The most commonly involved nerve in Leprosy is -

Correct option is A

Ans. (a) Ulnar Nerve
Explanation:
Leprosy (Hansen’s Disease) is a chronic infectious disease caused by Mycobacterium leprae, affecting the skin and peripheral nerves. It leads to nerve damage, sensory loss, muscle weakness, and deformities.
Most Commonly Affected Nerve: Ulnar Nerve
· The ulnar nerve is the most frequently affected nerve in leprosy, leading to:
· Claw hand deformity (due to paralysis of intrinsic hand muscles).
· Loss of sensation in the little finger and ring finger.
· Muscle wasting in the hypothenar eminence.
Other Commonly Affected Nerves in Leprosy:
1. Common Peroneal Nerve → (Second Most Affected)
· Leads to foot drop due to paralysis of dorsiflexors of the foot.
· Causes loss of sensation over the dorsum of the foot.
2. Tibial Nerve → (Less Commonly Affected)
· Affects plantar flexion and intrinsic muscles of the foot.
3. Fibular Nerve → (Not a Primary Nerve in Leprosy)
· The fibular nerve is a branch of the sciatic nerve and is less commonly involved in leprosy.
Why is the Ulnar Nerve Most Commonly Involved?
· Superficial location at the elbow (Cubital Tunnel) makes it prone to thickening and damage due to nerve infiltration by Mycobacterium leprae.
· High involvement in sensory and motor functions of the hand, leading to visible deformities.