(Fonte: Lattes)
Índice h a partir de 2011
Projetos de Pesquisa
Unidades Organizacionais
Departamento de Neurologia, Faculdade de Medicina - Docente
LIM/45 - Laboratório de Fisiopatologia Neurocirúrgica, Hospital das Clínicas, Faculdade de Medicina

Resultados de Busca

Agora exibindo 1 - 10 de 200
  • article 1 Citação(ões) na Scopus
    Wireless Device with Energy Management for Closed-Loop Deep Brain Stimulation (CLDBS)
    (2023) NORDI, Tiago Matheus; GINJA, Gabriel Augusto; GOUNELLA, Rodrigo; FONOFF, Erich Talanoni; COLOMBARI, Eduardo; MOREIRA, Melkzedekue M. Alcantara; AFONSO, Jose A. A.; MONTEIRO, Vitor; AFONSO, Joao L. L.; CARMO, Joao Paulo
    Deep brain stimulation (DBS) is an effective and safe medical treatment that improves the lives of patients with a wide range of neurological and psychiatric diseases, and has been consolidated as a first-line tool in the last two decades. Closed-loop deep brain stimulation (CLDBS) pushes this tool further by automatically adjusting the stimulation parameters to the brain response in real time. The main contribution of this paper is a low-size/power-controlled, compact and complete CLDBS system with two simultaneous acquisition channels, two simultaneous neurostimulation channels and wireless communication. Each channel has a low-noise amplifier (LNA) buffer in differential configuration to eliminate the DC signal component of the input. Energy management is efficiently done by the control and communication unit. The battery supports almost 9 h with both the acquisition and stimulation circuits active. If only the stimulation circuit is used as an Open Loop DBS, the battery can hold sufficient voltage for 24 h of operation. The whole system is low-cost and portable and therefore it could be used as a wearable device.
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    Force platform analysis after deep brain stimulation of peduncolopontine nucleus in progressive supranuclear palsy: Report of one case
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    Lateral Insertion of Leads and Treatment Outcomes in Ventral Capsule/Ventral Striatum Deep Brain Stimulation for Obsessive-Compulsive Disorder
    (2020) LOPES, Antonio; GODINHO, Fabio; MURAKAMI, Mario; IGLESIO, Ricardo; LEEMANS, Alexander; FONOFF, Erich; MIGUEL, Euripedes; TEIXEIRA, Manoel; ARANTES, Paula
  • article 5 Citação(ões) na Scopus
    Spinal cord stimulation improves motor function and gait in spastic paraplegia type 4 (SPG4): Clinical and neurophysiological evaluation
    (2021) SOUZA, Carolina Pinto de; COELHO, Daniel Boari; CAMPOS, Debora da Silva Fragoso; GHILARDI, Maria Gabriela dos Santos; VICENTE, Edrin Claro de Oliveira; GONZALEZ-SALAZAR, Carelis; FRANCA JUNIOR, Marcondes Cavalcante; BARSOTTINI, Orlando Graziani Povoas; PEDROSO, Jose Luiz; FONOFF, Erich Talamoni
    Introduction: Hereditary spastic paraplegia is a heterogeneous group of genetic disorders characterized by degeneration of the corticospinal tracts, coursing with progressive weakness and spasticity of the lower limbs. To date, there are no effective treatments for progressive deficits or disease-modifying therapy for those patients. We report encouraging results for spastic paraparesis after spinal cord stimulation. Methods: A 51-year-old woman suffering from progressive weakness and spasticity in lower limbs related to hereditary spastic paraplegia type 4 underwent spinal cord stimulation (SCS) and experienced also significant improvement in motor function. Maximum ballistic voluntary isometric contraction test, continuous passive motion test and gait analysis using a motion-capture system were performed in ON and OFF SCS conditions. Neurophysiologic assessment consisted of obtaining motor evoked potentials in both conditions. Results: Presurgical Spastic Paraplegia Rating Scale (SPRS) score was 26. One month after effective SCS was initiated, SPRS went down to 15. At 12 months follow up, she experienced substantial improvement in motor function and in gait performance, with SPRS scores 23 (OFF) and down to 20 (ON). There was an increased isometric muscle strength (knee extension, OFF: 41 N.m; ON: 71 N.m), lower knee extension and flexion torque values in continuous passive motion test (decrease in spastic tone) and improvement in gait (for example, step length increase). Conclusion: Despite being a case study, our findings suggest innovative lines of research for the treatment of spastic paraplegia.
