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Biomedical subjects

D A Bosch

Publications and source records attributed to D A Bosch.

At least 19 recordsLinked to original sources
PubMed2000

[Malignant intracranial germ cell tumor treated with chemotherapy and radiotherapy without histopathological confirmation].

In two men aged 19 and 24 years, a rare malignant intracranial germ cell tumour was diagnosed in the pineal gland region and in the second patient in a suprasellar position as well. Although histological confirmation is required in general to diagnose a malignancy, obtaining it can be difficult and potentially dangerous in case of intracranial neoplasms. The clinical picture of a young patient with an intracerebral tumour localised in the midline of the brain and increased levels of the tumour markers alpha-foetoprotein and/or human chorion gonadotrophin (beta-HCG) in blood and/or CSF makes any other diagnosis highly unlikely. There is no place for radical surgery in the first-line treatment of malignant intracerebral germ cell tumours because of the sensitivity to radio- and chemotherapy. Also, the sensitivity to chemotherapy makes it possible to reduce radiation volume and dose in an effort to avoid the serious complications of craniospinal irradiation. Both patients responded well to chemotherapy based on cisplatin followed by radiotherapy.

Adult↗
PubMed2000

A comparison of continuous thalamic stimulation and thalamotomy for suppression of severe tremor.

BACKGROUND: Deep-brain stimulation through an electrode implanted in the thalamus was developed as an alternative to thalamotomy for the treatment of drug-resistant tremor. Stimulation is thought to be as effective as thalamotomy but to have fewer complications. We examined the effects of these two procedures on the functional abilities of patients with drug-resistant tremor due to Parkinson's disease, essential tremor, or multiple sclerosis. METHODS: Sixty-eight patients (45 with Parkinson's disease, 13 with essential tremor, and 10 with multiple sclerosis) were randomly assigned to undergo thalamotomy or thalamic stimulation. The primary outcome measure was the change in functional abilities six months after surgery, as measured by the Frenchay Activities Index. Scores for this index can range from 0 to 60, with higher scores indicating better function. Secondary outcome measures were the severity of tremor, the number of adverse effects, and patients' assessment of the outcome. RESULTS: Functional status improved more in the thalamic-stimulation group than in the thalamotomy group, as indicated by increases in the score for the Frenchay Activities Index (from 31.4 to 36.3 and from 32.0 to 32.5, respectively; difference between groups, 4.4 points; 95 percent confidence interval, 2.0 to 6.9). After adjustment for base-line characteristics, multivariate analysis also showed that the thalamic-stimulation group had greater improvement (difference between groups, 5.1 points; 95 percent confidence interval, 2.3 to 7.9). Tremor was suppressed completely or almost completely in 27 of 34 patients in the thalamotomy group and in 30 of 33 patients in the thalamic-stimulation group. One patient in the thalamic-stimulation group died perioperatively after an intracerebral hemorrhage. With the exception of this incident, thalamic stimulation was associated with significantly fewer adverse effects than thalamotomy. Functional status was reported as improved by 8 patients in the thalamotomy group, as compared with 18 patients in the thalamic-stimulation group (P=0.01). CONCLUSIONS: Thalamic stimulation and thalamotomy are equally effective for the suppression of drug-resistant tremor, but thalamic stimulation has fewer adverse effects and results in a greater improvement in function.

Activities of Daily Living↗
PubMed1999

Unilateral pallidotomy in Parkinson's disease: a randomised, single-blind, multicentre trial.

BACKGROUND: The results of several cohort studies suggest that patients with advanced Parkinson's disease would benefit from unilateral pallidotomy. We have assessed the efficacy of unilateral pallidotomy in a randomised, single-blind, multicentre trial. METHODS: We enrolled 37 patients with advanced Parkinson's disease who had, despite optimum pharmacological treatment, at least one of the following symptoms: severe response fluctuations, dyskinesias, painful dystonias, or bradykinesia. Patients were randomly assigned to unilateral pallidotomy within 1 month or to pallidotomy after the primary outcome assessment (6 months later). The primary outcome was the difference between the groups in median changes on the motor examination section of the unified Parkinson's disease rating scale (UPDRS 3) score done in the off phase. Secondary outcome measures included levodopa-induced dyskinesias (dyskinesia rating scale [DRS]) and extent of disability (UPDRS 2). FINDINGS: The median UPDRS 3 off score of the pallidotomy patients improved from 47 to 32.5, whereas that of control patients slightly worsened from 52.5 to 56.5 (p<0.001). In the on phase the median DRS score improved 50% in pallidotomy patients compared with no change in controls. The UPDRS 2 off score improved with a median of 7 in the pallidotomy group. Two treated patients had major adverse effects. INTERPRETATION: Unilateral pallidotomy is an effective treatment in patients with advanced Parkinson's disease, who have an unsatisfactory response to pharmacological treatment.

