The 7 types of movement disorders: characteristics and symptoms

Movement disorders are a group of pathologies that are characterized by the decrease, loss or loss of presence in excess of body movements that seriously affect the quality of life of the people who suffer.

In this article we explain what they are, what types of movement disorders exist and what is their treatment.

• Related article: "The 15 most common neurological disorders"

What are movement disorders?

Movement disorders include a group of disorders in which the regulation of motor activity deteriorates and there are alterations in the form and speed of body movements, without directly affecting cerebellar strength, sensation or function.

These types of disorders can be caused by diseases, genetic conditions, medications, or other factors. Furthermore, a movement disorder may be the only clinical expression of a specific disease or may be part of a set of neurological manifestations of more complex diseases.

The risk of developing a movement disorder increases with age. A previous history of stroke and the presence of cardiovascular risk factors, such as having blood pressure high blood pressure or diabetes can increase the risk of developing a circulation-related movement disorder.

Types of movement disorders

From a clinical perspective, two large groups of movement disorders can be differentiated: hypokinetic, characterized by presenting slow or diminished movements; and hyperkinetics, which are characterized by excessive movements or the presence of involuntary abnormal movements.

Hypokinetic movement disorders

Movement disorders or hypokinetic syndromes include all those pathologies of the movement in which it is impoverished and slowed down, affecting voluntary and spontaneous movements associates.

The most common hypokinetic disorder is the so-called parkinsonian syndrome, which consists of an alteration in the functioning of the cortico-subcortical motor circuit in charge of correctly generating body movements. This syndrome has several common symptoms, such as: bradykinesia, tremors, and stiffness.

In bradykinesia, motor slowing occurs at the beginning; later, in the realization and completion of the voluntary movement, movements occur repetitive or alternating limbs, observing a progressive reduction in speed and amplitude.

Three components can be distinguished in the bradykinesia: motor slowing down or bradykinesia itself, akinesia or poor spontaneous movements (with delay in initiation movement or the change between fluid movements) and hypokinesia, which consists of a decrease in the amplitude of movement.

Regarding tremors, the most characteristic in hypokinetic movement disorders is that of rest, of low frequency (between 3 and 6 hz). This tremor usually appears when the muscles have not been activated and decreases when performing a specific action. There may also be an action tremor, but it is less frequent. However, there may be a parkinsonian syndrome without evidence of tremors.

Finally, stiffness is the resistance that a part of the body opposes to passive mobilization. In parkinsonian syndromes it can appear in the form of a cogwheel, where brief episodes of opposition appear alternated with episodes of relaxation.

It can also be manifested by a constant resistance, called lead tube, in which the intensity of the resistance remains constant throughout the range of motion, whether extended or flexed (not changing by varying the speed with which the body part moves, as opposed to spasticity).

Hyperkinetic movement disorders

Hyperkinetic movement disorders are those in which there is an excess of abnormal and involuntary movements. The main forms are: tics, chorea, ballism, athetosis, myoclonus and dystonia. Let's see what each of them consists of.

1. Tics

Tics are stereotyped movements, without a specific purpose, which are repeated irregularly. They are characterized because they can be voluntarily suppressed and increase with factors such as stress or anxiety. They can be classified into primary (sporadic or hereditary) and secondary, motor and vocal, simple and complex tics.

The most serious form of multiple tics is known as Gilles de la Tourette Syndrome, an autosomal dominant inherited disorder, associated with defects in chromosome 18. This disorder manifests with multiple motor tics and one or more phonic tics. These tics occur several times a day, practically every day for more than a year. Their severity and complexity can vary over time.

To treat this type of abnormal movements, such as tics, a pharmacological treatment based on neuroleptics, clonidine and antidopaminergic drugs is usually necessary.

• You may be interested: "Tourette syndrome: causes, symptoms, diagnosis and treatment"

2. Koreas

Chorea is a movement disorder that refers to arrhythmic, irregular, rapid, uncoordinated and continuous movements that affect any part of the body.

