Neuromodulation and Deep Brain Stimulation

Rhode Island Hospital offers advanced forms of neuromodulation for diseases ranging from Parkinson’s disease, dystonia and tremor, to various pain syndromes and certain intractable psychiatric illnesses. Many of these conditions can be treated at the Movement Disorders Program.

Many of these disorders involve dysfunction of a particular brain circuit, and our neurosurgeons specialize in techniques that modulate these circuits to alleviate some or all of the symptoms of these diseases.

Techniques range from deep brain stimulation (and other forms of brain stimulation) to lesions and even non-invasive Gamma Knife procedures.

Wael Asaad, MD, who sub-specializes in this type of neurosurgery, joined the program in 2011. Pediatric neurosurgery cases may also involve Albert Telfeian, MD, chief of pediatric neurosurgery at Hasbro Children’s Hospital.

All of our neurosurgeons work in close collaboration with neurologists and psychiatrists to make certain that patients receive the most comprehensive and appropriate care they need.

Conditions We Treat

Parkinson’s Disease  

Parkinson’s disease is a degenerative neurological condition in which patients gradually experience worsening movement and cognitive symptoms. Early in the disease, oral medications are remarkably effective in alleviating the worst symptoms. However, within about ten years, many patients begin developing large swings in their symptoms as the drugs’ chronic use leads to abnormal, involuntary movements (dyskinesias). When this happens, much time is spent feeling either under- or over-medicated, and less and less time is spent in a balance where the medications are working just right.

Deep brain stimulation smoothes out these fluctuations and can directly alleviate some of the baseline rigidity and tremor. Our neurosurgeons have an extensive combined experience in the surgical treatment of Parkinson’s disease. We work closely with neurologists to make certain patients are accurately diagnosed and that any individual’s particular situation is potentially amenable to surgical treatment. Our surgical procedures use state-of-the-art technologies, including high-resolution MRI for accurate targeting and methods for either traditional “frame-based” implantation techniques, or new “frameless” techniques. 


Tremors are rhythmic, involuntary movements that can significantly impair basic abilities such as writing, eating, drinking or getting dressed. Medications can often significantly decrease the tremor. Occasionally however, medications are ineffective or unable to be tolerated due to side effects.

Tremors are thought to result from impaired communication between the brain’s cerebral cortex and the cerebellum. Modulating this circuit, either through deep brain stimulation or through targeted disconnections (lesions), can in many cases completely or nearly completely abolish the tremor. Our neurosurgeons employ state-of-the-art technologies to maximize safety and accuracy, whether implanting deep brain stimulators, performing lesion procedures in an operating room or creating lesions non-invasively using the Gamma Knife.


Dystonia is a condition in which muscles involuntarily contract against each other, causing abnormal movements and postures. Some forms of dystonia appear in early childhood, whereas others appear much later in life, sometimes after a traumatic event. Certain forms of dystonia are hereditary.

Often, a combination of oral medications and local injections (using botulinum toxin, also known as Botox) can improve the symptoms by relaxing the hyperactive muscles. However, when these are insufficient, certain forms of dystonia are potentially treatable with deep brain stimulation or disconnection (lesion) approaches. 

Our neurosurgeons have experience in a variety of neuromodulation techniques, ranging from operative implantation of deep brain stimulators or lesion procedures, to newer techniques, such as Gamma Knife lesions.

Central Pain Syndromes

Occasionally, a stroke or trauma will result in a brain injury that causes the circuits responsible for pain to be constantly “turned on." Patients in this unfortunate situation may describe the feeling that half of their body is burning or aching. Similarly, severe spinal cord injury can in rare cases lead to intractable pain below the level of the trauma. Medications are notoriously ineffective in counteracting these forms of pain.

In severe cases, cortical brain stimulation or targeted disconnection (lesion) procedures (such as cingulotomy) can offer some degree of benefit. Neurosurgeons at Rhode Island Hospital surgically treat severe pain syndromes, and match patients to the right procedure to alleviate these types of suffering.

