Adam Jordan
January 31, 2013
An Alternative Solution for Chronic Pain
The INS2 Pain is an essential sensation for a long lasting, healthy life. It lets us know when our body has been damaged, allowing us to instantly remove ourselves from the source of the damage, or to treat it so that it doesn't become a problem in the future. While essential, pain can also be extremely annoying, and even debilitating, if it continues for a long period of time. Chronic pain, defined as a mild to severe pain lasting for over three months since the time of onset, can be caused by anything, from a severe injury to a medical operation, it can even be inherited through genes. Whatever the cause, chronic pain affects over one and a half million people in Canada alone. There are existing treatments for chronic pain in the form of drugs, such as narcotics, which can cause just as much harm as good. Fortunately, a new product is on the rise that can treat chronic pain without the harmful side effects of drugs. The Implantable Neural Sensing and Stimulation, or INS2, is a tiny chip that can be attached to the spinal cord capable of sufficiently blocking pain signals that are traveling to the brain. This "smart chip" has huge potential for effectively treating chronic pain, as well as other nervous system conditions, and can therefore help to decrease the need as well as the use of prescription narcotics. A sensory nerve cell transmits pain in a fairly straightforward process. At rest, three positively charged sodium ions move out of the nerve, while two positively charged potassium ions move into the cell. Blake et al states that the result is a net positive charge outside the nerve cell and a negative charge inside. When the nerve is stimulated sufficiently, sodium gates in the cell membrane open, allowing sodium ions to move into the cell in that area, resulting in a net positive charge inside of the cell. Nearby sodium gates then open, changing the charge in their area as well. Potassium gates soon open, allowing potassium to quickly move out of the cell, recreating the net negative charge inside the cell. This wave of changing charges is called action potential and travels through the nerves to the brain and is interpreted as a pain signal. The brain sends a signal in the same way through motor neurons, which we feel as pain. Chronic pain is long lasting, and provides no benefit to our body's health. It can become more severe as time goes on and eventually will become intense enough to impair one's ability to do any kind of physical work that involves using the affected area. However, the electro-chemical nature of pain signals has given leading scientists and engineers a place to start when developing treatments for chronic pain. Conventionally, people have turned to narcotics in the fight against chronic pain. These drugs attach to opiate receptor proteins in the brain and spinal chord and work to block the impulse of pain through nerves when received by the brain or spinal chord. Narcotics are highly addictive drugs, most with a long list of serious and potentially deadly side effects. Narcotics are not the only way out for sufferers of chronic pain as a more effective, less harmful alternative is becoming available and recently, has been proven effective in lab settings and on volunteer test subjects. The INS2 is an electrode chip, about the size of a match head, which is implanted directly into the spine. This smart chip will be able to sense a change in the resting potential in the non-myelinated nerves of the spinal cord and will have the computer processor interpret the change. Popular Science says the processor can then have a small shock - of up to ten volts - sent through electrodes placed in the smart chip. This input of electricity sufficiently blocks the action potential wave, stopping the pain signal. This process is called spinal cord stimulation. The mechanisms of action of spinal cord stimulation are not completely