  • article 5 Citação(ões) na Scopus
    Effects of sexed semen and interactive effects on commercial in vitro embryo production when oocytes are collected from cows of Bos indicus, and Bos taurus breeding and crossbred cows of these subspecies
    (2015) LOPEZ, William Omar Contreras; ALVIS-MIRANDA, Hernando Raphael; GAMARRA, Andres Felipe; RENDON, Bibiana; BORDA, Diego Armando Vega; ALBICKER, Ulrich; FONOFF, Erich Talamoni; MARTINEZ-DIAZ, Mario
    A large scale commercial in vitro embryo production and in vitro fertilization record is reported when there was use of oocytes from Bos taurus (BT), Bos indicus (BI), and Bos Taurus/indicus (BT/BI) crossbred subspecies fertilized with sexed (SS) and conventional (CS) semen. The aim of the study was to analyze the impacts of use SS in a commercial embryo production center in Colombia. Non-pregnant (n = 800), healthy, and estrous cycling BT, BI, and BI/BT crossbred cows were selected to be used as oocyte donors. Viable oocytes from 733 ovum pick up sessions in cows of the BT (4663) and BI (7305), BT/BI (3605) groups were matured and fertilized with frozen thawed semen from commercial sires. Of all cultured oocytes (n = 15,573), 52.3% of the embryos (n = 8607) underwent cleavage while 3062(19.7%) developed to the blastocyst stage. For cows of the BT, SS and CS groups, there were similar cleavage rates; however, use of SS decreased blastocyst formation (15.6% versus 18.9%). In the BI group, use of SS increased cleavage rates (59.1% versus 53%, respectively) although there was no effect on blastocyst rate development (22.9% versus 21.9). In the BI/BT groups, use of SS decreased cleavage (44.4% versus 57.1%, respectively) and blastocyst rate development compared with the CS group (15.3% versus 20.1%, respectively). Data from this study indicate embryos from cows of the BT purebred or BI/BT crossbred had less in vitro developmental capacity compared to embryos derived from oocytes of cows that were purebred BI in tropical-subtropical regions.
  • article 114 Citação(ões) na Scopus
    Motor cortex stimulation inhibits thalamic sensory neurons and enhances activity of PAG neurons: Possible pathways for antinociception
    (2012) PAGANO, Rosana L.; FONOFF, Erich T.; DALE, Camila S.; BALLESTER, Gerson; TEIXEIRA, Manoel J.; BRITTO, Luiz R. G.
    Motor cortex stimulation is generally suggested as a therapy for patients with chronic and refractory neuropathic pain. However, the mechanisms underlying its analgesic effects are still unknown. In a previous study, we demonstrated that cortical stimulation increases the nociceptive threshold of naive conscious rats with opioid participation. In the present study, we investigated the neurocircuitry involved during the antinociception induced by transdural stimulation of motor cortex in naive rats considering that little is known about the relation between motor cortex and analgesia. The neuronal activation patterns were evaluated in the thalamic nuclei and midbrain periaqueductal gray. Neuronal inactivation in response to motor cortex stimulation was detected in thalamic sites both in terms of immunolabeling (Zif268/Fos) and in the neuronal firing rates in ventral posterolateral nuclei and centromedian-parafascicular thalamic complex. This effect was particularly visible for neurons responsive to nociceptive peripheral stimulation. Furthermore, motor cortex stimulation enhanced neuronal firing rate and Fos immunoreactivity in the ipsilateral periaqueductal gray. We have also observed a decreased Zif268, delta-aminobutyric acid (GABA), and glutamic acid decarboxylase expression within the same region, suggesting an inhibition of GABAergic interneurons of the midbrain periaqueductal gray, consequently activating neurons responsible for the descending pain inhibitory control system. Taken together, the present findings suggest that inhibition of thalamic sensory neurons and disinhibition of the neurons in periaqueductal gray are at least in part responsible for the motor cortex stimulation-induced antinociception.
