Role of Transcranial Doppler Sonography in Confirmation of Brain Death

The aim of the study was to determine the specificity and sensitivity of Transcranial Doppler Sonography (TCD) as a confirmatory test for diagnosis of brain death and to assess the possibility of adding this test to the protocol for diagnosis of brain death in ICU. TCD examination was done in 20 patients (group I) with brain death confirmed either by clinical assessment and EEG (17 patients) or by clinical assessment alone (3 patients). The clinical diagnosis of brain death was performed, according to the Saudi Ministry of Health approved protocol which included lack of response to stimulation and absence of brain stem reflexes (pupillary to light, corneal, oculocephalic, oculovestibular, gag and cough). The clinical assessment was repeated after at least 6 hours. EEG was done, if possible and was reported by the neurologist on call. Apnea test was done after the second clinical documentation of brain death was completed. TCD studies of the ophthalmic arteries, middle cerebral arteries and basilar artery were carried out. A characteristic TCD flow pattern of reversed diastolic flow or short systolic spikes, in at least two cerebral arteries, was seen in 17 patients (85% sensitivity). TCD examination of 24 comatose patients who were not brain dead (group II) did not reveal the same characteristic pattern in any of those cases (100% specificity). Conclusion: TCD is a highly specific and sensitive non-invasive tool that can be included in the protocol for diagnosis of brain death as a rapid bedside confirmatory test in patients proven clinically to be brain dead. The described TCD patterns of brain death should be elicited in 2 or more of the cerebral arteries.