Brainstem Auditory Evoked Potentials to Guide Minimally Invasive Decompression in Chiari 1.5: Technical Case Report.

Chiari malformation types 1 and 1.5 can be treated with posterior fossa decompression, though surgical techniques vary considerably, with more aggressive approaches often considered for type 1.5. Given this variability, an objective intraoperative marker of adequate decompression would support more tailored surgery. While brainstem auditory evoked potentials (BAEPs) have been explored in pediatric populations, their utility in adults remains unstudied. We present a 26-year-old female with Chiari 1.5 and symptoms including migraines, visual disturbances, balance issues, and right-hand clumsiness. She underwent a BAEP-guided, minimally invasive decompression involving a C1 laminectomy, linear dural opening, and tonsillar cauterization. Intraoperative BAEP monitoring allowed for a targeted, less extensive decompression, resulting in significant clinical improvement. This case highlights the potential utility of BAEPs in adult Chiari decompression, suggesting a role for further investigation of this technique in optimizing outcomes while minimizing invasiveness.