Aged↗
PubMed1999

Unilateral pallidotomy in advanced Parkinson's disease: a retrospective study of 26 patients.

OBJECTIVE: To evaluate the effects of unilateral pallidotomy in patients with Parkinson's disease (PD). PATIENTS AND METHODS: Twenty-six patients with PD and disabling dyskinesias, painful and/or disabling dystonia, and/or pain as part of PD despite optimal pharmacotherapy underwent unilateral pallidotomy. For assessment, the Unified Parkinson's Disease Rating Scale (UPDRS; part II and III), Hoehn and Yahr staging, the Schwab and England scale, a Dyskinesia Rating Scale, and timed tests were used. Assessment was performed in defined "off' and "on," and on average 2 months before and 7.5 months after the unilateral pallidotomy. Adverse effects were classified as transient or permanent and as major or minor. RESULTS: In the "off' phase, the median UPDRS II score improved from 26.5 to 20.5 (23%) and the median UPDRS III score improved from 47.5 to 33.0 (31%). In the "on" phase, dyskinesias contralateral to the side of the procedure improved with 88% ipsilateral dyskinesias improved only temporarily, and the total UPDRS II and III scores remained unchanged. Thirteen patients had transient adverse effects, three patients had permanent, and two patients had a combination of transient and permanent adverse effects. The transient adverse effects in two patients were classified as major. CONCLUSION: Stereotactic unilateral pallidotomy can improve symptoms and disability in the "off' phase. In the "on" phase, dyskinesias disappeared at the side contralateral to the procedure. Permanent minor complications of pallidotomy occurred in 19% of the patients.

Adult↗
PubMed1999

A prospective comparison between three-dimensional magnetic resonance imaging and ventriculography for target-coordinate determination in frame-based functional stereotactic neurosurgery.

OBJECT: The purpose of this prospective study was to compare stereotactic coordinates obtained with ventriculography with coordinates derived from stereotactic computer-reconstructed three-dimensional magnetic resonance (3D-MR) imaging in functional stereotactic procedures. METHODS: In 15 consecutive patients undergoing functional stereotactic procedures, both preoperative frame-based stereotactic 3D-MR imaging and intraoperative ventriculography were performed. Differences between 3D-MR imaging and ventriculography in X, Y, and Z coordinates of the anterior commissure (AC), posterior commissure (PC), and target area were calculated, as well as the 3D distance between the position of AC, PC, and target within stereotactic space as obtained using both methods. The position of the stereotactic MR imaging fiducial markers measured using 3D-MR imaging compared well with the markers' known position embedded in the software (mean error 0.4 mm, maximal error for an individual slice 1.2 mm). For the individual coordinates, only for Y-PC was a difference found between 3D-MR imaging and ventriculography that significantly exceeded half the size of a pixel, the theoretical limit of precision when using a digitized imaging technique. However, the mean difference was smaller than 1 mm. The mean 3D distance between the 3D-MR imaging- and ventriculography-derived coordinates was 1.09 mm for AC, 1.13 mm for PC, and 1.29 mm for the targets. CONCLUSIONS: With these data it is shown that there is sufficient agreement between ventriculography-derived and 3D-MR imaging-derived stereotactic coordinates to justify the use of 3D-MR imaging target determination in frame-based functional stereotactic neurosurgery.

Brain Mapping↗
PubMed1998

Genetic sub-types of human malignant astrocytoma correlate with survival.

