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Biomedical subjects

W J Huk

Publications and source records attributed to W J Huk.

At least 19 recordsLinked to original sources
PubMed1999

Middle ear adenocarcinoma with intracranial extension. Case report.

Middle ear adenocarcinoma is a very rare, locally invasive neoplasm assumed to arise from the middle ear mucosa. Although endolymphatic sac tumor (aggressive papillary middle ear tumor) and jugulotympanic paraganglioma may show brain invasion, intracranial extension of histologically confirmed middle ear adenocarcinoma has not been previously reported. The authors describe a 53-year-old man who suffered from otalgia and tinnitus for more than 10 years and from neurological deficits for 1 year due to a large temporal bone tumor that invaded the temporal lobe. A combined neurosurgical and otolaryngological resection was performed. Pathological analysis revealed a low-grade adenocarcinoma of a mixed epithelial-neuroendocrine phenotype, which showed a close histological similarity to, and topographical relationship with, middle ear epithelium. The authors conclude that middle ear adenocarcinoma belongs to the spectrum of extracranial tumors that have possible local extension to the brain.

Adenocarcinoma↗
PubMed1997

CNS late effects after ALL therapy in childhood. Part I: Neuroradiological findings in long-term survivors of childhood ALL--an evaluation of the interferences between morphology and neuropsychological performance. The German Late Effects Working Group.

The effect of cranial irradiation on possible therapy-induced morphological central nervous system (CNS) side effects of children cured from acute lymphoblastic leukemia (ALL) is controversially discussed. In a retrospective multicenter study, 118 former ALL patients in first continuous remission were investigated using cranial computerised tomography (CCT) or magnetic resonance imaging (MRI) scans to evaluate CNS related impairments. Corresponding to the different kinds of CNS prophylaxis, the patient sample was divided: group A (n = 39) receiving intrathecal methotrexate (ITMTX) and systemical medium-high-dose methotrexate (SMHDMTX), group B (n = 41) cranial irradiated (in mean 16.8 Gy) and administering ITMTX and SMHDMTX, group C (n = 38) irradiated (in mean 17.1 Gy) and getting ITMTX. Pathologic scans showed atrophy, leukoencephalopathy, calcifications or grey matter changes. These findings were compared with the neuropsychological test results. Abnormal MRI or CCI scans were found in 61/118 patients (51.7%). Fifteen belonged to group A (38.5%), 23 to B (56.1%) and 23 to C (60.5%). Patients with definite CNS changes show reduced neuropsychological test results. The prevalence of brain alterations seems to appear twice increased after lengthening the posttherapeutic interval in irradiated patients as in nonirradiated patients. Irradiated patients as an age younger than 2 years at diagnosis may show a lower prevalence for developing CNS alterations. CNS alterations are not sex-related. Children treated with cranial irradiation in combination with SMHDMTX and/or ITMTX were at greater risk of developing morphological brain alterations than patients with chemotherapy alone. These alterations are partly correlated with reduced neuropsychological performances and seem to stay with a longer posttherapeutic interval.

Adolescent↗
PubMed1997

CNS late effects after ALL therapy in childhood. Part II: Conventional EEG recordings in asymptomatic long-term survivors of childhood ALL--an evaluation of the interferences between neurophysiology, neurology, psychology, and CNS morphology. German Late Effects Working Group.

