Question

A person presented with low back pain spreading along the distribution of S1 spinal nerve on the left. Which of the following statements is most likely to be correct?

	A.	he most likely has diabetic neuropathy
	B.	this is to be expected in early stage of ankylosing spondylitis
	C.	he is likely to show weakness of plantar flexion
	D.	he is showing early manifestations of Brown-Sequard's syndrome
	E.	he probably has a lesion of the spinothalamic tract on the opposite side

Answer 1

The diabetic neuropathy is the slow progressive damage of the perioheral nerves caused by high glucose levels in blood. Diabetic neuropathy is usualy associated with sensory impairment such as numbness, tingling, paraesthesia. Option A is incorrect.
Ankylosing spondylitis results in back pain but neeve roots are not affected. So option B is incorrect.
Brown sequard syndrome is caused due to damage to spinal cord resulting paralysis on the opposite side of lesion and sensory impairment on same side. Option d is incorrect.
Spinothalamic tract carries sensation if pain and touch to the brain and the lesion results in sensory deficits. Option e is  incorrect.
The S1 nerve root forms the tibial nerve. The tibial nerve supplies the gastrocnemius muscle of lower leg which is responsible for plantar flexion. With involvement of S1 nerve the plantar flexion of ankle will be affected resulting in weak plantar flexion. Option c is correct.
Answer : C