In human malignant astrocytoma, age of the patient and histological grade of the tumor are important prognostic variables. Several genetic changes have been reported to occur in these tumors, which may be of additional and independent prognostic relevance. To determine their prognostic significance, we analyzed 75 high-grade tumors, 12 anaplastic astrocytomas and 63 glioblastomas multiforme, for the presence of genetic changes that occur frequently in high-grade astrocytoma, i.e., loss of heterozygosity (LOH) for chromosome 10, p53-gene alteration (mutation and/or LOH), and EGFR-gene amplification. We defined 4 groups of patients who showed a specific combination of genetic changes in the tumor: group 1, p53-gene alteration without complete LOH 10; group 2, complete LOH 10 only; group 3, p53-gene alteration + complete LOH 10; group 4, complete LOH 10 + EGFR-gene amplification. In univariate analysis, the log-rank test revealed significant differences in survival between patients of group 1 (median survival of 13 months) and group 3 (median survival of 5.2 months, p = 0.0058) and between patients of group 1 and group 4 (median survival of 4 months, p = 0.0033). In multivariate analysis, age and genetic sub-type proved to be important prognostic variables, whereas histological grading was less important. The age-corrected survival time for group-4 patients is significantly shorter than that for group-1 patients (relative risk = 3.79, p = 0.0075). Our data indicate that genetic sub-type is an important prognostic variable in human high-grade astrocytoma.

Adult↗
PubMed1998

[Neurosurgical stereotactic treatment in Parkinson's disease].

For patients with Parkinson's disease who have become unresponsive to pharmacotherapy or have developed severe motor complications due to medical therapy, a number of symptomatic neurosurgical interventions are available: thalamotomy, thalamic stimulation and pallidotomy. These stereotactic operations are performed under local anaesthesia. The target is located using anatomical and physiological techniques, after which the neuro-ablative or neuromodulatory procedure is performed. The choice of the target depends on the symptoms of the patient that most impair daily functioning. In case of dominating tremor, thalamic surgery is performed. Patients who are mainly incapacitated by rigidity, hypokinesia or pharmacotherapy-induced dyskinesias are suitable candidates for pallidotomy. Contraindications are cognitive dysfunction, severe disturbance of gait and balance, advanced cerebral atrophy on CT or MRI, limited life expectancy and a poor general condition enhancing surgical risk, e.g. coagulation disorders or uncontrolled hypertension. Surgical treatment of Parkinson's disease is being carried out in clinical trials in the Netherlands in the Academic Medical Centre in Amsterdam, the Academic Hospital in Groningen and the St. Elisabeth Hospital in Tilburg.

Contraindications↗
PubMed1998

Resurgence of functional neurosurgery for Parkinson's disease: a historical perspective.

The history of functional neurosurgery for the treatment of Parkinson's disease is reviewed. Two major stages may be distinguished: (1) open functional neurosurgery, which started in 1921 with bilateral cervical rhizotomy by Leriche. In 1937 Bucy performed the first motor cortectomy in a tremor patient, and subsequently introduced lesioning of the corticospinal tract at different levels. In 1939 Meyers started open transventricular surgery of the basal ganglia, which was abandoned in the 1940s because of high mortality. However, this operation drew attention to the basal ganglia and their efferent pathways as surgical targets for the relief of parkinsonian symptoms. (2) Stereotactic (closed) functional neurosurgery in patients was in 1947 for the first time performed by Spiegel and Wycis, soon followed by surgeons in various countries. Originally, the globus pallidus and the ansa lenticularis were the surgical targets but were replaced at the end of the 1950s by the ventrolateral thalamus. A few surgeons positioned their lesions in the subthalamic area. In both targets favorable results were reported for the treatment of tremor and rigidity with acceptable adverse events. In selected patients, bilateral surgery was performed. In 1969 the results of more than 37,000 stereotactic operations had been published. Criteria for the surgical technique and selection of patients were described, and various stereotaxic atlases became available. At that time, L-dopa became generally available and the number of stereotactic operations declined dramatically. However, as a result of the shortcomings of the L-dopa therapy in the long-term treatment of Parkinson's disease, the thalamotomy gradually regained its place. New developments were the reintroduction of the pallidotomy by Laitinen in 1992 and the thalamic stimulation for pharmacotherapy-resistant tremor by Benabid and collaborators in 1991. New insights in the pathophysiology of Parkinson's disease supported the revival of the functional stereotactic neurosurgery and recently caused the introduction of the subthalamic nucleus as a surgical target in the treatment of Parkinson's disease.

History, 18th Century↗
PubMed1998

Thalamic surgery and tremor.

The results of thalamotomy for the various kinds of tremor are described. The nomenclature of the ventrolateral thalamic nuclei is discussed. Long-term thalamic stimulation seems a promising addition to or alternative for the thalamotomy, but this has still to be proven by a prospective trial that includes a cost-effectiveness analysis.

