Infectious Chorea: A Neurological Movement Disorder

Infectious Chorea

Definition

Infectious chorea, also known as Sydenham’s chorea, is a neurological disorder characterized by involuntary, purposeless movements of the limbs, face, and trunk. It is typically a childhood illness that occurs following a streptococcal infection, such as scarlet fever or a streptococcal sore throat.

Causes

The exact cause of infectious chorea is unknown, but it is believed to be an autoimmune reaction triggered by a streptococcal infection. The streptococcal bacteria produce toxins that cross-react with antigens in the brain, particularly in the basal ganglia, leading to inflammation and abnormal dopamine metabolism. This results in the characteristic movement abnormalities seen in chorea.

Symptoms

The symptoms of infectious chorea usually develop within a few weeks to months after a streptococcal infection. The most common symptom is chorea, which manifests as:

• Involuntary, writhing movements of the limbs, face, and trunk
• Difficulty walking, standing, or performing fine motor tasks
• Speech difficulties due to twitching of the muscles involved in articulation
• Emotional lability and behavioral changes

Other symptoms may include:

• Fever
• Sore throat
• Headache
• Fatigue
• Joint pain

Diagnosis

Infectious chorea is diagnosed based on the patient’s history, physical examination, and laboratory tests.

• History: The doctor will ask about the patient’s symptoms, recent streptococcal infections, and family history of movement disorders.
• Physical examination: The doctor will observe the patient’s movements and look for signs of chorea, such as involuntary twitching, grimacing, and difficulty walking.
• Laboratory tests: Blood tests may be done to check for evidence of streptococcal infection and to rule out other conditions that could cause chorea.

Treatment

The main treatment for infectious chorea is addressing the underlying streptococcal infection with antibiotics, such as penicillin or erythromycin. This can help prevent further damage to the basal ganglia and reduce the severity of symptoms.

Other treatments may include:

• Antipsychotic medications to control involuntary movements
• Muscle relaxants to reduce muscle spasms
• Behavioral therapy to improve coping skills and reduce anxiety
• Physical therapy to maintain muscle strength and coordination

Prognosis

The prognosis for infectious chorea is generally good. Most children recover completely within a few months to a year, although some may have persistent symptoms or develop other neurological problems later in life.

Complications

In rare cases, infectious chorea can lead to serious complications, such as:

• Brain damage
• Intellectual disability
• Seizures
• Movement disorders, such as Parkinson’s disease or Huntington’s disease

Prevention

Preventing streptococcal infections is the best way to prevent infectious chorea. This can be done by:

• Good hand washing
• Avoiding contact with people who have streptococcal infections
• Getting vaccinated against streptococcal pneumonia and scarlet fever