  • article 31 Citação(ões) na Scopus
    Magnetic resonance diffusion tensor imaging for the pedunculopontine nucleus: proof of concept and histological correlation
    The pedunculopontine nucleus (PPN) has been proposed as target for deep brain stimulation (DBS) in patients with postural instability and gait disorders due to its involvement in muscle tonus adjustments and control of locomotion. However, it is a deep-seated brainstem nucleus without clear imaging or electrophysiological markers. Some studies suggested that diffusion tensor imaging (DTI) may help guiding electrode placement in the PPN by showing the surrounding fiber bundles, but none have provided a direct histological correlation. We investigated DTI fractional anisotropy (FA) maps from in vivo and in situ postmortem magnetic resonance images (MRI) compared to histological evaluations for improving PPN targeting in humans. A post-mortem brain was scanned in a clinical 3T MR system in situ. Thereafter, the brain was processed with a special method ideally suited for cytoarchitectonic analyses. Also, nine volunteers had in vivo brain scanning using the same MRI protocol. Images from volunteers were compared to those obtained in the post-mortem study. FA values of the volunteers were obtained from PPN, inferior colliculus, cerebellar crossing fibers and medial lemniscus using histological data and atlas information. FA values in the PPN were significantly lower than in the surrounding white matter region and higher than in areas with predominantly gray matter. In Nissl-stained histologic sections, the PPN extended for more than 10 mm in the rostro-caudal axis being closely attached to the lateral parabrachial nucleus. Our DTI analyses and the spatial correlation with histological findings proposed a location for PPN that matched the position assigned to this nucleus in the literature. Coregistration of neuroimaging and cytoarchitectonic features can add value to help establishing functional architectonics of the PPN and facilitate neurosurgical targeting of this extended nucleus.
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    Non-motor symptoms in PD candidates for DBS treatment
    (2016) GHILARDI, M. G. dos Santos; MARTINEZ, R. C. R.; CURY, R. G.; ARANHA, J. R.; TEIXEIRA, M. J.; BARBOSA, E. R.; FONOFF, E. T.
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    The Effect Of Epidural Ozone Therapy In Patients With Chronic Pain Related To Failed Back Surgery Syndrome.
    (2013) FONOFF, Erich T.; MAGALHAES, Francisco N.; TEIXEIRA, Manoel J.
  • article 4 Citação(ões) na Scopus
    Use of computational fluid dynamics for 3D fiber tract visualization on human high-thickness histological slices: histological mesh tractography
    (2021) ALHO, Eduardo Joaquim Lopes; FONOFF, Erich T.; ALHO, Ana Tereza Di Lorenzo; NAGY, Jozsef; HEINSEN, Helmut
    Understanding the intricate three-dimensional relationship between fiber bundles and subcortical nuclei is not a simple task. It is of paramount importance in neurosciences, especially in the field of functional neurosurgery. The current methods for in vivo and post mortem fiber tract visualization have shortcomings and contributions to the field are welcome. Several tracts were chosen to implement a new technique to help visualization of white matter tracts, using high-thickness histology and dark field images. Our study describes the use of computational fluid dynamic simulations for visualization of 3D fiber tracts segmented from dark field microscopy in high-thickness histological slices (histological mesh tractography). A post mortem human brain was MRI scanned prior to skull extraction, histologically processed and serially cut at 430 mu m thickness as previously described by our group. High-resolution dark field images were used to segment the outlines of the structures. These outlines served as basis for the construction of a 3D structured mesh, were a Finite Volume Method (FVM) simulation of water flow was performed to generate streamlines representing the geometry. The simulations were accomplished by an open source computer fluid dynamics software. The resulting simulation rendered a realistic 3D impression of the segmented anterior commissure, the left anterior limb of the internal capsule, the left uncinate fascicle, and the dentato-rubral tracts. The results are in line with clinical findings, diffusion MR imaging and anatomical dissection methods.