Positive Romberg test with eyes closed detects defect in:
**Core Concept**
The Romberg test is a clinical assessment used to evaluate a patient's balance and proprioception. It involves standing with feet together and eyes closed, and the test is considered positive if the patient sways or loses balance.
**Why the Correct Answer is Right**
When a patient has a positive Romberg test with eyes closed, it indicates a defect in proprioception, which is the sense of body awareness and position. Proprioception is mediated by the proprioceptive receptors in muscles, tendons, and joints, which send signals to the central nervous system to maintain posture and balance. In a patient with a positive Romberg test, the proprioceptive input is impaired, leading to a loss of balance and coordination.
**Why Each Wrong Option is Incorrect**
* **Option A:** Romberg test is not primarily used to detect defects in visual-vestibular integration. While visual-vestibular integration is also important for balance, the Romberg test specifically assesses proprioception.
* **Option B:** The Romberg test does not primarily detect defects in cerebellar function. While the cerebellum plays a role in motor coordination and balance, the Romberg test is more specific to proprioception.
* **Option C:** The Romberg test is not primarily used to detect defects in peripheral nervous system function. While peripheral neuropathy can affect proprioception, the Romberg test is more specific to central nervous system function.
**Clinical Pearl / High-Yield Fact**
A positive Romberg test can be a red flag for conditions such as peripheral neuropathy, cerebellar disease, and spinal cord injury. It is essential to perform a thorough neurological examination, including tests of proprioception, vibration sense, and reflexes, to determine the underlying cause of a positive Romberg test.
**Correct Answer:** C.