Unilateral Greater Occipital Nerve Compression Causing Scalp Numbness.

CASE PRESENTATION A 50-year-old male developed a painless swelling over the scalp of the right occiput following an ablative cardiac procedure. Upon waking from general anesthesia, he noticed a “bump” on the back of his head and complete loss of sensation over his right scalp, extending rostrally to behind the hairline, caudally to the nuchal line, medially to the midline, and laterally to above the ear. He also had a new soft tissue mass over his right occiput. He denied hearing loss, tinnitus, visual disturbances, or difficulty speaking or swallowing. On physical examination, the right scalp was hypesthetic to light touch, pinprick, temperature, and vibration over the involved region. The left scalp, however, had intact sensation in all modalities. Over the right occiput, there was a mass measuring approximately 4 cm x 2 cm with overlying erythema. It was tense, non-fluctuant, and tender to palpation. The patient was treated with warfarin, and his INR was found to be supratherapeutic to 4.7. A CT scan of head and neck showed swelling and increased subcutaneous stranding over the right occiput, rather than hematoma formation, and a known stable lipoma over the left occiput. No intervention was undertaken to relieve the swelling. After 4 weeks, he reported that the swelling had completely resolved and the symptoms of sensory loss had subsided to approximately 80% of normal.