Feature (s) of syringomyelia is/are -a) Dissociated sensory lossb) Wasting of small muscles of handc) Ascending weaknessd) Frequent bladder- bowel involvement

**Core Concept**
Syringomyelia is a disorder characterized by the formation of a fluid-filled cavity (syrinx) within the spinal cord, which can lead to damage and destruction of the surrounding neural tissue. This condition typically affects the cervical spine and can result in various neurological symptoms due to the compression and destruction of the spinal cord.

**Why the Correct Answer is Right**
The correct answer features dissociated sensory loss and wasting of small muscles of the hand. This is because the syrinx in syringomyelia most commonly occurs in the cervical spine, affecting the spinothalamic tracts (responsible for pain and temperature sensation) and the posterior columns (responsible for light touch and proprioception). As a result, patients often experience dissociated sensory loss, where they lose pain and temperature sensation but retain light touch and proprioception. Additionally, the destruction of the anterior horn cells in the spinal cord can lead to wasting of the small muscles of the hand, including the thenar and hypothenar muscles.

**Why Each Wrong Option is Incorrect**
**Option A:** While dissociated sensory loss is a characteristic feature of syringomyelia, it is not the only feature, and frequent bladder-bowel involvement is not a typical presentation.

**Option B:** Ascending weakness is not a typical feature of syringomyelia, as the condition primarily affects the cervical spine and does not typically cause ascending paralysis.

**Option C:** Frequent bladder-bowel involvement is not a characteristic feature of syringomyelia, as the condition primarily affects the spinal cord and does not typically cause autonomic dysfunction.

**Clinical Pearl / High-Yield Fact**
Syringomyelia can be remembered by the classic triad of dissociated sensory loss, wasting of the small muscles of the hand, and scoliosis. This triad is often referred to as the "syringomyelia triad."

**Correct Answer:** a) Dissociated sensory loss