual acuity from no light perception (NLP) preoperatively to close to normal visual acuities have been reported after transethmoidal decompression and systemic steroids. The transnasal microscopic approach offers safe and effective access to the optic canal. MATERIALS AND METHODS: Retrospectively 15 patients (13 men/2 women) ranging in age from 17 to 67 years, who were surgically decompressed in the Ear-Nose-Throat Department between 1989 and 1994, were analyzed. Thirteen patients had experienced sudden visual loss after trauma; in 2 patients a tumor was diagnosed. After an initial ophthalmologic examination and CT scans, the patients underwent transnasal decompression of the optic canal for at least 180 degrees. In the postoperative period, visual acuity, pupillary reaction, visual field and optic nerve morphology were monitored. RESULTS: The overall visual results were poor. In 8 patients with no light perception (NLP) preoperatively, no improvement in visual acuity was found. Minor improvements were seen with an initial vision of 20/200 or less. Dramatic improvements were found in both patients with rapidly progressive neoplastic optic nerve compression. No intra- or postoperative complications were seen. CONCLUSION: In our study we were unable to reproduce the good visual results of some series. If there is NLP preoperatively, surgical intervention does not seem to be promising. However, in patients with incurable tumors transnasal decompression of the optic canal offers a minimally invasive palliative measure to preserve and restore vision.

Adolescent↗
PubMed1995

How angioarchitecture of cerebral arteriovenous malformations should influence the therapeutic considerations.

PURPOSE: To evaluate the angioarchitectural criteria of complex cerebral arteriovenous malformations (AVMs), concerning the risk of hemorrhage and therapy planing. METHODS: The magnetic resonance (MR) imaging and neuroangiographic findings of 227 AVMs (223 patients) were retrospectively evaluated. Statistical analysis was used to define the relative frequency of these lesions for hemorrhage in correlation with various parameters (i.e. age of the patient, size, location, associated aneurysms). RESULTS: Onset of symptoms was between 21 and 40 years of age in 50% of cases. The ratio of centrally to convexially located lesions was 1:2. Convexial AVMs are classified by MR imaging into sulcal and gyral, according to the arterial supply (by terminal or transit feeding arteries, respectively), as proven by super-selective neuroangiography. Central location of the AVM, size of the nidus smaller than 2 cm diameter, and presence of related aneurysms, are high risk factors for hemorrhage. AVMs with one or two draining enlarged veins, or those without reflux presented a higher incidence of hemorrhage as well. CONCLUSION: A team approach is required for the choice of the therapeutic method in patients with AVMs. Our results allow an approximate prognosis concerning the risk of hemorrhage in these patients and should be taken in consideration for the precise therapeutic planing.

Adolescent↗
PubMed1995

Amyloidomas of the gasserian ganglion.

An amyloidoma is a local deposition of amyloid that becomes a space-occupying lesion. Amyloidomas of the central nervous system are very uncommon lesions and only four amyloidomas of the gasserian ganglion have been reported so far. We present the neuroradiologic and surgical characteristics of three more amyloidomas of the gasserian ganglion seen at one neurosurgical department in 11 years.

Journal Article↗
PubMed1995

The preoperative assessment of stroke risk in lesions involving the internal carotid artery.

Patients with vascular or tumourous lesions involving the internal carotid artery are at risk of damage or occlusion of this vessel during surgical or endovascular procedures. To assess the stroke risk transcranial Doppler aided carotid compression tests were performed in 82 patients. Based on changes of blood flow velocity (BFV), pulsatility index, systolic/diastolic ratio and length of transient hyperaemic response three groups could be differentiated. Patients in group A (31%) showed only a slight reaction of BFV and were at minimal risk in case of carotid occlusion. Patients in group B (52%) underwent a distinct decrease of Doppler readings with partial improvement and were considered to have moderate to high stroke risk. In group C patients (17%) trial occlusion caused a dramatic reduction of BFV with no recovery (p < 0.01), which denotes a very high stroke risk. Transcranial Doppler aided carotid occlusion manoeuvres provide useful information on cerebrovascular collateral capacity and prognosis of stroke risk.

Adolescent↗
PubMed1993

Amyloidoma of the gasserian ganglion as a cause of symptomatic neuralgia of the trigeminal nerve: report of three cases.

