Scientists have discovered a mutation limited to brain tissue that causes hemimegalencephaly (HMG), a condition where one half of the brain is enlarged and dysfunctional, leading to intellectual disability and severe epilepsy. The research, published by Cell Press in the April 12 issue of Neuron, has broad significance as a potential model for other complex neuropsychiatric diseases that may also be caused by "brain-only" mutations. Mutations can be inherited or occur spontaneously. Inherited mutations are present throughout all cells of the body, but some spontaneous mutations can occur during development and hence be limited to cells in some organs but not others. For some time it has been suspected that there might be neurological diseases that are caused by mutations limited to the brain, but this had not yet been definitively demonstrated as it is very difficult to study brain tissue.
Based on their clinical experience and observations, a team of Johns Hopkins physicians and psychologists say that more than one-third of the patients admitted to The Johns Hopkins Hospital's inpatient epilepsy monitoring unit for treatment of intractable seizures have been discovered to have stress-triggered symptoms rather than a true seizure disorder. These patients - returning war veterans, mothers in child-custody battles and over-extended professionals alike - have what doctors are calling psychogenic non-epileptic seizures (PNES). Their display of uncontrollable movements, far-off stares or convulsions, Johns Hopkins researchers say, are not the result of the abnormal electrical discharges in the brain that characterize epilepsy, but instead appear to be stress-related behaviors that mimic and are misdiagnosed as the neurological disorder.
Epilepsy affects 50 million people worldwide, but in a third of these cases, medication cannot keep seizures from occurring. One solution is to shoot a short pulse of electricity to the brain to stamp out the seizure just as it begins to erupt. But brain implants designed to do this have run into a stubborn problem: too many false alarms, triggering unneeded treatment. To solve this, a Johns Hopkins biomedical engineer has devised new seizure detection software that, in early testing, significantly cuts the number of unneeded pulses of current that an epilepsy patient would receive. Sridevi V. Sarma, an assistant professor of biomedical engineering, is leading this effort to improve anti-seizure technology that sends small amounts of current into the brain to control seizures. "These devices use algorithms - a series of mathematical steps - to figure out when to administer the treatment, " Sarma said.
Neural imaging - maps of brain functions - is a primary tool used by researchers hoping to transform the lives of people living with chronic neurological conditions such as epilepsy. At present, researchers often require several different imaging techniques to fully map brain functions, making research and treatment of these conditions expensive and inefficient. Using cutting-edge illumination technology, Professor Ofer Levi and his research students from the Institute of Biomaterials & Biomedical Engineering (IBBME) and The Edward S. Rogers Sr. Department of Electrical & Computer Engineering (ECE) have developed a new cost-effective neural imaging system. It allows researchers to make much more complex maps of the brain with just one camera and one imaging system. The team's initial findings, released this week in Biomedical Optics Express, demonstrate that this new technology may one day transform the way researchers view the human brain.
An estimated 2.2 million people in the United States live with epilepsy, a complex brain disorder characterized by sudden and often unpredictable seizures. The highest rate of onset occurs in children and older adults, and it affects people of all ethnicities and socio-economic backgrounds, yet this common disorder is widely misunderstood. Epilepsy refers to a spectrum of disorders with seizures that vary in type, cause, severity, and frequency. Many people do not know the causes of epilepsy or what measures to take if they witness a seizure. A new report from the Institute of Medicine highlights numerous gaps in the knowledge and management of epilepsy and recommends actions for improving the lives of those with epilepsy and their families and promoting better understanding of the disorder.