Transcranial Doppler (TCD) Examination is One of the Ancillary Investigations Used to Establish the Diagnosis of Brain Death

Abstract

Background: The determination of brain death relies primarily on clinical neurological assessment; however, ancillary investigations are often required when standard examination or apnea testing cannot be fully performed. Transcranial Doppler (TCD) ultrasonography offers a noninvasive bedside method to assess cerebral hemodynamics and may provide supportive evidence of severely impaired cerebral perfusion. Case Presentation: We report a serial case of critically ill patients with severe neurological impairment following cardiac arrest, in whom TCD was performed as part of the evaluation for suspected brain death. TCD examinations focused on intracranial arterial flow patterns, particularly within the middle cerebral artery. The observed waveforms demonstrated high-resistance pulsatile flow with markedly reduced diastolic velocities, reflecting impaired cerebral perfusion rather than immediate cerebral circulatory arrest. Serial neurological deterioration and neuroimaging findings were consistent with severe hypoxic–ischemic brain injury. Conclusion: Transcranial Doppler ultrasonography serves as a valuable ancillary tool in the assessment of suspected brain death by providing real-time information on cerebral blood flow dynamics. Although TCD should not replace clinical criteria, its bedside availability and ability to demonstrate evolving high-resistance flow patterns make it a useful supportive modality in selected clinical situations.