RESUMO
Segmental zoster paresis is characterized by focal, asymmetric motor weakness in the myotome corresponding to the dermatome of the rash. A 73-year-old man, who presented with severe right shoulder pain and shoulder girdle muscle weakness, was diagnosed with segmental zoster paresis involvement of the C5 C6 motor roots as a complication of herpes zoster. Girdle muscles (supraspinatus, deltoid and infraspinatus) atrophy had developed in his right shoulder. An MRI showed rotator cuff tearing in his right shoulder; therefore, an arthroscopic rotator cuff repair was performed. Herein, this case is presented to emphasize the importance of considering post-herpetic segmental motor paresis in the differential diagnosis of acute painful motor weakness of the upper extremities.