Can rheumatoid arthritis cause numbness in the hands or arms?

Rheumatoid Arthritis Can Cause Numbness

Yes, rheumatoid arthritis frequently causes numbness in the hands and arms, primarily through peripheral neuropathy and nerve compression syndromes—with carpal tunnel syndrome being the most common mechanism. 1, 2

Prevalence and Clinical Significance

Peripheral neuropathy is one of the most common extra-articular manifestations of rheumatoid arthritis, occurring in approximately 75% of RA patients when assessed electrophysiologically. 2 However, only about 21% of these patients demonstrate sensory loss on clinical examination, meaning subclinical neuropathy is present in roughly 50% of cases—making it easily overlooked without specific testing. 2

The most frequently observed pattern is entrapment neuropathy, with carpal tunnel syndrome representing the predominant type. 1 This occurs when synovial inflammation and joint destruction compress adjacent peripheral nerves. 3, 4

Clinical Presentation of Numbness in RA

Patients typically experience:

• Stiffness in hands and feet accompanied by burning and tingling sensations 1
• Numbness in the ulnar nerve distribution (fourth and fifth fingers) or median nerve distribution (thumb, index, middle fingers) 5
• Stabbing pain with occasional weakness 1
• Progressive symptoms that may advance from subtle numbness to more severe neurological deficits 3

Mechanisms of Neurological Involvement

Compression Neuropathies

The inflammatory process in RA produces synovial hypertrophy and joint destruction that mechanically compresses adjacent nerves. 3, 4 At the wrist, carpal tunnel syndrome develops when inflamed synovium compresses the median nerve. 1 At the elbow, cubital tunnel syndrome from ulnar nerve compression is common, and in severe cases can progress to attrition rupture of the ulnar nerve when marked osteophyte formation occurs in the medial joint space. 5

Systemic Inflammatory Neuropathy

Beyond mechanical compression, the systemic inflammatory process itself can produce neuropathy through necrotizing arteritis of the vasa vasorum (blood vessels supplying nerves), leading to ischemic nerve damage. 4 This represents a more serious extra-articular manifestation associated with significant morbidity. 3

Risk Factors for Neuropathy in RA

Statistically significant associations exist between peripheral neuropathy and:

• Older age of the patient 2
• Longer disease duration 2
• Higher disease activity scores (DAS28) 2
• Presence of subcutaneous rheumatoid nodules 2
• Positive rheumatoid factor 1
• Female sex (greater predilection) 1

Diagnostic Approach

Clinical Examination

The American College of Rheumatology recommends examining hands for joint deformities, with early involvement showing tender swelling and severe motion impairment. 6 Perform a squeeze test of metacarpophalangeal joints to assess for clinical synovitis. 6 Evaluate for sensory deficits in specific nerve distributions and assess for muscle atrophy (particularly dorsal interossei muscles in ulnar neuropathy). 5

Electrophysiological Testing

Nerve conduction studies are the gold standard for diagnosing peripheral neuropathy in RA patients and can detect latent cases quickly, enabling immediate treatment initiation. 1, 2 These studies are particularly critical because they identify the 50% of patients with subclinical neuropathy who have normal clinical examinations. 2

Imaging

When marked osteophyte formation in the medial elbow joint space or valgus deformity is present on plain radiographs, consider attrition nerve rupture and proceed with active nerve exposure and dissection for ulnar nerve protection. 5 MRI can visualize nerve compression and surrounding inflammatory changes. 1

Critical Clinical Pitfalls

Do not dismiss numbness as simply "arthritis pain"—peripheral neuropathy in RA is associated with deteriorating health status, higher pain scores, and presence of extra-articular manifestations. 2 The presence of neuropathy indicates more severe systemic disease requiring aggressive management. 2

Do not rely solely on clinical examination—electrophysiological testing should be performed in all RA patients, especially elderly patients, because subclinical neuropathy is present in half of cases and early detection improves both physical and functional outcomes. 2

Watch for warning signs of severe nerve involvement: progressive weakness, muscle atrophy (particularly claw hand deformity), or immeasurable motor nerve conduction velocity on testing may indicate nerve rupture requiring urgent surgical intervention. 5

Management Implications

Medical management includes symptomatic treatment with analgesics, anticonvulsants, and antidepressants for neuropathic pain. 1 Surgical decompression (such as carpal tunnel release or anterior transposition of the ulnar nerve) is indicated when conservative measures fail or when structural nerve damage is present. 1, 5

Modern disease-modifying antirheumatic drugs (DMARDs) and biologic agents have diminished the incidence of serious neurologic manifestations in RA by controlling the underlying inflammatory process. 4 The American College of Rheumatology recommends methotrexate as first-line therapy with a target of remission or low disease activity to prevent progressive extra-articular complications including neuropathy. 6, 7