Transcranial duplex sonography of hyperacute intracerebral hemorrhages.
Explore the source record for details and available documents.
Acute Disease↗
Biomedical subjects
G Becker
Publications and source records attributed to G Becker.
Parkinson's disease and depression: evidence for an alteration of the basal limbic system detected by transcranial sonography.
OBJECTIVES: Depression is a frequent symptom in Parkinson's disease. Compelling evidence suggests a role of the brainstem in the control of mood and cognition. In patients with unipolar depression transcranial sonography (TS) studies have shown structural alteration of the mesencephalic brainstem raphe which could suggest an involvement of the basal limbic system in the pathogenesis of primary mood disorders. The objective of the present study was to evaluate whether a similar alteration could be found in depressed patients with Parkinson's disease using TS. METHODS: Thirty patients with Parkinson's disease and 30 age and sex adjusted controls were examined by TS. Raphe echogenicity was rated semiquantitatively. The severity of motor symptoms and depression was rated using standard research instruments. RESULTS: Raphe echogenicity was significantly reduced in depressed patients with Parkinson's disease compared with nondepressed patients with Parkinson's disease and control subjects. Raphe echogenicity correlated negatively with degree of motor impairment, and differences in raphe echo between depressed and non-depressed patients with Parkinson's disease were upheld when motor impairment was controlled for. CONCLUSION: These preliminary findings suggest that, as in unipolar depression, a morphological alteration of the brainstem raphe might be involved in the pathogenesis of depression in Parkinson's disease. This raphe alteration may reflect involvement in the basal limbic system in the pathogenesis of secondary depression. This concept is in line with current knowledge on the pathogenesis of both depression in Parkinson's disease and primary depressive disorders.
Aged↗
Rest perfusion of coiled aneurysms detected by transcranial color-coded duplex sonography: initial results.
Explore the source record for details and available documents.
Adult↗
Clinical, morphological, biochemical, and neuroradiological features of mitochondrial encephalomyopathies. Presentation of 19 patients.
Nineteen patients (9 females, 10 males) with mitochondrial encephalomyopathies (ME) were studied. The diagnosis was established according to clinical and histopathological criteria. Leading clinical features were chronic progressive external ophthalmoplegia (CPEO) and muscle weakness in 95% of the patients. Pigmentary retinopathy was seen in 63%, and was always associated with CPEO. Hypacusis was present in 47% and cerebellar ataxia in 63% of patients. Clinical or electrophysiological signs of involvement of the central nervous system (CNS) were found in 21% of the patients. In muscle biopsy ragged red fibers were the predominant histopathological findings (100% of the patients), while COX-negative fibers were seen in 74%, deletions of the mitochondrial DNA in 42%, and defects of the respiratory chain in 32% of the patients. Increased blood lactate levels were found in 79% of the patients. Needle electromyography revealed myopathic features in 74%, features of denervation in 16%, and was normal in the remainder. Imaging studies showed cerebral atrophy in 58%, cerebellar atrophy in 16%, and hyperintense lesions of the white matter, pyramidal tract or extrapyramidal system in 16% of the cases. It is concluded that the clinical manifestations of ME can be very variable. Diagnosis of ME should be always considered in young patients presenting with CPEO and muscle weakness. In most cases, diagnosis can be made by a few selected investigations, while detection of genetic abnormalities may lead to the diagnosis in the remaining cases.
Adult↗
[Event related potentials and emotional pictures:effect of stimulus presentation time].
