Head tremors are uncontrolled rhythmic movements caused by alternating contractions of the antagonist muscles of the neck. Trembling looks like nodding or shaking the head, occurs at rest, when moving or maintaining a posture. The cause of tremor is various pathologies with damage to the extrapyramidal, cerebellar, cortical sections of the regulation of motor functions. Diagnosis is carried out by laboratory, neuroimaging, neurophysiological methods. Treatment is carried out with medications, in resistant cases, botulinum therapy or surgery is offered.
A characteristic sign of cervical muscular dystonia associated with a violation of the tone of the muscles of the neck is an isolated tremor of the head. It occurs when maintaining a stationary position or at the beginning of a motor act (postural-kinetic), has a frequency below 7 Hz and a different amplitude. In some patients, trembling is also present at rest. Dystonic tremor increases when turning and tilting the head in the opposite direction from the affected muscles. Performing reverse movements or corrective gestures by the patient (touching the chin) leads to the disappearance of trembling.
Among the causes of head tremor, one of the main places is occupied by an essential process. Benign trembling, the mechanism of which remains unknown, can begin at any age. The disease debuts with a tremor of the hands, the head is involved later. Symmetric tremor in essential tremor is postural in nature or increases during movement, especially at its end point (terminal). The tremor of the head increases with excitement, has the form of nodding (“yes-yes”) or rocking (“no-no”) movements.
The frequency of jitter in different patients ranges from 6 to 1 Hz. Over time, a rest tremor may join, which is especially pronounced in the sitting position, but does not disappear with the onset of movement, being a continuation of the postural one. Other neurological disorders in essential tremor are usually absent, sometimes there are minor phenomena of ataxia, plastic hypertonicity ("jackknife" phenomenon), weakening of facial expressions. A number of patients have mild cognitive impairment.
The classic parkinsonian tremor is a trembling at rest when the muscles are completely relaxed. Its source is recognized as central oscillators in the basal ganglia. The muscles of the neck are involved simultaneously with the arms or somewhat later. Parkinson's disease is characterized by a yes-yes or no-no head tremor that disappears with movement. The picture is complemented by slowness, a shuffling gait, a “pose of a petitioner”. Muscle tone changes (symptom of "gear wheel"), the cognitive sphere suffers.
Tremor is considered a typical and common symptom of multiple sclerosis. Usually it is bibrachial, that is, it affects adjacent segments - one or both hands and head. Trembling is explained by damage to the cerebellum and its connections, therefore it usually has an intentional character, occurs during movement and intensifies when the goal is reached. But in people with multiple sclerosis, other types of it can occur, for example, tremor of the head at rest, due to the presence of a focus of demyelination in the thalamus, basal ganglia, or frontal lobes.
Multiple sclerosis, accompanied by trembling, has a number of clinical features. It is characterized by an earlier onset, the prevalence of cerebellar disorders in the debut. The advanced stage of pathology is manifested by imbalance in the form of static and dynamic ataxia, oculomotor disorders. Pyramidal symptoms (muscle weakness, spasticity) and sensory disturbances are much less pronounced.
As a symptom of metabolic disorders, tremor of the head is included in the picture of generalized trembling hyperkinesis, involving the muscles of the arms, neck and torso. It is observed at the stage of subcompensation and progresses as the brain is damaged. Hypoxic-ischemic perinatal encephalopathy in children is caused by a complicated course of pregnancy and childbirth (asphyxia, intrauterine infections, injuries). It can be manifested by low-amplitude trembling, pathological head attitudes, clonic convulsions, which are combined with inhibition of reflexes.
Symptoms of hepatic encephalopathy are quite diverse. With chronic intoxication, a tremor of the head and hands (including "clapping"), spasms of facial muscles develop. Pathology is characterized by slow convulsive and fast intermittent movements (choreoathetosis), ataxia, cognitive impairment. Severe uremia in chronic kidney disease is manifested by postural-kinetic trembling, rapid muscle twitching (myoclonus), and convulsive seizures. Any metabolic encephalopathy occurs against the background of impaired consciousness.
In the clinic of opsoclonus-myoclonus syndrome, tremor of the head, trunk and extremities is a sign of a fairly advanced process. This is an autoimmune paraneoplastic syndrome associated with the development of malignant neoplasms. Trembling is caused by damage to the cerebellar system, combined with a decrease in muscle tone, dysarthria, salivation, but opsoclonus and myoclonus are considered the most typical signs of the disease.
Opsoclonus is understood as chaotic multidirectional eye movements, which are accompanied by convulsive twitching of the muscles of the limbs and torso, static or dynamic ataxia. The second pathognomonic sign of the syndrome is polymorphic myoclonus, which takes the form of short muscle twitches of various amplitudes. Their predominant localization is the lips, eyelids, trunk and limbs.
The cause of head tremor may be hereditary diseases of a neurodegenerative or demyelinating nature. Hyperkinesis is caused by changes in the cerebral structures that control voluntary movements, maintain muscle tone and posture. Damage to the cerebellum, extrapyramidal system and corticospinal connections is observed in the following conditions:
Tremor of the head in those suffering from kuru - a rare prion disease, a type of spongiform encephalopathy - is a fairly characteristic symptom. It manifests itself as a strong trembling or intermittent movements, often combined with a spasm of facial muscles ("sardonic smile"). Pathology begins with dizziness and fatigue, as the neurodegenerative process progresses, the ability to control voluntary motor acts is lost, ataxia, hyperkinesis (choreoathetosis), and myoclonus appear.
It is not difficult to identify a tremor of the head, since the symptom is clearly visible during a routine examination. A much more difficult task facing the doctor is to determine the cause of the trembling. Taking into account the etiological heterogeneity of the pathological condition, there are a number of additional methods in the arsenal of a neurologist that provide significant assistance in the diagnostic process:
To clarify the causes of hyperkinesis, molecular genetic methods are of some importance. Suspicion of paraneoplastic syndrome requires an active search for a malignant process with ultrasound of the kidneys, liver and other organs. If head tremor is detected, differential diagnosis should be made between the most common dystonic, essential and parkinsonian tremors, not forgetting other conditions.
The completeness and effectiveness of the treatment of head tremor depend on the elimination of the cause, but since the etiology of many diseases remains not fully understood, the main areas of therapy remain symptomatic and pathogenetic. The situation is complicated by the fact that trembling of the head, in contrast to localized in the hands, is less amenable to pharmacotherapy. The main groups of medicines include:
Before actively treating head tremor, attention is paid to the exclusion of stimulants from the diet (coffee, strong tea), the abolition of certain drugs. In addition to pharmacotherapy, botulinum therapy is considered an important direction. Most often, injections are performed to treat dystonic tremor of the head. Physical methods include kinesiotherapy, wearing of fixing cervical collars, exercise therapy and massage.
With a strong tremor of the head, resistant to medical correction, surgical intervention is recommended. The most common treatment option is deep brain stimulation with electrodes implanted in the thalamic or subthalamic nuclei. They also practice cryotalamotomy and other methods of destroying a small area of the thalamus with the help of modern methods of stereotaxic surgery - radiofrequency ablation, directed ultrasound, gamma knife.