Cervical radiculopathy vs Parsonage-Turner syndrome: a case report.

Abstract

Case reportA 42-year-old recreational cyclist presented with a 3-month history of right-sided neck pain. The patientexperienced pain radiating to the right periscapular regionand paresthesias in digits 1–3. The onset of the pain wassudden. She described the pain as intermittent and sharp,ranging from 8–10/10 on numeric pain rating scale. Thepain was worse at nighttime, often so severe that it wouldwake her from sleep. She also noted severe headaches andright upper extremity numbness and weakness. She hadvisited the emergency room twice, both times beingadmitted to a neurology service because of the severenature of the pain and what was described as atypicalhemiplegia and migraines. A CT scan of the head andcervical spine and an MRI of the cervical spine werenormal. The patient was discharged on pain medication,which included prednisone, depakote, zoloft, motrin, andtopamax. There was no history of trauma, falls, or anyinciting events. She had no history of bowel or bladderincontinence, recent travel, or fever and chills. Her medicalhistory was significant for migraines, right carpal tunnelsyndrome, and depression. She was taking lexapro andclonazepam for depression.Physical examination revealed mild limited cervicalrange of motion with end range axial pain with flexion,extension, and lateral rotation. Spurling maneuver waspositive on the right side eliciting pain in digits 1 and 2.Active and passive range of motion of the right shoulderwas minimally limited compared to the left (asymptomatic)side. Additional findings included medial winging of theright scapula and mild weakness (4+/5) of the right triceps.Muscle strength throughout the rest of the upper extrem-ities was 5/5. The rest of the physical examination revealednormal muscle bulk and tone, normal sensation, symmetricupper extremity reflexes, and negative Hawkins_, Neer_s,Roos_, Wright_s, and Adson_s provocative tests.Clinical evaluation at this point was suggestive ofParsonage–Turner syndrome vs a cervical radiculopathy,although a broader differential diagnosis was considered(Fig. 1). Electrodiagnostic studies were performed andshowed evidence of severe denervation (2+ positive sharpwaves and fibs) corresponding to muscles of the right C7myotome and including the paraspinal muscles, consistentwith a right C7 radiculopathy (Fig. 2). Motor unitrecruitment was reduced in the involved muscles and therewere no polyphasic potentials. An MRI of the cervicalspine was repeated and revealed mid to lower cervicalspondylosis, moderate left-sided C5/6 foraminal stenosis,and mild right-sided C6/7 foraminal stenosis (Fig. 3).Because the MRI findings did not demonstrate significantnerve root compression, the patient was diagnosed withParsonage–Turner syndrome and Lyrica was prescribed.Over the next 6 weeks the patient_s symptoms improvedbut then suddenly worsened.The patient returned for follow-up with complaints ofrecurrent right neck pain and right upper extremityweakness. Neck range of motion was now normal andSpurling_s maneuver was now negative. There was greaterupper right extremity weakness, with motor strength ofright triceps 4+/5, right wrist extension 4j/5, and rightwrist flexion 4/5. Reflexes were normal and sensation wasintact. Parsonage–Turner syndrome was still the workingdiagnosis and the patient was referred to physical therapyto treat a superimposed cervical radicular component.Over the next 2 months, the patient continued to havesymptoms and developed a shingles-like rash on herbuttock. She was treated by her primary care physicianwith Valtrex and within a few days the patient_s neck andright arm pain completely resolved. One month later, shehad recurrence of the buttock rash along with return of theneck and arm pain. She again received a course of Valtrexand her symptoms completely resolved. To date, 1 yearlater, she has been pain-free with almost full strength andable to return to all previous activities, including recrea-tional cycling.DiscussionEvaluation of the patient with neck and unilateral arm paincan present a diagnostic and treatment challenge. Anatomic