Glucose and Methionine Metabolism in Disorders of Consciousness After Brain Injury

BACKGROUND AND OBJECTIVES: F]fluorodeoxyglucose (FDG) PET is a marker of residual activity in disorders of consciousness (DoC). Brain amino acid metabolism remains poorly characterized. We examined cross-sectional and longitudinal glucose and methionine uptake and associations with improvement of consciousness. METHODS: C]methionine (MET) PET during routine care. The primary outcome was improvement of consciousness, defined as a ≥2-point increase in CRS-R. Associations between metabolic measures and ΔCRS-R were assessed using Spearman correlation with 95% CIs, with exploratory logistic regression and receiver operating characteristic analyses. RESULTS: ≥2.28 discriminated improvement (area under the curve 0.686 [95% CI 0.527-0.846]). DISCUSSION: Increased brainstem MET uptake was associated with improvement of consciousness and may complement FDG-PET findings in DoC, although interpretation is limited by the single-center design, exploratory analyses, and sample size. TRIAL REGISTRATION INFORMATION: Japan Registry of Clinical Trials: jrct.mhlw.go.jp; identifier: jRCTs031180091. Registration, January 21, 2019.