Available data suggest that there may be gender differences in the effect of STN-DBS in the treatment of Parkinson's disease (PD). The aim of this study was to review data on gender discrepancies and gender differences in clinical outcomes in PD patients treated with deep brain stimulation of the subthalamic nucleus (STN-DBS). Included were original studies that specifically examined gender discrepancies or gender differences in PD patients with STN-DBS.
View Article and Find Full Text PDFDeep brain stimulation (DBS) of the subthalamic nucleus (STN) is successful in patients with advanced Parkinson's disease (PD) but may worsen cognitive outcome, including facial emotion recognition (FER). Data-analyses on 59 consecutive PD patients with complete pre- and postoperative assessments, using a sensitive FER test, showed no changes in FER 1 year after STN-DBS surgery, both after group and individual analyses. These findings do however not exclude the impact of FER in and on itself on the outcome after STN-DBS.
View Article and Find Full Text PDFParkinsonism Relat Disord
April 2023
Introduction: Axial disability, including gait disturbances, is common in Parkinson's disease (PD), especially in advanced stages. Epidural spinal cord stimulation (SCS) has been investigated as a treatment option for gait disorders in PD. Here, we review the literature on SCS in PD and evaluate its efficacy, optimal stimulation parameters, optimal electrode locations, possible effects of concurrent deep brain stimulation, and possible working mechanisms on gait.
View Article and Find Full Text PDFBackground: STN-DBS is a cornerstone in the treatment of advanced Parkinson's disease (PD). The traditional approach is to use an awake operative technique with microelectrode recording (MER). However, more centers start using an asleep MRI-guided technique without MER.
View Article and Find Full Text PDFThere is evidence that men are more likely to undergo deep brain stimulation (DBS) for Parkinson's disease (PD), suggesting that women are relatively undertreated. 121 consecutive PD patients undergoing awake DBS with microelectrode recording and intraoperative clinical testing (30 patients, 5 women) or asleep MRI-guided and CT-verified (91 patients, 38 women) bilateral subthalamic nucleus DBS were included in this study. The results showed an increase in the proportion of female patients from 16.
View Article and Find Full Text PDFBackground: Bilateral deep brain stimulation of the subthalamic nucleus (STN-DBS) has become a cornerstone in the advanced treatment of Parkinson's disease (PD). Despite its well-established clinical benefit, there is a significant variation in the way surgery is performed. Most centers operate with the patient awake to allow for microelectrode recording (MER) and intraoperative clinical testing.
View Article and Find Full Text PDFPurpose This systematic review focuses on the effect of bilateral deep brain stimulation (DBS) of the subthalamic nucleus (STN) on language function in Parkinson's disease (PD). It fills an important gap in recent reviews by considering other language tasks in addition to verbal fluency. Method We critically and systematically reviewed the literature on studies that investigated the effect of bilateral STN-DBS on language function in PD.
View Article and Find Full Text PDFObjective: To investigate the relationship of dystonia symptoms to cognitive function by comparing cognitive performance in patients with focal (cervical) and generalized dystonia subtypes and examining the differential contributions of severity of symptoms and mood disorders to cognition.
Background: Studies of the nonmotor syndrome in isolated dystonia have reported evidence of cognitive dysfunction, but the cause of this impairment remains unclear. Several studies have suggested that poor cognitive performance reflects the distracting effects of the motor symptoms and/or a mood disorder.
Case Report: The authors report a case of an 11-year-old boy that presented with headache and vomiting that was present for several months. CT and MR imaging revealed a large prepontine mass and an obstructive hydrocephalus. A ventriculoperitoneal shunt was inserted, and in a second operation, a radiologically proven total resection was performed, using a left frontotemporal transsylvian approach.
View Article and Find Full Text PDFExcellent timing resolution is required to enhance the signal-to-noise ratio (SNR) gain available from the incorporation of time-of-flight (ToF) information in image reconstruction for positron emission tomography (PET). As the detector's timing resolution improves, so does SNR, reconstructed image quality, and accuracy. This directly impacts the challenging detection and quantification tasks in the clinic.
View Article and Find Full Text PDFMedical imaging systems are composed of a large number of position sensitive radiation detectors to provide high resolution imaging. For example, whole-body Positron Emission Tomography (PET) systems are typically composed of thousands of scintillation crystal elements, which are coupled to photosensors. Thus, PET systems greatly benefit from methods to reduce the number of data acquisition channels, in order to reduce the system development cost and complexity.
