Speech-impaired patients can learn to interact with the outside world thanks to a newly developed, revolutionary method. At the Emory University, neurosurgeon Roy E. Bakay and neuroscientist Phillip R. Kennedy successfully have implanted a neurotrophic electrode into the brains of a woman, suffering from Amyotrophic Lateral Sclerosis (ALS) and a man with brainstem stroke. The computer chip is directly connected with the cortical nerve cells and permits the patient to "talk" by moving a cursor on the computer screen with his mere thoughts. The neural signals are transmitted to a receiver and connected to the computer in order to drive the cursor. Is this the first step to a generation of bionic people who are able to control devices with the brain and whose cerebral functions are influenced by chip implants?
Patients who have lost the ability to move and talk because of stroke, spinal cord injury or a degenerative motor neuron disease like ALS, also known as Lou Gehrig's disease, run the risk to become fully isolated from contact with their family and friends. The technique based on chip implants is only a few years old but the Bakay/Kennedy team has proven that its implementation may lead to realistic results. The neurotrophic electrode first is introduced into a tiny glass encasing before the surgeon can implant it into the motor cortex of the brain. The glass is being impregnated with neurotrophic factors, in order to stimulate the cortical cells to grow into the neurotrophic electrode. After a few weeks, the cortical tissue has grown into the electrode to establish electronic contact between the brain cells and the chip.
Inside the glass cone, recording wires are integrated to pick up the electronic signals, emitted by the neurons in the patient's ingrown brain tissue. These neural signals are being transmitted to a wireless receiver and amplifier on the outside of the skull by means of an induction coil placed over the scalp. The recorded signals are directly connected to the computer and move the cursor just like a traditional computer mouse would do. The patient has to learn how to control with his sheer thoughts both the strength and pattern of the electric impulses to force the cursor to stop on the desired icons on the screen, to send e-mail, to turn the light on or off, and to communicate with the people in his room. In a next phase, Dr. Bakay hopes to connect the neural signals to a muscle stimulator in the paralysed parts of the body to allow the patient to move his limbs, just like he controls the cursor.
Up till now, Dr. Bakay and Dr. Kennedy have performed the chip implant intervention on two patients. The first one was a female ALS patient with progressively deteriorating control motor functions, making her unable to walk, talk, and even breathe in the end. Still, this patient managed to monitor the computer signals in a more or less satisfactory way during 76 days before she died from her terminal condition. The second one currently stays at the Atlanta Veterans Affairs Medical Center. This male patient has had a heart attack after which he is suffering from brainstem stroke with complete paralysis except for the face. The man breathes with the help of a ventilator and is unable to talk. Yet, he can communicate by means of little phrases, spoken by the computer, each time when he lets the cursor move and stop on an icon in a horizontal direction.
Dr. Kennedy has worked for the past twelve years on the development of the neurotrophic electrode method at the Georgia Institute of Technology. Since the beginning, Emory University has been involved in the testing on animals. The research has been supported by the Emory/Georgia Technological and Biomedical Research Consortium, the American Paralysis Association and the Department of Veterans Affairs. The ongoing work with patients recently has been funded by the National Institutes of Health (NIH). Dr. Bakay and Dr. Kennedy are striving to turn the chip implant technology into a suitable method for clinical practice, not only for terminal patients but also for people with fine chances for recovery, who will have to live with the chip implant for many years. In the United States, stroke is now the leading cause of lasting disability for adults. Please, find more detailed information at the Emory Health Sciences Center Web site.