Intractable Obsessive Compulsive Disorder

In the most severe cases of obsessive compulsive disorder (OCD), patients become trapped in a seemingly endless cycle of repeating rituals and are limited in their activities by powerful obsessions.

Our interdisciplinary team of psychiatrists, neurosurgeons and neurologists evaluate referrals of the most difficult and intractable cases. We ascertain whether an OCD patient has indeed failed adequate and comprehensive medical and behavioral therapies and, if so, whether they might be appropriate surgical candidates. Potential surgical options include deep brain stimulation, operative lesions (circuit disconnections) and non-invasive Gamma Knife lesions.

Trigeminal Neuralgia and Hemifacial Spasm

Severe, unremitting pain on one side of the face, or involuntary contractions on one side of the face, are the hallmarks of trigeminal neuralgia and hemifacial spasm, respectively. Medications can often effectively control the worst of the symptoms. When medications are inadequate or cannot be tolerated due to side effects, and when the symptoms significantly impair the ability to carry on with routine daily activities, some surgical options may be available.

The classic (and most common) forms of these illnesses are due to a blood vessel (usually a vein) compressing a nerve near the brainstem. Depending on which nerve is compressed, trigeminal neuralgia (cranial nerve 5) or hemifacial spasm (cranial nerve 7) may result. Other forms of neuralgia resulting from nerve compression do exist, but are much more rare. Directly relieving this pressure by moving the blood vessel away from the nerve is usually curative.

Because these nerves are located near the brainstem, gaining access to this region to perform the decompression requires major surgery.

Our neurosurgeons are experts in the techniques needed to perform this surgery, and patients are routinely monitored for at least one night in our dedicated neuro-intensive care unit in order to provide the safest recovery. In addition, less invasive procedures can be considered for trigeminal neuralgia. These involve ablations (targeted inactivations) of the nerve as it exits the skull. These procedures are performed minimally-invasively.

Alzheimer’s Disease (Clinical Trial)

Alzheimer’s disease afflicts one in eight people over the age of 65, and nearly half of all people aged over 85. This disease primarily impairs memory, but may also render patients so disoriented as to interfere with many simple daily activities. Diagnosis is becoming increasingly accurate and is beginning to allow earlier diagnosis of individuals with the disease. However, despite several new drugs aimed toward alleviating the symptoms of this disease, no treatment has been found that can significantly slow down the worsening of symptoms.

Rhode Island Hospital is part of a multi-center trial of a new strategy to alleviate the symptoms of Alzheimer’s Disease using deep brain stimulation (DBS). An interdisciplinary team of neurologists, neurosurgeons and psychiatrists evaluates patients who are potential candidates for the trial and selects those most appropriate given the potential benefits and risks. Because this treatment is experimental, only a relatively small subgroup of patients with early Alzheimer’s disease are currently eligible.

Functional Neurosurgery at Rhode Island Hospital

The functional neurosurgery team helps people with movement disorders restore function and move better through innovative procedures.

Our Team


Wael F. Asaad, MD, PhD Headshot

Wael F. Asaad, MD, PhD

Director, Functional Neurosurgery & Epilepsy Program; Co-Director, Deep Brain Stimulation; Laboratory Director, Cognitive Neurophysiology & Neuromodulation

Albert E. Telfeian, MD, PhD Headshot

Albert E. Telfeian, MD, PhD

Director, Center for Minimally Invasive Endoscopic Spinal Surgery


Affiliated Neurologists

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Joseph H. Friedman, MD

Prarthana Prakash, MD Headshot

Prarthana Prakash, MD



Affiliated Psychiatrists

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Benjamin Greenberg, MD

Affiliated Psychiatrist

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Steven Rasmussen, MD

Chair, Department of Psychiatry and Human Behavior, The Warren Alpert Medical School of Brown University