A 44-year-old woman comes to the office due to pain, tingling, and numbness in her hands for the past several months. The symptoms are worse at night. She often takes ibuprofen or soaks her hands in warm water for symptom relief, but her wrists and fingers are stiff and painful again by the next morning. The patient has difficulty doing morning chores but feels better by midday. She also has excessive fatigue. The patient has no prior medical conditions and takes no prescription medications. Temperature is 37.6 C (99.7 F), blood pressure is 118/72 mm Hg, and pulse is 68/min. BMI is 28 kg/m². Physical examination shows that the bilateral wrists and joints of the fingers are mildly swollen and tender. Tapping on the flexor surface of the wrist elicits tingling in the first 3 digits of each hand. The remainder of the joints are normal. Lungs are clear on auscultation and heart sounds are normal. The abdomen is soft and nontender with no hepatosplenomegaly. The patient has no rashes or lower extremity edema. Which of the following is the best next step in evaluation of this patient's symptoms?

Question

Quizplus · Accepted Answer

11ec25c8_d230_99ab_bc81_f1eb21f13c50_MD0003_00 This patient has paresthesias in the distribution of the median nerve and a positive Tinel sign, which are consistent with carpal tunnel syndrome (CTS). CTS is caused by compression of the median nerve as it passes through the carpal tunnel in the wrist. Potential contributing factors include overuse and fibrosis, soft tissue swelling in the tunnel (eg, hypothyroidism, acromegaly), and extrinsic compression from arthritis in the wrist. Tinel sign carpal tunnel This patient also has prolonged morning pain and stiffness involving the fingers and wrists, systemic symptoms (eg, fatigue, elevated temperature), and polyarticular synovitis, suggesting rheumatoid arthritis (RA). RA can cause tenosynovitis of the flexor tendons that pass within the carpal tunnel; in addition, the synovium can expand within the carpal space. The resultant inflammation leads to compression of the median nerve under the flexor retinaculum, producing the symptoms of CTS. Patients with RA are 2-3 times as likely as the general population to develop CTS. Initial evaluation of RA should include inflammatory markers (eg, erythrocyte sedimentation rate, C-reactive protein), serologic studies (eg, rheumatoid factor, cyclic citrullinated peptide antibodies), and x-rays of the symptomatic joints. (Choice A) CT scan can confirm malignancy at the superior pulmonary sulcus (ie, Pancoast tumor), which can cause hand pain and paresthesias due to compression of the C8-T2 nerve roots. However, the features do not follow the distribution of the median nerve, and typical associated findings include shoulder pain, Horner syndrome (ipsilateral ptosis, miosis, anhidrosis), and supraclavicular lymphadenopathy. (Choice B) Diabetes mellitus (ie, elevated fasting blood glucose, elevated hemoglobin A1c) is a risk factor for CTS but would not cause synovitis or morning stiffness. (Choice C) MRI of the neck can evaluate a cervical radiculopathy and is warranted for suspected malignancy, rapid progression of symptoms, or significant weakness or diminished reflexes. However, cervical radiculopathy would not cause features confined to the median nerve at wrist. (Choice E) Cryoglobulinemic vasculitis can cause fatigue and arthralgias and can occasionally cause mononeuropathy or polyneuropathy. However, CTS is less typical, and most patients have purpuric skin lesions and liver disease (eg, hepatitis C). purpuric skin lesions (Choice F) Vitamin B₁₂ deficiency typically causes peripheral neuropathy of the lower extremities rather than CTS and is often associated with cognitive changes (eg, memory loss). Educational objective: Carpal tunnel syndrome is a common manifestation of rheumatoid arthritis involving the wrist. Initial evaluation should include inflammatory markers (eg, erythrocyte sedimentation rate, C-reactive protein), serologic studies (eg, rheumatoid factor, cyclic citrullinated peptide antibodies), and x-rays of the symptomatic joints. References: Neurologic manifestations of rheumatoid arthritis. (http://www.ncbi.nlm.nih.gov/pubmed/29061242)

A 44-Year-Old Woman Comes to the Office Due to Pain