WILLIAM OMAR CONTRERAS LOPEZ
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- Microendoscopy-guided percutaneous cordotomy for intractable pain: case series of 24 patients(2016) FONOFF, Erich Talamoni; LOPEZ, William Omar Contreras; OLIVEIRA, Ywzhe Sifuentes Almeida de; TEIXEIRA, Manoel JacobsenOBJECTIVE The aim of this study was to show that microendoscopic guidance using a double-channel technique could be safely applied during percutaneous cordotomy and provides clear real-time visualization of the spinal cord and surrounding structures during the entire procedure. METHODS Twenty-four adult patients with intractable cancer pain were treated by microendoscopic-guided percutaneous radiofrequency (RF) cordotomy using the double -channel technique under local anesthesia. A percutaneous lateral puncture was performed initially under fluoroscopy guidance to localize the target. When the subarachnoid space was reached by the guiding cannula, the endoscope was inserted for visualization of the spinal cord and surrounding structures. After target visualization, a second needle was inserted to guide the RF electrode. Cordotomy was performed by a standard RF method. RESULTS The microendoscopic double -channel approach provided real-time visualization of the target in 91% of the cases. The other 9% of procedures were performed by the single -channel technique. Significant analgesia was achieved in over 90% of the cases. Two patients had transient ataxia that lasted for a few weeks until total recovery. CONCLUSIONS The use of percutaneous microendoscopic cordotomy with the double-channel technique is useful for specific manipulations of the spinal cord. It provides real-time visualization of the RF probe, thereby adding a degree of safety to the procedure.
conferenceObject Effectiveness and micro-electrodes findings of deep brain stimulation of the STN via a parietal approach in post-infectious previously implanted Parkinson's patients(2016) LOPEZ, W. O. Contreras; BATISTA, L.; AZEVEDO, A.; TEIXEIRA, M. J.; FONOFF, E. T.- Hypertrophic Olivary Degeneration: A Neurosurgical Point of View(2016) CARVALHO, Carlos Henrique; KIMMIG, Hubert; LOPEZ, William Omar Contreras; LANGE, Manfred; OECKLER, ReinhardHypertrophic olivary degeneration (HOD) is a rare form of transsynaptic degeneration characterized by hypertrophy of the inferior olivary nucleus situated in the olivary body, part of the medulla oblongata, representing a major source of input to the cerebellum. HOD typically results from focal lesions interrupting connections from the inferior olive within the dentato-rubro-olivary pathway, a region also known as the triangle of Guillain-Mollaret (TGM) (red nucleus, inferior olivary nucleus, and contralateral dentate nucleus). Clinically, HOD presents classically as palatal tremor and can include dentatorubral tremor and/or ocular myoclonus. The pathologic changes associated with HOD feature radiologic changes with the inferior olivary nucleus appearing larger and increasing its T2-weighted signal intensity on magnetic resonance images. HOD is commonly managed with pharmacotherapy but may require surgical intervention in extreme cases. HOD has been found to develop as a consequence of any injury that disrupts the TGM pathways (e.g., pontine cavernoma). These findings highlight the critical importance of a thorough knowledge of TGM anatomy to avoid secondary HOD. We present a patient who developed HOD secondary to resection of a tectal plate cavernous malformation and review the literature with an emphasis on the current knowledge of this disorder.
- Mystery Case: Brown-Sequard syndrome caused by idiopathic spinal cord herniation(2016) FONOFF, Erich Talamoni; LOPEZ, William Omar Contreras; TEIXEIRA, Manoel JacobsenA 48-year-old man developed numbness in the left leg, which progressed gradually to paresis and urinary incontinence. Neurologic examination revealed a left Brown-Sequard syndrome with leg paresis, mild spasticity, reduced proprioception, and contralateral thermal and painful hypoesthesia below T6. MRI revealed a thoracic spinal cord herniation (SCH) (figure). Idiopathic SCH is relatively rare. Pathogenesis involves a dura mater defect (see video on the Neurology (R) Web site at Neurology.org); herniation develops over a progressive pressure gradient through the dural fissure.(2) Surgical reduction is typically performed if symptoms progress, but mild symptoms may be eligible for conservative treatment and monitoring. Surgical spinal reduction and dural repair usually reverses neurologic deficits.
