Dr. Luc Jasmin MD, PhD

GLG News by Dr. Luc Jasmin MD, PhD, Attending Neurosurgeon and a Research Scientist

GLG News is now G+ Insights

G+ is a community for professionals, academics and entrepreneurs to connect through online discussions and in-person meetings. You will continue to see G+ Insights (formerly GLG News) here as well as on the G+ website, where you can share and discuss the G+ Insights you read.

Brain stimulation for high blood pressure?

February 6, 2011

Analysis of:Deep brain stimulation relieves refractory hypertension | www.neurology.org

In the past few years there has been a few reports of an anti-hypertensive effect of deep brain stimulation with Medtronic quadripolar electrodes in patients treated for pain syndromes.  Interestingly the antihypertensive effect appears independant of the analgesic effect.  The blood pressure is normalized and all anti-hypertensive medications stopped.  The reduction of blood pressure appears at the time of the surgery and is still present 27 months later.  up. 

Duloxetine is not for all pains

December 27, 2010

Analysis of:Duloxetine in patients with central neuropathic pain caused by spinal cord injury or stroke: A randomized, double-blind, placebo-controlled trial. | www.ncbi.nlm.nih.gov

When faced with a patient with central pain we use drugs approved for peripheral neuropathy.  Some class I evidence support the use of gabapentin, pregabalin, lamotrigine, and tramadol for central pain. Hence, Vranken and his colleagues tested the analgesic effect on central pain of the mix noradrenergic-serotoninergic antidepressant duloxetine (Cymbalta). Unfortunately, their study confirms previous data showing that a mix noradrenergic-serotoninergic antidepressant is not an effective analgesic for central pain.

The first trial of mini spinal cord stimulators in early 2011

December 15, 2010

Analysis of:New miniature smart chip implant to combat chronic pain | www.physorg.com

After much talk in the past years, a new generation of neurostimulators will be tested in 2011 in Australia.  Because of miniaturisation, electrodes and the Implantable Pulse Generator (IPG) are now a single unit that can be directly implanted over the spinal cord or a peripheral nerve.  Now that's would be a prime example of minimally invasive surgery.

Botox gets the green light for migraine, but does it work?

November 17, 2010

Analysis of:OnabotulinumtoxinA for treatment of chronic migraine: Results from the double-blind, randomized, placebo-controlled phase of the PREEMPT 2 trial | cep.sagepub.com

Chronic migraine is a subtype of migraine, which is defined by 15 or more headaches days per month with 8 or more migraine days for at least 3 months.  For the PREEMT2 recruited in 66 sites. 347 patient received Botox and 358 received placebo. The double blind phase lasted 24 weeks, which was followed by an open-label period of 32 weeks.  Botox was injected every 12 weeks. The primary endpoint was the incidence of headache day, was significantly lower in the Botox and placebo group.

Spinal cord stimulation (SCS) for Parkinson’s disease? We're not there yet.

November 8, 2010

Analysis of:Spinal cord stimulation failed to relieve akinesia or restore locomotion in Parkinson’s disease | www.ncbi.nlm.nih.gov

Spinal cord stimulation (SCS) in dopamine-depleted mice and rats reverses the akinesia and improves locomotion (see Fuentes et al, Science 2009). Because SCS is much less invasive than deep brain stimulation, it is worth testing in Parkinson’s patients. Thevathasan and colleagues (2010) tested SCS in two patients with Parkinson’s disease.  There findings show no evidence that SCS improves the motor symptoms of Parkinson’s disease.

TRPs as Analgesic Drug Targets: Using HC-030031 to Probe the Role of TRPA1

September 28, 2009

Analysis of:The 3rd Annual Pain Therapeutics Summit | click.bsftransmit1.com

Transient receptor potential cation channel, subfamily A, member 1 (TRPA1) is a cold receptor, somewhat the opposite of the capsaicin receptor (TRPV1), which is a heat receptor. TRPA1 is a chemosensor and it has an abundance of agonists, exogenous (cigarette smoke, etc...) and endogenous (prostaglandins, etc…). All neurons that express TRPA1 also express TRPV1. Stimulating TRPA1 causes pain. Hydra Biosciences is developing TRPA1 antagonists (receptor blocker) to block pain and inflammation.

