C2-Related Radicular Pain Due to a Posterior Arch Defect of C1 in an Elderly Patient: A Case Report

A 94-year-old woman with rheumatoid arthritis presented with sudden-onset, intractable right occipital pain without trauma. Radiological studies revealed C1-C2 foraminal stenosis and spinal cord compression caused by an unrecognized posterior arch defect of C1. Conservative management failed, and microscopic decompression without fusion was performed. Intraoperatively, a small bone fragment was found compressing the right C2 nerve root and was carefully removed. Her visual analog scale (VAS) pain score improved from 100 mm preoperatively to 50 mm immediately after surgery and to 5 mm at the two-year follow-up. This case highlights the importance of considering C1-C2 foraminal pathology and subtle C1 posterior arch defects as potential causes of occipital neuralgia or C2 radiculopathy in elderly patients with rheumatoid arthritis. Early recognition and minimally invasive decompression can achieve favorable outcomes even without fusion.