Movement disorders are a set of pathologies characterized by the reduction, loss or excessive presence of bodily movements that seriously affect the quality of life of people who suffer from them.
In this article we tell you what they are, what types of movement disorders exist and what is their treatment.
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 shape and speed of body movements, Without directly affecting the strength, sensation or function of the brain.
These types of disorders can be caused by diseases, genetic conditions, drugs, or other factors. In addition, 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 history of stroke and the presence of cardiovascular risk factors, such as high blood pressure or diabetes, may increase the risk of developing a circulation-related movement disorder.
Types of movement disorders
From a clinical point of view, two major groups of movement disorders can be differentiated: Hypokinetics, characterized to present / display slow or diminished movements; and hypercinetics, which is characterized by excessive movement or the presence of abnormal involuntary movements.
Hypokinetic movement disorders
Movement disorders or hypokinetic syndromes include all movement pathologies in which it becomes impoverished and slows down, affecting the associated voluntary and spontaneous movements.
The most common hypokinetic disorder is called Parkinson’s syndrome, Which consists of an alteration in the functioning of the cortico-subcortical motor circuit responsible for the proper generation of bodily movements. This syndrome has several common symptoms, such as bradykinesia, tremors, and stiffness.
In bradykinesia, a slowdown in the motor occurs early; then, in the accomplishment and completion of the voluntary movement, repetitive or alternating movements of the limbs take place, observing a progressive decrease in speed and amplitude.
Three components can be distinguished in bradykinesia: motor slowing or bradykinesia itself, akinesia or poor spontaneous movements (delayed initiation of movement or change between fluid movements) and hypokinesia, which consists of into a decrease in range of motion.
As for tremors, the most characteristic of hypokinetic movement disorders is at rest, at 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 common. However, there may be Parkinson’s syndrome with no sign of tremors.
Finally, we speak of stiffness to resistance which opposes a part of the body to passive mobilization. In Parkinson’s syndromes, it can present as a cogwheel, where brief episodes of opposition appear alternating with episodes of relaxation.
It can also manifest as a constant resistance, called a lead tube, in which the intensity of the resistance remains constant throughout the range of motion, whether extended or flexed (without changing depending on how fast it is. varied). The part of the body is mobilized, 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, ballismus, athetosis, myoclonus and dystonia. Let’s see what each of them consists of.
Tics are stereotypical movements with no specific purpose, Which are repeated irregularly. They are characterized because they can be suppressed on purpose and increased with factors such as stress or anxiety. They can be classified into primary tics (sporadic or hereditary) and secondary, motor and vocal, simple and complex.
The most serious form of multiple tics is known as Gilles de la Tourette syndrome, An autosomal dominant inherited disorder associated with defects on chromosome 18. This disorder manifests itself by multiple motor tics and one or more phonic tics. These tics occur several times a day, almost every day for more than a year. Their severity and complexity may vary over time.
To treat this type of abnormal movement, such as tics, pharmacological treatment with neuroleptics, clonidine and anti-dopaminergic drugs is usually necessary.
Korea is a movement disorder that refers to arrhythmic, irregular, rapid, uncoordinated and continuous movements affecting any part of the body.
The causes of this movement disorder are multiple and infrequent: hereditary (Huntington’s disease, neuroacanthocytosis, Fahr syndrome, etc.), metabolic and endocrine (hyperparathyroidism, hyperthyroidism, etc.), by vasculitis (eg: systemic lupus erythematosus) , due to stroke the basal ganglia 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 the ages of 40 and 50, slowly progressing to death over a period of 10 to 25 years. Survival is shorter in patients with a juvenile onset of the disease.
Pneumonia and another series of intercurrent infections are often the most common cause of death. Almost all patients with Huntington’s disease have a family history. It is an inherited disease with an autosomal dominant character and complete penetrance, which results from a genetic defect on chromosome 4. This disease begins at earlier ages in successive generations.
Ballism is a severe form of Korea which it produces sudden and involuntary movements of great amplitude. It usually appears suddenly but can develop over several days or even weeks. This movement disorder usually goes away during sleep.
Ballistic movements are so violent that they can lead to death from exhaustion or cause injury to the joints or skin of the sufferer. It is common to affect a hemibody (hemibalism), although it can sometimes affect only one limb (monobalism), the lateral and lower limbs (parabalism) or, in more rare cases, all four limbs ballism. lateral).
Athetosis is a movement disorder that it occurs in a quarter of cases of cerebral palsy. This disorder is caused by damage to the extrapyramidal system and manifests itself in slow, uncontrolled, involuntary and aimless movements.
The muscles of the mouth are affected, which is why patients with athetosis often have speech difficulties. It can also occur as an abnormal reaction to estrogen or certain antidepressant drugs.
Myoclonus consists of involuntary, sudden and brief movements, caused by active muscle contraction or sudden inhibitions in muscle tone. They can be classified, according to their origin, into: cortical, subcortical, spinal or peripheral.
By their distribution, they are classified into focal (involving a discrete muscle group), segmental or generalized (generally of progressive cause and associated with seizure disorders). And because of their presentation, they can be spontaneous myoclonus, action or reflex.
These types of movement disorders occur involuntarily and over time, and they produce a deviation or twist of an area of the body. The person who suffers from them cannot eliminate them on purpose and they occur due to specific movements or actions.
They are usually removed during sleep. It is common for them to side with other movement disorders such as essential tremors. There is also a “dystonic tremor,” which occurs when the patient tries to move part of their body in the opposite direction to the force of the dystonia.
Movement disorders should be treated based on their etiology and severity. One of the treatments applied is deep brain stimulation, Which greatly reduces involuntary movements. This is caused by the generation of electrical impulses in the brain, with the patient adjusting the intensity of the impulse to control their symptoms.
Another treatment that has been used in these cases is guided nuclear magnetic resonance ultrasound (MRgFUS), a procedure that uses beams of sound energy to remove a small volume of brain tissue without affecting adjacent areas.
Use of drugs in therapy
Sometimes medications are also used to relieve symptoms, including:
1. Beta blockers
These are drugs that lower blood pressure, So that shock and other physical symptoms of many movement disorders are reduced.
these drugs they are used to reduce tremors (For example, in Parkinson’s syndromes), especially those produced in the hands.
These drugs are used to treat dystonias by reducing the effects of acetylcholine, a neurotransmitter involved in muscle contractions, causing less tremors and stiffness.
Anxiolytics act on the central nervous system causing muscle relaxation, Which relieves, in the short term, the effects of shocks and spasms.
5. Botulinum toxin
This toxin works by blocking the neurotransmitters responsible for muscle spasms, helping to stop them.
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- Leon-Sarmiento FE, Baiona-Prieto J, Cadena Y. Neural plasticity, neurorehabilitation and movement disorders: the change is now. Act Neurol Col 2008; 24: 40-42.