Epilepsy | June 11, 2014 | Author: The Super Pharmacist
Establishing new breakthroughs in seizure prevention is an ongoing movement in the medical world. Epilepsy is a chronic brain disorder characterised by recurring seizures caused when nerve cells, or neurons, suddenly begin to transmit with rapid fire speed. The normal rate is around 80 pulses per second; in epileptics that rate can soar to more than 500 pulses a second. Some people only experience seizures occasionally; others can suffer dozens or even hundreds a day. Epilepsy is the fourth most common neurological disorder, affecting men and women of all ages, ethnic backgrounds, and races although racial minorities are at higher risk than Caucasians. Many people with epilepsy have more than one type of seizure and may have other symptoms of neurological problems as well. Research is ongoing on several fronts in clinical drug trials: brain imaging, improved diagnostic tools, preventative devices, genetics and stem cells. Some therapies are used for a broader range of epilepsies, others are more targeted, but all the new treatments are designed to improve the daily lives of those who suffer seizures.
For patients with intractable epilepsy (those who do not respond to drug therapy) surgery is an important treatment option. The bad news is only a small percentage of those individuals will qualify for such surgeries. Ilo E. Leppik, adjunct professor of neurology at the University of Minnesota and director of research at MINCEP Epilepsy Care in Minneapolis, explains, “The problem is that you need to be able to identify the part of the brain where seizures are originating and then remove that section without causing speech problems, paralysis, or other complications— none of which is easy.” If the area where the seizure starts can be identified and isolated, it improves the odds for surgical success. A dense array EEG uses many more attachments than a standard EEG to record the electrical activity of the brain so that there is improved accuracy and localization of the source of any abnormal electrical brain activity.
Deep Brain Stimulation for Epilepsy Deep brain stimulation has recently been approved as a therapy for patients with intractable, or drug-resistant, epilepsy. An electrode is implanted into the brain that directly stimulates neurons blocking the activity that triggers seizures. Deep brain stimulation was known to be an effective treatment for various movement disorders such as Parkinson’s disease, and as such researchers studied its value with other neurological and psychiatric diseases such as chronic pain syndromes and epilepsy. Responsive Neurostimulation Similar to deep brain stimulation, responsive neurostimulation (RNS) is another device that directly stimulates the brain to minimise or control seizures. The treatment calls for implanting a stimulator in the skull that is attached to one or two EEG leads that are also implanted in or on top of the brain where the seizures start. The stimulator’s battery is designed to detect and keep a record of the brain’s electrical activity. When it identifies a seizure, it sends an electrical current to disrupt the seizure activity. The device is programmed based on the patient’s individual EEG and responses. The procedure is approved for the treatment of adults with partial seizures that do not respond to seizure medications, have seizures starting in more than one location, or have seizures arising or occurring in areas of the brain that cannot be removed.
Eslicarbazepine Acetate Eslicarbazepine acetate is a once-daily anti-epileptic drug that selectively inhibits the rapid-firing nerve cells that cause seizures. It significantly reduces the frequency of partial seizures in patients with a certain type of epilepsy (refractory partial) when used in combination with other anti-epileptic medications. E. Ben-Menachem, a professor at University of Goteborg in Sweden and the lead clinical investigator for eslicarbazepine acetate explains, “When assessing the potential of anti-epileptic agents, it is as important to consider the implications on the quality of a patient’s day-to-day life, as well as effective seizure control. Eslicarbazepine acetate demonstrated a significant improvement in patient quality of life and reduction in depressive symptoms.” Perampanel Perampanel is a new type of anti-epilepsy medication that selectively targets proteins in the brain to control excitability. Researchers believe it may significantly reduce the frequency of seizures in patients resistant to other new medications. According to study leader Gregory L. Krauss from Johns Hopkins University School of Medicine, “Many other drugs to treat frequent seizures have been released in the last ten years and for many people, they just don’t work. For a drug-resistant population that has run out of options, this study is good news. These are patients who are tough to treat and are fairly desperate.” Perampanel is the first in a new class of drugs that appears to temper an excitatory response in the brain without causing major side effects. Retigabine Retigabine is a new antiepileptic drug that has gone through numerous testing since 1997 and is expected to be approved by the FDA and available for sales in 2015.
Advanced digital technologies are providing new insights into the brain. Researchers are continually improving MRIs and imaging devices to assist in the diagnosis of epilepsy and the ability to identify the lesions that are the source of brain seizures. In an overview presented at the 67th Annual Meeting of the American Epilepsy Society in May 2014, Graeme Jackson, senior deputy director of the Brain Research Institute at the Florey Institute of Neuroscience and Mental Health in Victoria, Australia, said, “We’re going through another paradigm shift. Techniques for the use of data are crucial. Surgery success is much better when you’ve found the lesion and you understand what that lesion is. That really should be one of the primary purposes [of imaging].” The United States National Institutes of Health explains current research is focused on how neurotransmitters interact with brain cells and how non-neuronal cells in the brain contribute to seizures. The University of Montana reports promising results on a gene therapy approach to epilepsy where key nerve cells in the brain are transferred with certain genes that stop seizures. The treatment is showing enough promise in animals that now researchers are conducting experimental drug trials. There is also interest in the role inflammation may play in epilepsy. Specifically, researchers are investigating whether our natural immune system and related inflammatory reactions in the brain may mediate some of the molecular and structural changes occurring during and after seizure activity. It is unknown if immune responses that occur in the brain are beneficial or injurious in relation to epilepsy. But perhaps the most promising potential therapy lies in stem-cell research. Cell replacement is considered a possible treatment for certain types of epilepsy where there is neuronal injury. The idea is to grow new healthy neurons using stem-cells to replace the damaged cells. Already some hospitals and clinics are using umbilical cord stem cell injections combined with rehabilitation therapy to treat certain forms of epilepsy.
New Therapies Pipeline: www.epilepsy.com/accelerating-new-therapies/new-therapies-pipeline#MAP
Elger C, Halasz P, Maia J et al. Efficacy and safety of eslicarbazepine acetate as add-on treatment in adults with refractory partial-onset seizures: BIA-2093-301 Study. Abstract and oral communication, presented at the 8th European Congress on Epileptology, Berlin, Germany, 21-25 September 2008.
Hufnagel A, Ben-Menachem E, Gabbai A et al. Efficacy and safety of eslicarbazepine acetate as add-on treatment in adults with refractory partial-onset seizures: BIA-2093-302 Study. Abstract and oral communication, presented at the 8th European Congress on Epileptology, Berlin, Germany, 21-25 September 2008.
Seizures and Epilepsy: Hope through Research: www.ninds.nih.gov/disorders/epilepsy/detail_epilepsy.htm#263313109