Monitoring of therapy-related late effects after acute lymphoblastic leukemia (ALL) therapy in childhood has become an increasingly important area in posttherapeutic patient surveillance. The usefulness of conventional electro-encephalographic (EEG) investigations as part of these attempts is controversially discussed. However, EEG recordings have become a popular approach for judgement on the functional integrity of the central nervous system in this subject group. The present report focuses on this problem and discusses the question whether and to what extent conventional EEG recordings were correlated with further measures of central nervous system (CNS) integrity and therapeutic differences. EEGs were recorded in 110 subjects, asymptomatic long-term survivors of ALL in childhood, during a large retrospective multicenter study evaluating CNS late sequelae following antileukemic therapy in Germany and Austria. EEG findings were correlated with demographic data, illness- and treatment-related parameters, as well as with data on the morphological, neurological and psychological status of the participating subjects. At the time of follow-up the EEG was abnormal in 47 cases (42.7%). The most frequent EEG abnormalities observed were disturbances of the background activity (n = 45, 95.8%), followed by hypersynchrone activities (n = 1.0, 21.3%) and interhemispheric differences/focal slowing (n = 6, 12.8%). With exception of age at diagnosis, none of the observed EEG abnormalities showed a correlation with any of the aforementioned illness- or treatment-related parameters. Eighty percent of the observed EEG abnormalities were found in children younger than 5 years at diagnosis. Children less than 2 years of age as well as those above 5 years at onset of disease showed a significantly reduced prevalence of EEG disturbances compared to subjects between 2 and 5 years at diagnosis. Neither the degree of illness nor therapy-specific differences showed any relationship to EEG outcome. There was no specific EEG finding for a specific morphological substrate, neurological or psychological deficiency and vice versa. Overall, there was no beneficial effect of routine EEG testing in children following therapy for ALL. According to our data, the evaluation of conventional EEG recordings of otherwise asymptomatic ALL long-term survivors is not a very helpful measure for predicting the degree of behavioral deficiencies, neurological disturbances, or morphological CNS abnormalities, which may be present or will develop in this special subject group.

Adolescent↗
PubMed1997

Three-dimensional MR myelography of the lumbar spine: comparative case study to X-ray myelography.

Conventional myelography was compared with a new type of MR technique using a fat-suppressing 3D fast imaging with steady precession (FISP) sequence for diagnosis of the lumbar root compression syndrome. 80 patients with discogenic disease in the lumbar spine were examined with a 1.0-T whole-body MR system (Siemens Magnetom Impact, Erlangen, Germany). A strongly T2(*)-weighted 3D FISP sequence was applied in the sagittal orientation. To obtain fat suppression, a frequency-selective 1-3-3-1 prepulse was applied prior to the imaging sequence. The acquired 3D data set was evaluated using a maximum intensity projection (MIP) program. The measurement time was 7 min, 47 s. Magnetic resonance myelography has significant advantages over conventional myelography, particularly in cases of extreme spinal canal stenosis. Compared with the conventional method, this new MR technique shows comparable sensitivity in the visualization of the spinal nerve roots in the lumbar spine.

Case-Control Studies↗
PubMed1997

[Value of CT-angiography in the diagnosis of cerebral artery aneurysms].

PURPOSE: In a clinical study 35 patients with intracranial aneurysms were examined using CT-angiography, MR-angiography (MRA) and digital subtraction angiography (DSA). The aim of the study was to establish the ability of noninvasive techniques to detect intracranial aneurysms. MATERIAL AND METHODS: The CT examinations were performed using a spiral CT scanner and the MR investigations with a 1.5 T whole body MR-system. We used for MR-angiography Time of Flight (TOF) and Phase Contrast (PC) techniques. For postprocessing reconstructions modalities Maximum Intensity Projection (MIP), Surface and Volume Rendering Technique (VRT) techniques were used. The results were evaluated by the intraoperative findings. RESULTS: Aneurysms up to 5 mm could be detected best using CTA and DSA. Giant aneurysms could be evaluated best using CTA. Volume rendering technique was the most useful postprocessing procedure. MRA using Time of Flight was superior compared with MRA using PC technique. CONCLUSION: CTA is the best method to detect and to evaluate giant intracranial aneurysms. Nevertheless the reconstruction mode has a decisive influence on the results.

Adult↗
PubMed1997

MR cisternography: a new method for the diagnosis of CSF fistulae.

