History: A 29-year-old woman with an uncomplicated pregnancy of five months presented with a chief complaint of bilateral neck and shoulder pain accompanied by right upper limb paresthesia and intermittent hand weakness. The weakness, when present, was described as a difficulty with picking up or holding small objects (e.g., pen/pencil, cup of coffee). The complaint began insidiously after she started a new job as a program manager that involved more responsibility, approximately 4 months ago, with signs and symptoms progressively worsening over the last 3 weeks. There was no history of trauma. The pain was described as tension in the neck and shoulders with associated “numbness” and “tingling” that radiated down the right arm and into the right hand. The 5th finger on the patient’s right hand would also occasionally abduct involuntarily at rest (i.e., Wartenberg’s sign). The patient was active, had normal blood pressure and was in otherwise good general health, aside from moderate swelling in her hands and feet contributed to by the pregnancy.
Exam Findings: On examination, the patient’s cervical spine and shoulder ranges of motion were within normal limits. All cervical orthopedic tests performed were normal. These included Spurling’s compression, Jackson’s and cervical distraction tests. Unremarkable findings were also concluded with cranial nerve examination, as well as upper extremity motor, reflex, and sensory testing, with the exception of mild hypoesthesia to pin-prick along the right C8 dermatome and 4/5 muscle strength of the right C8 and T1 myotomes. Upper motor neuron testing was negative for Babinski, Hoffman and clonus responses, and there was no discoloration of the patient’s skin or fingernails. Tinel tapping was also negative over the cubital, carpal and Guyon’s canals. Further testing using shoulder depression and Soto-Hall tests produced significant other findings of cervicothoracic muscle soreness and pain. Adson’s test elicited pain and paresthesia into the patient’s right hand. An upper extremity nerve tension test performed with the patient supine also produced mild discomfort and paresthesia. Cervical rotation to the ipsilateral side exacerbated the patient’s symptoms. Prolonged elevation of the right arm above the head (i.e., Roos test) was unremarkable. Tender trigger points were palpated in the cervicothoracic spinal musculature including the anterior scalenes, levator scapulae, rhomboids, upper trapezius, and suboccipital muscles bilaterally. Palpation and pressure of the right anterior scalene at its insertion with the first rib elicited pain and paresthesia that radiated into the arm and hand.
Diagnostic Testing: The patient was referred to her family physician for electrodiagnostic testing and diagnostic imaging. Cervical spine radiographs were ordered and revealed a right-sided cervical rib (C7 level). Electromyography of the right upper limb also revealed abnormal electrical activity involving the ulnar nerve.
Working Diagnosis: Based on the age, history and exam/diagnostic findings for this patient, the working diagnosis was TOS involving the right interscalene triangle.