Justin Nofar1, Mina Sitto3, Ashhar Ali1, Yamin Sallowm2
1Neurology, 2Anesthesiology, Henry Ford Health, 3Wayne State University School of Medicine
Background:
Occipital nerve blocks are routinely performed for the treatment of various headache disorders. When conventional medications are not sufficient, minimally invasive methods such as occipital nerve blocks become a viable treatment option. The targeted nerves can be reached using anatomical landmarks or imaging. We present a case of an occipital nerve block inadvertently leading to the discovery of a high-grade neoplasm.
Design/Methods:
78-year-old female complaining of headache for 2 years. It was moderate to severe intensity, originated from the left > right occipital region, and radiated anteriorly. Quality was sharp/shooting/stabbing. She was previously diagnosed with occipital neuralgia by outside provider and had undergone two occipital nerve blocks, with significant but temporary relief. She was evaluated by neurology at our institution, who concurred with the diagnosis of bilateral occipital neuralgia, and referred her for bilateral occipital nerve blocks. Using standard protocol, a 25-gauge, 1.5-inch needle was advanced 0.5 inches on the left, but no contact was made with the occipital bone. The thickness of the scalp was re-evaluated by palpation and was normal. A lateral X-ray was taken to assess the distance between the needle tip and the periosteum, and demonstrated an abnormal appearance of the occipital bone. The procedure was aborted.
Results:
Non-contrast CT head demonstrated destructive osseous changes involving the majority of the occipital bone with extraosseous soft tissue extension. MRI brain with and without gadolinium demonstrated an expansile, heterogeneous lesion involving the occipital calvarium without intracranial enhancement. CT-guided biopsy confirmed neoplasm favoring carcinosarcoma.
Conclusions:
Occipital nerve blocks are commonly performed without prior imaging or image-guidance. This case raises the potential need of pre-intervention screening (e.g. x-ray) or ultrasound guidance, particularly in elderly patients with new-onset occipital neuralgia. This would accommodate varying skull sizes, pathologies, and anatomical variations, which can improve the effectiveness of the block, minimize recurrence, and avoid complications.