The perception of the emotional content of a stimulus is a preattentive automatic process which causes an emotional reaction. As the ongoing stream of behavior might be disturbed by the emotional reaction, a controlled process is initialited at the same time, which normally leads to an inhibition of the emotional response. By means of event related potentials it should be possible to observe these controlled processes. In a first study using photographs from the International Affective Picture System, Diedrich et al. (1997) reported enhanded P300 amplitudes for emotional stimuli, even when the task distracted from the emotional content of the stimuli. This was interpreted as an index of the additional, controlled information processing elicited by the emotional content of the stimuli. Additionally, Diedrich et al. observed a frontel slow positivity, which might indicate the inhibition of the emotional response. However, this frontal slow wave might also be explained by the stimulus presentation time, which lasted 500 ms. This study is a conceptual replication of the experiment of Diedrich et al. Stimulus presentation time of neutral and emotional slides was varied in three steps (250 ms, 500 ms and 2000 ms). Subjects either performed a structural or an emotion-focused task on the stimuli. The results for the P300 component were exactly replicated. However, the variation of slow frontal positivity differed from that in the first study. Differences in the intensity of the emotional stimuli are discussed as a reason für this result.
Adult↗
Transcranial duplex ultrasound: experience with contrast enhancing agents.
Transcranial duplex real time sonography (TCCS) is a non-invasive imaging modality that allows repetitive examinations of central nervous system vascular and parenchymal anatomy; a broad spectrum of cerebral pathology may be disclosed: vascular changes include ischemic and hemorrhagic stroke, arteriosclerotic vascular degeneration, arteno-venous malformations and aneurysms, as well as neoplastic and degenerative parenchymal disorders. Imaging was performed with a duplex ultrasound system, employing a 2.25 resp. 2.0 MHz phased-array transducer. Imaging was achieved through the acoustic bone window of the temporal bone and through the foramen magnum. For three-dimensional image reconstruction a mechanical position sensor and online video grabbing was applied. To evaluate the potential of a transpulmonary stable ultrasound contrast enhancing agent we used galactose-based SH U 508 A (Levovist, Schering, Berlin) with 1 to 6 i.v. injections per patient in a phase 2/3 clinical protocol. The signal to noise ratio is significantly improved; the Doppler signal intensity is increased by approx. 25 dB. Levovist was well tolerated and no adverse events occurred, approx. 30% of patients had a sensation of heat and slight pain at the injection site during and shortly after the injection. With the increase in signal intensity, the complete circle of Willis, the peripheral arterial branches, the vertebro-basilar system and the basal venous system may be depicted. In addition, tumour parenchyma vascularisation may be detected, as well as improved delineation of arteriovenous malformations and aneurysms. Three dimensional image reconstruction may represent a novel option in contrast enhanced transcranial duplex imaging including additional information about 3D structure and continuity.
Adolescent↗
Primary T-cell lymphoma of the cerebellum. A case report.
Most primary CNS non-Hodgkin lymphomas are of B-cell lineage. Only a very few immunocytochemically well documented cases of T-cell lymphomas have been reported. We report a case of a high malignant T-cell lymphoma localized primarily to the vermis of the cerebellum and compare the characteristics of the clinicopathological presentation with those of B-cell lymphomas as well as with the other T-cell lymphomas reported.
Aged↗
Correlation of intra-operative ultrasound with histopathologic findings after tumour resection in supratentorial gliomas. A method to improve gross total tumour resection.
The aim of this study was to evaluate whether intra-operative ultrasound (= IOUS) is a suitable tool to detect residual tumour tissue after gross total resection in supratentorial gliomas. During a period of 18 months 45 patients with supratentorial gliomas (38 high-grade and 9 low-grade, according to the WHO-grading system [42]) were operated on. A series of 78 biopsies was taken from the resection cavity under continuous sonographic control at the end of surgery. Gross total tumour resection was intended in 34 patients (= 76%). The biopsy specimens were matched with the sonographic features at each biopsy site. The sonographic appearance of the resection margins were classified into 2 groups: (1) Irregular hyperechoic areas extending from the cavity into the iso-echogenic brain tissue and (2) a dense small (< or = 3 mm in diameter) rather regular hyperechoic rim surrounding the resection cavity. 47 out of 53 biopsies taken from hyperechoic areas (group I) (36 high-grade/11 low-grade) revealed solid tumour tissue (= 89%). 34 (= 72%) of these 47 areas were microscopically assessed as inconspicuous by the surgeon. 6 samples (4 high-grade/2 low-grade) contained tumour infiltration zone. 25 biopsies (23 high-grade/2 low-grade) taken from the hyperechoic rim [group 2] were diagnosed as follows: Normal brain tissue in 11, tumour infiltration zone in 8 and solid tumour tissue in 6 cases. Of 34 cases with "gross total removal" according to the surgeon's assessment 25 showed sonographic signs of residual tumour tissue, which was confirmed histologically as solid tumour tissue in 22 of these cases. It is concluded, that IOUS following resection of supratentorial gliomas can detect residual tumour tissue with high specificity and thus improve gross total resection. However, a thin hyperechoic rim surrounding the resection cavity (less than 3 mm in diameter) is a non-specific finding, which can mask thin residual tumour layers and therefore needs further evaluation of its nature.