Electric Stimulation↗
PubMed1998

Lack of perfusion enhancement after administration of nicotinamide and carbogen in patients with glioblastoma: a 99mTc-HMPAO SPECT study.

BACKGROUND: Nicotinamide (NAM) and carbogen both have been shown to enhance the radiation effect in rodent tumour models and are currently being tested in clinical trials. These agents have demonstrated to act against hypoxia and one of their underlying mechanisms could be an increase of tumour blood perfusion. PURPOSE: To analyse the effect of both agents on normal brain perfusion and tumour perfusion in patients with glioblastoma. MATERIALS AND METHODS: Nineteen patients with glioblastoma were studied with 99mtechnetium-hexamethylpropyleneamine oxime single photon emission computed tomography (99mTc-HMPAO SPECT) before and after administration of carbogen and/or NAM. Another six patients were studied with the same procedure but without any flow modulator and were used as controls. RESULTS: Although the variations between patients were large, no significant enhancement in mean tumour and normal brain perfusion could be demonstrated with NAM or carbogen compared to the control patients. Also no consistent changes in the mean perfusion ratio between tumour and surrounding normal brain were found, suggesting an absence of a selective perfusion effect. CONCLUSIONS: No significant influence of carbogen and/or NAM on tumour perfusion and normal brain perfusion could be detected with SPECT in patients with glioblastoma.

Analysis of Variance↗
PubMed1998

Symptoms and signs related to the trigeminal nerve: diagnostic yield of MR imaging.

PURPOSE: To assess the diagnostic yield of magnetic resonance (MR) imaging in patients with symptoms and signs related to the trigeminal nerve. MATERIALS AND METHODS: Medical records and MR imaging studies in 112 consecutive patients referred for MR imaging over 5 years were evaluated. MR images were independently reviewed by two neuroradiologists unaware of the clinical findings. Signs and symptoms at presentation were associated with either a positive or negative MR imaging outcome. Logistic regression analysis was performed to identify clinical variables related to imaging results. RESULTS: Sixty-eight (61%) patients had positive MR imaging findings related to symptoms and signs. Trigeminal neuralgia was correlated with a negative MR imaging outcome (P < .001). Numbness (P < .01), impaired sensation (P < .001), other neurologic symptoms and signs (P < .01), progression of symptoms and signs (P < .001), and duration of symptoms of less than 1 year (P < .001) corresponded to a positive MR imaging outcome. Two regression models, each with three clinical parameters (progression, duration < 1 year, and trigeminal neuralgia or impaired sensation), had comparable accuracy for prediction of the MR imaging outcome. CONCLUSION: Clinical findings can be used to identify groups in which a high or a low yield of MR imaging is correlated with symptoms and signs related to the trigeminal nerve.

Cranial Nerve Diseases↗
PubMed1997

Bilateral posteroventral pallidotomy in advanced Parkinson's disease in three patients.

In this report, we describe the effect of staged bilateral posteroventral pallidotomy in three patients with advanced Parkinson's disease who were all of the young-onset type. Two patients had developed response fluctuations after the use of levodopa, with severe hypokinesia, painful dystonia, and rigidity in the "off" phase and violent dyskinesias in the "on" phase. One patient, in a continuous hypokinetic rigid state, was totally unresponsive to dopaminergic medication. All were at Hoehn and Yahr stage 5 in the "off" phase before surgery. After surgery, the hypokinetic state was reversed and dyskinesias were abolished in all patients. Hoehn and Yahr stages were 3 in the "off" phase postoperatively. Overall functional improvement was marked and lasting after follow-up for 7, 12, and 13 months, respectively. Complications were visual field deficit and transient central facial paresis, both in the same patient. Bilateral posteroventral pallidotomy can ameliorate response fluctuations, hypokinesia, rigidity, and painful dystonia in advanced Parkinson's disease.

Activities of Daily Living↗
PubMed1997

Posteroventral pallidotomy in movement disorders.

