Hemiballism

Definition

Hemiballism is a separate type of hyperkinesis caused by a lesion of the subthalamic corpus. It is characterized by typical violent high-amplitude movements covering the proximal limbs of one half of the body and diagnosed according to the data of neurological status, brain imaging, and analysis of cerebrospinal fluid. Drug treatment is carried out with dopamine receptor blockers and GABAergic agents against the background of therapy of the causative pathology. In resistant cases, neurosurgical treatment (thalamotomy, pallidotomy) is possible. 

General information

The medical term “ballismus” is derived from the Greek “ballismos” – throwing and refers to abrupt involuntary throwing motor acts. Ballistic hyperkinesis is most often observed in one-half of the body’s upper and lower extremities. Such a unilateral variant of ballism has been termed hemiballismus. Involvement in hyperkinesis of all limbs is denoted by the term “paraballism”, one arm or leg – the term “monoballism”, but these conditions are diagnosed much less frequently. According to statistics, hemiballism makes up 1.7% of all movement disorders, is widespread, and has no gender preference.

Causes of hemiballismus

In neurology, hyperkinesis develops due to dysfunction of the subthalamic basal ganglion. In most cases, the etiologic factors of Lewy body lesions are acute cerebral circulatory disorders, which occur due to angioma or arteriovenous malformation of vessels supplying blood to the subthalamic nucleus. Other causes are less common. All etiologic factors of hemiballism are subdivided into:

• Vascular: ischemic, hemorrhagic strokes. Disruption of blood supply to the subthalamic ganglion causes hypoxia of its neurons. Oxygen deprivation adversely affects the function of nerve cells and leads to their death.
• Dysmetabolic: hyperglycemia. Transient hemiballismus is observed in elderly patients with type 2 diabetes mellitus with insufficient effect of sugar-reducing drugs. Increased blood glucose disrupts metabolic processes in ganglion cells, leading to its dysfunction.
• Traumatic: craniocerebral trauma, neurosurgical interventions. Hemiballism develops due to direct damage to the structures of the subthalamic nucleus and its compression by the formed posttraumatic hematoma.
• Tumor: intracranial masses localized in the subthalamic region. The lesion of the corpus lucidum occurs as a result of tumor tissue sprouting into it and compression of neurons by the neoplasm increasing in volume.
• Infectious: HIV-associated neuroinfections., brain abscess, herpetic encephalitis. Infectious agents provoke the development of an inflammatory reaction with swelling, infiltration, and microcirculatory disorders. These processes lead to dysfunction of the subthalamic nucleus, which causes hemiballism.
• Inflammatory: collagenosis, antiphospholipid syndrome. These diseases are accompanied by the production of antibodies to the body’s own tissues. As a result, there is a systemic autoimmune inflammation, including affecting the basal ganglia, which disrupts the functioning of the subthalamic nucleus.
• Medications. Some medications (levodopa pharmaceuticals, contraceptives) provoke changes in neurotransmitter interactions of various brain structures. The consequence is dysfunction of the extrapyramidal system, which regulates voluntary movements.

Symptoms of hemiballism

The clinic is based on large-scale violent movements in the extremities of the half of the body opposite to the localization of the affected ganglion. Motor acts have a sudden arrhythmic character, are more pronounced in the proximal parts (shoulders, hips), and may have a rotational component. Patients complain of the inability to control or reduce the manifestations of hyperkinesis. Increased movements are observed with excitement, anxiety, and mental tension. The complete disappearance of involuntary movements in sleep is typical.

In half of cases, hemiballism is combined with involuntary contractions of mimic muscles, which leads to the appearance of grimaces, speech disorders (dysarthria), and swallowing. According to the location and size of the pathological focus, hemiballism is accompanied by a decrease in muscle strength (hemiparesis), sensory disorders (hemihypesthesia), cognitive disorders, and changes in muscle tone.

The course of ballism depends on its etiology. In the case of stroke, there is an acute manifestation, followed by a slow regression of hyperkinesis. Hemiballism tumors of infectious genesis are characterized by a gradual debut with further aggravation of motor disorders. Systemic autoimmune lesions are accompanied by recurrent attacks of hemiballism, localized in one or the other half of the body.

