Nerves are fibers that convey information between nervous system cells, called neurons, located throughout the body and the brain. Either intentionally, due to surgery, or unintentionally, through accidents, these fibers may be cut, in a process known as nerve transection. Many times, this is something to be avoided during surgery, because it destroys the ability of neurons to communicate with one another. In some cases, such as surgery to alleviate epileptic seizures, transection is a desirable outcome.
Epilepsy is a disorder characterized by overactivity in neurons, resulting in uncontrolled signals being sent through nerves in a phenomenon known as a seizure. Sometimes, drugs cannot control the seizures, and doctors may not be able to safely remove the brain areas causing them. Situations like these can require a nerve transection to prevent the seizure activity from spreading, thus limiting the damage that they cause.
With any nerve transection undertaken to create relief for epileptics, there is an extensive pre-operative evaluation period. This is viewed as a last resort remedy, but is being delivered more rapidly than in the past. Previously, people that elected to undergo this type of medical procedure had taken medications for their condition for ten years or more, without relief.
In order to minimize the physical and psychological harm of frequent seizures, doctors are now opting to pursue nerve transection sooner, within one or two years of evaluating the effects of medications. Children may have surgeries even more quickly, with doctors determining the efficacy of medications within weeks to months of their initial use. Tests are used to determine the origin of the seizures, and to anticipate possible side effects from the procedure before it is undertaken.
A special type of nerve transection known as a multiple subpial transection is one possible seizure treatment. Partial seizures that occur in the largest part of the brain, the cerebral cortex, can be treated with this medical procedure. This invasive surgery involves exposing the brain, and making a number of cuts into the surface of the cortex. The cuts are shallow to limit the damage to the brain, and are meant to sever the nerve connections between cortical areas.
Permanent damage to the brain does not usually occur from this medical procedure, although transection of areas involved in language can lead to problems generating and comprehending language. Depending on where the transection takes place, individuals may experience an increased perception of pain due to changes in how pain signals are delivered to the brain. This side effect can often be averted by giving the patient a nerve block before the surgery begins.