What are tics?
The nervous tics are gestures or repetitive and involuntary movements that are produced as consequence of the contraction of one or several muscles of the body, and that normally affect the face.
All the tics have in common that they are convulsive and excessive movements that are diminished if the person manages to be distracted or by an effort of will.
The tics are more frequent in children of between 8 and 12 years, and usually disappear in the adolescence. But there are also tics that affect adults.
Types of tics
According to the duration of the movement they can be:
- Clonic tics, which are fast and short.
- Dystonic tics, which are slow and last more.
- Tonic tics, which are manifested with isometric contractions but are not accompanied by movements.
According to the zone of affectation they can be motor or phonic, besides being able to be simple and complex:
- Motor tics are movements that affect some specific muscle groups. In the simple motor tics only one muscle is involved, they last milliseconds and usually affect the face. Examples: eye movements, of lips or neck, mandibular, insistent blinking… The complex motor tics affect a group of isolated muscles, last seconds and the repetitive movements are more complex: to incline the neck while the shoulders are raised, jerks, small sounds, intentional movements (to touch people, to smell objects, to imitate gestures…).
Involuntary sounds affecting the laryngopharyngeal musculature are phonatory tics, which can be:
- Simple vocal tics, involving brief and meaningless noises and sounds, such as blowing, clicking or coughing.
- Complex vocal tics, which involve more complex expressions with meaning, such as swearing or imitating phrases.
Prognosis of the disease
Although tics, in most cases, do not correspond to a serious problem and can be treated as long as the patient is aware of them, sometimes they can reflect primary neurological diseases or constitute symptoms of systemic diseases.
Thus, some patients have isolated cases of motor or phonic tics, but most of them also develop neuropsychiatric disorders, such as obsessive-compulsive disorder, attention deficit, autistic behaviors, as well as depression and anxiety.
Symptoms of tics
The tics are manifested with involuntary, exaggerated, repetitive movements or sounds and, depending on the case, a little out of context.
There are premonitory sensations that affect the zone where the tic will take place, and for that reason it is not known to certainty if the tics are voluntary or not. During a time the person suffers tension or slight pain in the zone, and sees the necessity to release it, making the tic. In doing so, the person feels a certain relief for “getting rid” of this tension. Nevertheless, these premonitory sensations are not always felt, and the tics will only be able to be suppressed if one is conscious of the situation.
The tics that become chronic are characterized by the presence of one or more motor or vocal tics (not both), that last more than one year. In these cases a Tourette’s Syndrome can be associated.
Medical tests for tics
Tics develop along a spectrum, and can range from mild, transient or chronic, to severe.
It should be noted that tics are more common in children and, when they occur in adults, are sometimes related to secondary agents, such as the influence of drugs or encephalitis. The history and examination of the types of tics can help in the diagnosis and study. On the other hand, the specialist must distinguish tics from other movement disorders, such as dystonia, chorea or myoclonus, as well as other movements that are associated with psychiatric pathologies, such as mannerisms, convulsions or stereotypies.
Thus, in order to obtain an accurate diagnosis, genetic conditions and the type of tic performed must be taken into account, since it can be related to pathologies: Duchenne muscular dysphrophy, Huntington’s disease, Sydehham’s chorea, idiopathic dystonia, Down Syndrome and Fragile X Syndrome, among others.
The study of the tics, in addition, will include studies of cerebral image, to discard anomalies, and also a magnetic resonance.
Which are the causes of the tics?
Although the causes are not totally known, recent studies reveal that many areas of the brain can be implied. Hence, tics can express certain disorders.
Also, it is believed that tics arise from the cortico-striatal-thalamo-cortical circuits, as a result of the alteration of the nuclei in the basal ganglia, and hence interact with sensory, motor neuronal, limbic and executive networks. It is this alteration that causes different types of abnormal movements to manifest themselves during the evolution of tic.
Can it be prevented?
It is difficult to prevent the tics. In the cases of children, as it has been mentioned, they can be transient.
Treatments for the tics
There are some trainings of habits that help the person who suffers the tics, as well as to make trainings of relaxation and teamwork, helping the person to be conscious of it.
The specific treatment will depend on the severity and frequency of the tic in the person, and the most advisable would be to try to modulate the stressors. In case treatment is necessary, it can be distinguished in:
- Pharmacological treatment, with drugs that counteract anxiety and that includes: classic neuroepiletics (haloperidol and pimocide), a2-adrenergic agonists (clonidine and guanfacine), benzodiazepines (clonazepam), atypical neuroepileptics (risperidone, aripiprazole, olanzapine and ziprasidone), and botulinum toxin.
- Motor treatment with exercises of muscular distension to reduce the motor instability that is associated with some tics.
- Psychotherapeutic treatment, with the objective to reduce the anxiety and to improve the control of the tics. The cognitive behavioral therapy offers good results at the moment.
Which specialist treats it?
The tics are normally treated by the specialist in Neurology, but also the specialists in Psychiatry and in Infantile and Adolescent Psychiatry can treat them.