Arm Pain And Weakness In A Soccer Player

Abstract

HISTORY: Patient is a 17 year old right hand dominant male soccer player with history of infectious mononucleosis. He complains of spontaneous, progressive distal right upper limb weakness and cramping for one year. His cramping pain is 1-4/10 in severity, worse with exercising. He has early fatigue and approximately 30% of his baseline strength in his elbow, wrist and finger extensors; he denies neck pain, numbness, paresthesias or history of stingers. He reports no lower limb involvement, incontinence or gait disturbances. PHYSICAL EXAMINATION: MSK:-ROM: Neck, bilateral upper limb ROM intact -Strength: RUL: 5/5 SAb; 5/5 EF; 5/5 EE; 4+/5 WE; 3+/5 FE; 5/5 FF LUL, RLL, LLL: 5/5 in all muscles -Palpation: No palpable mass, edema in forearm/arm Neuro: -Provocative: +Tinel along dorsal aspect of RUL brachium -Sensation: grossly intact -Cranial nerves: grossly intact -Reflexes: 1+ biceps, triceps, brachioradialis bilaterally DIFFERENTIAL DIAGNOSIS: -Radial nerve neuropathy -Posterior cord brachial plexopathy -Peripheral nerve sheath tumor (eg schwannoma, neurofibroma) -Diffuse neuritis -Soft tissue mass TEST AND RESULTS: -MRI R wrist, forearm, arm (with and without contrast): Area of mild enlargement around the spiral groove (possible cyst vs tumor) -PET scan: No suspicious focal uptake or other evidence of malignancy -NCS/EMG 4/2018: severe right radial neuropathy proximal to the brachioradialis and distal to the triceps brachii/anconeus innervation -Ultrasound 4/2018: Enlargement of the radial nerve near the spiral groove. Hypoechoic central fascicles (ie the motor axons); normal appearing peripheral fascicles (ie the sensory axons). Fascicle enlargement is consistent with a demyelinating process, not an axonal process FINAL WORKING DIAGNOSIS: Neuralgic amyotrophy AKA Parsonage-Turner Syndrome TREATMENT AND OUTCOMES: He underwent physical therapy without improvement in symptoms. However, NCS/EMG revealed a demyelinating process that was consistent with spontaneous or autoimmune process such neuralgic amyotrophy; ultrasound revealed mostly motor axonal involvement. He opted for conservative management, monitoring for spontaneous improvement. He did not seek further follow up.