Guide to Essential Tremor and Movement Disorders
Norman Prince Neurosciences Institute
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Lifespan Living
About this Guide The Norman Prince Neurosciences Institute (NPNI) at Lifespan is a national leader in the
neurosciences, providing exceptional neurological and neurosurgical care to adults with brain or
spine disorders and comprehensive care for patients in need of mental and behavioral healthcare. Our renowned specialists offer innovative and collaborative approaches to treating the most
complex and challenging illnesses and injuries, while our depth of experience ensures the highest level of expertise in treating the most common conditions.
We created this Guide to Essential Tremor and Movement Disorders to help you understand more
about the treatments that are available if you, or someone you love, are one of the millions of people around the world with essential tremor (ET).
Did you know...? • Essential tremor (ET) is a neurological condition that causes a rhythmic trembling of the hands, head, voice, legs, or trunk. • While trembling of the hands, head, voice, legs, or trunk are common in ET, some people have a feeling of internal tremor. • ET is often misdiagnosed as Parkinson’s disease, yet according to the National Institute of Neurological Disorders and Stroke, eight times as many people have ET as have Parkinson’s.
• There is evidence that ET is genetic. Each child of a parent who has ET has a 50 percent chance of inheriting a gene that causes the condition. • It is estimated that less than 60 percent of people with ET are helped by these medications. • Researchers estimate that 4 to 5 percent of people age(s) 40 to 60 have ET. The incidence rate for people aged 60 and older is estimated at 6.3 to 9 percent.
For more information, contact the Movement Disorders Program: 401-444-6528 | HIFU@lifespan.org | Lifespan.org
What is Essential Tremor Umer Akbar, MD, and Wael F. Asaad, MD, PhD March 11, 2022
Essential Tremor (ET) is a relatively common movement disorder that affects about 10 million Americans and millions more worldwide.
What is essential tremor? Tremor is an involuntary – usually rhythmic – movement that results in shaking of a body part.
“Tremore seplice essenziale,” or essential tremor (ET), was the term coined by an Italian physician, Pietro Burresi in 1874. ‘Essential’ does not mean that it is needed or important, rather that it is
idiopathic, or has no known cause. This condition has been referred to as “benign familial tremor,” which is a misnomer, since ET is not always ‘benign’ and runs in families about half the time.
For more information, contact the Movement Disorders Program: 401-444-6528 | HIFU@lifespan.org | Lifespan.org
Is essential tremor the same as Parkinson’s disease? ET is not Parkinson’s disease (PD), although both can involve tremor. Typically, with PD, tremor is more noticeable while the extremity is at rest and can actually improve or disappear when the
affected limb is in motion. It is not common to have both ET and PD, but it is possible. That is why if you are experiencing tremor, it’s important to see a neurologist who specializes in movement disorders.
What are the symptoms of essential tremor? The cardinal symptom of ET is tremor. The commonly affected body parts include: • arms
• torso
• head/neck
• legs
• vocal cords (voice tremor) The tremor can occur when an extremity is being held in posture, or in action, while performing
a voluntary movement. For example, the hand can tremor when holding a TV remote (postural tremor), or when bringing a cup to one’s mouth (action tremor).
Interestingly, many patients will report that their tremor improves when they drink alcohol. But there are better and safer ways to treat the condition.
Is essential tremor common? If you are experiencing ET, it may help to know you are not alone. Essential tremor affects about
about 4-5% of people between the ages of 40 and 60, and an estimated 6.3-9% of people who are 60 or older. For example, in Rhode Island there are about 240,000 people who are older than 60;
there would be about 15,000-21,600 people over the age of 60 in Rhode Island with this condition. ET can start at any age, but it is more common in middle or later years of life. Many times, the tremor begins in young adulthood but is not very noticeable or disturbing until middle-age.
What is the prognosis for essential tremor? Typically, ET worsens over time, but very slowly — usually years and sometimes decades. ET is not life-threatening. However, it can be socially embarrassing and even disabling, affecting one’s ability to perform daily activities.
For more information, contact the Movement Disorders Program: 401-444-6528 | HIFU@lifespan.org | Lifespan.org
What causes essential tremor? We do not yet know the cause of ET. However, we do know that up to half of patients who have ET also have a family history of the condition. Researchers have identified genes that may be involved, but genetic testing is not yet available for routine workup of ET.
Imaging studies of the brain suggest that the part of the brain known as the cerebellum and its connections are disrupted in people with ET. The cerebellum is located at the back of the brain
and is responsible for complex motor functions and allows for balance when walking or standing. Other possible causes for tremor include: • certain medications such as anti-depressants • drugs such as amphetamines and caffeine
• metabolic conditions such as hyperactive thyroid • physiological states such as anxiety/stress
How is essential tremor diagnosed? The diagnosis is made by a thorough review of a patient’s medical history and a clinical
examination. There is no blood test or brain scan that can diagnose ET, but these tests are
sometimes performed to rule out other causes of tremor. As a result, it is important to see a
neurologist, preferably one who specializes in movement disorders and therefore can provide the correct diagnosis.
How is essential tremor treated? Unfortunately, there is no cure for ET, but there are a few treatments that might improve the tremor. In some cases, the tremor is mild enough that it doesn’t warrant treatment.
Medications for essential tremor Most of the medications work to calm the nerves, although they may have other functions as well. For example, drugs for blood pressure control or anti-seizure medications are often the first-line treatment. If they are not effective enough, the treating physician may use other drugs or drug classes to achieve better tremor control. Some medications may be used in combination.
