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Background: In several countries, a computed tomography angiography (CTA) is used to confirm brain death (BD). A six‑hour interval is recommended between clinical diagnosis and CTA acquisition despite the lack of strong evidence to support this interval. The aim of this study was to determine the optimal timing for CTA in the confirmation of BD., Methods: This retrospective observational study enrolled all adult patients admitted between January 2009 and December 2013 to the intensive care units of a French university hospital with clinically diagnosed BD and at least one CTA performed as a confirmatory test. The CTAs were identified as conclusive (e.g. yielding confirmation of BD) or inconclusive (e.g. showing persistent brain circulation)., Results: One hundred and four patients (sex ratio M/F 1.8; age 55 years [41‑64]) underwent 117 CTAs. CTAs confirmed cerebral circulatory arrest in 94 cases yielding a sensitivity of 80%. Inconclusive CTAs were performed earlier than conclusive ones (2 hours [1‑3] vs. 4 hours [2‑9], P=0.03) and were associated with decompressive craniectomy (5 cases [23%] vs. 6 cases [7%], P=0.05) and the failure to complete full neurological examination (5 cases [23%] vs. 4 cases [5%], P=0.02). Six hours after BD clinical diagnosis, the proportion of conclusive CTA was only 51%, with progressive increase overtime with more than 80% of conclusive CTA after 12 hours., Conclusions: A 12‑hour interval might be appropriate in order to limit the risk of inconclusive CTAs.

Background: The aim of this study was to evaluate the usefulness of early Transcranial Doppler (TCD) in guiding initial resuscitation of traumatic and non-traumatic comatose patients before diagnostic imaging and invasive neurologic monitoring., Methods: This was a prospective, interventional study and included patients in coma, before performing diagnostic imaging. A TCD was performed as soon as possible upon admission. Diastolic velocity (DV) <20 cm/s and Pulsatility Index (PI) >1.4 at both middle cerebral arteries were considered abnormal and specific therapy was started with fluid expansion with 2 L 0.9% saline solution, followed by norepinephrine infusion to increase MAP above 110 mmHg. An increment in DV >20 cm/s was considered as a good response., Results: Twenty-eight patients were included, 9 had normal TCD and 19 (68%) had abnormal TCD values. Mean values pre- and post-treatment were: MAP 84 ± 16/121 ± 9 mmHg; PI 2.26 ± 0.52/1.28 ± 0.47; DV 13 ± 7/33 ± 18 cm/s (P<0.0001 for all values); 13 patients (68%) were responders. Global mortality was 46 %. We find that the presence of oscillating flow, systolic peak or DV <20 cm/s after treatment, were associated with brain death in 100% of cases. Presence of a normal TCD was associated with no mortality., Conclusion: Our study suggests that early TCD is feasible to evaluate qualitative information about cerebral perfusion in comatose patients while they are waiting for diagnostic imaging studies.

According to Italian legislation to diagnose brain death (BD) after the initial documentation of the clinical signs, repetition of clinical testing and confirmation of the loss of bioelectrical activity of the brain (EEG) is required. However, when EEG is unreliable it is necessary to demonstrate cerebral circulatory arrest (CCA). Accepted imaging techniques to demonstrate CCA include: cerebral angiography, cerebral scintigraphy, transcranial Doppler (TCD) and computed tomography angiography (CTA). This latter technique, due to its large availability, low invasivity and easy and fast acquisition is widely used over the country. Nevertheless its diagnostic reliability is affected by some limitations in patients with decompressive craniectomy. Here we report two cases of brain injury with clinical signs of BD and at the same time, opacification of intracranial arteries on CTA and a pattern consistent with flow arrest on the corresponding insonable arteries on TCD. The discrepancy between CTA and TCD results points out a methodology limitation that could be overcome by updating Italian legislation according to other European Countries legislation.

Nuclear Medicine studies performed with tomographic acquisition and tracers such as Technetium-99m hexamethyl-propyleneamine oxime (99mTc-HMPAO) are able to assess cerebral blood flow. A case is reported of a patient with a large intracranial tumor, of possible pituitary origin, with a clinical and electroencephalographic suspicion of brain death. The patient had endocrinous-metabolic impairments for a history of impotence, since 18 months, and diabetes insipidus with a urine output of 350 ml/hr in the first 24 hours from the clinical suspicion of brain death. Due to the endocrinous-metabolic impairments, according to Italian law, it was necessary to confirm the diagnosis of brain death by performing a study able to assess cerebral blood flow. A single Photon Emission Tomography (SPET) scan was performed after the intravenous administration of 99mTc-HMPAO using a high resolution, brain dedicated device. No tracer uptake was evident in cerebral, cerebellar and brain stem structures. The cerebral blood flow study by SPET confirmed the diagnosis of brain death and made the organ transplant possible in a short period of time. High resolution SPET studies are useful to confirm the diagnosis of brain death when there are factors that can influence clinical and electroencephalographic signs, reducing time to authorise the organ explant.

The diagnosis of brain death has great importance for the social and medical purposes, such as organs transplantation, and is based on clinical examination and EEG records. We report two doubtful cases of brain death in whom the 99mTc HMPAO scintigraphy was used to confirm the complete absence of cerebral perfusion.

The delay in the diagnosis of brain death represents a cause of deficiency of organs for transplant. In this prospective study we evaluate the role of Doppler sonography, to investigate typical velocimetric profiles of brain death, and to evaluate the delay between finding the typical profiles and diagnosis expressed according to law. In this ongoing study, we evaluated 32 patients affected from serious primitive intracranial diseases (Glasgow Coma Scale < or = 7). Of the 32 patients examined, 18 underwent or still remained in brain death. All the patients showed typical profiles, classified in 3 fundamental types. Start of monitoring, according to the current law, showed a delay from 12 to 27 hours. The authors conclude that Transcranial Doppler and Doppler c.w. represent an early and sensitive technique, rightly to include in the procedure of the diagnosis of brain death.