What is an Essential Tremor?

Jul 28

Essential tremor is a disorder of the nervous system that results in uncontrollable rhythmic shaking. It typically affects the hands and sometimes the head, but it can affect almost any part of the body. The tremor typically worsens with movement, such as using your hands to tie your shoelaces or pick up a glass. It is usually not a dangerous condition unless it becomes severely progressive. It can sometimes be confused with Parkinson’s disease. An essential tremor can occur at any age, but it typically is most common in people over the age of 40 (1).

How Common is Essential Tremor?

Essential tremor is the most common movement disorder, affecting an estimated 7 million people in the United States. The incidence increases with age. More than 4% of the population over the age of 40 has an essential tremor (2).

What Are the Early Signs of Essential Tremor?

The initial signs of essential tremor include:

Gradual rhythmic shaking of the body part, usually in the hands first

Tremor is usually made worse with movement and is minimal at rest
One hand is usually affected before the other
Can include a “yes-yes” or “no-no” motion of the head
Tremor can also affect head, voice, jaw or tongue
May be aggravated by fatigue, caffeine, low blood sugar, illness, emotional stress or drastic changes in temperature

Other types of tremors may be described by patients, such as postural tremor which emerges as they try to maintain a fixed position against gravity, or an internal tremor described as a feeling of shakiness within their bodies (2). They may also struggle to coordinate their leg movements while walking, making them appear clumsy, which is called ataxia.

What Are the Later Signs of Essential Tremor?

Later in the disorder, the tremor may be larger and more disruptive to daily life. It may affect both hands and move up the arm or may affect the head. The tremor may begin to be present at rest, as well as with movement. Other motor and non-motor symptoms may arise simultaneously with essential tremor, including cognitive impairment, changes to sense of smell, depression or anxiety (2). Unfortunately, essential tremor may have psychological and social consequences and they may attempt to avoid stressful or social situations out of anxiety and frustration.

What Causes Essential Tremor?

Essential tremor etiology is not as of yet fully understood. In most cases there appears to be a genetic mutation passed down in the family. Other times it affects a person who does not have any family history of the condition. First degree relatives of a person with an essential tremor are almost five times more likely than the general population to also develop a tremor (15).

The risk of passing the gene from parent to child is 50% for each pregnancy, despite sex of the child. Research is still being done to identify the specific genes on a pair of different chromosomes that seem to play a role in essential tremor (18).

Recent research is also demonstrating that it may be a neurodegenerative disorder affecting important cells of the cerebellum called Purkinje cells (3).

What is Going on in the Brain with Essential Tremor?

While essential tremor is the most common movement disorder in America, there is little understanding as to its cause and what exactly is taking place in the central nervous system. New research has demonstrated post-mortem that Purkinje cells, important cerebellar neurons involved in inhibiting excessive movement, may be degenerating to cause an essential tremor. This degeneration is likely due to a gene mutation, although it has not yet been determined which gene(s) are responsible (17).

Essential tremor may also involve dysfunction in circuits involving the basal ganglia (14). This system functions as the “gas and brake pedals” of the motor system, and is involved in turning on and off all forms of motor expression. These circuits are also highly reliant on GABA, so it makes sense that they would also be affected.

How is Essential Tremor Diagnosed?

A physician will take your medical history and perform a physical and neurological exam, looking at when the tremor occurs specifically (at rest or during movement), the location of the tremor and ask you additional questions about your tremor. Other systems that may be involved, such as balance, speech and tone of the muscles will also be assessed in this exam. Additional tests may also be ordered [4]:

Laboratory tests, testing the urine and blood to look for underlying causes that may be treatable.

Magnetic Resonance Imaging (MRI), which uses multiple magnets and radio-frequency impulses to curate a 3D image of the brain and underlying structures to identify possible areas of damage
Electromyogram (EMG), to assess involuntary nerve and muscle activity

How is Essential Tremor Usually Treated?

Some patients with a milder form may not require any treatment. Once patients experience disruption in their activities of daily living that are causing significant embarrassment, medication management is the first line of treatment in a general medical setting (16).

Purkinje cells in the cerebellum use the neurotransmitter GABA in order to modulate motor function and inhibit unwanted movement. This is likely why medications that improve GABA neurotransmission are somewhat successful at reducing essential tremors (3).

Botulinum toxin injections (Botox) are also offered to control muscle activity. They offer temporary paralysis of the muscle groups affected in head and voice tremor when other drugs have been ineffective (2). Repetitive treatments are required, as the effects of each treatment do wear off over time.

Deep brain stimulation of subcortical structures, specifically the thalamus, may be employed when medication and Botox are ineffective. DBS involves the surgical implantation of a device similar to a pacemaker, with a remote control that is kept external to the brain in order to control the amount of stimulation. Many individuals notice significant relief from their tremors following DBS treatment (7).

How Is the NeuroRescue Program Different?

While we cannot cure essential tremor, we employ a host of advanced therapies and technologies that can help improve the function of your remaining systems. By doing so, we can often help restore your mobility, reduce your tremor, improve your balance and gait, and enhance your quality of life.