Biopsy↗
[Gamma knife versus stereotactic linear accelerator. Utilization, clinical results and cost-benefit relations].
INTRODUCTION: The principles of radiosurgery were developed in 1951 by Leksell. Their technical realization led to the development of the gamma knife and stereotactically modified linear accelerator. METHODS: In addition to the gamma knife, we present the different principles of convergent beam irradiation (radiosurgery with linear accelerator), the further development to fractionated stereotactic conformal radiotherapy, and the necessary quality-assurance steps. RESULTS: The greatest uncertainties in the precision of radiosurgery result from medical imaging (CT 0.7 x 0.7 x 1 mm; DSA 1-5 mm; MR angiography < 2 mm). The focusing accuracy of the gamma knife (+/- 0.3 mm) can also be achieved today by linear accelerators using a stereotactic floorstand. For the same indication and the same dosage for the target volume, there are no clinical differences between the gamma knife and the linear accelerator (AVM: 80% complete obliteration; metastases: 85% local tumor control; AN: 90% tumor control). However, there are greater differences in costs. There is no constellation where the gamma knife is just as expensive or more cost-effective than the linear accelerator treatment. The most cost-effective solution is modification of an available linear accelerator, resulting in treatment costs per patient of 9,201.25 DM (50 patients/year). CONCLUSION: There seem to be no methodological, physical, clinical or cost reasons for using a gamma knife, especially because the trend is going towards fractionated conformation radiotherapy instead of the application of high single doses.
Brain Neoplasms↗
Treatment planning for bicentric stereotactic irradiation.
We have investigated a bicentric stereotactic convergent beam irradiation technique for the treatment of irregularly shaped, especially elongated, target volumes. Depending on the size and shape of the target volume optimum values for the isocenter distance, collimator apertures and dose inhomogeneity have been determined which serve as starting parameters for the interactive optimization of dose distribution. The treatment planning system of the stereotactic unit SRS-200 (Philips) has been used to calculate the parameter tables. However, the presented results are also applicable to other stereotactic systems.
Film Dosimetry↗
Diltiazem minimizes tubular damage due to FK506-mediated nephrotoxicity following ischemia and reperfusion in rats.
We examined the nephrotoxicity of tacrolimus (FK506) in a model of mild warm ischemia. After clamping of both renal arteries of male Sprague-Dawley rats for 20 min, the animals received tacrolimus (3 mg/kg/day i.p.), vehicle of a combination of tacrolimus (3 mg/kg/day i.p.) and diltiazem (12 mg/kg, orally) or vehicle and diltiazem (12 mg/kg, orally). The excretion of urinary enzymes was determined on a daily basis, creatinine clearance at day 10. Tacrolimus significantly increased NAG (N-acetyl-beta-glucosaminidase) excretion and associated histological damage, finally decreasing creatinine clearance. The toxic potential of tacrolimus was markedly enhanced by ischemia. The additional application of diltiazem reduced NAG excretion and histological damage without affecting creatinine clearance. Thus, the protective effect of diltiazem on tacrolimus-induced nephrotoxicity seems to be at least partially a tubular one.
Acetylglucosaminidase↗
Clusterin (Apo J) protects against in vitro amyloid-beta (1-40) neurotoxicity.
