Persistence of intracranial diastolic flow in transcranial Doppler sonography exploration of patients in brain death

Abstract 

Objective

The persistence of cerebral blood flow (CBF) in patients with whole brain death (BD) diagnosis is an unusual phenomenon. We describe patients with whole BD diagnosed despite persistence of intracranial blood flow on transcranial Doppler sonography (TDS).

Materials and methods

From January 2001 to December 2002, we reviewed the records of 11 patients. Etiology of BD was craniocephalic trauma in 2 cases, schemic cerebrovascular accident (CVA) in 4 cases, Hemorrhagic CVA in 3 cases, subaracnoid hemorrhage in 1 case, and acute hydrocephalus in 1 case. Six patients had a cerebral decompressive mechanism. In all patients, TDS was used to confirm BD after clinical diagnosis. Additionally, all patients underwent an electroencephalogram (EEG). In 3 patients cerebral angiography (CA) and in 2 others radionuclide angiography (RA) with Tc99m HMPAO were done.

Results

All TDS studies showed persistent telediastolic positive flow in at least 1 artery. Because the TDS did not confirm the clinical diagnosis of BD, EEG tests were performed showing silence of bioelectrical activity. Those cases showed CA or RA results with a complete absence of CBF.

Conclusion

The TDS technique directly evaluates the intracranial but not the intracerebral circulation. For this reason, during the BD diagnosis for patients with previous decompressive techniques, it was possible to find persistance of intracranial telediastolic flow using TDS. In those cases, it is advisable to use other tests to confirm the clinical diagnosis of BD.