Text Box: Neuro-what? - the Basics Neurotechnology, the use of medical electronics interacting with the human nervous system, can restore substantial function, combat secondary conditions and aide rehabilitation following nervous system disease or injury. The foundation of neurotechnology is the electrical signals the body uses to send messages. The stimulation of these signals is a main feature of this technology. In the 1950’s, the first attempt was made to apply electrical stimulation to the phrenic nerve allowing a person to breathe without a ventilator. This developed into a field of science called FES (Functional Electrical Stimulation). FES encompasses a variety of therapeutic techniques and treatments used to activate muscles that may not be functioning properly due to injury, disease or a physical abnormality. Over the decades, this field of science that combines medicine, biomedical engineering and technology evolved into what is now called neurotechnology. Even though a muscle is paralyzed, it does not mean that the muscle cannot contract when it is stimulated. For those with mobility impairments that do not have peripheral nerve damage, electrical stimulation may be utilized; however not all people with SCI are appropriate for particular technologies. Researchers and clinicians currently working in this area, understand the existing criteria and are developing new guidelines to determine for whom neurotechnology devices and therapies will be most beneficial and successful. Systems are segmented into three main areas implanted, external or hybrid (a combination) of both. Implanted systems tend to be more “invasive” and therefore require a surgical or other procedure to install the system into the body of a potential user. Whereas, external systems are applied outside the body or on the surface of the skin. Finally, hybrid systems have components that are both implanted and external. As systems move from the lab to the clinic, there are a variety of things to consider before jumping into a treatment, therapy or device protocol. Individuals must consider the time commitment, financial requirements and health benefits and risks that come with any program. Proper evaluation and supervision by a trained clinician, such as a physician or therapist is essential. Applications Just as there are many aspects to a spinal cord injury, there are as many applications of neurotechnology. Below are descriptions of applications for different areas related to spinal cord injury. This includes a few advances that are currently available, as well as some progress in research for what is coming in the near future. Lists of devices are available in the Resources section. Breathing and Cough Assistance Current neurotechnology alternatives to mechanical ventilation are hybrid systems that include either a phrenic nerve stimulator or diaphragmatic stimulator. Unlike ventilator systems, which use mechanical pressure to force air into the lungs, the stimulation system pulls air into the lungs by stimulating the diaphragm muscle or the phrenic nerve. As the diaphragm contracts, the chest cavity expands and air is pulled into the lungs. Additionally, persons with cervical and thoracic level SCI often have paralysis of the muscles responsible for coughing. Cough assistance systems (CAS) that are currently available use different pressures to clear the lungs through an external breathing mask attached to a separate control unit. Under investigation is a new hybrid system that uses an external controller and implanted electrodes to achieve a cough. The goal of this electrical stimulation system is to create a ‘cough on demand’, reduce the need for frequent patient suctioning and allow the person with SCI to clear secretions more easily. Hand Grasp and Rehabilitation for the Upper Extremities The loss of hand and arm function due to a cervical level SCI can severely impact an individual. Regaining hand function is a high priority for this group. Hand control systems can enhance rehabilitation or provide function to the upper extremities which include the hand, wrist or arm. Upper extremity systems can generally be classified as either external or hybrid systems. External systems use electrodes that are attached to the skin over the muscles to be stimulated. These systems are often used for exercise, muscle conditioning and limited function. Other options include hybrid systems that have an implanted stimulator and an external control method. These are for long-term functional use. The first commercial system, the FreehandTM, was available through NeuroControl Corporation in the late 1990’s. Although the system was successful in producing hand function, the company could not maintain profitability and left the SCI market in 2001. Today, researchers are developing second generations of upper extremity systems designed to provide hand and arm function with control that is as natural as possible, cosmetically acceptable, practical to use, and adaptable to activities and environments. Pain and Spasticity Management Neuropathic (nervous system generated) pain is a significant problem for many with SCI. Discussions with your physician can help you better understand where the pain is coming from and with that understanding, what can be done about it. There are many new areas of neurotechnology for the treatment of pain, such as deep brain stimulation and transcranial magnetic stimulation. Here, we will discuss three areas of treatment that are currently available; transcutaneous electrical nerve stimulation (TENS), implanted drug delivery systems (IDDS) and spinal cord stimulators (SCS). TENS units (transcutaneous electrical nerve stimulation) are external systems that work by delivering low level electrical stimulation through electrodes placed directly on the skin of the affected area. The contraction of muscles through electrical stimulation may help alleviate pain by blocking pain messages being sent to the brain. TENS can be a non-invasive and economical solution. Implanted Drug Delivery Systems (IDDS), also known as Intrathecal Analgesia Therapy, refers to the administration of medicine, either pain-relieving or spasticity-relieving, such as baclofen, via a medication delivery pump. The IDDS includes an implanted pump and reservoir for the drug that delivers the medication through a catheter directly into the spinal canal (intrathecal). This system may reduce the need for oral medications, can be more effective and is now a mainstay of therapy for intractable pain including neuropathic pain and spasticity as a result of SCI. Spinal Cord Stimulation (SCS) systems are hybrid systems comprised of implanted electrodes in the spine and an external control unit. It uses electrical stimulation to block the pain pathways to the brain that travel through the spinal cord. Some pain experiences by people with SCI are particularly suitable to spinal cord stimulation. SCS has also been known to decrease spasticity. The system flexibility allows the user to keep it on permanently or as needed. Bladder Management Most people living with SCI have reduced bladder control. Neurotechnology devices offer several different approaches of bladder management that use electrical stimulation to hyper-reflexive or flaccid functioning bladders. Appropriateness of each specific device or treatment depends on the level of injury and bladder condition. There are five basic types of devices using electrical stimulation in different ways. 1) Sacral nerve stimulator is an implanted device that manages the bladder by sending electrical impulses to the nerve that controls the bladder, sphincter, the muscles around it, and the sacral nerve roots. 2) Tibial nerve stimulator controls the bladder through percutaneous stimulation (an electrode inserted through the skin) of the tibial nerve in the lower leg. 3) Pelvic stimulator uses electrical stimulation applied to the pelvic floor muscle, which is generally delivered by a vaginal or anal probe connected to an external pulse generator. 4) Bladder muscle stimulator is a device that directly stimulates the bladder muscle with an implanted electrode. 5) An implanted device, soon to be in clinical trials, uses an electrode to stimulate the pudendal nerve to provide bladder function. These approaches should be discussed with your urologist and evaluated for your individual situation to determine which may or may not be appropriate for you. Please Note: In some instances, bowel function may coincidently be a benefit from the use of stimulators for urinary function.