Clusterin is a secreted glycoprotein that is markedly induced in many disease states and after tissue injury. In the CNS, clusterin expression is elevated in neuropathological conditions such as Alzheimer's disease (AD), where it is found associated with amyloid-beta (A beta) plaques. Clusterin also coprecipitates with A beta from CSF, suggesting a physiological interaction with A beta. Given this interaction with A beta, the goal of this study was to determine whether clusterin could modulate A beta neurotoxicity. A mammalian recombinant source of human clusterin was obtained by stable transfection of hamster kidney fibroblasts with pADHC-9, a full-length human cDNA clone for clusterin. Recombinant clusterin obtained from this cell line, as well as a commercial source of native clusterin purified from serum, afforded dose-dependent neuroprotection against A beta (1-40) when tested in primary rat mixed hippocampal cultures. Clusterin afforded substoichiometric neuroprotection against several lots of A beta (1-40) but not against H2O2 or kainic acid excitotoxicity. These results suggest that the elevated expression of clusterin found in AD brain may have effects on subsequent amyloid-beta plaque pathology.
Amyloid beta-Peptides↗
Cerebrovascular reserve capacity in patients with occlusive cerebrovascular disease: assessment with dynamic susceptibility contrast-enhanced MR imaging and the acetazolamide stimulation test.
PURPOSE: To quantitatively assess cerebrovascular reserve capacity in patients with occlusive cerebrovascular disease. MATERIALS AND METHODS: In 21 symptomatic patients with occlusive cerebrovascular disease, magnetic resonance (MR) imaging was performed with a 1.5-T system. Before, during, and after a brief bolus injection of gadopentetate dimeglumine into the antecubital vain, a series of 32 rapid T2*-weighted gradient-echo images of two different sections were acquired simultaneously to measure the concentration-time-curves in the brain tissue and in the brain-feeding arteries. Principles of indicator dilution analysis were applied to compute regional cerebral blood flow (rCBF) and volume. Each patient underwent two examinations, the first before and the second after acetazolamide stimulation. RESULTS: In the asymptomatic hemisphere, a mean increase in rCBF value of 47.1% was observed after acetazolamide stimulation. In the affected areas of the symptomatic hemisphere, a statistically significantly reduced response to acetazolamide stimulation was found, indicating a severely compromised cerebrovascular reserve capacity. CONCLUSION: MR imaging with the described techniques provides quantitative information about the cerebrovascular reserve capacity in patients with occlusive cerebrovascular disease.
Acetazolamide↗
Lenticular nucleus lesion in idiopathic dystonia detected by transcranial sonography.
We report the transcranial sonography (TCS) findings of the basal ganglia in 86 patients with dystonic disorders including idiopathic dystonia (facial, cervical, upper limb, and generalized dystonia), drug-induced tardive dystonia, dopa-responsive dystonia, and kinesigenic dystonia. The TCS was focused on alterations of the lenticular, caudate, raphe nuclei, and the thalamus. Seventy-five percent of patient with idiopathic cervical and 83% of those with idiopathic upper limb dystonia had a hyperechogenic lesion of the middle segment of the lenticular nucleus on the side opposite to the clinical dystonic symptoms. The ipsilateral side was also affected in 20%. In facial dystonia, only one-third of the patients revealed lenticular nucleus lesions. The mean area of the lenticular nucleus lesion opposite to the clinically affected side was 30 mm2 in cervical dystonia, 17 mm2 in upper limb dystonia, and 7.5 mm2 in facial dystonia. These lenticular abnormalities were significantly more frequent (p < 0.001) and their areas were significantly greater (p < 0.001) compared with a control group of 50 patients afflicted with radiculopathy. There was a significant correlation of the severity of symptoms with the intensity of lenticular nucleus hyperechogenicity in patients with cervical and upper limb dystonia (p < 0.05). Increased caudate nucleus echogenicity was present in 20% of patients with cervical and upper limb dystonia, mostly contralateral to the clinically affected side and raphe abnormalities were present in 7% of all patients with idiopathic dystonia. In contrast, there were no abnormalities of the lenticular nucleus or thalamus in nonidiopathic dystonias. We conclude that idiopathic dystonia is associated with lesions in the basal ganglia, particularly the lenticular nucleus, that can be visualized by TCS. An alteration of the basal ganglia matrix may be the pathologic basis of idiopathic dystonia with secondary affliction of striatopallidothalamic pathways.