View Article and Find Full Text PDFPurpose: Side readout of scintillation light from crystal elements in positron emission tomography (PET) is an alternative to conventional end-readout configurations, with the benefit of being able to provide accurate depth-of-interaction (DOI) information and good energy resolution while achieving excellent timing resolution required for time-of-flight PET. This paper explores different readout geometries of scintillation crystal elements with the goal of achieving a detector that simultaneously achieves excellent timing resolution, energy resolution, spatial resolution, and photon sensitivity.
Methods: The performance of discrete LYSO scintillation elements of different lengths read out from the end/side with digital silicon photomultipliers (dSiPMs) has been assessed.
In this work, a method is presented that can calculate the lower bound of the timing resolution for large scintillation crystals with non-negligible photon transport. Hereby, the timing resolution bound can directly be calculated from Monte Carlo generated arrival times of the scintillation photons. This method extends timing resolution bound calculations based on analytical equations, as crystal geometries can be evaluated that do not have closed form solutions of arrival time distributions.
View Article and Find Full Text PDFWe have performed Monte Carlo simulations of the scintillation light transport between adjacent monolithic LYSO crystals that are optically coupled together using coupling media of varying refractive index. The scintillation light from the crystals was read out by SiPM arrays from the large crystal face. Scintillation event positioning results show that this optical coupling technique preserves the shape of the light spread function near and across the interface between the two crystals in order to substantially reduce the edge-artifacts observed in monolithic scintillation crystals, while not degrading the timing performance.
View Article and Find Full Text PDFPrecise timing resolution is crucial for applications requiring photon time-of-flight (ToF) information such as ToF positron emission tomography (PET). Silicon photomultipliers (SiPM) for PET, with their high output capacitance, are known to require custom preamplifiers to optimize timing performance. In this paper, we describe simple alternative front-end electronics based on a commercial low-noise RF preamplifier and methods that have been implemented to achieve excellent timing resolution.
View Article and Find Full Text PDFPositron emission tomography detectors based on monolithic scintillation crystals exhibit good spatial and energy resolution, intrinsically provide depth-of-interaction information, have high γ-photon capture efficiency, and may reduce the manufacturing costs compared to pixelated crystal arrays. Here, we present the characterization of a detector consisting of a 18.0 mm×16.
View Article and Find Full Text PDFSeveral new methods for determining the depth of interaction (DOI) of annihilation photons in monolithic scintillator detectors with single-sided, multi-pixel readout are investigated. The aim is to develop a DOI decoding method that allows for practical implementation in a positron emission tomography system. Specifically, calibration data, obtained with perpendicularly incident gamma photons only, are being used.
View Article and Find Full Text PDFBackground And Purpose: Previous studies have shown that peroxisome proliferator-activated receptor gamma (PPARgamma), a ligand-activated transcription factor expressed in vascular cells, is protective of the vasculature. We hypothesized that activation of PPARgamma could prevent hypertensive remodeling of cerebral arteries and improve vascular function.
Methods: Ten female Sprague-Dawley rats were treated with the nitric oxide synthase inhibitor N(G)-nitro-l-arginine methyl ester (l-NAME) for 5 weeks, 8 were treated with l-NAME plus the PPARgamma activator rosiglitazone, and 8 received no treatment and served as controls.
The use of time-of-flight (TOF) information in positron emission tomography (PET) enables significant improvement in image noise properties and, therefore, lesion detection. Silicon photomultipliers (SiPMs) are solid-state photosensors that have several advantages over photomultiplier tubes (PMTs). SiPMs are small, essentially transparent to 511 keV gamma rays and insensitive to magnetic fields.
View Article and Find Full Text PDFSilicon photomultipliers (SiPMs) are of great interest to positron emission tomography (PET), as they enable new detector geometries, for e.g., depth-of-interaction (DOI) determination, are MR compatible, and offer faster response and higher gain than other solid-state photosensors such as avalanche photodiodes.
View Article and Find Full Text PDFNovel measurement techniques based on intravenous ultrasound (IVUS) technology ('IVUS-Flowmetry') require the location of a catheter inside the coronary bed. The present study quantifies disturbances in the 3-D velocity profile induced by catheter placement inside a tube, applying computational fluid dynamics. Two curved, circular meshes (radius K = 0.
View Article and Find Full Text PDFArterioscler Thromb Vasc Biol
October 1997
The predilection sites of atherosclerotic plaques implicate rheologic factors like shear stress underlying the genesis of atherosclerosis. Presently no technique is available that enables one to provide 3D shear stress data in human coronary arteries in vivo. In this study, we describe a novel technique that uses a recently developed 3D reconstruction technique to calculate shear stress on the endothelium with computational fluid dynamics.
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