Extinction (neurology)

Gray's anatomy image 742

Explanation of the grouping effect in extinction

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Visual extinction

Extinction (neurology) is a neurological disorder that occurs when a person is unable to perceive multiple stimuli of the same type simultaneously. This condition is often observed in patients who have suffered damage to one hemisphere of the brain, particularly in the parietal lobe.

Overview

Extinction is typically identified during a neurological examination. When a single stimulus is presented to either side of the body, the patient can usually detect it. However, when stimuli are presented simultaneously to both sides, the patient fails to perceive the stimulus on the side opposite to the brain lesion. This phenomenon is most commonly associated with unilateral neglect, a condition where the patient ignores one side of their body or environment.

Causes

The primary cause of extinction is damage to the parietal lobe, which is responsible for integrating sensory information from different parts of the body. This damage can result from various conditions, including:

• Stroke
• Traumatic brain injury
• Brain tumors
• Neurodegenerative diseases

Symptoms

Patients with extinction may exhibit the following symptoms:

• Inability to perceive simultaneous stimuli on both sides of the body
• Difficulty in recognizing objects or people on the affected side
• Impaired spatial awareness

Diagnosis

Diagnosis of extinction involves a series of tests conducted by a neurologist. These tests may include:

• Visual field tests
• Tactile stimulation tests
• Auditory processing tests

During these tests, the patient is asked to respond to stimuli presented to one or both sides of their body. The inability to detect stimuli on the affected side when presented simultaneously is indicative of extinction.

Treatment

Treatment for extinction focuses on addressing the underlying cause of the brain damage. This may involve:

• Physical therapy
• Occupational therapy
• Cognitive rehabilitation
• Medications to manage symptoms of the underlying condition

Prognosis

The prognosis for patients with extinction varies depending on the severity and cause of the brain damage. Some patients may experience significant improvement with rehabilitation, while others may have persistent symptoms.

Related Pages

• Unilateral neglect
• Parietal lobe
• Stroke
• Traumatic brain injury
• Neurodegenerative diseases