Three cases of symptomatic neuralgia of the trigeminal nerve due to an amyloidoma in the gasserian ganglion are described. The correct diagnosis was not made prior to histological examination of the surgical biopsy specimens. Medical history and clinical observation led to the diagnosis of a malignant process of the nasal cavities in the first patient; of an inflammatory dental focus in the second patient; and of multiple sclerosis in the third patient. CT findings were normal in cases 1 and 2; in case 3, a schwannoma was suspected from the CT appearances. In case 1, MRI had not been performed; in cases 2 and 3, MRI revealed a tumour mass which was also considered to be a schwannoma. Histologically, the tumours consisted of masses of amyloid deposits which had largely replaced the pre-existing ganglionic cells and satellite cells. Electron microscopy confirmed the fibrillar structure of the deposits. Immunohistochemistry and immunocytochemistry revealed the amyloid to belong to the AL-lambda subtype.

Adult↗
PubMed1993

Magnetic resonance imaging in juvenile Canavan disease.

We present a 2-year-old boy and a 6-year-old girl with mild Canavan disease (CD). Aspartoacylase activity in skin fibroblasts was deficient. Magnetic resonance imaging (MRI) of the brain did not show the prominent leucodystrophy previously reported in CD, but there was a hyperintense signal from the lentiform nuclei and the heads of the caudate nuclei on the T2-weighted MR images. This suggests a specific vulnerability of the corpus striatum in these patients. In the older patient, the white matter became affected at the age of 6 years. Proton magnetic resonance spectroscopy (1H-MRS) of white matter revealed a normal concentration of N-acetyl-L-aspartate (NAA) and a markedly decreased concentration of choline containing compounds (Cho) in the boy but a normal ratio of NAA to Cho in the girl. We conclude that deficient NAA catabolism affects myelin metabolism. This may present as changes in the striatum and/or as a low concentration of Cho before leucodystrophy appears on MRI.

Amidohydrolases↗
PubMed1992

CT-guided stereotactic biopsy aided by Doppler ultrasonic vascular monitoring.

The use of a 20 MHz pulsed Doppler technique during stereotactic brain tumour biopsies is described. By means of a miniaturized ultrasonic probe the tissue planned for biopsy was investigated for vessel signals. Out of 41 patients, with this technique a flow-pulse curve in front of the biopsy cannula was registered in 14 cases. In 9 cases one pulse curve was determined and in 5 cases two or more flow curves were found, indicating the presence of arterial vessels. The depth of the vessels signal could be localized and this area avoided for biopsy sampling. In a series of 41 stereotactic biopsies carried out in this way there was no intra-operative haemorrhage or postoperative haematoma.

Adolescent↗
PubMed1992

Localization of emotional and volitional facial paresis.

Emotional facial paresis is characterized by impaired activation of face muscles with emotion but normal voluntary activation. We report seven patients with this sign. Their lesions involved the frontal lobe white matter, the striatocapsular territory, the anterolateral thalamus and insula, the posterior thalamus and operculum, and the mesial temporal lobe and insula each in one patient, and the posterior thalamus in two patients. Volitional facial paresis affects facial movements with voluntary effort, sparing activation on emotion. We report four such patients, with lesions involving the motor cortex in one and the pyramidal tract in the cerebral hemisphere in three.

Adult↗
PubMed1991

[Neuroradiologic exploration of cerebral arteriovenous malformations].

MR and superselective neuroangiographic investigation of 223 patients with cerebral arteriovenous malformations (AVMs) were retrospectively analyzed with regard to topography, morphology, vascular architecture and signs of increased bleeding risk. MR proved highly efficient in defining the topography of the lesion and highly sensitive in detecting AVM-induced parenchymal changes. Superselective neuroangiography enables complete endovascular mapping of the AVM and provides relevant information on its intrinsic vascular composition. In addition, this method gives new insights into the venous drainage patterns and the unexpectedly high incidence of associated venous changes. MR-neuroangiographic correlation in each individual case forms the basis for any therapeutic decision and treatment planning. In concordance with previous statements in the literature this study disclosed that the presence of stenotic draining veins or related aneurysms on feeding arteries represents an increased risk for AVM rupture.

Adolescent↗