Epilepsy is a neurological condition characterized by frequent, severe, unpredictable, and unprovoked seizures. Approximately 3 million Americans and 50 million people worldwide are affected by epilepsy. Seizures occur when the brain’s normal activity is disturbed leading to loss of control generating in the cortical sites.
Essentially, there is an excessive over- firing of neurons within the brain that causes the brain to temporarily become unresponsive to control. Seizures that characterize epilepsy can initiate in any of the four lobes within the brain: frontal, temporal, occipital, or parietal lobe. Specific behavioral manifestations of a seizure can help identify the exact lobe that is affected. The specific location where the seizure initiates can be found through the electroencephalogram (EEG), a clinical test that measures brain waves and can therefore assess when the brain deviates from normal and fires excessively. The eight probes are attached to all lobes and placed in the left and right regions to better pinpoint the exact location of the seizure.
Localized or partial seizures are isolatable to one specific region of the brain while generalized seizures usually begin in one region and quickly spread to the rest of the brain. Partial seizures can be characterized as simple (preservation of consciousness) or complex (impairment of consciousness). Generalized seizures can be characterized as absence, myoclonic, or tonic-clonic. Absence seizures impair consciousness, and myoclonus is the involuntary movement of muscles (specifically the arms or legs). Tonic-clonic seizures, or grand mal seizures, are when the patient loses consciousness and the patient starts convulsing from a rapid tension and contraction of muscles.
Patients suffering from epilepsy have a higher mortality rate and a lower life expectancy. This mortality has no relation to a person’s age. Predictably, the lack of control for seizures, and therefore the longer a patient has uncontrolled seizures as a consequence of epilepsy, the greater the risk of death. Therefore, it is the doctor’s primary priority to treat epilepsy to avoid seizures. Usually, the first treatment is to prescribe anticonvulsant medications that essentially better control the firing of neurons in the brain.
However, some conditions cannot be treated simply with medicines and so different options are considered. The least invasive method is to prescribe a ketogenic diet, which strictly limits the amount of carbohydrates a patient can consume. Removing many of the carbohydrate sources from one’s diet reduces the firing of neurons within
the brain. This can mitigate a patient’s epilepsy. Surgery is often considered for patients that are unresponsive to the previous treatment options. Other preventative procedures include surgery. For the epileptic patients with generalized seizures, often corpus callosotomy is considered to disconnect both hemispheres from each other and prevent the spread of the seizure. The treatment provided for epilepsy will generally remove or reduce the prevalence of seizures. The specific condition Lennox-Gestaut Syndrome is characterized by severe and uncontrollable seizures. Often, for this condition, multiple medications must be prescribed to better contain the seizures or surgery is considered. It is essential to treat epilepsy; untreated epilepsy has the potential to create major cephalic problems.
Engineering solutions have become more prevalent as potential cures to the seizures caused by epilepsy. Research in many engineering institutes has found potential technology that could address this issue. Research at Duke University utilizes the ability of cooling the brain, which can soothe the abnormal brain functions within the brain that cause seizures. This technology, a small cooling- chip that can be implanted into the specific region of the brain malfunctioning, is efficient. The main benefit is that this chip has the potential to be effective in all regions, meaning that it is not location-specific. After implantation, the chip has the potential to detect when the brain has erratic brain waves and react almost instantaneously, cooling the brain.
The FDA recently approved an epilepsy device with similar potential that closely mimics a pacemaker. The vagal nerve stimulator (VNS) is implantable, and is placed under the clavicle, with an electrode extending towards the vagus nerve. This device has the potential to decrease the seizure rate, on average of 20-30%. There is a 10% chance of effectively stopping the seizures altogether.
Recently, it has become clear that the brain’s activity is changed hours before it is demonstrated electrically. The VNS can thus better monitor the brain’s neural signals and respond rapidly. One day engineering may lead to the elimination of this devastating condition.
Editorial Note: CEM has a long history of publishing technical pieces from the latest in scientific and engineering research. In the early years of the publication, the lion’s share of our publication was technical— featuring graphs, equations, and models. Recently, we have shifted the focus of the magazine towards a more prosaic review of innovation. That said, with this issue we are proud to present “Research in Review,” a recurring feature that delves a little more deeply into a research topic each issue. We hope you enjoy it!