Brain death due to supratentorial masses: diagnosis using transcranial Doppler sonography.

Since cadaveric donation is the main source of organs for transplantation in many countries, the diagnosis of brain death is an important issue. The cessation of cerebral circulation is one phenomenon closely related to brain death. Transcranial Doppler sonography is one of the accepted techniques to establish cessation of cerebral circulation. One of the limitations attributed to Doppler is the lack of sensitivity for this diagnosis. The objective of this research was to establish whether transcranial Doppler sonography showed acceptable sensitivity and whether this was affected by the location of the intracranial mass effect. Twenty-four patients underwent transcranial Doppler sonography to establish the incidence of the three sonographic patterns associated with brain death: separation diastole-systole, reverberating flow, and systolic spikes. In all the cases the insonation of the arteries of the base of the skull was performed. In supratentorial lesions, the predominant pattern was a reverberating flow, while in infratentorial lesions systolic spikes pattern was most frequent. Our study showed a high sensitivity of transcranial Doppler sonography for the diagnosis of brain death and the existence of different mechanisms of cerebral circulatory arrest depending on the location of the intracranial pressure wedge.