Cervical cord injury does not cause -a) Horner’s syndromeb) Loss of sensation over facec) Spasticity of footd) Wasting with fasciculations of lower limb
First, I need to recall what cervical cord injuries typically affect. The cervical spinal cord controls various functions depending on the level of injury. Horner's syndrome is caused by damage to the sympathetic nervous system, which can happen with a C8-T1 injury. So a cervical injury could cause Horner's.
Next, loss of sensation over the face. The face is innervated by the trigeminal nerve (cranial nerve V), which is a brainstem nerve, not the spinal cord. So a cervical injury wouldn't affect the face's sensation. That makes sense. The other options: spasticity of the foot and wasting/fasciculations of the lower limb. Spasticity is upper motor neuron signs, which can occur with spinal cord injury. Wasting and fasciculations are lower motor neuron signs, which would be seen in peripheral nerve injury, not spinal cord. So the answer is B, loss of sensation over the face.
**Core Concept**
Cervical spinal cord injury affects sensory and motor pathways below the injury level. The face is innervated by the trigeminal nerve (CN V), which is a cranial nerve, not a spinal nerve. Spasticity and upper motor neuron signs occur below the injury, while lower motor neuron signs (fasciculations) are absent in spinal cord lesions.
**Why the Correct Answer is Right**
Loss of sensation over the face (**Option B**) is mediated by the trigeminal nerve (CN V), which originates in the brainstem, not the spinal cord. Cervical cord injuries cannot disrupt this cranial nerve pathway. In contrast, cervical injuries can cause Horner’s syndrome (via sympathetic pathways), spasticity (via upper motor neuron damage), and lower limb wasting (via disuse atrophy, not fasciculations).
**Why Each Wrong Option is Incorrect**
**Option A:** Horner’s syndrome can occur with cervical cord injury (C8-T1) due to disruption of the sympathetic chain.
**Option C:** Spasticity of the foot is a classic upper motor neuron sign below the injury level.
**Option D:** Lower limb wasting may occur due to disuse atrophy, but fasciculations are lower motor neuron signs, absent in spinal cord lesions.
**Clinical Pearl / High-Yield Fact**
Remember: **"Cranial nerves are brainstem-based; spinal cord injuries don’t affect them."** Fasciculations and lower motor neuron signs are never seen in spinal cord lesions—save these for peripheral neuropathies or motor neuron diseases.
**Correct Answer: B. Loss of sensation over face**