Carpal Tunnel Syndrome (CTS)

Carpal Tunnel Syndrome (CTS) Description

• CTS is a common entrapment neuropathy
• It is characterized by compression of the median nerve as it passes through the carpal tunnel in the wrist
• CTS symptoms include pain, numbness, and tingling in the distribution of the median nerve
• Typically the thumb, index, middle, and radial half of the ring finger are affected
• CTS impacts millions of people worldwide and significantly affects their quality of life and work productivity
• Diagnosis and management are crucial to prevent permanent nerve damage and optimize functional outcomes
• CTS involves compression of the median nerve in the carpal tunnel at the wrist
• The median nerve enters the hand through the carpal tunnel by coursing under the transverse carpal ligament
• CTS symptoms: numbness and paresthesias variably in the thumb, index, middle, and half of the ring finger
• Paresthesias can include the entire hand, extend into the forearm or upper arm, or be isolated to one or two fingers
• Pain is another common symptom and can be located in the hand, forearm, and sometimes the proximal arm
• CTS is often misdiagnosed as thoracic outlet syndrome
• CTS signs: decreased sensation in the median nerve distribution
• Reproduction of tingling when a percussion hammer is tapped over the wrist (Tinel sign) or the wrist is flexed for 30-60 seconds (Phalen sign)
• Weakness of thumb opposition and abduction are also signs
• EDx is extremely sensitive and shows slowing of sensory and, to a lesser extent, motor median potentials across the wrist
• Ultrasound can show focal swelling of the median nerve at the wrist
• Treatment options: avoidance of precipitating activities, control of underlying systemic-associated conditions, nonsteroidal anti-inflammatory medications, neutral (volar) position wrist splints (especially for night use), glucocorticoid/anesthetic injection into the carpal tunnel, and surgical decompression by dividing the transverse carpal ligament
• Surgery should be considered if there is a poor response to nonsurgical treatments, thenar muscle atrophy and/or weakness, and significant denervation potentials on EMG
• Proximal median neuropathies include pronator teres syndrome and anterior interosseous neuropathy, often occurring as a partial form of brachial plexiti

Etiology

• Primary mechanism of CTS involves increased pressure within the carpal tunnel
• This leads to compression and ischemia of the median nerve
• Increased pressure can result from inflammation of the synovial tissue surrounding the flexor tendons
• Can be caused by fluid retention, or anatomical variations that reduce the space within the carpal tunnel
• Repetitive hand and wrist movements, particularly those involving flexion and extension, can exacerbate the condition by increasing inflammation and edema within the tunnel
• The etiology is often multifactorial, involving a combination of anatomical, physiological, and environmental factors

Incidence

• Estimated prevalence of CTS in the general population ranges from 1-5%
• Higher rates are observed in certain occupational groups
• In the United States, the annual incidence is approximately 3 per 1,000 person-years
• Women are affected 3-4 times more frequently than men

Risk Factors

• Jobs involving repetitive hand movements, forceful gripping, or exposure to vibration increase the risk of CTS
• Women are at higher risk, particularly during pregnancy and menopause, likely due to hormonal factors
• Risk also increases with age
• Medical conditions such as diabetes, rheumatoid arthritis, hypothyroidism, and obesity are associated with increased CTS risk due to their effects on nerve function or tissue inflammation
• Other risk factors include repetitive movement, pregnancy, obesity, arthritis, DM, HTN, hypothyroidism, and trauma

Prevention

• Implement ergonomic modifications in the workplace to reduce repetitive wrist stress
• Practice proper hand and wrist positioning during repetitive tasks
• Take regular breaks and perform stretching exercises during prolonged hand use
• Maintain a healthy weight and manage underlying medical conditions
• Use wrist splints during sleep to maintain a neutral wrist position

Clinical Manifestations

• Numbness and Tingling: Paresthesias in the median nerve distribution, often worse at night or early morning
• Pain: Aching discomfort in the wrist, palm, and forearm, sometimes radiating to the elbow
• Weakness: Reduced grip strength and difficulty with fine motor tasks, particularly in advanced cases
• Nocturnal Symptoms: Waking up due to hand numbness or pain, often relieved by shaking or rubbing the hands
• Thenar Muscle Atrophy: In severe, long-standing cases, visible wasting of the thenar eminence

Review of Systems

• Musculoskeletal: Hand/wrist pain, difficulty with grip strength
• Neurological: Numbness, tingling, or burning sensations in affected fingers
• Integumentary: Changes in hand sensation, possible skin changes with severe compression
• Endocrine: Assess for symptoms of diabetes or thyroid dysfunction
• General: Sleep disturbances due to nocturnal symptoms

Physical Assessment Findings

• Neurological System: Tinel's Sign: Tingling sensation in median nerve distribution when tapping over the carpal tunnel
• Phalen's Test: Reproduction of symptoms when holding wrists in full flexion for 60 seconds
• Two-Point Discrimination: May be increased (>6mm) in affected fingers
• Musculoskeletal System: Assess for weakness in thumb abduction and opposition
• Hand Inspection: Look for thenar muscle atrophy in advanced cases
• Other signs include Flick's sign, hypalgesia, square wrist sign, and thumb abduction weakness

