Deep Brain Stimulation – A Novel Treatment Option for Patients with Parkinsonism
At the start of each year, we propose a number of research focus areas and then work through a process to determine which disease state to focus our preclinical activities on…so our first year it was chronic pain and tinnitus, the second year urinary incontinence, the third year was motor deficit after stroke and this year we have chosen motor deficit from Parkinson’s disease. We advance candidates through 4 essential phases, hypothesis, preclinical evaluation, clinical evaluation and then commercialization. To date, we have shown that our tinnitus therapy is through the 3rd hurdle of clinical evaluation, but still needs support from NIH and investors to get into commercialization. We are making some progress on this by establishing the regulatory pathway needed for a European and US approval. This process is a long one, but one in which we are familar with. Right now, both FDA and BSI are evaluating our data to determine the amount of evidence we will need to submit to receive approval. Once we get this information we will collect that data and make our submissions for commercial approvals.
In the interim, we also hope to fund a small pilot study to evaluate our targeted plasticity therapy for patients that have sufferered a stroke. We have published some promising preclinical data in rats and now have a very complete set of preclinical data to support our first clinical study. We hope to start this sometime this year (of course depending on funding).
Given our expertise in sensory and motor deficits, we hope to begin studying motor deficit from Parkinson’s this year in rat studies. I provide a brief overview of where we are with this disorder using deep brain stimulation…hopefully we will get a strong signal in PD rats in 2012 and begin clinical trials in 2013.
Deep brain stimulation has been proven to markedly improve the motor functions in patients suffering from severe Parkinson’s disease. How does it work? Stimulation of various neurons of the central nervous system is known as deep brain stimulation (DBS). DBS can alter the electrical activities of different parts of the brain via a controlled mechanism; accordingly, it is utilized in conjunction with neuroimaging studies to map the various mechanisms of brain functions. A basic DBS system comprises 2 main components: 1- Special electrodes that are implanted in special parts of the brain in order to conduct stimulation electrical impulses to the brain cells. 2- An electrical pulse generator (PG) which creates the stimulation impulses that are conducted to the electrodes implanted on the brain. What are the neurological disorders that can benefit from DBS? DBS has been beneficial in a group of neurological diseases namely dystonia, tremors, cluster headaches and various mood disorders such as obsessive compulsive disorders, Tourette syndrome, depression and bipolar disorders. Parkinsonism and DBS: A study that was published this January in Lancet Neurology marked the technological improvement of brand new DBS devices. Dr Michael S. Okun led a group of researchers in Florida University who used constant current voltage controlled devices in DBS of the subthalamic nuclei of a group of patients with advanced Parkinson’s disease. The team used a special Neurostimulation system, called the Libra, which was created in St. Jude Medical neuromodulation Division. After implantation of the Neurostimulation system by a year, patients exhibited improvement of their motor function during periods that ranged from 4 to 12 hours per day. Apart from improvements of the motor functions, DBS aided in alleviation of the depressive symptoms of patients within 3 months following surgery. On the other hand, patients receiving DBS showed worsening of the scores of their verbal fluency. Deficits of verbal fluency represent the most common cognitive side effect of deep brain stimulation of the subthalamic nucleus. Neurologists claim that these cognitive side effects are caused by the surgery itself rather than by deep brain stimulation of the subthalamic nucleus. Fatigue, dysarthria, edema and paraesthesia are among the most common side effects following placement of the Neurostimulation device. The improvement in motor functions can be even maximized via addition of rasagiline to the treatment plan of patients following surgery. To sum up, DBS has opened new horizons for patients with Parkinson’s disease. More and more neurologists and manufacturers are getting interested in Neurostimulation which will certainly be reflected on a better quality of life for patients with Parkinsonism.