segunda-feira, 30 de janeiro de 2012

Voltagem X Corrente

Research cracking Parkinson’s

MONDAY, JANUARY 30, 2012 | Progress in the fight against Parkinson’s disease has been made in a recent study authored by two University of Cincinnati professors.

This study is the first examining the effectiveness of constant-current stimulation of the brain as a treatment for Parkinson’s symptoms.

The study was co-authored by Dr. Fredy J. Revilla, an associate professor of neurology and UC Health neurologist, and Dr. George Mandybur, an associate professor of neurosurgery, and was published Jan. 11 in the medical journal The Lancet Neurology.

Deep brain stimulation, or DBS, has been proven to reduce the symptoms of Parkinson’s disease and side effects of some medications, such as motor fluctuations and dyskinesia. DBS devices apply voltage to brain tissue, which stimulates the subthalamic nucleus — a lens shaped compact cluster of neurons — found deep in the brain tissue.

 “The purpose of the study was to find a new way of applying stimulation to the brain through these devices,” Revilla said.  “Traditionally the stimulation was done by delivering constant voltage, and this study looked at delivering constant current.”

Constant voltage stimulates brain tissue with a steady voltage, but the current, or rate of application, is not always the same.  On the other hand, constant current applies stimulation at a constant rate, but the voltage may vary.

The Libra and LibraXP, DBS devices manufactured by St. Jude Medical, were examined in the Lancet Neurology study and provide constant-current stimulation.

These devices are not yet available in the U.S., but St. Jude Medical has applied for U.S. Food and Drug Administration approval.  Medtronic — the only company that currently makes DBS devices in the U.S.— has recently added a constant-current feature to compete in the medical innovation market.

“At this point, we know that the constant-current stimulation is at least as effective as the traditional constant-voltage stimulation,” Revilla said. “What is not known yet is if constant-current stimulation is better than constant-voltage.”

Medication for Parkinson’s disease helps reduce the symptoms for a period of time, giving the patient a period of “on time” where symptoms are minimal.  When the medication wears off, the symptoms return and the patient experiences “off time.”

“What the study did was measure the number of hours the patient had in the ‘on’ state, and then after deep brain stimulation with a constant-current device the same number was measured,” said Dr. Revilla.  “What was found is an increase in the number of hours in the ‘on’ state, and as a consequence the patient has a longer period of time every day where they can function closer to normal.” Fonte: News Record.

segunda-feira, 23 de janeiro de 2012

Presentan un sistema basado en electrodos para combatir el Parkinson

PROMETEDOR AVANCE
22 de enero de 2012 - Los pacientes sometidos al estudio de la Universidad de Florida presentaron una reducción de los síntomas relacionados con la enfermedad y un mayor periodo de tiempo entre los temblores, según los datos de la investigación.

Un equipo médico liderado por la Universidad de Florida presentó un sistema pionero para controlar los síntomas del Parkinson a través de estimulación cerebral basada en pequeñas descargas eléctricas. Los pacientes que recibieron el tratamiento redujeron considerablemente el número de temblores y la duración de los mismos.

"Esta investigación marca una evolución en la tecnología de dispositivos de estimulación cerebral profunda", explicó Michael Okun, líder del proyecto, quien vaticinó que en los próximos cinco o diez años se verá una carrera para mejorar los aparatos que exploren las señales neurales del cerebro.

El sistema está basado en un dispositivo que emite señales eléctricas leves al cerebro a través de unos electrodos. En los resultados obtenidos se apreció un mayor periodo temporal entre cada temblor (4,22 horas frente a la 1,77 registrada previamente), así como movimientos involuntarios más lentos a los habituales.

En la investigación participaron pacientes que sufrían la enfermedad desde hacía cinco años o más y se les siguió por un periodo de un año a partir de la cirugía a las que se les sometió para implantarles los electrodos. "El estudio respalda el uso de corrientes eléctricas leves en las estructuras del cerebro con el objetivo de minimizar los síntomas de la enfermedad de Parkinson", explicó Michael Okun. Fonte: Hechos de Hoy.es.

quarta-feira, 18 de janeiro de 2012

Sucesso na dbs de caxiense do sul

Bom dia Hugo, tudo bem?
Gostaria que colocasse no blog: http://dbs-parkinson-brasil.blogspot.com/2011/06/caxiense-tenta-cirurgia-para-amenizar.html, que a cirurgia foi realizada no dia 11/10/11, foi um sucesso, meu pai esta retomando a vida novamente, pois antes ele tinha muitos movimentos involuntarios, o que deixava de permitir a ele uma vida social.
Quem realizou a mesma foi Dr Telmo Reis, que atua no Moinhos de Vento em Porto Alegre.
A cirurgia foi concedida através do Estado do RS e do Munícipio de Caxias do Sul.
Agradeço a todos que de alguma forma colaboraram.
Um grande abraço...
crismaltauro@pop.com.br

quarta-feira, 11 de janeiro de 2012

Subthalamic deep brain stimulation with a constant-current device in Parkinson's disease: an open-label randomised controlled trial

Jan 11, 2012 - Constant-current DBS of the subthalamic nucleus produced significant improvements in good quality on time when compared with a control group without stimulation. Future trials should compare the effects of constant-current DBS with those of voltage-controlled stimulation.

Deep brain stimulation in Parkinson's disease: opening up the race towards better technology
Jan 11, 2012 - In this issue of The Lancet Neurology, Michael Okun and colleagues1 report on a randomised controlled trial of subthalamic neurostimulation for the treatment of advanced Parkinson's disease. The study confirms the marked benefit that deep brain stimulation (DBS) exerts on parkinsonian motor symptoms, and also offers interesting and novel findings about this surgical therapy.

Fonte: The Lancet.