For more information, contact the Movement Disorders Program: 401-444-6528 | HIFU@lifespan.org | Lifespan.org
Surgical treatment for essential tremor When the tremor does not respond well to medications, or severe symptoms impair an individual’s quality of life, then surgical treatment can be considered. The two main surgical treatments are deep brain stimulation (DBS) and focused ultrasound (FUS).
DBS involves implanting a thin wire into the brain, which is attached to a pulse generator battery in the chest wall. The stimulator can then send an electrical signal to the area of the brain that
controls the tremor, similar to a pacemaker for heart conditions. The stimulation acts as a way to
block the messages from your brain that cause the tremor. It has been shown to be very effective in providing relief for some patients and improving their ability to perform daily activities. DBS is a
commonly used surgical approach for ET because it is effective, can treat tremors on both sides of the body, has relatively low risk and its effects are reversible.
FUS involves placing a small, precisely targeted lesion (disconnection) in the brain region
associated with tremor. Unlike DBS, FUS does not require implanted hardware or even a skin
incision, because the ultrasound energy can be delivered through the skin and skull into the brain with MRI guidance (it does, however, require a full head-shave). FUS is a single-day, outpatient procedure and can result in immediate and long-lasting improvements in tremor. FUS can
significantly reduce tremors on one side of the body, but is not typically used to treat tremors on both sides.
Any surgical procedures carry risk and should be thoroughly discussed with an experienced specialist prior to surgery.
If you or someone you love is experiencing tremor, we can help. Learn more about the movement disorders program and our team.
Treatment for essential tremor near you The Fast Track Deep Brain Stimulation Clinic and the Focused Ultrasound Program at Rhode Island Hospital in Providence, Rhode Island offer an experienced multidisciplinary team
consisting of a movement disorders neurologist, a functional neurosurgeon, a neuropsychologist, psychiatrist, and physical, occupational and speech therapists. Our team of experts provides evaluations for potential DBS and FUS candidates and works together to determine the most appropriate recommendations for each patient.
For more information, contact the Movement Disorders Program: 401-444-6528 | HIFU@lifespan.org | Lifespan.org
Our Team The Movement Disorders Program, part of the Norman Prince Neurosciences Institute, provides
multidisciplinary care to patients with Parkinson’s disease, essential tremor, dystonia, and other
related conditions. The center is composed of neurologists, neurosurgeons, neuropsychologists,
physical and speech therapists, and others who deliver individualized care that optimizes medical and surgical treatments.
The movement disorders team evaluates patients in a comprehensive “fast track” clinic
where those considering deep brain stimulation, focused ultrasound, laser ablation (removal or destruction), or other surgical options can learn about their disease and explore these possibilities.
Our doctors and clinicians, many of whom are members of the faculty at The Warren Alpert
Medical School of Brown University, combine this patient-centered approach with the latest
technologies to deliver the highest quality care. These technologies include “incision-less” focused ultrasound therapy, advanced deep brain stimulation with neural sensing, MRI-guided laser
ablation, 3D-printed, patient-customized brain targeting systems, and real-time, intra-operative neuroimaging.
In our world-class learning environment that fosters innovation, we conduct research to better understand these neurological disorders and develop and test new therapies to treat them.
Team Leadership Umer Akbar, MD is a neurologist with expertise in the medical and surgical
management of movement disorders. He is co-director of the movement disorders and deep brain stimulation programs at Rhode Island Hospital.
Wael Asaad, MD, PhD is a neurosurgeon with expertise in neurosurgery for
movement disorders, epilepsy, and intractable psychiatric disease. He is director of
the functional neurosurgery and epilepsy surgery program, and director of the NIHfunded laboratory for neurophysiology and neuromodulation.
For all our experts, see our website.
For more information, contact the Movement Disorders Program: 401-444-6528 | HIFU@lifespan.org | Lifespan.org
Focused Ultrasound What it is
Focused Ultrasound (FUS) is a recent neurosurgical technology that involves treating the deep brain in a single outpatient procedure without the need for a surgical incision. Specifically, the
technology uses ultrasound waves to create a small ablation to disrupt pathological brain activity to reduce the signs or symptoms of essential tremor and tremor-dominant Parkinson’s disease. How it works
FUS uses accurately focused beams of ultrasound energy to target and heat specific circuits
of the brain. The FUS procedure is conducted under near-real-time MRI visualization. A patient
reclines on the treatment bed, places their head into the FUS helmet and together, patient and
helmet, are positioned within the MRI scanner. The MRI can monitor the temperature of the target location while hundreds of ultrasound transducers in the helmet deliver highly focused energy to that target.
Initially, low energy is delivered to the target to disrupt abnormal brain activity in that circuit.
This allows the physician to receive feedback from the patient of any potential side effects and
adjust the target accordingly. When the tremor is reduced or eliminated, then the temperature is increased so that the target can be ablated by disrupting the circuit responsible for the tremor. The Archimedes Spiral Test – Before and After FUS Treatment
Before FUS
After FUS
Before undergoing FUS, patients are examined to decide their eligibility for this procedure. A CT scan prior to the procedure will allow us to determine whether it is safe to proceed with MRI-
guided FUS. Specifically, ultrasound energy does not travel well through air, the element that is
contained within the skull. If the skull is too thick, the energy cannot be focused accurately, which
makes some patients ineligible for this procedure. Another requirement, though temporary, is that patients must shave their heads for the procedure.
For more information, contact the Movement Disorders Program: 401-444-6528 | HIFU@lifespan.org | Lifespan.org