Background: Chiari I malformations secondary to other causes represent a small subset of presenting symptomatic cases. Typically, the primary cause of the malformation is addressed first and results in resolution of the malformation and symptoms. However, in some cases, a patient may present with both a primary Chiari I malformation and another unrelated neurosurgical lesions.
Objective: To present a unique case in which resection of a ventral tumor allowed for spontaneous resolution of a simultaneously noted dorsal Chiari I malformation.
Methods: Pertinent data, including presenting symptoms, hospital course, surgical notes, preoperative images, and postoperative images, were collected using the electronic medical record.
Results: We present a case of a 46-yr-old man with a Chiari I malformation in conjunction with a ventral cranio-cervical junction chordoma. Endoscopic endonasal resection of the chordoma and ventral foramen magnum decompression resulted in radiographic resolution of the Chiari malformation and resolution of his symptoms. Our report represents a rare case of ventral foramen magnum decompression as a treatment for Chiari I malformation.
Conclusion: It is felt that the chordoma mass effect was not the source of the Chiari I malformation. Thus, both ventral and dorsal decompressions of the posterior fossa may be considered for Chiari I decompression in select circumstances.
Keywords: Chiari 1 malformation; Chordoma; Endoscopic endonasal approach; Ventral decompression.
© Congress of Neurological Surgeons 2021.