He Stereotyped movement disorder Is a disorder that appears in childhood and adolescence, in which the person performs movements of a peculiar nature that interfere with the life of the person and affect the personal and social environment.
To make it clearer about what this disorder is, I give an example of a girl case.
Mary's body is involved when it is aroused by something. At home, for example, when he sees a movie he likes, he often rubs and writhes his hands when he knows he will get the part of the film he likes best, or sometimes he reaches out, straight in front of her and draws on his Face in a happy smile, with wide eyes full of happiness.
He can twist his hands, spread his fingers and grimace dozens of times while watching the movie. But when someone asks what he is doing, he usually stops immediately. At school or in other environments where you are less relaxed and more aware of the reactions of others, you rarely rub your hands or grimace.
What are stereotypies?
The definition that best fits with what it implies is that of Sambraus who defines them as repetitive movements, which seem impulsive, have a rhythmic character and lack an objective and purpose to be addressed. They are individual and present temporally, with a very transient or persistent variation.
However, the definition of stereotypies is not as simple as it seems since it can be confused with other movement disorders.
Stereotypies in humans
Returning to the human species, it is important to take into account that non-pathological stereotypies can be produced by various causes such as mimicry, social isolation, when there are no stimuli in the environment, when the person is frustrated, when excitement or joy occurs...
Many of these behaviors appear at specific times of development, for example when the child reaches a new milestone in his development, such as learning to walk, saying his first word... These immature behaviors represent a step towards mature behavior, however When they last for a considerable time and acquire a pathological function, we speak of a greater degree of severity that affects the individual and causes discomfort.
Stereotypies may be present in various psychopathological disorders such as generalized developmental disorders such as autism , Asperger , Disintegrative disorder in childhood , Rett disorder , as well as Mental retardation . However, the referral disorder is stereotyped movement disorder.
Causes of Stereotyped Movement Disorder
As for theories that have attempted to explain the subject we can refer to a biological theory, whose self-destructive and stereotyped behaviors are a consequence of biological factors, normal or altered.
And to a behavioral theory, where the behaviors are classes of operated responses maintained by reinforcement. That is, stereotypical behavior may indicate the presence of something that stimulates them, that is to say, the behavior may be a complement to any other action that the subject makes, for example to relax.
A more complex aspect to understand is the fact that self-injurious behaviors are maintained. Some studies show that these can influence the release of Endorphins In the brain (neurotransmitters responsible for pleasant sensations).
Classification of Stereotyped movement disorder
The disorder of stereotyped movements is classified in different categories according to the reference manual that we handle, CIE, DSM-IV-TR and DSM-5.
With respect to the International Classification of Diseases, CIE classifies such disorder in behavioral disorder and emotions of habitual onset in infancy and adolescence, under the name of stereotyped motor disorders. The diagnostic criteria in the ICD are more stringent since the diagnosis of this disorder can not be made in the presence of any other disorder, with the exception of mental retardation. Another differential characteristic is that it requires a duration of one month of presence of stereotyped movements to diagnose the disorder.
With regard to the Diagnostic Manual of Mental Illness in its version 4, DSM-IV, locates the disorder of stereotyped movements within disorders normally diagnosed for the first time in childhood and adolescence, in the other category.
Finally, the Diagnostic Manual of Mental Illness, in its version 5, the most recent one, since it was published in the year 2014, makes an important change because it starts to denominate the disorders of initiation in the childhood, the childhood or the adolescence like disorders Of neurodevelopment. And, in this case, the disorder of stereotyped movements happens to fall into a broad category called motor disorders alongside others such as tics disorders and developmental coordination disorder.
Diagnostic categories DSM-5
With respect to the categories proposed by DSM-5 to diagnose the Stereotyped movement disorder , We find the following:
Criterion A . Repetitive motor behavior, apparently guided and without purpose (eg shaking or shaking hands, rocking the body, banging the head, wiggling, beating one's body).
Criterion B . Repetitive motor behavior interferes with social, academic, or other activities and can lead to self-harm.
Criterion C . It begins in the early stages of the development period.
Criterion D . Repetitive motor behavior can not be attributed to the physiological effects of a substance or neurological condition and is not best explained by another neurodevelopmental or mental disorder (eg, trichotillomania, obsessive-compulsive disorder).
The DSM proposes that it must be specified if it is with self-injurious behavior or behavior that would result in injury if preventive measures were not used. Or without self-injurious behavior.
In addition, it should be specified whether it is associated with a medical or genetic condition, a neurodevelopmental disorder or a known environmental factor such as, for example, Lesch-Nyhan syndrome , Intellectual disability and intrauterine exposure to alcohol.
Finally, the DSM-5 adds a new dimension regarding gravity. It is therefore possible to classify this disorder as to whether it is mild, moderate or severe.
- Mild : If the symptoms disappear easily through sensory stimulation or distraction.
- Moderate : If symptoms require explicit protective measures and behavior modification.
- Serious : If continuous monitoring and protective measures are necessary to prevent serious injury.
Self-injurious behavior varies in severity in different dimensions, such as frequency, impact on adaptive functioning, and severity of bodily injury (from mild bruises by hand shock to the body, through amputation of fingers to retinal detachment by Blows to the head.
