Anatomical Basis of Saturday Night Palsy

Introduction

Saturday Night Palsy, also known as radial neuropathy, is a condition resulting from prolonged compression of the radial nerve. It typically occurs when an individual falls asleep with their arm draped over a hard surface, leading to nerve dysfunction.

Anatomical Structures Involved

Radial Nerve

The radial nerve originates from the brachial plexus (C5-T1) and supplies motor and sensory innervation to the posterior aspect of the upper limb. It travels along the humerus in the spiral groove, making it vulnerable to compression injuries.

Surrounding Tissues

The radial nerve courses through various anatomical landmarks such as:

• Axilla (near the triceps muscle)
• Spiral groove of the humerus
• Radial tunnel (proximal forearm)

Pathophysiology

Prolonged compression of the radial nerve leads to ischemia and conduction block, resulting in characteristic symptoms such as wrist drop, weakness of finger extension, and sensory deficits along the radial aspect of the forearm and hand.

Clinical Presentation

Patients often report:

• Wrist drop due to extensor muscle weakness
• Numbness along the posterior arm and forearm
• Difficulty extending the fingers

Diagnosis and Management

Diagnosis is primarily clinical, supported by electromyography (EMG) and nerve conduction studies.

Treatment

• Conservative management (rest, splinting)
• Physical therapy for muscle strengthening
• Surgical intervention in severe cases