The aim of this study was to compare a new MRI method for detecting the existence of cerebrospinal fluid (CSF) fistulae, i. e. MR cisternography, with CT cisternography. In a prospective study, 30 patients with post-traumatic CSF fistulae were examined. The MR examinations were performed with a 1.0-T whole-body MR system, using two T2(*)-weighted sequences, a 3D PSIF (time-inversed fast imaging with steady-state precession, FISP) and a 3D constructive interference steady-state (CISS) sequence. The results of MRI and CT cisternography were compared with the surgical findings. The sensitivity in detecting CSF fistulae with MR cisternography (PSIF: 89.9 %; CISS: 93.6 %) was higher than with CT cisternography (72.3 %). The sensitivity of CT cisternography at detecting CSF fistulae in patients with a size of dural lesion less than 2 mm or in patients with multiple dural lesions is significantly lower compared with the MR method. Although the localization of CSF fistulae always proved possible with MR cisternography, this could only be accomplished wih CT in 70 % of cases. The MR cisternography technique is a new examination method with a higher sensitivity for the detection of CSF fistulae than CT cisternography. The CISS technique is superior compared with PSIF and should be used in patients with high-flow CSF fistulas.

Adolescent↗
PubMed1997

Neurophysiological findings in long-term survivors of acute lymphoblastic leukaemia in childhood treated with the BFM protocol 81 SR-A/B.

UNLABELLED: Monitoring of therapy-related late effects after acute lymphoblastic leukaemia (ALL) therapy in childhood has become an increasingly important field in posttherapeutic patient surveillance. The usefulness of neurophysiological investigations (e.g. EEG, evoked potentials (EP)) as part of these attempts is controversial. The present report focuses on this problem and the question whether and to what extent routinely performed EEG recordings and visual evoked potentials (VEP) were correlated with further measures of CNS integrity. EEGs and VEPs were recorded in 163 asymptomatic long-term survivors of ALL in childhood during a large retrospective multicentre study evaluating CNS late sequelae following antileukaemic therapy. Fifty-two ALL long-term survivors (4.5-10.6 years after end of therapy, median: 8.8 years), who had been treated according to BFM-81 SR-A (n = 30) or SR-B (n = 22) were selected for this analysis focusing on therapy-related CNS late effects. Therapy protocols differed with regard to the mode for CNS prophylaxis: SR-A, cranial irradiation with intrathecal methotrexate; SR-B, intrathecal and iv methotrexate. Neurophysiological findings were correlated with illness- and treatment-related parameters, as well as with data on the morphological, neurological and psychological status of the CNS. At the time of follow-up neurophysiological measures were abnormal in 28/52 cases (53.8%). Neither illness- nor therapy-specific differences in CNS prophylaxis showed any relationship to EEG/VEP outcome any relationship to EEG/VEP outcome in this reduced group of the whole study population. Children with EEG/VEP abnormalities showed a significantly higher incidence of structural CNS disturbances compared to those with inconspicuous neurophysiological recordings (60.9% vs 31.8%). However, in this special subject group there was no specific neurophysiological finding for a specific morphological substrate, neurological or psychological deficiency and vice versa. CONCLUSION: Routinely performed EEG/VEP investigations are not very helpful measures to predict the presence or degree of behavioural deficiencies, neurological disturbances, or morphological CNS abnormalities. Patients who received cranial irradiation or systemic methotrexate applications showed the same incidence of neurophysiological disturbances without evidence for specific neurotoxic correlates.

Adolescent↗
PubMed1997

[MR diagnosis of cerebrospinal fluid fistulas using a 3D-CISS sequence].

PURPOSE: We compared a new MR method for diagnosis of CSF fistulas with CT cisternography. MATERIAL AND METHODS: In a prospective case study we examined 35 patients with posttraumatic CSF fistulas and compared the results with the intraoperative findings. The MR investigation was performed using a 1.0T whole body MR-system. We used a strongly T2*-weighted 3D-CISS sequence. The examinations were performed in prone position, in patients with severe CSF rhinorrhoea additionally in supine position. RESULTS: The sensitivity and specificity of the MR method (88.9% and 95.1%) is higher compared with CT cisternography (77.8% and 87.8%). The reason for the lower sensitivity of CT compared with MRI are complex fracture systems, involving several paranasal cavities in patients with false positive results in CT cisternography. Reasons for the lower specificity of CT cisternography are false negative results in patients with small dural lesions below 2 mm2. CONCLUSION: Using a new method MRI can detect CSF-fistulas. The MR method is superior to CT cisternography, is noninvasive, the administration of contrast and agent is no longer necessary.

Adolescent↗
PubMed1996

Quantitative EEG in long-term survivors of acute lymphoblastic leukemia.

