Nauman S Chaudhry1, Alp Ozpinar2, Wenya Linda Bi1, Vamsidhar Chavakula1, John H Chi1, Ian F Dunn3. 1. Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA. 2. Department of Neurological Surgery, Oregon Health Sciences University, Portland, Oregon, USA. 3. Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA. Electronic address: idunn@partners.org.
Abstract
BACKGROUND: Basilar invagination is a rare clinical condition characterized by upward protrusion of the odontoid process into the intracranial space, leading to bulbomedullary compression. It is often encountered in adults with rheumatoid arthritis. Transoral microscopic or endonasal endoscopic decompression may be pursued, with or without posterior fixation. We present a case of basilar invagination with C1-C2 autofusion and discuss an algorithm for choice of anterior versus posterior approaches. CASE DESCRIPTION: A 47-year-old woman with rheumatoid arthritis presented with severe occipital and cervical pain, dysphagia, hoarseness, and arm paresthesias. Findings on magnetic resonance imaging revealed moderate cranial settling with the odontoid indenting the ventral medulla but no posterior compression. Computed tomography demonstrated bony fusion at C1-C2 without lateral sag. Given autofusion of C1-C2 in proper occipitocervical alignment and the absence of posterior compression, the patient underwent endoscopic endonasal odontoidectomy without further posterior fusion, with satisfactory resolution of symptoms. CONCLUSION: Endoscopic endonasal odontoidectomy offers a safe and effective method for anterior decompression of basilar invagination. Preoperative assessment for existing posterior fusion, absence of posterior compression, and preservation of the anterior C1 ring during operative decompression help stratify the need for lone anterior approach versus a combined anterior and posterior treatment.
BACKGROUND: Basilar invagination is a rare clinical condition characterized by upward protrusion of the odontoid process into the intracranial space, leading to bulbomedullary compression. It is often encountered in adults with rheumatoid arthritis. Transoral microscopic or endonasal endoscopic decompression may be pursued, with or without posterior fixation. We present a case of basilar invagination with C1-C2 autofusion and discuss an algorithm for choice of anterior versus posterior approaches. CASE DESCRIPTION: A 47-year-old woman with rheumatoid arthritis presented with severe occipital and cervical pain, dysphagia, hoarseness, and arm paresthesias. Findings on magnetic resonance imaging revealed moderate cranial settling with the odontoid indenting the ventral medulla but no posterior compression. Computed tomography demonstrated bony fusion at C1-C2 without lateral sag. Given autofusion of C1-C2 in proper occipitocervical alignment and the absence of posterior compression, the patient underwent endoscopic endonasal odontoidectomy without further posterior fusion, with satisfactory resolution of symptoms. CONCLUSION: Endoscopic endonasal odontoidectomy offers a safe and effective method for anterior decompression of basilar invagination. Preoperative assessment for existing posterior fusion, absence of posterior compression, and preservation of the anterior C1 ring during operative decompression help stratify the need for lone anterior approach versus a combined anterior and posterior treatment.
Authors: Lance Michael Villeneuve; Zoya Voronovich; Alexander Evans; Edward T El Rassi; Ian F Dunn; Zachary A Smith Journal: Surg Neurol Int Date: 2021-10-11