Anterior cutaneous nerve entrapment syndrome

Anterior Cutaneous Nerve Entrapment Syndrome (ACNES) is a condition characterized by chronic pain in the abdominal wall. It occurs when the anterior cutaneous branches of the thoracoabdominal nerves are compressed or entrapped as they pass through the abdominal muscles into the subcutaneous tissue. This condition is often underdiagnosed and can lead to significant discomfort and impairment in quality of life for affected individuals.

Etiology

ACNES is primarily caused by the entrapment of the anterior cutaneous nerves. This entrapment can occur due to several factors, including:

• Anatomical variations in the path of the nerve
• Increased abdominal pressure from obesity, pregnancy, or heavy lifting
• Scar tissue formation following surgery or trauma
• Tight clothing or belts

Symptoms

The hallmark symptom of ACNES is localized, sharp, or burning pain in the abdominal wall. The pain is typically confined to a small area and can be exacerbated by certain movements or pressure. Other symptoms may include:

• Altered sensation or numbness in the affected area
• Tenderness upon palpation
• Pain that worsens with certain activities, such as bending, coughing, or twisting

Diagnosis

Diagnosis of ACNES involves a thorough medical history and physical examination. Key diagnostic procedures include:

• Carnett's test, where the pain increases or remains unchanged when the abdominal muscles are tensed
• Local anesthetic block, which can provide temporary relief and confirm the diagnosis if the pain is significantly reduced
• Imaging studies, such as ultrasound or MRI, to rule out other causes of abdominal pain

Treatment

Treatment options for ACNES aim to relieve pain and improve quality of life. These may include:

• Conservative measures, such as physical therapy, pain management with medications, and lifestyle modifications
• Nerve blocks with local anesthetics and corticosteroids
• Surgical intervention, including neurectomy or nerve release, in cases where conservative treatments fail

Prognosis

With appropriate treatment, many individuals with ACNES experience significant pain relief and improvement in their daily activities. However, some may continue to have chronic pain and may require ongoing management.

Prevention

Preventing ACNES involves minimizing risk factors that can lead to nerve entrapment. This includes maintaining a healthy weight, avoiding tight clothing, and using proper techniques when lifting heavy objects.