Conventional and quantitative aspects of electroencephalographic recordings obtained during a follow-up surveillance study in long-term survivors of acute lymphoblastic leukemia in childhood were investigated with respect to differences in central nervous system prophylaxis given during antileukemic therapy and compared with data derived from healthy controls. Central nervous system prophylaxis consisted either of cranial irradiation (18 Gray, group A, n = 8) or intermediate high-dose methotrexate (2000 mg/m2; group B, n = 5), each combined with intrathecal methotrexate. Conventional electroencephalographic analysis revealed comparable results in all three study groups. However, quantitative electroencephalography showed significantly increased absolute power scores for all frequency bands in both long-term survivor groups. Relative power estimates revealed a significant increase in delta/tau activities in both prophylaxis groups compared to healthy controls, which were countered by decreased percentage power scores in the alpha-range. Quantitative electroencephalographic comparisons between both central nervous system prophylaxis groups revealed only small differences in quantity, not quality, of the observed power disturbances with slightly higher deviations in irradiated long-term survivors than in nonirradiated ones. Topographical distributions of spectral band power were comparable between all three study groups without evidence for therapy-related topographical differences.

Adolescent↗
PubMed1996

[Dissection of the carotid artery and vertebral artery--diagnosis and therapy].

Carotid and vertebral artery dissections typically occur in young adults after major trauma, although they can arise spontaneously or after trivial injury. Many patients with carotid dissections have minor symptoms such as a subject bruit or Horner's syndrome. Cephalic pain is also frequent and often inaugural in carotid dissection. However, extracranial dissection is a well recognised cause of ischaemic stroke. The diagnosis of dissection was based on angiographic findings. Noninvasive imaging also allows prompt and reliable diagnosis. Our goal was to demonstrate the spectrum of neuroradiologic (CT, MR and angiographic) findings in craniocervical arterial dissection and compare the diagnostic utility of CT, MR, MR angiography. Clinical data imaging studies, and outcome were reviewed and compared with the results in four patients with carotid artery dissection.

Adolescent↗
PubMed1995

Ultra-rapid gradient echo imaging.

A novel ultra-rapid gradient echo (URGE) NMR imaging technique is introduced, which is capable of continuous high resolution 3D scanning while neither subject to fast gradient switching nor excessive RF power deposition. Sampling free induction decays instead of creating spin echoes enables maintaining a workable steady state magnetization. Due to segmented k-space acquisition, chemical shift, diffusion, and field inhomogeneity effects do not present major problems. We report on implementations acquiring from 32 x 64 x 64 partial-Fourier image sets in 0.72 s, allowing for single-shot magnetization-prepared 3D imaging, to 128 x 128 x 128 image sets in 13.3 s and 21.5 s on a standard MRI scanner.

Artifacts↗
PubMed1995

High-resolution magnetic resonance imaging of the endolymphatic duct and sac.

An anatomical study was carried out to determine the extent to which magnetic resonance imaging (MRI) could delineate inner ear structures. Anatomical preparations of human petrous temporal bone were examined and compared with the results of MRI in 20 healthy subjects to see whether the structures of the inner ear could be visualized. Imaging of the subjects was carried out in a 1.0-T MRI scanner (Siemens Magnetom Impact). Two strongly T2*-weighted sequences were used: a 3D-PSIF sequence and a 3D-CISS sequence. The 3D data sets were postprocessed using a Maximum Intensity Projection (MIP) program. Our investigations show that it is possible to obtain accurate visualization of structures with a diameter of under 1 mm. In all 20 subjects it was possible to identify both the endolymphatic duct and the endolymphatic sac.

Adult↗
PubMed1995

[Quality assurance in neuroradiology].

Due to growing economic pressure, quality management in medicine has to be performed under the aspect of rationing and rationalization simultaneously. High quality and cost effectiveness in medicine, however, can only be achieved by institutions with an adequate quality of structure, procedure and outcome. While the technical criteria of the quality of structure can easily be measured, the assessment of the quality of the performance and the outcome are much more difficult so establish. Therefore standards of quality for the various diagnostic and interventional subspecialties of Neuroradiology have to be designed. The same is true for the evaluation of the quality assurance. The quality of neuroradiology has reached a comparatively high level simply because of the specialization compared to general radiology. This advantage should be utilized more often when major diagnostic departments are to be installed, particularly under the aspect of cost effectiveness plus high quality medicine.

