Extrapyramidal disorder

Extrapyramidal Disorder

Extrapyramidal disorders are a group of movement disorders that result from dysfunction of the extrapyramidal system, which is a neural network that is part of the motor system causing involuntary movements. These disorders are often associated with the use of certain medications, particularly antipsychotics, and can also be caused by neurodegenerative diseases.

Pathophysiology

The extrapyramidal system includes the basal ganglia, which are a group of nuclei in the brain that are involved in coordinating movement. The basal ganglia include structures such as the caudate nucleus, putamen, and globus pallidus. These structures interact with the thalamus and the cerebral cortex to regulate voluntary motor control, procedural learning, and routine behaviors or "habits."

Extrapyramidal disorders occur when there is an imbalance in the neurotransmitters, particularly dopamine and acetylcholine, within the basal ganglia. This imbalance can lead to a variety of movement disorders, including tremors, rigidity, bradykinesia, and involuntary movements.

Causes

Extrapyramidal disorders can be caused by:

• Medications: The most common cause is the use of antipsychotic drugs, which block dopamine receptors and can lead to extrapyramidal symptoms (EPS).
• Neurodegenerative diseases: Conditions such as Parkinson's disease, Huntington's disease, and Wilson's disease can affect the basal ganglia and lead to extrapyramidal symptoms.
• Brain injuries: Trauma or lesions affecting the basal ganglia can also result in these disorders.

Symptoms

The symptoms of extrapyramidal disorders can vary depending on the underlying cause but often include:

• Tremors: Involuntary shaking, often seen in the hands.
• Rigidity: Stiffness and resistance to movement in the muscles.
• Bradykinesia: Slowness of movement.
• Dystonia: Sustained muscle contractions causing twisting and repetitive movements or abnormal postures.
• Akathisia: A feeling of inner restlessness and an uncontrollable need to be in constant motion.
• Tardive dyskinesia: Involuntary, repetitive body movements, often involving the face and tongue.

Diagnosis

Diagnosis of extrapyramidal disorders is primarily clinical, based on the observation of symptoms and a detailed patient history. Neurological examinations and imaging studies such as MRI or CT scans may be used to rule out other conditions.

Treatment

Treatment of extrapyramidal disorders depends on the underlying cause:

• Medication adjustment: If caused by antipsychotic drugs, adjusting the dosage or switching to a different medication may help.
• Medications: Drugs such as anticholinergics, beta-blockers, or benzodiazepines may be used to manage symptoms.
• Physical therapy: Can help improve mobility and reduce symptoms.

Prognosis

The prognosis for individuals with extrapyramidal disorders varies. Some symptoms may improve with treatment, while others may persist or worsen over time, especially if associated with a progressive neurodegenerative disease.

Also see

• Parkinson's disease
• Tardive dyskinesia
• Basal ganglia
• Dopamine