Assessment of Heat Stroke-Induced Brain Injury: A Preclinical Study with a Rat Model Using ¹⁸F-FDG Brain PET

Area of Science:

• Neuroscience and Imaging
• Preclinical research on heat stroke pathophysiology

Background:

• Heat stroke is a severe heat-related illness with significant neurological complications.
• Limited research exists on the neuroimaging findings associated with heat stroke.
• Rising global temperatures increase the public health concern of heat stroke.

Purpose of the Study:

• To identify 18F-FDG brain PET imaging findings in a preclinical model of heat stroke.
• To evaluate the utility of FDG PET in assessing heat stroke-induced brain injury.

Main Methods:

• Heat stroke was induced in Sprague Dawley rats.
• 18F-FDG brain PET scans were acquired 3 hours post-induction in control and heat stroke groups.
• Region-based and voxel-based analyses of standardized uptake values were performed.

Main Results:

• Rats that did not survive heat stroke exhibited significantly higher SUVR in the hypothalamus and lower SUVR in cortical regions compared to controls and survivors.
• Survived rats showed some regional metabolic changes in the cortex compared to controls.
• Voxel-based analysis did not reveal significant differences in survived rats.

Conclusions:

• Three-hour post-injury 18F-FDG brain PET scans reveal distinct regional metabolic patterns in non-surviving heat stroke rats.
• FDG PET may serve as an early indicator of severe brain injury in heat stroke.
• FDG PET can reflect early neurological pathophysiology following heat stroke.