Transcranial Doppler characteristics in persistent vegetative status, locked-in syndrome and brain death

Comparison of the transcranial Doppler (TCD) characteristics of cerebral circulation in persistent vegetative status (PVS), locked-in syndrome and brain death patients.

Using TCD ultrasound to detect the flow velocity and waveform patterns of middle cerebral artery (MCA) and basilar artery (BA) in patients with PVS, locked-in syndrome and brain death.

The mean velocities of middle cerebral artery (Vmca) and basilar artery (Vba) were 30.0 cm/s and 24.3 cm/s in PVS patients respectively, which decreased 45.0% and 14.4% in comparing with normal value. For patients with locked-in syndrome, Vmca and Vba were 49.7 cm/s and 9.8 cm/s, which decreased 5.0% and 61.7% than the normal value respectively. These results showed that the decrease of anterior circulation was predominant in PVS, and the decrease of posterior circulation was predominant in locked-in syndrome. A unique diastolic reverse flow, short peak systolic wave or undetectable flow signal in middle cerebral artery were predominant in brain death patients, which was completely different from that of either PVS or locked-in syndrome.

TCD was a valuable tool in distinguishing PVS, locked-in syndrome and brain death patients according to the differences in velocities and patterns of anterior and posterior cerebral arteries.