Observation of cerebral blood flow in persistant vegetative state patients with single-photon emission computerized tomography in comparison with cerebral CT and MRI findings

Aim: To evaluate the therapeutic effects of hyperbaric oxygen(HBO) in treatment of persistent vegetative state (PVS) by observation of cerebral blood flow in PVS patients. Methods: Twenty-six PVS patients received examination with 99Tc m-ethylcysteinate dimmer(ECD) single-photon emission computerized tomography (SPECT) to assess the regional cerebral blood flow (rCBF). A dynamic study was conducted in 9 cases during a follow-up for 60 d to 3 years, and 17 cases were also examined with brain CT and 14 with brain MRI. Results: All of the 26 cases exhibited abnormal cerebral blood flow. The locations of abnormal rCBF defined by SPECT were consistent with cerebral CT or MRI findings in 9 cases, but not in the other cases. Of the 9 cases followed up, cerebral blood flow recovered to normal level in 6 cases with the improvement of abnormal rCBF areas, showed no significant changes in 2 cases with PVS and further worsened in 1 case who died after 3 years. Conclusions: 99Tc m-ECD SPECT is a safe and reliable diagnostic modality for PVS, which directly reflects the status of cerebral blood flow and can be complementary to brain CT and MRI, with also value in monitoring the effect of HBO and medication for PVS and helping make prognostic judgment.