Implantable brain device delivers shocks to improve cognitive function

Alex Haber

Staff Writer

For those that have spent their lives suffering from dementia or memory loss, or the pain of watching a loved one go through it, scientists may have a therapeutic approach to help improve cognitive functioning.

Currently options are limited for treating those with cognitive deficits because of traumatic brain injury or suffering from dementia. Stimulation of the nervous system via implanted electrodes has produced mixed results in the past. Previously, there were people who responded both positively and negatively to the surgery. The concept behind this implant is synonymous with pacemakers placed in patients with a cardiac arrhythmia.

In patients with an abnormal heart rate, they are implanted with a pacemaker which replaces the body’s natural pacemaker’s cells role of regulating heart rate. The device delivers electric shocks to keep the heart rate constant. Additionally, some patients are outfitted with an implantable cardioverter defibrillator (ICD). And ICD, unlike a pacemaker, delivers not only low-energy electrical pulses, but also high-energy pulses to treat life threatening arrhythmias. The device implanted in the brain shares more similarities with the ICD than the pacemaker.

Photo courtesy of Wikimedia Commons
An implantable device has been developed that can deliver shocks to the brain in areas of cognitive deficiencies to improve their function.

The ‘pacemaker’ for the brain is an implantable device that must be placed surgically. It involves careful placement of electrodes on the afflicted portions of the brain. The same technique was used in previous implantable devices. In the past, and currently, much of the research is done with epilepsy patients, but they hope to expand it to neurodegenerative patients such as those with Alzheimer’s disease. One setback in the past for the project was the timing of the shocks. The success of the new device is in part because of a correction made on old devices.

Older devices would shock the brain tissue without discerning whether the tissue was malfunctioning. During moments of nervous system malfunction, i.e. when a person was experiencing a seizure, the shock would help correct the issue and improve cognitive function. However, when the device would shock the brain when it was normally functioning, which it does for most of the time, this would lead to a decrease in cognitive functioning of the patient.

A paper recently published in “Current Biology” addressed the use of this device in a variety of conditions; it addressed situations in which it would work and where it would not. The real takeaway from the paper was the demonstration of how the state of brain can be monitored and how that can be used to determine when a shock is needed. It is a step forward in demonstrating how we can move to more sophisticated and safe devices for patients that need it. Already there are results that support the effectiveness of the device. Patients that had epilepsy and had the device implanted showed fewer seizures following the surgery and an improvement in their memory. Although the present study focused patients with epilepsy, there are other proposed uses.

Those that need this device the most are those suffering from neurodegenerative diseases or those that have impaired cognitive function because of an injury. Most of the funding for the project initially came from the government in anticipation of its applications to injured soldiers returning from war. The use of the device, as mentioned, extends much further than that. A solution to debilitating diseases may not be far off.

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