Neuromodulation

Neuromodulation technology allows us to adjust the nerve activity by delivering electrical stimulation or medications directly to a target area in the brain, spinal cord, or nerves. It is one of the fastest-growing medical specialties. Neuromodulation is now a standard-of-care treatment for selected patients with movement disorders, chronic pain, spasticity, epilepsy, and psychiatric disorders.

Neuromodulation is delivered through less-invasive treatments like deep brain stimulation, spinal cord stimulation, nerve stimulation, and intrathecal pumps. More recently, focused ultrasound treatment offers an incision-less alternative for patients who are not a candidate or unwilling to pursue less-invasive treatments.

DEEP BRAIN STIMULATION

The majority of patients with movement disorders can be effectively treated with medications. However, some patients either don’t respond to medication or initially respond to medication that eventually becomes ineffective. For these patients, deep brain stimulation surgery can be a life-changing option.

In deep brain stimulation procedures, precise electrodes are implanted into specific targets in the brain. Then, a pacemaker installed below the collarbone delivers continuous electrical stimulation to the affected brain target. An overwhelming majority of patients experience a remarkable improvement in symptoms and quality of life after deep brain stimulation surgery.

A successful deep brain stimulation program requires the partnership of several medical specialties, including neurosurgery, neurology, neuropsychology, radiology, and anesthesiology.

FOCUSED ULTRASOUND ABLATION

Focused ultrasound (FUS) is an incision-less treatment for patients with movement disorders. Like DBS, FUS can be an excellent option for some patients who either don’t respond to medication or initially respond to medication that eventually becomes ineffective.

Guided by real-time MR imaging, FUS can achieve precise and targeted ablation in the brain. Patients are awake and participate in testing during FUS treatment. A functional neurosurgeon first delivers ultrasound at low power to test whether ablation of the targeted area is safe. Once the safety is established, the target area is ablated for sustained improvement in patient symptoms.

SPINAL CORD OR NERVE STIMULATION

Spinal cord or nerve stimulation uses a surgically implanted device that sends pulses through the body to stop pain messages from reaching the brain. This treatment option is considered when medications and other pain interventions cannot relieve pain.

Patients undergo a multidisciplinary assessment by experts in interventional pain, neuropsychology, and neurosurgery. A trial of the spinal cord or nerve stimulation is then performed. Patients who experience substantial pain improvement then receive permanent stimulator implants to reduce pain long-term.

SCOPE OF FUNCTIONAL NEUROSURGERY

For the last 30 years, neurosurgeons have used electrical stimulation of deep brain structures to improve the slowness, stiffness, and tremor of advanced Parkinson’s disease. Most recently, we have seen the introduction of more sophisticated devices that improve therapy by allowing the electricity to be directed preferentially in specific directions within the brain to reduce unwanted spread of current and improve outcomes. We have also seen the advancement of gene therapy trials that have the promise of reversing the degeneration in the brain that leads to the disease. Many of these are being done using MRI guidance to monitor the infusion of therapies into the brain in real-time.

While we have been using electrical stimulation of the spinal cord for the past many years to treat certain types of chronic pain, we now have advanced methods of stimulation that bring more relief to patients suffering from debilitating pain. In the past, the stimulation effect relied on causing paresthesias — a dull buzzing or tingling feeling — in the affected body region to block the pain signals. However, many patients complained about this sensation, and the intensity of the sensation could vary significantly with the person’s position. We now have multiple methods of stimulation, using higher frequencies or short bursts of pulses, that produce very little of these sensations and are not altered by positional changes. The result is tremendous reductions in pain, allowing patients to wean off some or all of their pain medication.

We are also working to bring hope to those with brain and spinal cord injury through innovative research programs. Functional neurosurgeons are heavily involved with brain-computer interface devices that allow a person to execute commands on a computer screen or with a robot arm using just their thoughts that are detected up by a small microchip implanted in the brain. This can allow someone who is paralyzed or has a degenerative disease like ALS (Lou Gehrig’s disease) to communicate and be more independent. Advances in this technology are exploring the restoration of sensory functions and enhancing memory function as well.