Carpal Tunnel Syndrome (CTS)

A table summarizing the key details of Carpal Tunnel Syndrome (CTS):

Category	Details
Definition	Compressive neuropathy of the median nerve in the wrist.
Epidemiology	- Incidence: 0.1-10% of the general population. - Up to 70% have bilateral symptoms. - Affects adults 40-60 years old, more common in females (3:1 ratio).
Risk Factors	Female sex, obesity, pregnancy, hypothyroidism, rheumatoid arthritis, trauma, repetitive motions, diabetes, advanced age, menopause, chronic renal failure, space-occupying lesions, smoking, alcoholism.
Pathophysiology	Increased pressure on the median nerve, leading to impaired blood supply and nerve ischemia.
Anatomy	Carpal tunnel is bordered by scaphoid tubercle and trapezium (radial), hook of hamate and pisiform (ulnar), transverse carpal ligament (roof), proximal carpal row (floor). Contains median nerve and flexor tendons (FDS, FDP, FPL).
Clinical Presentation	- Symptoms: Numbness, tingling in radial 3½ digits, hand clumsiness, night pain. - Physical Exam: Thenar atrophy, positive Durkan’s, Phalen’s, and Tinel’s tests.
Diagnosis	Clinical diagnosis supported by EMG/NCS, ultrasound, or MRI for structural abnormalities.
Treatment	- Nonoperative: Night splints, NSAIDs, activity modification, corticosteroid injections. - Operative: Carpal tunnel release (open or endoscopic) for refractory cases.
Complications	Scar tenderness, pillar pain, recurrence, nerve injury, arterial injury.
Prognosis	Generally good with early diagnosis and treatment; night symptoms and steroid injection relief predict better outcomes.

Overview

Carpal Tunnel Syndrome (CTS) is the most common compressive neuropathy of the median nerve. It typically presents with symptoms such as numbness, tingling, and pain in the median nerve distribution of the hand. These symptoms are often worse at night and can lead to hand weakness and clumsiness.

Epidemiology

Incidence: Affects 0.1-10% of the general population, with up to 70% of patients experiencing bilateral symptoms.
Demographics: Most commonly affects adults aged 40-60 years. It is rare in children. Females are more commonly affected than males, with a ratio of 3:1.

Risk Factors

Female sex
Obesity
Pregnancy
Hypothyroidism
Rheumatoid arthritis
Trauma (e.g., distal radius fractures)
Repetitive motion activities
Acromegaly
Advanced age
Menopause
Chronic renal failure
Space-occupying lesions (e.g., ganglion cysts)
Use of oral contraceptives
Diabetes
Smoking and alcoholism

Etiology and Pathophysiology

CTS results from increased pressure on the median nerve within the carpal tunnel. Normally, the carpal tunnel pressure ranges from 2.5 mmHg at rest to 30 mmHg with wrist flexion. In CTS, pressures can range from 30-110 mmHg, impeding intraneural blood supply and leading to nerve ischemia and dysfunction. Causes include:

Repetitive wrist motions (e.g., typing, cycling)
Space-occupying lesions or synovial hypertrophy
Trauma

Anatomy

The carpal tunnel is a narrow passage in the wrist, bordered by:

Radially: Scaphoid tubercle and trapezium
Ulnarly: Hook of hamate and pisiform
Roof: Transverse carpal ligament
Floor: Proximal carpal row

Contents include the median nerve and tendons of flexor digitorum superficialis (FDS), flexor digitorum profundus (FDP), and flexor pollicis longus (FPL).

Clinical Presentation

Symptoms: Numbness and tingling in the radial 3½ digits, hand clumsiness, and pain that awakens the patient at night.
Physical Examination:
- Inspection: Possible thenar atrophy
- Palpation: Tenderness over the carpal tunnel is rare.
- Provocative Tests:
  - Carpal Tunnel Compression Test (Durkan's Test): Most sensitive test; pressing on the carpal tunnel can provoke symptoms within 30 seconds.
  - Phalen Test: Flexing the wrist against gravity for 60 seconds may reproduce symptoms.
  - Tinel’s Sign: Tapping over the median nerve can elicit tingling or pain.
  - Semmes-Weinstein Monofilament Testing: Useful for detecting sensory deficits.
  - Two-Point Discrimination Test: Failure to distinguish two points 5 mm apart may indicate CTS.

Diagnosis

Diagnosis is primarily clinical, supported by history and physical examination findings. Electromyography (EMG) and nerve conduction studies (NCS) can confirm diagnosis and assess severity. Ultrasound or MRI may be used to identify structural abnormalities.

Treatment

Nonoperative:
- First-Line: Night splints, NSAIDs, activity modification
- Corticosteroid Injections: For diagnostic or therapeutic purposes
Operative:
- Indications: Persistent symptoms despite conservative management, or acute CTS due to trauma.
- Techniques: Open or endoscopic Carpal tunnel release, which involves cutting the transverse carpal ligament to relieve pressure.

Complications

Scar tenderness: Common, managed with massage and occupational therapy.
Pillar pain: Deep-seated ache post-surgery, managed similarly.
Recurrence: Occurs in about 1.6% at 10 years.
Nerve Injury: Involves the median or palmar cutaneous nerve.
Arterial Injury: Rare, typically with endoscopic procedures.

Prognosis

The prognosis is generally good, especially with early diagnosis and treatment. Factors predicting a good outcome include night symptoms and relief with steroid injections.

Conclusion

Carpal Tunnel Syndrome is a common and treatable condition. Early recognition and appropriate management can prevent progression and improve outcomes for patients. Regular follow-ups and patient education are crucial in managing this condition effectively.