Adult↗
[Stereotaxic convergent-beam irradiation. Initial experiences with the SRS 200 system].
BACKGROUND: The system SRS 200 for the stereotactic convergent beam irradiation described in this paper has a stereotactic floor stand, which allows the high precision rotation of a secondary collimator around an isocenter. This system is used since 1991 at the University Hospital of Tübingen for the treatment of patients with solitary brain metastases, acoustic neurinomas and arteriovenous malformations. PATIENTS AND METHODS: The attainable accuracy of the mechanics and dosimetry was studied within the scope of extensive quality assurance measures during its installation and before each patients' irradiation. The individual treatment steps from radiotherapy planning to irradiation were evaluated by means of a specially developed head phantom. Since the installation of the SRS 200 a total of 50 patients (21 solitary brain metastases, 12 acoustic neurinomas, 17 arteriovenous malformations) has been treated with the system. RESULTS: With 0.3 mm +/- 0.2 mm an excellent accuracy of the target point transfer and isocenter stability during irradiation was attained. The difference between calculated dose and dosimetric control measurements was smaller than 3%. The physical accuracy, however, is limited by the imaging resolution (CT and digital subtraction angiography). Of the patients 15% with solitary brain metastases developed complete remission, 20% partial remission and with 50% no further neurological deterioration was observed. Imaging revealed for 88% of the patients a reduced uptake of contrast medium or a regression of the tumor size. Six patients with acoustic neurinoma had anacusis already before radiotherapy. Regarding the other patients in the follow-up, hearing improved in 1 patient, 1 patient showed hearing deterioration, and all other patients hearing remained constant. MR and CT imaging revealed in 10 patients with acoustic neurinoma a reduced uptake of contrast medium and in 1 patient a tumor diminution. From the patients with arteriovenous malformation only 4 have been followed for more than 2 years after treatment. Therefore, statements about the rate of obliteration are not possible yet. Concerning pretherapeutic symptoms (headache 22%, convulsion 28%, neurological deficits 11%) 8/17 (47%) of the arteriovenous malformation patients showed an improvement, in 8 patients clinical findings were unchanged and 1 patient showed neurological deterioration. CONCLUSION: The stereotactic system SRS 200 allows an excellent mechanical accuracy in the radiosurgery with linear accelerators.
Adolescent↗
Transcranial duplex sonography using ultrasound contrast enhancers.
Explore the source record for details and available documents.
Adolescent↗
Transcranial duplex-sonography in intracranial hemorrhage. Evaluation of transcranial duplex-sonography in the diagnosis of spontaneous and traumatic intracranial hemorrhage.
The aim of this prospective clinical study was to evaluate the potential of bedside transcranial color-coded duplex sonography (TDS) in the assessment of patients with acute intracranial hemorrhage and respective complications. 74 patients (35 with spontaneous and 27 with traumatic hemorrhage, 12 excluded due to insufficient insonability) underwent 152 TDS examinations. The results were compared to computer-tomography (CT) as well as conventional transcranial Doppler sonography (TcD). The size and localisation of intracerebral hemorrhages as detected in TDS coincided in 39/42 examinations with CT findings; in cases of traumatic intracranial extracerebral hematoma TDS correlated in all but one case (18/19). The TDS findings for the diameter of third and lateral ventricles (n = 126) as for midline-shift (n = 26) showed a good correlation (p < 0.0005) to CT-measurements. TDS appears to be a useful bedside, non-invasive tool in order to detect and exclude intracranial complications in patients with intracranial hemorrhages.
Cerebral Hemorrhage↗
Tacrolimus (FK 506) therapy in simultaneous pancreas kidney transplantation.
Explore the source record for details and available documents.
Adult↗