Educate: Multiple Applications for Spinal Cord Injury

Educate: Multiple Applications for Spinal Cord Injury

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Personal Experiences: From the SCI community

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On the Horizon: Updates in the World of Neurotech

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Resources for Spinal Cord Injury

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Neurotech Speaks Out

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Adaptive Controls Transform Neuroprosthetics

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Neurotechnology for Spinal Cord Injury
Text Box: An estimated 12,000 new spinal cord injuries occur per year with an estimated lifetime health costs between $500,000 and $3 million depending on level and age at the time of injury. Most injuries occur in males between the ages of 19 to 30 and life expectancy is close to that of an average American. Although a relatively small population, this group is a significant consumer in our health care system that investors cannot continue to ignore. Neurotechnology has made rapid advancements in recent history: components have shrunk, electronics improved, and we, as a society, have become more accepting of interacting with technology. Devices are available commercially for SCI treatment in such areas as pain management, spasticity control, breathing assistance and new rehabilitation techniques. There are also many new technologies being investigated in research centers. These devices and technologies are not attempting to “cure” spinal cord injury; they cannot reverse the damage to the spinal cord. Instead, they are tools that can be used to, for instance, minimize damage to the cord, combat secondary conditions, provide further independence or aid in the rehabilitation process. This isn’t your uncle’s electrical stimulation generation. Images of rusting electrodes, wires protruding from the skin and printer-sized processors are a thing of the past. Although the surface stimulation devices have evolved to become more consumer-friendly, amazing progress has been made in safe and effective implanted devices. Let’s explore the many options of neurotechnology for spinal cord injury.

Neurotech Network Newsletter   

Fall 2008     Volume 3, Issue 3

The Current

Inside this issue:
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