C5

C5 Nerve Root

The C5 nerve root is a critical component of the cervical spine, playing a vital role in the innervation of the upper limb. Understanding its anatomy, function, and clinical significance is essential for medical students and healthcare professionals.

Anatomy

The C5 nerve root emerges from the spinal cord at the level of the fifth cervical vertebra. It exits the vertebral column through the intervertebral foramen between the C4 and C5 vertebrae. The C5 nerve root is part of the brachial plexus, which is a network of nerves that supplies the upper limb.

Pathway

After exiting the intervertebral foramen, the C5 nerve root joins with the C6 nerve root to form the upper trunk of the brachial plexus. This trunk then divides into anterior and posterior divisions, which contribute to the formation of the lateral and posterior cords of the brachial plexus, respectively.

Function

The C5 nerve root is primarily responsible for:

• Motor Function: It innervates the deltoid and biceps brachii muscles, facilitating shoulder abduction and elbow flexion.
• Sensory Function: It provides sensation to the lateral aspect of the arm.

Clinical Significance

C5 Radiculopathy

C5 radiculopathy occurs when there is compression or irritation of the C5 nerve root. Common causes include:

• Cervical spondylosis
• Herniated disc
• Spinal stenosis

Symptoms of C5 radiculopathy may include:

• Pain in the shoulder and lateral arm
• Weakness in shoulder abduction and elbow flexion
• Sensory loss in the lateral arm

Diagnostic Evaluation

Diagnosis of C5 radiculopathy typically involves:

• Clinical Examination: Assessing motor strength, reflexes, and sensory function.
• Imaging Studies: MRI and CT scans to visualize the cervical spine.
• Electromyography (EMG): To evaluate the electrical activity of muscles and confirm nerve involvement.

Treatment

Treatment options for C5 radiculopathy may include:

• Conservative Management: Physical therapy, pain management, and anti-inflammatory medications.
• Surgical Intervention: In cases where conservative treatment fails, surgical options such as decompression or discectomy may be considered.

See Also

• Brachial plexus injuries
• Cervical spine
• Nerve root

References

• Moore, K. L., Dalley, A. F., & Agur, A. M. R. (2013). *Clinically Oriented Anatomy*. Lippincott Williams & Wilkins.
• Ropper, A. H., & Samuels, M. A. (2009). *Adams and Victor's Principles of Neurology*. McGraw-Hill.