**Question:** Injury to which of the following nerves leads to the following?

A. Sciatic Nerve
B. Radial Nerve
C. Ulnar Nerve
D. Cervical Nerve Roots (C5-C6)

**Core Concept:** Nerves are essential components of the human nervous system, composed of cells called neurons that transmit signals along specialized structures called axons. Injury to nerves can lead to a range of clinical manifestations depending on the specific nerve involved.

**Why the Correct Answer is Right:**

Damage to the **Cervical Nerve Roots (C5-C6)** can lead to **Fallon's Sign**, which is characterized by a positive Tinel's sign over the distribution of the affected nerve root. This sign occurs when the patient flexes their shoulder and then rapidly extends it, eliciting a tingling sensation along the affected dermatomes due to mechanical stimulation of the nerve root. In this case, the correct answer (D) is related to the cervical nerves, specifically C5-C6, which are responsible for the distribution of the affected dermatomes.

**Why Each Wrong Option is Incorrect:**

1. **Sciatic Nerve (A)** is a large, single nerve formed by the union of the L4-S3 posterior spinal roots and the sacral plexus. Injury to the sciatic nerve typically results in a combination of symptoms, not specifically related to a single dermatome.
2. **Radial Nerve (B)** injury typically results in a radial nerve palsy, affecting the muscles innervated by the radial nerve. However, this answer is incorrect because the specific dermatome-related symptoms are not mentioned.
3. **Ulnar Nerve (C)** injury can result in the specific symptoms related to the ulnar nerve dermatomes, but the question asks for a dermatome-related symptom, which is not provided in this option.

**Clinical Pearl:** When assessing patients with suspected nerve root injury, it is important to consider the specific dermatome-related symptoms that may guide the diagnosis. This can help narrow down the possibilities and guide further evaluation and management strategies.

**Correct Answer:** D) Cervical Nerve Roots (C5-C6)

**Why the Correct Answer is Right:**

Injury to the cervical nerve roots (C5-C6) can result in a specific dermatome-related symptom. In this case, the correct answer (D) is related to the cervical nerves, specifically C5-C6, which are responsible for the distribution of the affected dermatomes. When a nerve root is injured, the corresponding dermatome-related symptoms should be observed.

**Why Each Wrong Option is Incorrect:**

1. **Sciatic Nerve (A)** injury typically results in a combination of symptoms, not specifically related to a single dermatome.
2. **Radial Nerve (B)** injury usually presents with symptoms related to the radial nerve palsy, affecting the muscles innervated by the radial nerve, not a dermatome-related symptom.
3.