TRPV1 Agonists: 500 Years in Development

September 28, 2009

Analysis of:The 3rd Annual Pain Therapeutics Summit | click.bsftransmit1.com

Qutenza is a flexible film that wraps on the skin and leads to a rapid release of 8% capsaicin. Possible applications: OA, Post-herpetic neuralgia, HIV neuropathy, and diabetic neuropathy. The results show efficacy in both post-herpetic neuralgia and HIV neuropathy as determine by 30% decrease in pain. More trials are being presently conducted. NeurogesX is developing a liquid form is that is works in a much shorter time (5 min instead of the current 30 to 60 min).

Antagonists: Are They Too Hot to Handle?

September 28, 2009

Analysis of:The 3rd Annual Pain Therapeutics Summit | click.bsftransmit1.com

Merck TRPV1 Antagonists MK-2295: Results of clinical studies and reasons why it will not make it to market MK-2295 was administered to normal individuals for 14 days. The investigator tested for heat sensitivity by applying a heat probe to the skin or the subjects having taken MK-2295 or placebo.  They also immersed their hands in hot water (48 degree C) or asked them to drink hot water. The results were impressive with the subjects taking MK-2295 displaying a raised threshold to heat.  The problem is that often they did do not find unpleasant temperatures around 48 degree C.

Responsive vs unresponsive depressive patients have similar electrode sites

September 7, 2009

Analysis of:Deep brain stimulation of the subcallosal cingulate gyrus for depression: anatomical location of active contacts in clinical responders and a suggested guideline for targeting | thejns.org

Based on an association between successful and unsuccessful clinical response, the authors present stereotaxic coordinates, allowing standardization of the implantation site.The post-implantation analysis position of the intracerebral quadripolar electrodes was analyzed in twenty patients. Eleven out of 20 patients achieved a significant reduction of their depression scores at 1 year. The responder's electrodes were only slightly more ventral by 1-2 mm. See J Neurosurg (on line) / May 29, 2009. 

Vertebroplasty vs kyphoplasty vs arcuoplasty

August 20, 2007

Analysis of:Medtronic Buys Kyphon For $3.9 Billion | www.forbes.com

Will the recent purchase of Kyphon by Medtronic signals the end of kyphoplasty? No because arcuoplasty does not restore vertebral height. Vertebroplasty, kyphoplasty and arcuoplasty essentially achieve the same goals, which brings up the question, do we need all three techniques? Arcuoplasty is the safest of a three for lower thoracic and lumbar vertebrae but until Medtronic comes up with a smaller injection needle system, vertebroplasty will be more appropriate for upper thoracic and cervical spinal levels. The arcuate system is market for osteoporotic fractures but could be improved for cancer (metastasis) related fracture.

Glial Cells: The Nervous System is more than Neurons

December 28, 2006

Analysis of:New Insights into Neuron-Glia Communication | www.pubmedcentral.nih.gov

It has always been suspected that the supporting cells of the brain, called glial cells, have long held a secondary role behind neurons, the “telephone wires” of the brain. But, this role may have been grossly underestimated as new evidence suggests that glial cells may be able to sense and monitor the activity of neurons. They can do so by communicating with neurons as neurons do with other neurons, but through chemical signals instead of electrical impulses.

Although simple on the surface, this information opens the door to revolutionary and ground breaking ideas in science. Within the heart of neuro-glial communication, lies a brilliant and promising target for therapies aimed at eliminating chronic pain, epilepsy, and against Alzheimer’s dementia as well as multiple sclerosis, amongst others.

RNA Interference (RNAi) Offers New Options in Medical Treatment

December 21, 2006

Analysis of:The Therapeutic Potential of RNAi | www.technologyreview.com

Post-translational gene silencing (PTGS) techniques, particularly the very popular RNA Interference (RNAi) technique, may be used to temporarily suppress the expression of particular genes in virtually all organisms. Where once believed to be limited to the plant species, the new discovery of its universal application stirs thoughts of limitless opportunities. In addition to the experimental application of RNAi as a preferred mode of probing and understanding the cells of the body, some future implications of RNAi include the silencing of biological processes in order to fight off HIV infection and for protection against viruses or heart disease.

A number of recent publications (and more in 2007) demonstrate that RNAi allows the investigation of the role of specific genes in single organs (brain, digestive tract, etc…) in adult animals, avoiding the need to produce knockout mice for the same purpose.

Currently multiple clinical trials are being conducted with RNAi to treat pancreatic cancer, liver cancer, leukemia, and HIV, among others.

This technique is much more acceptable to the patient than gene therapy, because RNAi does not affect in anyway one’s DNA. One Nobel prize was given in 2006 for RNAi to Dr. Andrew Fire of Stanford University and Dr. Craig Mello of the University of Massachusetts Medical School for their joint discovery.

Page : 11 to 12 of 12