A 73-Year-Old Man Presenting with Shoulder Muscle Pain and a Diagnosis of Guillain-Barré Syndrome.

BACKGROUND Guillain-Barre syndrome (GBS) commonly presents with motor weakness and neurological symptoms and signs that include loss of tendon reflexes. However, patients with GBS also experience nerve pain (radicular pain) and deep muscle pain. This report is of a 73-year-old man presenting with shoulder muscle pain and a diagnosis of Guillain-Barre syndrome. CASE REPORT A 73-year-old man initially sought medical attention for severe left shoulder muscle pain. One week prior, he had experienced a cold and diarrhea, which improved with over-the-counter medication. Physical examination revealed normal shoulder joint motion without swelling or stiffness. Cervical spine magnetic resonance imaging (MRI) revealed osteophytes and disc protrusions from C3/4 to C6/7, leading to an initial diagnosis of cervical spondylosis. Two days later, he developed progressive numbness and weakness in both upper limbs. Upon hospital admission, further evaluation revealed partial cranial nerve dysfunction, elevated cerebrospinal fluid (CSF) protein levels without pleocytosis, and peripheral nerve damage on electromyography (EMG). GM1 antibody was positive, confirming GBS. Treatment with intravenous immunoglobulin (IVIG), gabapentin for pain management, and acupuncture targeting pain and limb symptoms resulted in the complete recovery of pain and limb function within a short period. CONCLUSIONS This report shows that deep muscle pain can be a symptom of Guillain-Barre syndrome. Recognizing such atypical presentations is crucial for timely diagnosis and effective management. This case provides a clinical basis for the diagnosis of atypical GBS and offers insights into pain management in GBS.