Hemiballismus

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Obesity, Sleep & Internal medicine
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Hemiballismus
Synonyms	N/A
Pronounce	N/A
Specialty	N/A
Symptoms	Involuntary movements, flailing of limbs
Complications	Injury due to uncontrolled movements
Onset	Sudden
Duration	Variable
Types	N/A
Causes	Stroke, brain tumor, trauma, infection
Risks	Hypertension, diabetes mellitus, atherosclerosis
Diagnosis	Clinical diagnosis, neuroimaging
Differential diagnosis	Chorea, athetosis, dystonia
Prevention	N/A
Treatment	Antipsychotics, anticonvulsants, surgery
Medication	Haloperidol, clonazepam, valproic acid
Prognosis	Variable, often resolves over time
Frequency	Rare
Deaths	N/A

Hemiballismus is a rare movement disorder characterized by involuntary, violent, and wide-amplitude movements of the limbs on one side of the body. It is often associated with lesions in the subthalamic nucleus of the basal ganglia, which is a group of nuclei in the brain involved in the coordination of movement.

Signs and symptoms

The primary symptom of hemiballismus is the presence of involuntary, flinging movements of the limbs. These movements are typically unilateral, affecting only one side of the body, and can be severe enough to interfere with daily activities. The movements are often described as violent and can involve the proximal parts of the limbs, such as the shoulders and hips. Patients with hemiballismus may also experience hemichorea, which involves smaller, more rapid movements, and dystonia, which is characterized by sustained muscle contractions leading to abnormal postures.

Causes

Hemiballismus is most commonly caused by a lesion in the subthalamic nucleus, often due to a stroke. Other causes can include traumatic brain injury, tumors, infections, or metabolic disorders. In some cases, the exact cause of the lesion may not be identified.

Pathophysiology

The basal ganglia play a crucial role in the regulation of movement. The subthalamic nucleus is part of a circuit that modulates motor activity. Lesions in this area can disrupt the normal inhibitory control of the basal ganglia, leading to the excessive and uncontrolled movements seen in hemiballismus.

Diagnosis

Diagnosis of hemiballismus is primarily clinical, based on the characteristic movements and their unilateral nature. Neuroimaging techniques, such as MRI or CT scan, can be used to identify lesions in the subthalamic nucleus or other parts of the brain that may be responsible for the symptoms.

Treatment

Treatment of hemiballismus focuses on managing symptoms and addressing the underlying cause. Medications such as antipsychotics (e.g., haloperidol) or anticonvulsants (e.g., valproic acid) can help reduce the severity of the movements. In some cases, surgical interventions, such as deep brain stimulation, may be considered.

Prognosis

The prognosis for hemiballismus varies depending on the underlying cause. In cases where the condition is due to a reversible cause, such as a metabolic disorder, symptoms may improve with appropriate treatment. However, if the condition is due to a permanent lesion, such as a stroke, the symptoms may persist, although they often decrease in severity over time.

See also

• Chorea
• Dystonia
• Basal ganglia
• Subthalamic nucleus