Partial recurrent laryngeal nerve palsy produces vocal cord in which position -a) Cadevericb) Abductedc) Adductedd) Paramedian
## **Core Concept**
Partial recurrent laryngeal nerve palsy affects the function of the vocal cords by impairing the innervation of the intrinsic muscles of the larynx, particularly those involved in adduction and abduction. The recurrent laryngeal nerve primarily controls these movements.
## **Why the Correct Answer is Right**
The correct answer, **D. Paramedian**, is right because in partial recurrent laryngeal nerve palsy, the vocal cord is typically fixed in a paramedian position. This is due to the paralysis of the posterior cricoarytenoid muscle (the only muscle responsible for abduction of the vocal cord), and the unopposed action of the cricothyroid muscle, which is innervated by the external branch of the superior laryngeal nerve and helps to tense and elongate the vocal cord, positioning it in a paramedian or near-median position.
## **Why Each Wrong Option is Incorrect**
- **Option A: Cadaveric** - This position refers to a more medial or central position that a vocal cord assumes when there is complete paralysis of all intrinsic laryngeal muscles. It does not accurately describe the position seen in partial recurrent laryngeal nerve palsy.
- **Option B: Abducted** - Abduction refers to the movement of the vocal cord away from the midline. This would not be a position resulting from partial recurrent laryngeal nerve palsy, as the nerve palsy would more likely result in an inability to fully abduct or move the vocal cord towards the midline.
- **Option C: Adducted** - Adduction refers to the movement of the vocal cord towards the midline. While adduction is affected in recurrent laryngeal nerve palsy, the vocal cord is not fixed in an adducted position due to the partial nature of the palsy and the muscles involved.
## **Clinical Pearl / High-Yield Fact**
A key point to remember is that the position of the vocal cord in laryngeal nerve palsy can vary depending on the extent of the palsy. Complete paralysis leads to a cadaveric position (more lateral), while partial paralysis, especially of the recurrent laryngeal nerve, often results in a paramedian position due to the relatively preserved function of some intrinsic muscles.
## **Correct Answer: D. Paramedian**