Complications

Involuntary movements in hemiballism have large amplitude and are accompanied by the impact of limbs on various surrounding objects. Often, traumatization of the patient is noted: bruises and fractures of the arm or leg. Unilateral localization of uncontrolled movements provokes loss of balance and patient falls, leading to mechanical injuries. Traumatism is the most frequent, repeated complication of ballism, often requiring medical attention.

Diagnosis

The involuntary motor acts characterizing hemiballism have a pathognomonic pattern, which makes them easy to diagnose. However, hyperkinesis is only a syndrome of the underlying disease, the determination of which is the ultimate goal of diagnosis. The list of investigations necessary for the final diagnosis includes:

• Neurological examination. During the examination, the neurologist evaluates muscle strength, tone, intensity, symmetry of reflexes, level of sensitivity, coordination, and the state of the cognitive sphere. The nature of the accompanying focal symptomatology detected suggests the localization of the focus of the lesion.
• Cerebral CT scan. CT of the brain is more informative in diagnosing traumatic injuries and hematomas. MRI of the brain better visualizes tumor processes, inflammatory changes, and ischemic areas.
• Examination of cerebrospinal fluid. The material is taken by lumbar puncture. The analysis allows the detection of inflammatory changes, tumor cells, infectious agents, and the presence of blood in hemorrhage.

Differential diagnosis involves other types of hyperkinesis: chorea and athetosis. Choreic hyperkinesis is characterized by a smaller amplitude of violent movements and localization in the distal parts of the limbs. Athetosis is characterized by slow movements, mainly in the hands.

Treatment of hemiballismus

Therapy is carried out against the background of treatment of the underlying disease. Taking into account the etiology, vascular, neuroprotective, antibacterial, antiviral, immunosuppressive drugs are used. In the case of a voluminous formation, the issue of neurosurgical removal is considered. Pathogenetic treatment of hemiballism includes the following methods:

• Pharmacotherapy with neuroleptics that block dopamine receptors. The drugs reduce the manifestations of hemiballism by blocking excessive activation of the thalamocortical pathway.
• Administration of GABA agonists. Hyperkinesis is controlled by potentiating the action of gamma-aminobutyric acid – the main inhibitory neurotransmitter of the CNS.
• Stereotactic destruction of the basal ganglia. The indication for surgery is severe cases resistant to pharmacotherapy. The decision on the expediency of surgical intervention is made jointly with a neurosurgeon. Thalamotomy is performed – the destruction of the ventrolateral thalamic ganglion; pallidotomy – the destruction of the pale globe.
• Electrical stimulation of the ventrolateral nucleus. Electrical blocking stimuli are delivered by implanted electrodes, reducing excitatory thalamocortical impulse and associated hemiballism.

All these treatment options are available in more than 400 hospitals worldwide (https://doctor.global/results/diseases/hemiballismus). For example, Pallidotomy can be performed in these countries at following approximate prices:

Turkey $6.7 K in 18 clinics

China $24.6 K in 4 clinics

Germany $26.7 K in 24 clinics

United States $40.1 K in 13 clinics

Israel $41.5 K in 12 clinics.

Prognosis and prevention

The nature of the underlying disease, the age of the patient, and the time of the beginning of qualified treatment have predictive value. Hemiballism after stroke, trauma, and infection can completely regress against the background of effective drug therapy. Several patients have persistent residual hyperkinesis that requires constant treatment. The most difficult prognosis is hemiballism of tumor genesis since radical excision of the tumor is associated with the removal of tissues of the subthalamic nucleus. There is no specific prevention. Preventive measures include timely treatment of cerebrovascular, infectious, and autoimmune diseases, prevention of traumatic brain injury, and hyperglycemic conditions.

Prevention of traumatization of the patient is of great importance in the prevention of. For this purpose, it is recommended to equip the patient’s room in a special way, cover protruding parts of the furniture with foam, and, if necessary, fix the limb.