- Simultaneous bilateral stereotactic procedure for deep brain stimulation implants: a significant step for reducing operation time(2016) FONOFF, Erich Talamoni; AZEVEDO, Angelo; ANGELOS, Jairo Silva dos; MARTINEZ, Raquel Chacon Ruiz; NAVARRO, Jessie; REIS, Paul Rodrigo; SEPULVEDA, Miguel Ernesto San Martin; CURY, Rubens Gisbert; GHILARDI, Maria Gabriela dos Santos; TEIXEIRA, Manoel Jacobsen; LOPEZ, William Omar ContrerasOBJECTIVE Currently, bilateral procedures involve 2 sequential implants in each of the hemispheres. The present report demonstrates the feasibility of simultaneous bilateral procedures during the implantation of deep brain stimulation (DBS) leads. METHODS Fifty-seven patients with movement disorders underwent bilateral DBS implantation in the same study period. The authors compared the time required for the surgical implantation of deep brain electrodes in 2 randomly assigned groups. One group of 28 patients underwent traditional sequential electrode implantation, and the other 29 patients underwent simultaneous bilateral implantation. Clinical outcomes of the patients with Parkinson's disease (PD) who had undergone DBS implantation of the subthalamic nucleus using either of the 2 techniques were compared. RESULTS Overall, a reduction of 38.51% in total operating time for the simultaneous bilateral group (136.4 +/- 20.93 minutes) as compared with that for the traditional consecutive approach (220.3 +/- 27.58 minutes) was observed. Regarding clinical outcomes in the PD patients who underwent subthalamic nucleus DBS implantation, comparing the preoperative off-medication condition with the off-medication/on-stimulation condition 1 year after the surgery in both procedure groups, there was a mean 47.8% +/- 9.5% improvement in the Unified Parkinson's Disease Rating Scale Part III (UPDRS-III) score in the simultaneous group, while the sequential group experienced 47.5% +/- 15.8% improvement (p = 0.96). Moreover, a marked reduction in the levodopa-equivalent dose from preoperatively to postoperatively was similar in these 2 groups. The simultaneous bilateral procedure presented major advantages over the traditional sequential approach, with a shorter total operating time. CONCLUSIONS A simultaneous stereotactic approach significantly reduces the operation time in bilateral DBS procedures, resulting in decreased microrecording time, contributing to the optimization of functional stereotactic procedures.
article 11 Citação(ões) na Scopus Pain Relief in CRPS-II after Spinal Cord and Motor Cortex Simultaneous Dual Stimulation(2016) LOPEZ, William O. C.; BARBOSA, Danilo C.; TEIXEIRA, Manoel J.; PAIZ, Martin; MOURA, Leonardo; MONACO, Bernardo A.; FONOFF, Erich T.We describe a case of a 30-year-old woman who suffered a traumatic injury of the right brachial plexus, developing severe complex regional pain syndrome type II (CRPS-II). After clinical treatment failure, spinal cord stimulation (SCS) was indicated with initial positive pain control. However, after 2 years her pain progressively returned to almost baseline intensity before SCS. Additional motor cortex electrode implant was then proposed as a rescue therapy and connected to the same pulse generator. This method allowed simultaneous stimulation of the motor cortex and SCS in cycling mode with independent stimulation parameters in each site. At 2 years follow-up, the patient reported sustained improvement in pain with dual stimulation, reduction of painful crises, and improvement in quality of life. The encouraging results in this case suggests that this can be an option as add-on therapy over SCS as a possible rescue therapy in the management of CRPS-II. However, comparative studies must be performed in order to determine the effectiveness of this therapy.- Caudal Zona Incerta/VOP Radiofrequency Lesioning Guided by Combined Stereotactic MRI and Microelectrode Recording for Posttraumatic Midbrain Resting-Kinetic Tremor(2016) LOPEZ, William Omar Contreras; AZEVEDO, Angelo R.; CURY, Rubens G.; ALENCAR, Francisco; NEVILLE, Iuri S.; REIS, Paul R.; NAVARRO, Jessie; MONACO, Bernardo; SILVA, Fabio E. Fernandes da; TEIXEIRA, Manoel J.; FONOFF, Erich T.OBJECTIVE: Reporting the outcome of two patients who underwent unilateral ablative stereotactic surgery to treat pharmacologic resistant posttraumatic tremor (PTT). METHODS: We present two patients (31 and 47 years old) with refractory PTT severely affecting their quality of life. Under stereotactic guidance, refined by T2-weighted magnetic resonance imaging and double-channel multi-unit microelectrode recording (MER), three sequential radiofrequency lesions were performed in the caudal zona incerta (cZi) up to the base of thalamus (VOP). Effects of cZi/VOP lesion were prospectively rated with a tremor rating scale. RESULTS: Both patients demonstrated intraoperative tremor suppression with sustained results up to 18 months follow-up, with improvement of 92% and 84%, respectively, on the tremor rating scale. Tremor improvement was associated with enhancement functionality and quality of life for the patients. The patients returned to their work after the procedure. No adverse effects were observed up to the last follow-up. CONCLUSION: Radiofrequency lesion of the cZi/VOP target was effective for posttraumatic tremor in both cases. The use of T2-weighted images and MER was found helpful in increasing the precision and safety of the procedure, because it leads the RF probe by relying on neighbor structures based on thalamus and subthalamic nucleus.
conferenceObject Treatment of Complex Regional Pain Syndrome type II (CRPS-II) with Simultaneous Multi-Target Spinal Cord and Motor Cortex Stimulation: A Case Report(2016) VELEZ, Faddi G. Saleh; DURAN, Juanita; FONOFF, Erich T.; CONTRERAS, William O.conferenceObject Long-term comparative outcomes of functional neurosurgical procedures for treatment of secondary hemidystonia(2016) LOPEZ, W. O. Contreras; AZEVEDO, A. R. C.; GUILARDI, M. G.; SEPULVEDA, M. San Martin; MARTINEZ, R. C. R.; TEIXEIRA, M. J.; FONOFF, E. T.