Essential Tremor
Information on symptoms, the most effective treatments, and the prognosis of involuntary movement affecting certain muscles in the body.
Symptoms and Causes
Essential tremor is a neurological condition that causes involuntary oscillatory movements primarily in the hands, though it may also occur in the head or legs.
The involuntary movement characteristic of essential tremor may be of two types:
- Kinetic tremor: appears when attempting to perform a voluntary movement, such as picking up an object, writing, or scratching.
- Postural tremor: arises when trying to maintain a position against gravity, such as raising the arms.
Essential tremor is a degenerative disorder with no cure, but it does not usually pose a life-threatening risk. However, its effects significantly impact quality of life, as it interferes with activities of daily living such as eating, dressing, or writing.
Symptoms
The involuntary oscillatory and rhythmic movement is the main symptom of essential tremor. Unlike Parkinson’s disease— with which it is often confused— the tremor appears when the patient attempts to move, not at rest. It typically occurs in the hands, head, legs, or voice. These shakes may worsen when the patient feels observed, is in a situation of emotional stress, is fatigued, or has consumed stimulants such as caffeine or alcohol.
Other common symptoms include balance problems and difficulty swallowing.
Causes
The exact causes of essential tremor are unknown. Some research suggests it may be related to improper functioning of the part of the brain responsible for controlling muscle movements.
Risk Factors
The following factors increase the risk of developing essential tremor:
- Age: more common after age 40.
- Family history: familial essential tremor is inherited in an autosomal dominant pattern.
- Stress.
- Anxiety.
- Excessive consumption of caffeine, nicotine, or alcohol.
- Extremely hot weather.
- Certain medications.
Complications
The most common complications of essential tremor are:
- Difficulty speaking.
- Problems performing daily tasks (eating, writing, driving, working, dressing).
- Social isolation.
- Depression.
Prevention
Essential tremor cannot be prevented.
What specialist treats essential tremor?
Essential tremor is diagnosed and treated within the specialty of neurology, with involvement of neurosurgery in certain cases.
Diagnosis
The diagnosis of essential tremor is primarily clinical, as evaluating symptoms, reviewing the patient’s medical history, and performing a physical examination are usually sufficient.
Additional tests (blood tests, thyroid function tests, magnetic resonance imaging, or neurophysiological studies) are typically performed to rule out other conditions.
Treatment
Essential tremor has no cure, so treatment focuses on slowing its progression and reducing symptoms. The most effective options include:
- Medications to control the tremor, such as anticonvulsants or beta-blockers.
- Botulinum toxin injections to relax the muscles.
- HIFU (High-Intensity Focused Ultrasound): high-intensity ultrasound is applied to a targeted point in the brain, guided by magnetic resonance imaging. This is a non-invasive approach applied directly to neurons involved in involuntary movement.
- Deep brain stimulation: a surgical intervention typically used in patients with severe disability. Electrodes are placed in a specific brain region and connected to an electrical pulse generator implanted in the chest. The electrical stimulation restores the function of the impaired neural circuits, thereby alleviating the tremor.
