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Biomedical subjects

W Paulus

Publications and source records attributed to W Paulus.

At least 127 records · Page 7Linked to original sources
PubMed1999

Cisternal S100 protein and neuron-specific enolase are elevated and site-specific markers in intractable temporal lobe epilepsy.

In the brain, S100 protein and neuron-specific enolase (NSE) are mainly found in glial cells and neurons, respectively. We investigated concentrations of S100 protein and NSE in cisternal cerebrospinal fluid obtained during implantation of foramen ovale electrodes in eight patients with temporal lobe epilepsy (TLE). In addition, the meningeal markers cystatin-C and beta-trace as well as total protein were measured. Patients with trigeminal neuralgia (TN) undergoing glycerol rhizotomy served as controls. S100 protein and NSE levels ipsilateral to the site of seizure onset were significantly higher than in TN. Contralateral TLE values were also markedly but not significantly elevated. The meningeal markers cystatin-C and beta-trace protein as well as total protein did not differ in TLE and TN. We conclude that interictal temporal lobe dysfunction corresponds with neuronal and glial marker elevations in the extracellular space and that site-specific elevations may predict the site of seizure origin biochemically.

Adult↗
PubMed1999

Regression of a large solid papillary craniopharyngioma following fractionated external radiotherapy.

We present a patient harboring a large squamous papillary craniopharyngioma. The diagnosis was confirmed by a stereotactic biopsy. Because of vegetative symptoms indicating hypothalamic derangement, we were reluctant to perform surgical resection. Following fractionated megavoltage radiotherapy, MR imaging and CT demonstrated complete regression of the craniopharyngioma and the patient recovered from endocrine deficiency, chiasmal syndrome and vegetative hypothalamic symptoms.

Brain Neoplasms↗
PubMed1999

Classification, pathogenesis and molecular pathology of primary CNS lymphomas.

Classification, pathogenesis and molecular pathology of primary central nervous system lymphomas (PCNSL) pose major clinico-pathologic problems. Application of histopathologic classification schemes developed for nodal lymphomas, i.e. the Kiel Classification and the Working Formulation, is not reliable and clinically not relevant for PCNSL. The more recent REAL Classification will simplify subtyping of PCNSL, but reliability and clinical significance remain to be determined. There are virtually no experimental data on whether PCNSL develop outside of the brain, or whether they arise from polyclonal lymphoproliferations within the brain. Mutations of oncogenes and tumor suppressor genes have been analyzed in only a few tumors, and their type and frequency is essentially unknown. In conclusion, compared with both neuroectodermal brain tumors and nodal lymphomas, and given the increasing incidence and clinical impact of PCNSL, there is a remarkable lack of histopathologic consensus as well as a surprising shortage of pathogenetic and molecular genetic information.

Brain Neoplasms↗
PubMed1999

Temporal lobe microdysgenesis in epilepsy versus control brains.

Histopathologic evaluation of brain tissue derived from surgically treated patients with medically refractory temporal lobe epilepsy (TLE) frequently reveals structural brain lesions in the surgical specimen. While several of the most commonly encountered lesions such as low-grade neoplasms or vascular malformations are well established as structural substrates of epilepsy, the significance of subtle microscopic characteristics has remained controversial. Within the spectrum a broad range of microscopic features has previously been reported as "mild cortical dysplasia," "focal cortical dysplasia," or "microdysgenesis," including cortical laminar disorganization, columnar arrangement of cortical neurons, marked clustering of neurons throughout cortical layers II-VI, increased numbers of molecular layer neurons, marked perivascular clustering of oligodendroglia in the white matter, single heterotopic neurons in the deep white matter, glioneuronal hamartia, giant neurons, and balloon cell change. In this paper we report the frequency of these features in temporal lobe tissue of 47 surgically treated TLE-patients vs 29 normal autopsy controls. While most of them were found in both cases and controls, clustering of neurons throughout cortical layers II-VI, perivascular clustering of oligodendroglia in the white matter, increased single heterotopic white matter neurons, and glioneuronal hamartias predominated in tissue from patients with epilepsy (p < 0.05). A count of more than 10 white matter neurons/HPF was associated with a worse postoperative outcome (p < 0.05). These data suggest that certain microscopic characteristics are associated with the epileptic process, while others appear as normal variants.

Case-Control Studies↗
PubMed1999

CD24 promotes invasion of glioma cells in vivo.