Assessment Tools & Grading

• Boston Carpal Tunnel Questionnaire: Assesses symptom severity and functional status
• Hi-Ob Scale: Grades CTS severity based on clinical and electrophysiological findings
• Carpal Tunnel Syndrome 6-Item Scale (CTS-6): Quick screening tool for CTS probability

10 High Yield Questions to Ask Patient

• Do you experience numbness, tingling, or pain in your hands, particularly at night?
• Which fingers are affected by these sensations?
• Do you wake up at night due to hand symptoms?
• Have you noticed any weakness or clumsiness in your hands?
• What is your occupation, and does it involve repetitive hand movements?
• Have you tried any treatments for your symptoms? If so, what has been effective?
• Do you have any medical conditions such as diabetes, thyroid disease, or arthritis?
• Have you experienced any recent weight gain or fluid retention?
• Are your symptoms affecting your daily activities or work performance?
• Have you had any previous hand or wrist injuries?

Differential Diagnoses

• Carpal Tunnel Syndrome: Median nerve distribution symptoms; diagnose with nerve conduction studies
• Cervical Radiculopathy: Neck pain, broader arm symptoms; diagnose with MRI of cervical spine
• Ulnar Neuropathy: Symptoms in ring and little fingers; diagnose with ulnar nerve conduction study
• Thoracic Outlet Syndrome: Upper extremity symptoms, vascular changes; diagnose with provocative tests, imaging
• Peripheral Neuropathy: Symmetric distal symptoms; diagnose with EMG, blood tests

Diagnostic Studies & Possible Findings

• Nerve Conduction Studies: Prolonged median nerve distal latency and reduced sensory nerve action potential amplitude
• Electromyography (EMG): May show denervation in thenar muscles in severe cases
• Ultrasound: Increased cross-sectional area of median nerve at carpal tunnel inlet (>10mm²)
• MRI: Can visualize median nerve compression and surrounding soft tissue abnormalities, not routinely needed
• X-rays: May be used to rule out bony abnormalities or arthritis if suspected
• Other diagnostic tests include history and PE, X-ray, Labs (CBC, ESR ANA, RF, TSH), Electromyography, and nerve conduction studies

Treatment Prioritization

• Implement conservative measures (splinting, activity modification) for mild to moderate cases
• Address underlying medical conditions that may contribute to CTS
• Provide symptomatic relief through pharmacological interventions if needed
• Consider corticosteroid injections for moderate cases or those not responding to conservative treatment
• Evaluate for surgical intervention in severe or refractory cases

Nonpharmacological Management

• Wrist splinting, especially at night, to maintain neutral wrist position
• Ergonomic modifications at work and home to reduce wrist stress
• Nerve gliding exercises to improve median nerve mobility
• Activity modification to avoid aggravating movements
• Physical therapy for hand strengthening and stretching exercises
• Other treatments include rest, work-home modification, ice, splinting, and physical therapy (ultrasound)

Pharmacological Management

• 1st Line: NSAIDs: Ibuprofen 400-800 mg three times daily or Naproxen 250-500 mg twice daily for pain relief
• 2nd Line: Oral corticosteroids: Prednisone 20 mg daily for 10-14 days, then taper; Local corticosteroid injection: Methylprednisolone 20-40 mg into the carpal tunnel
• 3rd Line: Gabapentin: Start at 300 mg at bedtime, increase as tolerated up to 600 mg three times daily for neuropathic pain
• Monitor: Symptom improvement, medication side effects, and for any signs of disease progression

Consultation/Referral

• Hand surgeon or orthopedic specialist for severe or refractory cases - Carpal tunnel release
• Occupational therapy for ergonomic assessment and hand rehabilitation

Initial Diagnosis Patient Guidance

• Explain the nature of CTS and its relationship to median nerve compression
• Demonstrate proper wrist positioning and ergonomic techniques
• Instruct on the use of night splints and their importance
• Discuss lifestyle modifications to reduce symptom exacerbation
• Review treatment options and expected outcomes

Follow Up

• Schedule follow-up visits every 4-6 weeks initially to assess response to conservative treatment
• If symptoms improve, follow-up can be extended to every 3-6 months
• For patients receiving injections or considering surgery, more frequent follow-up may be necessary

Expected Course

• With appropriate conservative management, many patients experience significant improvement within 6-12 weeks
• Some may require more aggressive interventions, including surgery, especially if symptoms are severe or long-standing
• Another non-surgical treatment if no improvement in 2-7 weeks
• Conservative Management for 6 weeks to 3 months
• Refer to orthopedist or hand specialist if symptoms severe or no improvement

Possible Complications

• Permanent nerve damage leading to persistent numbness and weakness
• Thenar muscle atrophy and loss of hand function in severe cases
• Reduced quality of life and work productivity
• Chronic pain syndrome if left untreated
• Rare complications from corticosteroid injections (e.g., infection, tendon rupture)
• Potential surgical complications if carpal tunnel release is performed
• Referral to Rheumatology if underlying inflammatory condition is suspected
• Endocrinology for management of associated conditions like diabetes or thyroid dysfunction