It should be borne in mind that the presence of these stereotyped movements may indicate an undetected neurodevelopmental problem, especially in children 1 to 2 years of age.
Additional diagnostic features
The disorder of stereotyped movements, with or without self-injury, occurs in all races and cultures. In many, the presence of unusual behaviors are usually considered more normal, which can cause the diagnosis to be late.
Stereotyped movements are often rhythmic movements of the head, hands or body without obvious adaptive function. These movements may or may not be stopped, in children with neurodevelopmental disorders it is more complicated that they can control these movements, although in some cases children use strategies such as sitting on their hands, wrapping their arms in their clothes, or finding a protective object .
In children with normal development, movements can be stopped when the child heeds the movement or when distracted by the movement.
This varied repertoire of movements is particular to each individual. Some examples are given below.
As for stereotyped, non-self-injurious movements, they include: rocking the body, flapping or rotating movements of the hands, rapid movements of the fingers in front of the face, shaking or flapping the arms, as if they were birds and nods .
With regard to self-injurious stereotyped movements may be: repetitive blows to the head, slapping the face, biting hands, lips or other parts of the body and putting fingers in the eye, particularly worrisome as they are also commonly occur in children with disabilities visual. You can combine a multitude of movements such as tilting the head, rocking the torso, waving a rope in front of the face repetitively.
As for frequency and duration aspects, the DSM specifies that they can occur many times during the day or may vary several weeks between epidods. They can also last from a few seconds to several minutes.
The context in which they occur is also fundamental, since they are usually given when the individual is involved in other activities, with all the attention placed on them or when he is excited by some event, stressed, fatigued or bored.
Prevalence, development and course
With respect to the prevalence of the disorder must be taken into account if they are simple or complex stereotyped movements.
The simple ones occur in organic brain disorders such as cortical atrophy and arteriosclerosis , And have a stimulating function. For example they are movements of scratching, rubbing or far slapping. These movements are common in young children with normal development and may be involved in motor domain acquisition.
The complexes are those that occur in psychiatric disorders, and are striking and handsome movements of hands and arms (touch and play with objects, hair). For example, the rituals of Obsessive compulsive disorder Are stereotyped acts. These movements occur in 3-4% of the population. In addition, between 4 and 16% of the subjects with intellectual disability present stereotypies and self-injurious behaviors.
Studies have found that headbanding prevalence is more prevalent in males, and females are self-middling.
With regard to the onset of the disorder is known to appear normally in the first 3 years of life. Children with complex motor stereotypies, approximately 80% show symptoms before 2 years of age, 12% between 2 and 3 years and 8% at 3 years or later. The movements reach their maximum in the adolescence, and from this moment they can gradually decline.
In most children these movements reach their early resolution or are suppressed. However, in individuals with intellectual disabilities, stereotyped and self-injurious behaviors may persist for years, although the typography or pattern of self-harm may change.
Risk factors and prognosis
Among the risk factors and prognosis of this disorder can be mentioned those referring to the environment, or those genetic or physiological.
With respect to the environmental, several studies have agreed that social isolation is a risk factor for self-stimulation, and this may lead to stereotyped movements with repetitive self-harm in the future. It also refers to environmental stress and fear that can influence the triggering of these.
As for the genetic aspects, the low cognitive functioning can generate these movements. It is for this reason that they frequently appear in the intellectual handicapped as in the Down's Syndrome . However, they are more common in those with moderate, severe or profound intellectual disabilities. Self-injurious and repetitive behavior may be a behavioral phenotype in neurogenetic syndromes, such as Lesh-Nyhan syndrome, characterized by severe heart-murders.
Comorbidity
As I mentioned earlier stereotypies are a common manifestation of several neurogenetic disorders. When stereotyped movements coexist with another medical condition, the two disorders will have to be coded.
conclusion
Although this mental disorder is not as frequent as others that occur in childhood and adolescence, such as the presence of tics or learning difficulties, it is important to attend to these subjects, especially if the behaviors can become Self-injurious.
Therapeutic interventions of the conductive type, derived from the operant conditioning . These are intended for the realization of alternative entertainment activities, or others that keep people busy, or reducing the stress to which they are subjected by teaching problem-solving techniques.
Bibliography
- AMERICAN PSYCHIATRIC ASSOCIATION (APA). (2002). Diagnostic and Statistical Manual of Mental Disorders DSM-IV-TR . [Links]
- AMERICAN PSYCHIATRIC ASSOCIATION (APA). (2014). Diagnostic and Statistical Manual of Mental Disorders DSM-5 . [Links]
- ICD-10 (1992). Mental and behavioral disorders. London: Oxford University Press.
- Múñoz-Yunta, J.A., Palau-Baduell, M., Díaz, F., Aznar, G., Veizaga, J.G., Valls-Santasusana, A., Salvadó-Salvadó, B. and Maldonado, A. (2005). Pathophysiology of stereotypies and their relation to generalized developmental disorders. Revista Neurológica, 41 (suppl 1).
- Sambraus H.H. Stereotypies. In Fraser AF, ed. Ethology of farm animals. Amsterdam: Elsevier; 1985.