Tremor is a movement disorder that is manifested by involuntary rhythmic fluctuations in various parts of the body, arising from the stereotypically repeated contraction and relaxation of the muscles. Most often, hyperkinesis covers the hands, head, feet, severe trembling limits the physical, social and professional activity of patients. Diagnosis is based on anamnesis data, neurological examination, results of additional studies (laboratory tests, neurophysiological and neuroimaging methods). Tremor treatment involves eliminating the cause, symptomatic correction.
Trembling hyperkinesis is a common variant of involuntary movements. Although symptoms occur at any age, including childhood, higher rates are found in people over 65 years of age. The tremor is felt as a rhythmic trembling. It is often observed in the hands, resembling counting coins or rolling pills, but can also affect other parts of the body: the head (movements like “yes-yes” or “no-no”), torso, feet. Sometimes the chin, tongue, vocal cords are involved in the pathological process, which interferes with eating, disrupts the function of speech production.
An isolated tremor is not life-threatening, but violent movements make daily activities much more difficult. Hand trembling creates difficulty in writing, drawing, holding cutlery and other activities that require the participation of fine motor skills (dressing, manual labor). Tremor limits professional and social activity, creates psychological discomfort, and reduces the quality of life. Some types of hyperkinesis progress with time, accompanied by a neurological deficit, while others disappear with the elimination of the causative factor.
Tremor or trembling is a motor disorder, which in the structure of neurological syndromes refers to hyperkinesis. By origin, it is primary (essential) and secondary, which is a sign of the underlying disease, intoxication or the action of medications. Taking into account the etiopathogenetic features, two types of tremor are distinguished:
Considering the clinical and morphological features, there are slow (in the range from 3 to 5 Hz) and fast trembling (6-12 Hz), low- and high-amplitude (small or large-scale), intermittent or constant. An important criterion for systematization is the conditions of development, in accordance with which the tremor of rest and action (action) is distinguished. The latter has several varieties:
Topographic classification involves the division of tremor depending on localization. Focal affects only one anatomical zone (hand, head, soft palate, etc.), segmental covers adjacent areas (bibrachial), if several areas are affected, hemitremor is noted on one side, and involuntary movements throughout the body allow us to talk about generalized trembling. When making a diagnosis, the time of the first appearance of the symptom, family history, connection with the intake of certain substances are taken into account.
The most characteristic localization of trembling is the hands. Considering the physiological mechanisms of tremor development, note the ability to increase with muscle fatigue, hypothermia, the action of psychogenic factors (emotional upheaval, anxiety). The spectrum of pathological causes is very extensive - the main positions in it are assigned to essential tremor and Parkinson's disease, but there are many other conditions that can cause hand trembling:
The development of physiological tremor is largely due to mechanical factors - the weight of the limb, muscle tone, stiffness of the articular apparatus. The leading role in the formation of pathological trembling is occupied by changes in the central nervous system associated with the appearance of so-called tremor generators (central oscillators) with spontaneous or induced rhythmic activity. The second important point is the loss of control over voluntary movements from the cerebellar system.
Rhythmic nods and head turns are quite common, but usually enter the picture of mixed trembling, when involuntary motor acts cover several parts of the body. Often we are talking about parkinsonian (primary, secondary) or essential tremor. The following diseases are recognized as other causes of hyperkinesis:
Tremor of central origin is caused by damage to the neural ring of the extrapyramidal system, in which there are subcortical structures - basal, stem, cerebellar nuclei. An important place is given to changes in the striopallidar system, rubrospinal tract, and thalamic connections. Head trembling occurs in the pathology of the cervical spine, which is associated with impaired blood circulation, compression of the spinal nerves.
Trembling of the lower jaw can be an early symptom of Parkinson's disease or neuroleptic parkinsonism (rabbit syndrome). Tremor of the chin is due to other causes that require attention in the differential diagnosis. Increased alertness is traditionally caused by conditions characteristic of early childhood:
The physiological tremor of the neonatal period occurs against the background of crying, when undressing or getting the child out of the water, under the influence of fright, cold. Risk factors for damage to cerebral structures are infectious diseases, obstetric and somatic pathology in a pregnant woman. It is impossible to exclude the development of intoxication and withdrawal syndrome in a child when the mother uses psychoactive drugs.
Diagnostic search begins with the analysis of complaints, anamnestic information and neurological examination. To objectify the intensity of trembling allows the scale of the clinical assessment of tremor. If the syndromic diagnosis usually does not cause difficulties, then certain difficulties may arise with the nosological verification of the pathology. For differentiation, additional methods are used:
Cerebral vascular pathology is detected by transcranial ultrasound and angiography. The displacement of the median structures and the state of the ventricular system are visible on the echoencephalogram. It is possible to confirm the hereditary nature of some diseases with molecular genetic tests. Conditions accompanied by tremors are differentiated among themselves and with other hyperkinesias.
Treatment of tremor is designed to reduce the functional limitations and social maladaptation of patients. The basis of therapy is conservative methods, which are usually symptomatic. If a secondary tremor is detected, treatment involves the elimination of the causes of its occurrence, the correction of the underlying pathology. Among the therapeutic measures are used:
The ineffectiveness of conservative therapy is the reason for considering options for surgical treatment of tremor. In severe disabling forms, it is possible to implant electrodes in the ventrolateral thalamic or subthalamic nuclei, followed by deep brain stimulation with high-frequency electrical impulses. Promising methods are radiofrequency ablation, ultrasound or cryotalamotomy under MRI control.