Essential tremor

Essential tremor

Definition  :

Essential tremor is a disorder of the nervous system that causes a rhythmic shaking. Essential tremor can affect almost any part of your body, but the trembling occurs most often in your hands — especially when you try to do simple tasks, such as drinking from a glass, tying shoelaces, writing or shaving. Essential tremor also may affect your head, voice, arms or legs.

Although usually not a dangerous condition, essential tremor worsens over time and can be severe in some people. It isn't caused by other diseases, although it's sometimes confused with Parkinson's disease. Essential tremor can occur at any age but is most common in older adults.

Symptoms:

Essential tremor signs and symptoms:

• Begin gradually
• Worsen with movement
• Usually occur in the hands first, affecting one hand or both hands
• Can include a "yes-yes" or "no-no" motion of the head
• Are aggravated by emotional stress, fatigue, caffeine or extremes of temperature

Essential tremor vs. Parkinson's disease
Many people associate tremors with Parkinson's disease, but the two conditions differ in key ways:

• When tremors occur. Essential tremor of the hands typically occurs when you use your hands. Tremors from Parkinson's are most prominent when your hands are at your sides or resting in your lap.
  
• Associated conditions. Essential tremor doesn't cause other health problems, whereas Parkinson's is associated with a stooped posture, slow movement and a shuffling gait. However, people with essential tremor may sometimes develop other neurological signs and symptoms — such as an unsteady gait (ataxia).
  
• Parts of body affected. Essential tremor can involve your hands, head, voice and legs. Tremors from Parkinson's typically affect your hands but not your head or voice.

Causes:

 About half of essential tremor cases appear to occur because of a genetic mutation. This is referred to as familial tremor. What causes essential tremor in people without a known genetic mutation isn't clear.

Complications:

Essential tremor is not life-threatening, but symptoms often worsen over time. If the tremors become severe, you may find it difficult to:

• Hold a cup or glass without spilling
• Eat normally
• Put on makeup or shave
• Talk, if your voice box or tongue is affected
• Write — handwriting may become increasingly large, shaky and illegible

Treatments and drugs:

Some people with essential tremor may not require treatment if their symptoms are mild. But if your essential tremor is making it difficult to work or perform daily activities, you may want to discuss treatment options with your doctor.
Medications

• Beta blockers. Normally used to treat high blood pressure, beta blockers — such as propranolol (Inderal), atenolol, metoprolol and nadolol — help relieve tremors in some people. They may not be an option if you also have asthma, diabetes or certain heart problems.
  
• Anti-seizure medications. Epilepsy drugs — including primidone (Mysoline), gabapentin (Neurontin) and topiramate (Topamax) — may be effective in people who don't respond to beta blockers. The main side effects are drowsiness and flu-like symptoms, which usually disappear within a short time.
  
• Tranquilizers. Doctors sometimes use drugs such as diazepam (Valium) and alprazolam (Xanax) to treat people whose tremors are made much worse by tension or anxiety. Side effects can include confusion and memory loss. Additionally, these medications should be used with caution because they can be habit-forming.
  
• OnabotulinumtoxinA (Botox) injections. You're probably familiar with Botox as a treatment for facial wrinkles, but it can also be useful in treating some types of tremors, especially of the head and voice. Botox injections can improve problems for up to three months at a time. But if it's used to treat hand tremors, it can sometimes cause weakness in your fingers.

Therapy
Physical therapy exercises can sometimes reduce tremor and improve coordination and muscle control. Occupational therapists may suggest some of the following adaptive devices to reduce the effect of your tremors on your daily activities:

• Heavier plates, glasses and utensils
• Wrist weights
• Wider writing implements

Surgery
Surgery may be an option for people whose tremors are severely disabling and who don't respond to medications. The type of surgery performed is known as deep brain stimulation.

Deep brain stimulation involves inserting a long, thin electrical probe into your thalamus — the portion of your brain responsible for causing your tremors. A wire from the probe is tunneled under your skin to your chest, where a pacemaker-like device has been inserted. This device transmits painless electrical pulses to interrupt signals from your thalamus that may be causing your tremors.

Side effects of surgery may include problems with motor control or speech, problems with balance and temporary or permanent cognitive impairment, such as learning difficulties, or problems with your vision. Deep brain stimulation, however, is very effective for severe essential tremor, and these side effects are rare.