Essential Tremor

What is an Essential Tremor?

The medical term “Essential Tremor” refers to a nervous system (neurological) disorder that causes involuntary and rhythmic shaking in different parts and on different sides of the body ¹. This can affect almost any part of the body, but trembling mostly occurs in the hands and forearms. In rare cases, tremors can occur in the legs and feet.

This progressive neural disorder can occur at any age but most prevalent in people age 40 and older. According to the journal Tremor and Other Hyperkinetic Movements, approximately 10 million people in the United States suffer from essential tremors ². Tremor itself usually not a life-threatening condition unless this keeps someone from caring for themselves. The continuous shaking makes the patient’s daily activities, such as eating and drinking, difficult.

Signs and symptoms of essential tremors begin gradually and usually more prominent on one side of the body. This condition becomes worse with movement. The main symptoms of essential tremors include nodding head, shaking voice, uncontrolled shaking for a period of time, balance problem, a “yes-yes” or “no-no” motion of the head, etc. Tremors can range from minor to severe. Certain factors that make tremors temporarily worse may include emotional stress, fatigue, hunger, caffeine, smoking cigarettes, or temperature extremes.

The exact cause of the essential tremor remains unknown. Scientists reported that almost half of essential tremor cases occur due to genetic mutation, called familial tremor. This condition may result from alcohol abuse, overactive thyroid, stroke, and a variety of neurological conditions. The National Institute of Neurological Disorders and Stroke (NINDS) stated that the essential tremor triggers by changes in certain areas of the brain ³. The risk factors of essential tremors include Parkinson’s disease, multiple sclerosis, fatigue after exercise, brain tumors, metabolic problem, genetic mutation, older age, etc.

How do Neurosurgeons Diagnose Essential Tremor?

The initial diagnosis of an essential tremor involves a brief medical history, family history, symptoms, physical examination, and a complete neurological exam of patients ⁴. Neurological examination may reveal the tendon reflexes, muscle strength, posture, and coordination, gait pattern, etc. Other laboratory tests such as blood and urine tests help to differentiate between thyroid disease, metabolic problems, etc. Sometimes, physicians may ask to drink from a glass, write, draw a spiral, and hold the arm outstretched to evaluate the performance of the patient. A dopamine transporter scan helps to differentiate between the essential tremor and Parkinson’s disease.

How do Neurosurgeons Treat Essential Tremor?

Not all individuals with essential tremors require treatment, but patients with severe symptoms need proper guidelines for upgrading their condition. Treatment of essential tremors includes medications, therapy, and surgery. Although, the progression of tremor symptoms becomes slow and gradual. Treatment options for essential tremor may include ⁵:

1. Medication: Oral medications can make essential tremor symptoms less severe. Medications may include beta-blockers, anti-seizure medications, tranquilizers, etc. to relieve the symptoms of tremors. Beta-blockers like propranolol limits adrenaline and prevent tremors from getting worse. Anticonvulsant medications like primidone also help to reduce the excitability of nerve cells.
2. Therapy: Doctors may suggest physical therapy to improve muscle strength, control, and coordination. Occupational therapy also helps the patient to adapt to essential tremors. Therapists also suggest using adaptive devices to reduce the effect of tremors on daily activities, such as wrist weight, wide-grip pens, heavier glasses, and utensils, etc.
3. OnabotulinumtoxinA (Botox) injections: Botox injection also helps to treat some types of tremors, especially head and voice tremors. This injection can improve tremors for up to three months at a time.
4. Surgery: Surgical treatment for this condition includes deep brain stimulation, focused ultrasound thalamotomy, MRI-guided focused high-intensity ultrasound, stereotactic radiosurgery, etc. Direct contact with the physicians may help to select the best option for the patient.

References

1. Benito-León, J. & Louis, E. D. Essential tremor: Emerging views of a common disorder. Nat. Clin. Pract. Neurol.2, 666–678 (2006).
2. Louis, E. D. ‘essential Tremor Plus’: A Problematic Concept: Implications for Clinical and Epidemiological Studies of Essential Tremor. Neuroepidemiology 54, 180–184 (2020).
3. Sepúlveda Soto, M. C. & Fasano, A. Essential tremor: New advances. Clin. Park. Relat. Disord. 3, 100031 (2020).
4. Pahwa, R. & Lyons, K. E. Essential tremor: Differential diagnosis and current therapy. Am. J. Med. 115, 134–142 (2003).
5. De Albuquerque, A. V. Essential Tremor. Rev. Neurociencias 18, 401–405 (2010).