Another name for the long thoracic nerve is the "nerve to serratus anterior"; it’s also historically called Bell’s nerve (nerve of Bell). It typically arises from C5–C7 roots of the brachial plexus and supplies the serratus anterior muscle, which is crucial for scapular protraction and preventing winging of the scapula.

The long thoracic nerve innervates serratus anterior; injury causes medial scapular winging, difficulty pushing or with overhead abduction, often after trauma or mastectomy. The spinal accessory nerve supplies trapezius (and SCM); injury produces shoulder droop, lateral winging, impaired scapular elevation and abduction above horizontal, and weak shoulder shrug—commonly after posterior-triangle surgery. Both are motor-only lesions without sensory loss.

Yes — the terms "spinal accessory nerve" and "accessory nerve" generally refer to the same cranial nerve (CN XI). It mainly comprises spinal roots that innervate the sternocleidomastoid and trapezius muscles, enabling head rotation and shoulder elevation. Some texts describe an additional small cranial root often linked with the vagus nerve, but clinically CN XI usually denotes the spinal accessory component.

The spinal accessory nerve is also commonly called the accessory nerve or cranial nerve XI (CN XI). It has a spinal root from upper cervical segments and a cranial part; it primarily innervates the sternocleidomastoid and trapezius muscles, enabling head rotation, shoulder elevation, and some swallowing actions. Injury can cause weakness of shoulder shrug and head turning.

Treatment begins with conservative care: pain control, activity modification and targeted physiotherapy for scapular stabilization and serratus anterior strengthening; many recover in six to twelve months. If no improvement, electrodiagnostic testing guides surgery such as nerve repair, grafting or transfer, tendon transfers (e.g., pectoralis major) or scapulothoracic fusion for persistent winging. Botulinum toxin to antagonist muscles can provide symptom relief.

Damage to thoracic nerves can cause localized or radiating pain, burning or sharp sensations, numbness and tingling, and muscle weakness or atrophy in the chest and upper abdomen. Intercostal nerve injury may impair chest wall movement and breathing, increase risk of chronic pain, and cause sensory loss across dermatomes. Severe lesions can affect autonomic fibers, causing sweating or circulation changes.