Critical Care Registered Nurse (CCRN) Practice Exam

What does "extinction" refer to in a neurological examination?

1. The inability to identify multiple stimuli on one side

2. The loss of sensation in one limb

3. The failure to recognize shapes by touch

4. The inability to localize touch on the body

The correct answer is: The inability to identify multiple stimuli on one side

In a neurological examination, "extinction" specifically refers to the phenomenon where a patient can perceive a stimulus on one side of the body when it is presented alone, but fails to acknowledge the same stimulus when it is presented simultaneously on both sides. This typically occurs in situations of unilateral neglect or hemisensory loss, commonly associated with right or left hemisphere lesions, particularly in the parietal lobe. Understanding this concept is crucial for assessing the integrity of sensory pathways and the brain's ability to process simultaneous stimuli. In cases of extinction, the patient may report feeling the stimulus on one side but not the other when both sides are stimulated at the same time, indicating a problem with how the brain integrates sensory information from both sides. This is distinct from other sensory impairments such as loss of sensation or inability to recognize shapes, which focus on different aspects of sensory processing and perception.