Since 1992 there has been renewed interest in pallidotomy now that the limitations and adverse effects of long-term dopaminergic therapy have become more apparent and more difficult to control in patients with advanced Parkinson's disease. The authors describe the effect of pallidotomy in 19 patients, sixteen of whom had advanced Parkinson's disease with painful dystonia and/or response fluctuations with severe akinesia while in "off" and dyskinesias while in "on". One patient had cortico-basal degeneration with rigidity, one patient had secondary dystonia and one had dystonic posturing due to Wilson's disease. Fifteen patients underwent unilateral pallidotomy, four patients had a staged bilateral procedure. Follow-up ranged from 3 to 42 months (mean 18 months). All patients with peak-dose dyskinesias and/or dystonia had marked reduction of symptoms, including the cases of Wilson's disease and secondary dystonia. The akinesia and rigidity scores of Parkinson-patients in "off" were greatly reduced, mainly but not only on the contralateral side. Evaluation by the patients showed remarkable improvement of symptoms in 79%, leading to substantially improved functional abilities in 68%. In this series the decrease in dopamine-response fluctuations, dystonia, hypokinesia and rigidity with functional improvement as judged by examiners and patients reflect a significant regain of independence.

Adolescent↗
PubMed1997

5-year survival and clinical prognostic factors in progressive supratentorial diffuse "low-grade" astrocytoma: a retrospective analysis of 46 cases.

In order to study survival and identify prognostic factors in progressive supratentorial low grade astrocytoma, 46 cases of diffusely growing glioma (1982-1989), in which stereotactic biopsy revealed a diagnosis of astrocytoma grade II according to Kernohan, were evaluated. Only patients with definite tumour growth on consecutive CT scans were included. All patients received a full course of fractionated radiotherapy. All tumour biopsy specimens were re-evaluated according to both the Kernohan and Daumas-Duport grading systems. Follow-up for at least 5 years showed a median survival of 47.5 months (1 year 71%, 5 year 41%). In Cox' multivariate analysis 4 factors turned out to give the best fitting prognostic model for survival: age, duration of symptoms, pre-operative neurological examination and CT-contrast enhancement. Numerical scoring was performed by giving either 1 or 0 for: age > or < 40 years, symptom duration < or > 1 year, presence or absence of focal deficit, and presence or absence of CT-contrast enhancement. Combining these factors in a score ranging from 0-4 resulted in 3 distinct groups with respect to median survival (< 2:66.5 months, 2:40 months, > 2:10 months, P = 0.0015). Although 17 cases with Kernohan grade II were upgraded using Daumas-Duport criteria (13 grade III, 4 grade IV), these cases did not form a separate survival-group. Additional parameters are needed to assess prognosis by neuropathological means, as some "low-grade" tumours are less benign than others, giving rise to a variable natural history.

Adolescent↗
PubMed1997

Differential expression of CD44 splice variants in the normal human central nervous system.

Cluster of differentiation 44 (CD44) is a broadly distributed group of glycoproteins that are involved in many functions related to cell-cell and cell-matrix interactions. In the present study, the expression of the standard form of CD44 (CD44s) and of CD44 variants (CD44v) was explored immunohistochemically on frozen sections of various areas of the human CNS. The results demonstrate that CD44s epitopes are expressed predominantly by white matter astrocytes, whereas different CD44 variant molecules are present in neurons, on axonal membranes, on endothelium or on choroid plexus epithelium. Interestingly, neurons and axons differentially expressed CD44 variant epitopes but consistently lack immunoreactivity for CD44s epitopes. Another interesting finding was that some CD44 variant epitopes expressed by neurons were localized in the cytoplasm instead of on the cell membrane. The broad distribution of variant CD44 molecules in the human CNS suggests that CD44 may play an important role in many biological processes in the CNS.

Aged↗
PubMed1997

Hypofractionated radiation induces a decrease in cell proliferation but no histological damage to organotypic multicellular spheroids of human glioblastomas.

The aim of this study was to examine the effect of radiation on glioblastoma, using an organotypic multicellular spheroid (OMS) model. Most glioblastoma cell lines are, in contrast to glioblastomas in vivo, relatively radiosensitive. This limits the value of using cell lines for studying the radiation effect of glioblastomas. The advantage of OMS is maintenance of the characteristics of the original tumour, which is lost in conventional cell cultures. OMS prepared from four glioblastomas were treated with hypofractionated radiation with a radiobiologically equivalent dose to standard radiation treatment for glioblastoma patients. After treatment, the histology as well as the cell proliferation of the OMS was examined. After radiation, a significant decrease in cell proliferation was found, although no histological damage to the OMS was observed. The modest effects of radiation on the OMS are in agreement with the limited therapeutic value of radiotherapy for glioblastoma patients. Therefore, OMS seems to be a good alternative for cell lines to study the radiobiological effect on glioblastomas.

Cell Division↗