Cost-Benefit Analysis↗
PubMed1994

Raymond's syndrome following petrosal sinus sampling.

Inferior petrosal sinus sampling (IPSS) is used to evaluate the pituitary-dependency of Cushing's disease, and to predict the laterality of a microadenoma prior to transsphenoidal operation. A serious complication occurred in a 14-year-old boy: he suffered brain stem ischaemia with abducens nerve palsy and hemiparesis (Raymond's syndrome). The case prompted us to reconsider the indication for this investigation.

Abducens Nerve↗
PubMed1994

Magnetic source localization and morphological changes in temporal lobe epilepsy: comparison of MEG/EEG, ECoG and volumetric MRI in presurgical evaluation of operated patients.

Is MEG source analysis able to precisely locate the primary focal epileptic activity? 22 patients with pharmacoresistant temporal lobe epilepsy were recorded during presurgical evaluation simultaneously with multichannel MEG/EEG and invasive (subdural) electrodes to evaluate the increase of information gained by MEG concerning the localization of focal epileptic activity and lesions. With this systematic study it should become clearer how often MEG can establish a diagnostic bridge between function and morphology. In addition, MEG localization accuracy of focal epileptic activity was to be validated empirically by invasive EEG recordings and postsurgical outcome. Spikes in the MEG were used for magnetic source localization, and the result was combined with magnetic resonance imaging (MRI). All patients definitely suffered from temporal lobe epilepsy and revealed a structural abnormality in MRI. 17 patients with lesions in the temporal lobe were operated meanwhile and became markedly improved or seizure free. In 7 of 8 patients with a tumor and validated operation outcome, a very close correlation of the 3D-magnetic source localization and the border of the tumor in the brain was found (distance less than 10 mm). In 8 of 9 patients with a temporal/hippocampal atrophy and validated operation outcome, dipoles of epileptiform activity were located within the atrophic lobe.(ABSTRACT TRUNCATED AT 250 WORDS)

Brain↗
PubMed1994

[3D-MR myelography in diagnosis of lumbar spinal nerve root compression syndromes. Comparative study with conventional myelography].

65 patients with nerve root compression syndrome were examined using a new type of MR-technique, which is comparable to the conventional X-ray myelography. The results of the prospective case study were compared with previous clinical experiences (1). For the examinations a 1.0T whole body MR-system (Siemens Magnetom Impact) was used. A strong T2*-weighted 3D-FISP sequence (TR = 73 ms, TE = 21 ms, alpha = 7 degrees) was applied in sagittal orientation using a circularly polarized oval spine coil. To obtain fat suppression a frequency selective 1-3-3-1 prepulse was applied prior to the imaging sequence. The acquired 3D-data set was evaluated using a Maximum Intensity Projection (MIP) program. Our results confirmed earlier experiences which showed that the diagnostic sensitivity of 3D-MR myelography (3D-MRM) is comparable to that of conventional X-ray myelography. In cases of severe spinal canal stenosis and spondylolisthesises, and in cases of postoperative scar tissue with nerve root compressions, the sensitivity of the 3D-MRM is higher as compared to that of conventional X-ray myelography.

Adult↗
PubMed1993

The role of transsphenoidal microsurgery in the management of sellar and parasellar meningioma.

We report on eight meningiomas that have been operated on via the transsphenoidal route since May 1988. Six patients harbored cavernous sinus meningiomas with intrasellar extension. The intrasellar tumor extension and the parasellar tumor portion medial to the carotid artery were removed. Decompression of the pituitary gland with normalization of prolactin levels was achieved in all patients. It is a well-tolerated approach to confirm the diagnosis and still allows the option of major transcranial surgery in the event of tumor progression. Additionally, we report complete tumor removal in two rare cases with intrasellar and suprasellar merely subdiaphragmatic meningiomas.

Adult↗