Hemiballismus or hemiballism is a basal ganglia syndrome resulting from damage to the subthalamic nucleus in the basal ganglia.
It is a rare hyperkinetic movement disorder.
HB is characterized by violent involuntary limb movements, on one side of the body, and can cause significant disability.
Ballismus affects both sides of the body and is much rarer.
Symptoms can decrease during sleep.
Hemiballismus movements occur in the proximal limbs whereas in chorea the limb movements are in the distal limbs.
Also in chorea the movements are more dance-like, flowing from one region to another.
Ballism is repetitive, almost ceaseless , but constantly varying, large amplitude involuntary movements of the proximal parts of the limbs.
Baiilism movements are often complex and hemiballismus is usually characterized by involuntary flinging motions of the extremities.
Baiilism movements are often violent and have wide amplitudes of motion,
are continuous and random and can involve proximal or distal muscles on one side of the body.
Some cases even include the facial muscles.
It is common for arms and legs to move together.
Increased activity increases movements, while relaxation decreases in movements.
Causes of hemiballismus:
Stroke
Hemisballismus as a result of stroke occurs in only about 0.45 cases per hundred thousand stroke patients.
Stroke is by far the most common cause of hemiballismus.
A stroke causes tissue to die in the basal ganglia, this can result in the death of tissue that helps to control movement.
The damaged brain tissue sends damaged signals to the skeletal muscles in the body, occasionally resulting in hemiballismus.
Hemiballismus can also occur as a result of a traumatic brain injury.
Amyotrophic lateral sclerosis
disease causes neuronal loss and gliosis, which can include the subthalamic nucleus and other areas of the brain.
Any disorder that causes some form of neuronal loss or gliosis in the basal ganglia has the potential to cause hemiballismus.
Patients with nonketotic hyperglycemia can develop hemiballismus as a complication to the disease through the development of a subthalamic nucleus lesion, and is the second most common reported cause of hemiballismus.
Hemiballismus occurs primarily in the elderly and many cases have come from East Asian origin, which suggests that there may be some genetic disposition to development of hemiballismus as a result of hyperglycemia.
A neoplasm in the basal ganglia, and vascular malformations may be associated with hemiballismus.
Tuberculous meningitis infection can also damage parts of the basal ganglia, sometimes resulting in hemiballismus.
Demyelinating plaques attack the myelin sheaths on neurons decreasing the conduction velocity neurons and making the signals received by the basal ganglia to be garbled and incomplete.
Such disorganized signals cause the chaotic movements characterized by hemiballismus.
Hypoglycemia due to pentamidine use in patients with AIDS has been known to cause hemiballismus.
Hemiballismus may be a result of a secondary infection that occurs due to the compromised immune system seen most commonly with the infection by cerebral toxoplasmosis.
Most of the lesions that result from toxoplasmosis infection are found in the basal ganglia.
The basal ganglia structure is the site that hemiballismus primarily occurs in the brain.
This structure within the basal ganglia innervates other structures, including a connection to the internal globus pallidus.
The subthalamic nucleus provides the excitement needed to drive the globus pallidus, and injury to this area or its efferent or afferent connections can induce this disorder contralateral to the side of the lesion.
The subthalamic nucleus is a regulator of motor function and is also involved in associative and limbic functions.
Hemiballismus caused by lesions in the subthalamic nucleus is more severe than other forms of the disorder.
Hemiballismus can be associated with a decreased output of the globus pallidus, with firing rates decrease from 70/s to 40/s, and with degenerative neurological disorders that cause patients to exhibit hemiballistic movements show a marked decrease in the globus pallidus mass as well.
The putamen, part of the basal ganglia and can be involved in hemiballismus due to the fact that it projects to the premotor cortex through the globus pallidus.
Damage to the putamen area can also cause hemiballistic movements to be seen as it is also part of the chain in movement.
The caudate nucleus is the portion of the basal ganglia that helps control voluntary movement, and damage to this area can also result in hemiballismus as it is directly related to voluntary movement.
The majority of damage that causes hemiballismus occurs within the basal ganglia: cases that have been documented on which damage to cortical structures has caused hemiballistic movements.
Diagnosis of hemiballismus is a clinical one.
Hemiballismus is a clinical sign, and a diagnosis underlying this clinical sign should be sought.
Sudden, flinging movements of a limb(s) and occasionally the face are seen.
This is commonly unilateral.
The diagnosis must be distinguished from other hyperkinetic movement disorders such as tremor, which are generally more rhythmic, and smaller amplitude, and chorea, akathisia and athetosis, all are often of lower amplitude and less violent.
Treatment:
Treating the underlying cause disorder: hyperglycemia, infections, or neoplastic lesions.
Some patients may not even need treatment because the disorder is not severe and can be self-limited.
The most standard type of drug to use is an antidopaminergic drug.
Blocking dopamine is effective in about ninety percent of patients (Perphenazine, pimozide, haloperidol, and chlorpromazine).
Dopamine has not been directly linked to hemiballismus.
Intrathecal baclofen (ITB) therapy can help treat hemiballismus.
Tetrabenazine use has a positive response, but lowering the dosage leads to a return of symptoms.
Tetrabenazine drug works by depleting dopamine.
Surgery as a treatment should only be used on patients with severe hemiballismus that has not responded to treatment.
Globus pallidus surgery or deep brain stimulation of the globus pallidus are procedures that can be used for hemiballismus..
Presently patients are respond remarkably to current treatments and the majority of patients go into spontaneous remission.
The symptoms of hemiballismus can generally be controlled with medication.