Much of what happens in an essential tremor is likely related to dysfunction in the brain and cerebellum from two genetic mutations. The visual system is the most highly developed sensory system that we have as humans. We rely heavily on vision to track our environment, both voluntarily and reflexively. Therefore, the various types of eye movements that we generate utilize a large part of our cortical, subcortical, cerebellar and brainstem regions. Often the areas of degeneration will result in changes to eye movements being produced by those same areas (8).

In order for you to move through and interact with the world, you first need to know where the world is. We utilize fast eye movements called saccades to take in our visual environment quickly, shifting our gaze from one object to another. This requires that saccades are fast, accurate, stable, and have very quick reaction times. As the cortical and cerebellar regions are involved in saccades, all of these qualities break down with essential tremor. Saccades may become slow, lose accuracy, and are easy to fatigue (19). We find that by rehabilitating saccades in a very precise manner, we can often improve frequency and intensity of essential tremor by improving function of the specific regions of the brain that are unstable and degenerating.

There are a host of other therapies that we engage in with our essential tremor patients. All of these have different functions and allow us to rehabilitate specific capacities. These range from visual and vestibular rehabilitation to improve stimulation to the cerebellum and subcortical regions (5), to utilizing complex motor tasks with the affected limbs in order to rehabilitate cerebellar regions that are degenerating (11). Engaging your arm and leg in complex movement patterns can help with the cerebellum’s ability to refine movement and cognition. The cerebellum uses feed-forward mechanisms that allow it to create a framework for movement, and refine the framework in real-time (13). Repetition and progression of these complex movements can allow for a more effective filter of movement and cognition. We regularly see that by engaging these mechanisms we see improvement in tremor regulation.

Your NeuroRescue program will also include a number of different types of electrical stimulation to improve cognition, eye movements, balance, and other sensorimotor functions (9). They even include therapies such as transcranial magnetic stimulation to improve motor function and emotional regulation (6,7), and virtual reality exercises to improve the ability to function in the world and decrease tremor intensity and frequency, improving coordination and smoothness of movement (12).

No two essential tremor presentations are exactly alike, and the same holds true for the NeuroRescue program. A cookie-cutter approach will be doomed to fail in a condition as complicated as essential tremor. All of our therapy protocols are tailored to the unique needs of the individual.

How Does the NeuroRescue Program Work?

We design your unique NeuroRescue Program to be among the most comprehensive diagnostic and therapeutic protocols available today. We create individual NeuroRescue Programs based on a comprehensive analysis of every relevant neurological system and pathway, using gold-standard, cutting edge neurodiagnostic technologies and examination procedures and state-of-the-art therapies.

We begin with your Discovery Day, wherein we perform a comprehensive history of not only your condition, but your life on a timeline. This allows us to dive deeply into your case and see all of the factors that led to where you are now. It helps us uncover hidden problems and associated conditions that may be making it difficult for you to move your recovery forward.

Our examination allows us to identify the areas and pathways of your brain that have been impacted to cause your essential tremor. We begin by precisely quantifying the function of your visual, vestibular, and proprioceptive systems through computerized analysis of your eye movements, your inner ear reflexes, and your balance in a host of different sensory conditions.

We employ technologies including Videooculography and Saccadometry to measure several classes of eye movements. We use Video Head Impulse Testing to measure the function of your inner ear, and Computerized Dynamic Posturography to assess your balance in different sensory conditions.

We use NeuroSensoriMotor Integration testing to evaluate hand-eye coordination and cognition, and Virtualis testing to assess dynamic eye tracking and perception of vertical in a virtual reality environment.

We combine all of this with a comprehensive physical and neurological examination of your sensory, motor, autonomic, and cognitive systems. We review any relevant laboratory testing, radiological imaging, and prior neurodiagnostic testing, and integrate that information with our findings.

We use this information to identify which parts of your brain are working properly, which systems are struggling, and the precise point at which your systems fatigue.

We can then design a NeuroRescue Program that is unique and specific to your brain, and yours alone. Your NeuroRescue Program works to rejuvenate and reintegrate the damaged neurons and pathways in your brain. It works to improve energy, endurance, and functional capacity within your fragile systems.

We use our technologies and procedures to not only see what we need to address, but also when it is time to stop and let you rest. We address your impaired neurological function from multiple angles of therapy, and provide metabolic support to improve neurological recovery.

While we cannot bring back neurons that have been lost in this condition, your NeuroRescue Program allows us to take the pathways that remain and maximize their efficiency and endurance. And by focusing on the integration of systems, we can do more than just get pathways working better, we can get them working together again. This gives us our best opportunity to help you live a healthy, vibrant, and fulfilling life.

Your Next Best Step:

Living with an essential tremor can be challenging. While we cannot offer a cure for any genetic condition, we have been helping people get their essential tremors under control for decades. With appropriate diagnostics and specific therapies, in most cases symptoms can be managed, function can be enhanced, and quality of life can often be significantly improved.

To see if the NeuroRescue Program is right for you, contact one of our patient care coordinators to schedule your Discovery Day.

And remember, it’s never too late to start getting better.