What is essential tremor?
Essential tremor or familial essential tremor is a pathology of neurological origin with a progressive course. It is a movement disorder and is characterized by the patient suffering a rhythmic movement or tremor in hands, head, trunk, legs and can even affect the voice.
It is estimated that one in 20 people over the age of 40 and one in five people over the age of 65 may suffer from essential tremor. It usually affects people over the age of 40 to a greater extent, but can occur at any age.
There are two main types of essential tremor:
- Kinetic tremor: consists of a voluntary movement (bringing a food or object to the mouth, for example).
- Postural tremor: this is also a voluntary fixation but against gravity (extending the arms and holding them in that position, bringing a hand or arm closer…).
Essential tremor is often associated with Parkinson’s disease. This is, to some extent, justified, since motor symptoms are the main manifestations of Parkinson’s disease and one of the most common is tremor. However, the fact that the patient suffers involuntary tremors does not mean that he or she has Parkinson’s disease. In fact, it is important to keep in mind these differences between essential tremor and Parkinson’s disease:
- Tremor in Parkinson’s occurs when the person is at rest but in essential tremor develops when the person is in action or movement.
- In Parkinson’s other motor symptoms are associated: rigidity and slowness of movement.
- In Parkinson’s the tremor does not usually affect the head, in essential tremor it does.
Essential tremor presents with rhythmic movement in the hands, head, legs and even voice.
Prognosis of the disease
Essential tremor does not endanger the patient’s life, but it does alter it. Thus, sufferers lose the ability to do simple tasks that they used to do normally, such as going to work or driving.
Symptoms of essential tremor
The main characteristic of essential tremor is a rhythmic tremor that occurs during voluntary movements carried out by the patient, or also when trying to maintain a position in suspension, or against gravity. Most people with essential tremor have both postural tremor and kinetic tremor.
Medical tests for essential tremor
A physical and neurological examination should be performed, as well as the patient’s medical history. The physical examination will assess the tremor:
- Whether it occurs when the muscles are in action or at rest
- The location of the tremor (in what part of the body)
- How the tremor occurs (frequency and amplitude of the tremor).
Possible balance disturbances, speech abnormalities, increased muscle stiffness, etc., will also be evaluated in the neurological examination.
Additional tests can help determine the functional limitations of the patient. Thus, a common test for essential tremor is based on asking the patient to draw a spiral. In this way, the patient’s psychomotor skills are evaluated. Difficulty in handwriting or the ability or inability to hold certain objects, as well as exercises such as touching the tip of the nose with a finger also serve to assess the patient’s motor system impairment.
What are the causes of essential tremor?
Essential tremor is the consequence of abnormal communication between areas of the brain, including the thalamus, cerebellum and brainstem. A malfunction of the cerebellum is also related, according to some studies. However, the essential cause of essential tremor is unknown. In most cases essential tremor is hereditary. It is estimated that each child of a parent with essential tremor has a 50% chance of having the gene. However, not all people who inherit the gene (autosomal dominant inheritance) develop the disease.
Can it be prevented?
Essential tremor cannot be prevented. It is a neurological disease that appears without warning. What can be prevented is that it severely affects the patient’s life. This means that, as far as possible, the patient’s daily life can be adapted to make it as comfortable as possible for the patient. Thus, it is best to use solid objects that are easy to grasp and close tightly, and deep containers so that they are not filled to the brim and the contents can easily fall out. It is also preferable to place within reach of the patient objects that may pose a risk but that he/she uses on a daily basis, such as the telephone, microwave… Also, tremor is reduced if heavy objects with large handles are used. There are also other everyday objects that are already adapted and can be useful (cutlery or pens, for example), or the use of electric toothbrushes or Velcro, to close shoes more easily and make life easier for the patient.
Treatments for essential tremor
To date, there is still no treatment that can stop the progression of essential tremor or cure it. The goals of treatment for essential tremor will be to reduce the severity of symptoms and improve the functioning of the patient’s locomotor system. This will be combined with medication, usually antiepileptic, anticonvulsant and psychotropic medications with mild sedative or relaxant effect. If the patient does not respond well to medication and the symptoms make daily life difficult, deep brain stimulation and localized focal ultrasound have recently become popular. To these should be added the aforementioned measures to make the patient’s daily life more comfortable.
Which specialist treats it?
The specialist who treats essential tremor is the neurologist. Neurology is the specialty that studies, diagnoses, prevents and treats all diseases of the central nervous system (cerebellum, cerebrum, brain stem and spinal cord), as well as the peripheral nervous system (plexus, nerves, neuromuscular junction and muscles).