Functional Neurosurgery Innovations Can Help Many Patients With Intractable Conditions
Article Date: 05 Aug 2007
Functional neurosurgery encompasses many neurosurgical interventions that can enhance the quality of life for patients with a wide range of neurological diseases and conditions. These include epilepsy and related seizure disorders, Parkinson's disease (PD) and other movement disorders, intractable pain, spasticity, and several psychiatric disorders. This fast-growing subspecialty is being highlighted by the American Association of Neurological Surgeons (AANS) in August during Neurosurgery Outreach Month.
"In many cases, patients have received diagnoses and been treated with little success over a period of many years, using a variety of medication and therapies," stated Michael Schulder, MD, chairperson of the AANS/CNS Section on Stereotactic and Functional Surgery and American Society for Stereotactic and Functional Surgery.
"Some exciting, innovative technologies have recently been developed, which may offer new hope for select patients who have not achieved satisfactory results from other surgical or nonsurgical treatment methods," said Dr. Schulder.
Millions of people worldwide are affected by one of the conditions that may now be treated through functional neurosurgery procedures:
-- About 2.5 million people in the United States have epilepsy, and as many as 9 percent of the entire population may experience a seizure at some point in their lives. It is likely that around 50 million people in the world have epilepsy at any given time.
-- It is estimated that 60,000 new cases of PD are diagnosed each year in the United States, adding to the estimated one to 1.5 million Americans who currently have the disease. The latest epidemiology studies indicate that worldwide numbers will increase to 8.7 million people with PD by 2030.
-- Essential tremor affects about 5 million people in the United States. As many as 250,000 Americans have dystonia, making it the third most common movement disorder after essential tremor and PD.
-- Recent statistics indicate that one in five people worldwide suffer from moderate to severe chronic pain and that of these, one in three are unable to maintain an independent lifestyle due to their pain.
-- Spasticity affects more than an estimated 12 million people worldwide. This condition is often present in patients with cerebral palsy, multiple sclerosis, and amyotrophic lateral sclerosis (ALS).
-- Severe psychiatric illness, including treatment resistant depression and obsessive compulsive disorder, affects about 6 percent of the U.S. population, or an estimated 18 million Americans.
Deep brain stimulation (DBS) has been used to treat intractable pain for several decades. More recently, use of this technology has proven to be a safe and effective treatment for essential tremor, as well as for the tremor and involuntary movements associated with PD, dystonia, and multiple sclerosis, with more than 35,000 DBS implants worldwide. The indications for DBS therapy are expanding rapidly.
DBS surgery involves the placement of tiny implantable electrodes into specific parts of the brain that are functioning abnormally. Stimulation is presumed to help modulate dysfunctional circuits in the brain so that the brain can function more effectively. This is accomplished by sending continuous electrical signals to specific target areas of the brain, which block the impulses that cause neurological dysfunctions. The advantage of DBS over older "ablative" techniques (where small holes or "lesions" were made in the brain to block abnormal circuits) is that it is reversible, nondestructive, and can be modified by adjustment of the stimulator settings after implantation.
Vagus nerve stimulation (VNS) sends regular, mild pulses of electrical energy to the brain via the vagus nerve, through a device that is similar to that utilized in DBS. This treatment was approved by The Food and Drug Administration (FDA) as a seizure treatment in 1997. VNS may be considered as a treatment option in patients who have tried two or more anti-epileptic drugs (AEDs) without adequate control of their seizures, or in patients who have not responded to AEDs and cannot undergo brain surgery. In 2005, the FDA approved VNS for people with chronic or recurrent treatment resistant depression who have failed to respond to four or more adequate treatments. However, there is very little efficacy data available on VNS for depression. Other surgical options are available for patients with intractable epilepsy.
Founded in 1931 as the Harvey Cushing Society, the American Association of Neurological Surgeons (AANS) is a scientific and educational association with more than 7,200 members worldwide. The AANS is dedicated to advancing the specialty of neurological surgery in order to provide the highest quality of neurosurgical care to the public. All active members of the AANS are certified by the American Board of Neurological Surgery, the Royal College of Physicians and Surgeons (Neurosurgery) of Canada or the Mexican Council of Neurological Surgery, AC. Neurological surgery is the medical specialty concerned with the prevention, diagnosis, treatment and rehabilitation of disorders that affect the entire nervous system, including the spinal column, spinal cord, brain and peripheral nerves.
