The role of PET imaging in the evaluation of prognosis in patients with chronicdisorders of consciousness

Objective To explore the role of 18F-fluoro-2-deoxy-D-glucose (18F-FDG) PET imaging for evaluation of the prognosis of patients with chronic disorders of consciousness. Methods 18F-FDG PET was performed to analyze glucose metabolism of external and internal awareness networks in 20 patients with chronic disorders of consciousness, and to calculate standardized uptake value (SUV) of each region. Compare the SUV of each region between conscious [Glasgow Outcome Scale-Extended (GOS-E) > 2] and unconscious (GOS-E ≤ 2) patients after 6 months follow-up. Results After 6 months, one case was lost, 8 cases recovered consciousness during the follow-up, 11 were unconscious (2 cases) or dead (9 cases). The age of unconscious or dead patients was significantly higher than that of conscious (P = 0.001), while the Coma Recovery Scale-Revised (CRS-R) score (P = 0.030) and the SUV of bilateral prefrontal lobes (left P = 0.000, right P = 0.002), bilateral parietal lobes (left P = 0.003, right P = 0.007), bilateral precuneus (left P = 0.000, right P = 0.003), anterior (P = 0.001) and posterior (P = 0.006) cingulate cortices of unconscious or dead patients were significantly lower than that of conscious patients. Conclusions The SUV of externaland internal awareness networks in 18F-FDG PET imaging is related to the prognosis of patients with chronic disorders of consciousness. The higher the SUV is, the better prognosis will be achieved.