Which is not true of Tabes dorsalis?
**Tabes Dorsalis**
**Core Concept**
Tabes dorsalis is a late manifestation of untreated syphilis, characterized by degeneration of the posterior columns of the spinal cord. This condition leads to impaired proprioception, loss of vibration sense, and ataxia.
**Why the Correct Answer is Right**
The correct answer is related to the pathophysiology of tabes dorsalis. The disease primarily affects the posterior columns of the spinal cord, specifically the fasciculus gracilis and fasciculus cuneatus. This results in impaired proprioception, loss of vibration sense, and ataxia due to the disruption of the sensory pathways. The affected individuals often experience shooting pains, lightning pains, and loss of coordination.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because tabes dorsalis is indeed associated with syphilis. Syphilis infection can lead to the degeneration of the posterior columns of the spinal cord, resulting in tabes dorsalis.
* **Option B:** This option is incorrect because ataxia is a common manifestation of tabes dorsalis. The degeneration of the posterior columns disrupts the sensory pathways, leading to impaired coordination and ataxia.
* **Option C:** This option is incorrect because loss of vibration sense is a characteristic feature of tabes dorsalis. The disease affects the posterior columns of the spinal cord, which are responsible for transmitting vibration and proprioception.
**Clinical Pearl / High-Yield Fact**
Tabes dorsalis is a classic example of a late manifestation of untreated syphilis, emphasizing the importance of timely diagnosis and treatment of the disease.
**Correct Answer:** D