The causes of this movement disorder are multiple and rare: hereditary (Huntington's disease, neuroacanthocytosis, Fahr's syndrome, etc.), metabolic and endocrine disorders (hyperparathyroidism, hyperthyroidism, etc.), from vasculitis (for example, systemic lupus erythematosus), due to basal ganglia stroke and pharmacological.

Huntington's disease is the most common type of inherited chorea. It can start at any age, although it has a higher incidence in people between 40 and 50 years old, slowly evolving towards death in a period ranging from 10 to 25 years. Survival is shorter among patients with juvenile onset of the disease.

Pneumonia and a series of breakthrough infections are usually the most common cause of death. There is a family history in almost all Huntington's disease patients. It is an inherited disorder with an autosomal dominant character and complete penetrance, and is the result of a genetic defect on chromosome 4. This disease makes its debut at an earlier age in successive generations.

3. Ballism

Ballism is a severe form of Korea that produces sudden, involuntary movements of a great amplitude. It usually appears suddenly but can develop over days or even weeks. This movement disorder usually subsides during sleep.

The movements of ballism are so violent that they can lead to death from exhaustion or cause joint or skin injuries in the person who suffers it. It is common to affect a half body (hemibalism), although sometimes it can only affect one limb (monobalism), to both lower limbs (parabalism) or, in rarer cases, to the four extremities (bibalism or ballism side).

4. Athetosis

Athetosis is a movement disorder that occurs in a quarter of cerebral palsy cases. This disorder is caused by injuries to the extrapyramidal system and manifests itself in slow, meandering, uncontrolled, involuntary movements without a specific objective.

The muscles of the mouth are affected, and that is why patients with athetosis often have language disorders. It can also occur as an abnormal reaction to estrogens or some antidepressant drugs.

5. Myoclonus

Myoclonias consist of brief, jerky, involuntary movements, caused by active muscle contraction or sudden inhibitions of muscle tone. They can be classified, according to their origin, into: cortical, subcortical, spinal or peripheral.

Due to their distribution, they are classified as focal (involving a discrete muscle group), segmental, or generalized (generally progressive in origin and associated with epileptic disorders). And due to their presentation, they can be spontaneous, action or reflex myoclonus.

6. Dystonias

These types of movement disorders occur in an involuntary and sustained way, and produce a deviation or twisting of an area of ​​the body. The person who suffers from them cannot voluntarily eliminate them and they occur due to specific movements or actions.

They are generally suppressed during sleep. It is common for them to occur together with other movement disorders such as essential tremors. There is also a "dystonic tremor", which arises when the patient tries to move a part of his body in the opposite direction to the force of the dystonia.

Treatment

Movement disorders should be treated based on their etiology and severity. One of the applied treatments is deep brain stimulation, which significantly reduces involuntary movements. This occurs by generating electrical pulses in the brain, with the patient himself adjusting the intensity of the impulse to control his symptoms.

Another treatment that has been used in these cases is nuclear magnetic resonance guided focused ultrasound (MRgFUS). English), a procedure that uses beams of sound energy to remove a small volume of brain tissue without affecting areas adjacent.

Use of drugs in therapy

Sometimes drugs are also used to alleviate symptoms, including:

1. Beta-blockers

They are drugs that lower blood pressureso that the shaking and other physical symptoms of many movement disorders are reduced.

2. Antiepileptics

These drugs are used to reduce tremors (for example, in parkinsonian syndromes), especially those produced in the hands.

3. Anticholinergics

These drugs are used to treat dystonia by reducing the effects of acetylcholine, a neurotransmitter involved in muscle contractions, causing a decrease in tremors and rigidity.

4. Anxiolytics

Anxiolytics act on the central nervous system causing muscle relaxation, which relieves, in the short term, the effects of shaking and spasms.

5. Botulinum toxin

This toxin works by blocking the neurotransmitters responsible for muscle spasms, helping to stop them.

Bibliographic references:

• Jankovic J. Treatment of hyperkinetic movement disorders. Lancet Neurol 2009; 8: 844 - 856.
• Leon-Sarmiento FE, Bayona-Prieto J, Cadena Y. Neural plasticity, neurorehabilitation and movement disorders: the change is now. Act Neurol Col 2008; 24: 40 - 42.