Wrist drop, also known as radial nerve palsy, is characterized by an inability to extend the hand at the wrist. This condition often includes weakness in finger extension, referred to as "finger drop." It's not a disease itself but rather a sign of a problem affecting the nerves controlling these movements.
Understanding Wrist Drop
Definition
Wrist drop refers to an impairment in hand extension at the wrist, usually accompanied by finger extension weakness (“finger drop”). This inability to lift the wrist and fingers makes it challenging to perform everyday activities.
Causes
Several factors can cause wrist drop. The most common causes relate to nerve damage:
- Peripheral Nerve Issues: Problems affecting the nerves outside the brain and spinal cord are frequently the source.
- C7 Radiculopathy: Irritation or compression of the C7 nerve root in the neck can cause wrist drop.
- Radial Nerve Compression: The radial nerve, which runs down the arm and controls wrist and finger extension, can be compressed at various points.
- Spiral Groove: Compression of the radial nerve at the spiral groove of the humerus (upper arm bone), known as “Saturday night palsy,” is a common cause. This typically occurs due to prolonged pressure on the arm, such as falling asleep with the arm draped over a chair.
- Other Causes: While nerve compression is common, less frequent causes include:
- Trauma: Fractures or injuries to the arm can damage the radial nerve.
- Lead Poisoning: Lead can damage nerves, leading to symptoms including wrist drop.
- Rare diseases or conditions can also cause wrist drop.
Symptoms
- Inability to lift the wrist: The primary symptom is the inability to extend the wrist joint upwards.
- Weakness in finger extension: This often accompanies wrist drop, causing difficulty straightening the fingers.
- Numbness or tingling: These sensations might be present along the back of the hand and arm depending on the location of the nerve problem.
- Pain: While not always present, some people might experience pain associated with nerve damage.
Diagnosis
Diagnosing wrist drop usually involves:
- Physical Examination: A doctor will assess wrist and finger movements, sensation, and reflexes.
- Nerve Conduction Studies: These tests measure the speed of electrical signals through nerves.
- Electromyography (EMG): This test checks muscle response to electrical stimulation and confirms nerve injury or compression.
- Imaging: X-rays or MRI may be used to identify fractures or other causes of compression.
Treatment
The treatment approach depends on the underlying cause:
- Conservative Management:
- Rest and Bracing: A splint can help support the wrist and hand and allow the nerve to heal.
- Physical Therapy: Exercises help improve muscle strength, range of motion, and nerve function.
- Medications: Pain relievers or corticosteroids may help with pain and inflammation.
- Surgical Intervention: If nerve compression or damage is severe, surgery to relieve pressure on the nerve or repair the nerve may be needed.
- Addressing Underlying Conditions: If other conditions are causing the wrist drop (such as lead poisoning), addressing them is essential.
Rehabilitation
Rehabilitation is a key part of recovery and can take time. It may involve:
- Specific Exercises: To regain strength and movement of the wrist and fingers.
- Occupational Therapy: Learning adaptive strategies for daily tasks.
In Conclusion
Wrist drop is a condition indicating an issue with nerve function. It’s characterized by weakness in hand extension at the wrist and fingers, often caused by radial nerve compression. Getting an accurate diagnosis is key to getting the right treatment and improving symptoms.