Based on the hypothesis that adhesion molecules expressed on the surface of glioma cells mediate brain invasion, we examined the effect of CD24 on growth and migration of gliomas in vitro and in vivo. CD24, a glycosylphosphatidylinositol anchored, highly glycosylated adhesion molecule, is expressed in hematopoietic and neural cells. We found immunohistochemical expression of CD24 in human glioblastomas. We then established a clone from C6 rat glioblastoma cells, where mouse CD24 (also called heat stable antigen) is under control of a tetracycline-responsive promoter. In the presence of tetracycline (1 microg/ml) CD24 was downregulated by 20-fold. In vitro migration assays were performed on a basement membrane preparation (matrigel) and on myelin, the main substrates of in vivo glioma migration. While the cells were more motile on matrigel as compared with myelin, no relation between CD24 expression and motility was observed. We then transplanted the C6 clone into the striatum of nude mice and regulated CD24 expression via tetracycline in the drinking water (1 mg/ml). After 3 weeks, CD24 positive tumors of mice getting no tetracycline showed diffuse invasion of tumor cells in a brain area 10-fold larger than in CD24-suppressed tumors of mice receiving tetracycline. These data show that CD24 stimulates migration of gliomas in vivo and they suggest a role for this adhesion molecule in diffuse brain invasion of human gliomas.

Animals↗
PubMed1999

Influence of acetazolamide and CO2 on extracranial flow volume and intracranial blood flow velocity.

BACKGROUND AND PURPOSE: The vasomotor response can be tested by means of transcranial Doppler sonography. If a constant vessel diameter is assumed, the flow velocity changes will reflect blood flow volume changes. This hypothesis is difficult to verify. Simultaneous assessment of intracranial flow velocity and extracranial flow volume changes may solve this problem. METHODS: We tested vasomotor response in 32 volunteers (age, 42+/-18 years) with 5% CO2. Acetazolamide (1 g) was tested in 15 volunteers (age, 28+/-8 years). To evaluate drug-dependent flow changes in the external carotid artery territory, acetazolamide was administered in 7 patients with unilateral occlusion of the internal carotid artery without evidence of collateralization through the ophthalmic artery (age, 67+/-12 years). Simultaneous recording included measurements of flow volume in the common carotid arteries (M-mode color duplex system) and flow velocity in the middle cerebral arteries. RESULTS: With CO2 and acetazolamide, intracranial flow velocity increased by 31% and 39%, respectively, with a simultaneous increase of common carotid artery flow volume of 47% and 50%, respectively. No change in extracranial flow volume was observed in patients with an occluded internal carotid artery. CONCLUSIONS: These data show not only the expected increase of flow velocity in the middle cerebral artery but also suggest an increase in cross-sectional vessel diameter of 6% and 4% with CO2 and acetazolamide, respectively. It remains unresolved whether this observation is due to a direct effect of the drug on the vessel walls or is simply pressure dependent.

Acetazolamide↗
PubMed1999

Surgical treatment of craniopharyngiomas: experience with 168 patients.

OBJECT: The goal of this study was to assess the outcome of surgical management in 168 consecutive patients harboring craniopharyngiomas treated between January 1983 and April 1997. METHODS: In 148 patients undergoing initial (primary) surgery, the pterional approach was most frequently used (39.2%), followed by the transsphenoidal approach (23.6%). For large retrochiasmatic craniopharyngiomas, the bifrontal interhemispheric approach was used increasingly over the pterional approach and led to improved surgical results. Total tumor removal was accomplished in 45.7% of transcranial and 85.7% of transsphenoidal procedures. The main reasons for incomplete removal were attachment to and/or infiltration of the hypothalamus, major calcifications, and attachment to vascular structures. The success rate in total tumor removal was inferior in the cases of tumor recurrence. The operative mortality rate in transcranial surgery was 1.1% in primary cases and 10.5% in cases of tumor recurrence. No patient died in the group that underwent transsphenoidal surgery. The rate of recurrence-free survival after total removal was 86.9% at 5 years and 81.3% at 10 years. In contrast, the 5-year recurrence-free survival rate was only 48.8% after subtotal removal and 41.5% after partial removal. Following primary surgery, the actuarial survival rate was 92.7% at 10 years, with the best results after complete tumor removal. At last follow up, 117 (79%) of 148 patients who underwent primary surgery were independent and without impairment. CONCLUSIONS: Total tumor removal while avoiding hazardous intraoperative manipulation provides favorable early results and a high rate of long-term control in craniopharyngiomas.

Adolescent↗
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↗
PubMed1998

High-frequency repetitive transcranial magnetic stimulation delays rapid eye movement sleep.

Repetitive transcranial magnetic stimulation (rTMS) is a promising new treatment for patients with major depression. However, the mechanisms underlying the antidepressive action of rTMS are widely unclear. Rapid eye movement (REM) sleep has been shown to play an important role in the pathophysiology of depression. In the present study we demonstrate that rTMS delays the first REM sleep epoch on average by 17 min (102.6 +/-22.5 min vs 85.7+/-18.8 min; p < 0.02) and prolongs the nonREM-REM cycle length (109.1+/-11.4 min vs 101.8+/-13.2min, p< 0.012). These rTMS-induced changes in REM sleep variables correspond to findings observed after pharmacological and electroconvulsive treatment of depression. Therefore, it is likely that the capability of rTMS to affect circadian and ultradian biological rhythms contributes to its antidepressive action.

Adult↗