To investigate changes in brain temperature (T_CRE) in patients with treatment resistant epilepsy (TRE) who receive Cannabidiol (CBD).

CBD’s efficacy in TRE may stem from targeting neuroinflammation. Brain temperature elevations (T_CRE=−102.61(Δ_H20−CRE)+206.1°C) may be considered a proxy for neuroinflammation and can be non-invasively mapped using magnetic resonance spectroscopic imaging and thermometry (MRSI-t). Although MRSI-t studies have documented T_CRE elevations in TRE patients’ seizure onset zones (SOZs), no study has investigated if T_CRE are affected by a treatment that has anti-inflammatory effects (CBD).

Five adults aged 20 - 43 years (3 females) with TRE were imaged at 3T before (baseline) and after 12-weeks of CBD (on-CBD). Data were processed within the Metabolite Imaging and Data Analysis System software package. Voxelwise brain temperature calculations generated 3D T_CRE maps; voxelwise subtraction maps visualized each participants’ baseline vs. on-CBD T_CRE changes. Mean T_CRE was also estimated for 47 atlas-defined brain regions and evaluated using repeated measures t-tests.

The Chalfont Seizure Severity Scale (CSSS) evaluated CBD efficacy and medical records provided seizure frequency. Mood was assessed using the Total Mood Disturbance (TMD) score on the Profile of Mood States (POMS). Repeated measures t-tests computed changes in seizure symptoms and mood.

Baseline T_CRE elevations (>37.5°C) were localized to clinically implicated seizure generation and/or propagation sites. All participants’ seizure severity (p=0.015) and brain temperature (p<0.0001) decreased from baseline to on-CBD. There was also a non-significant decrease in POMS TMD.

MRSI-t documented T_CRE decreases in patients treated with CBD for treatment-resistant epilepsy. The observed effects may be related to CBD exposure, decreased seizure frequency/severity, or both. T_CRE derived from MRSI-t may be a promising imaging-based biomarker for tracking neuroinflammation in patients with neurological conditions including epilepsy. Future findings from this on-going study will provide critical insights into CBD’s effects in the human brain.