ABSTRACT
Introduction: Deep brain stimulation (DBS) is a standard surgical procedure for the treatment of advanced Parkinson Disease (PD) with motor complications that cannot be adequately managed by medical treatment. Currently available literature can guide physicians on basic aspects of patients' selection and indications for DBS. However, there is a range of real-world clinical settings where the indications of DBS for Parkinson disease are debatable. Objective: to present the experience on PD patients with complex clinical manifestations treated with DBS in our hospital. Method: Report of four PD cases treated with DBS. Case 1: 63-year old woman with advanced PD and severe motor complications; Case 2: 60-year old man with 5 years of disease duration and mild motor complications; Case 3: 67-year old man with severe ventriculomegaly that may have precluded direct electrode passage to the surgical target; Case 4: 67- year-old woman with putative severe axial disability. Results: After one year of follow-up, all patients showed improvement on motor symptoms as well as quality of life. Discussion: We provide a brief rationale for the patient selection in each case to support the decision-making in the management of PD patients with complex clinical cases. (AU)
Subject(s)
Humans , Male , Female , Adult , Middle Aged , Parkinson Disease/therapy , Deep Brain Stimulation/methods , Chile , Deep Brain Stimulation/trends , Hydrocephalus, Normal Pressure/therapyABSTRACT
We discuss in this paper the validation of an open source framework for the solution of problems arising in hemodynamics. The proposed framework is assessed through experimental data for fluid flow in an idealized medical device with rigid boundaries and a numerical benchmark for flow in compliant vessels. The core of the framework is an open source parallel finite element library that features several algorithms to solve both fluid and fluid-structure interaction problems. The numerical results for the flow in the idealized medical device (consisting of a conical convergent, a narrow throat, and a sudden expansion) are in good quantitative agreement with the measured axial components of the velocity and pressures for three different flow rates corresponding to laminar, transitional, and turbulent regimes. We emphasize the crucial role played by the accuracy in performing numerical integration, mesh, and time step to match the measurements. The numerical fluid-structure interaction benchmark deals with the propagation of a pressure wave in a fluid-filled elastic tube. The computed pressure wave speed and frequency of oscillations, and the axial velocity of the fluid on the tube axis are close to the values predicted by the analytical solution associated with the benchmark. A detailed account of the methods used for both benchmarks is provided.
Subject(s)
Blood Flow Velocity/physiology , Blood Vessels/physiology , Computer Simulation , Models, Cardiovascular , AlgorithmsABSTRACT
This study documents differences in fish assemblages for 32 freshwater streams located between 258 and 2242 m a.s.l. on the eastern slopes of the central range of the Colombian Andes. A total of 2049 fishes belonging to 62 species, 34 genera and 16 families were collected. Species richness declined rapidly with altitude; nearly 90% of the species were recorded between 250 and 1250 m a.s.l. Three of the four physico-chemical variables, of the water, temperature, dissolved oxygen and pH, explained 53.5% of the variation in species richness along the altitudinal gradient, with temperature the most important (37.6%). An analysis of species composition showed that the distinctiveness of the fish fauna increased with elevation, with the greatest turnover observed between 1000 and 1750 m a.s.l. On this altitudinal gradient, turnover was dominated by the loss of species rather than gain, and dominance by just a few species was greater at higher elevations. Turnover was also observed along the altitudinal gradient in the structure of the three functional groups (torrential, pool and pelagic species). The study focused on understanding the pattern of diversity of fish communities inhabiting the Andes in Colombia. Anthropogenic effects on the altitudinal distribution of fish species in the region, however, are largely unknown and would require further investigations.
