Correlating Thermodynamics with Cognitive Outcomes in Magnetic Resonance-guided Laser Interstitial Thermal Therapy (MRgLITT) of a Pediatric Hypothalamic Hamartoma

Abstract

Magnetic resonance-guided laser interstitial thermal therapy (MRgLITT) is a commonly used clinical method of destroying intracranial brain foci. Our objective was to correlate the thermal damage estimate transition zone with cognitive outcomes in MRgLITT of a pediatric hypothalamic hamartoma. Uncomplicated MRgLITT was used to disconnect an 8-mm left Delalande grade II hypothalamic hamartoma (HH) revealed on neuroimaging of a 17-year-old male patient with drug-resistant epilepsy and a "gelastic+" semiology including both gelastic and tonic-clonic seizures. Despite meticulous planning, submillimetric stereotactic accuracy, and reassuring intraoperative thermography, the patient experienced transient, but profound, global amnesia. Retroactively, we applied a new iteration of thermographic software that overlays a magenta-colored transition zone (TZ) around the necrotic zone defined by the orange-pigmented thermal damage estimate (TDE). Clear involvement of the bilateral mesial circuits was demonstrated by the overlay of the TZ on the TDE. Involvement of the bilateral mesial circuits visualized with TDE and TZ could account for the neurocognitive outcomes of our patient. We highlight this case as our understanding of thermography analysis evolves, emphasizing principles of technique and trajectory planning, as well as considerations during thermablation to help inform surgical decision-making.