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Objective: The diagnosis of brain death syndrome by cardiotocography (CTG) and Doppler ultrasonography (US) is reported in a fetus at 35 weeks of gestation., Case Report: A 23-year-old, gravida 2, para 0, woman was referred to our hospital because of the absence of fetal movements. CTG showed fixed fetal heart rate (FHR) pattern. A detailed Doppler US examination of the fetus showed extensive cystic lesions of both cerebral hemispheres, polyhydramnios, total absence of neuromuscular parameters of biophysical profile (BPP) and the cessation of cerebral blood flow. Umbilical cord artery blood gas analysis showed pH 7.3, PaO2 30 mmHg and PaCO2 35 mmHg. A floppy male infant weighing 2,450 g was delivered vaginally at 36 weeks of gestation and the Apgar scores were 1 and 1 at 5 and 10 minutes, respectively. The neonate died 2 days after delivery. Postmortem examination of the brain showed diffuse, anoxic changes with multicystic encephalomalacia in both hemispheres and the brain stem. No other maternal or placental abnormalities were seen., Conclusion: The possibility of intrauterine brain death should be considered in all cases of prolonged fixed FHR pattern, accompanied by absence of neuromuscular parameters of BPP, polyhydramnios and demonstrated cessation of cerebral blood flow by Doppler US. Increased awareness of this event may prevent unnecessary emergency cesarean section.

Objective: The reported sensitivity of transcranial Doppler ultrasonography (TCD) for confirming brain death (BD) ranges from 91% to 100%. We assessed the frequency and causes of false-negative results in TCD examination in a series of patients with BD and in the literature., Methods: We carried out a prospective TCD examination of consecutive patients with the clinical diagnosis of BD., Results: In 204 (75.5%) of 270 patients, TCD showed a pattern compatible with BD. The causes of the false-negative results were persistent flow in the intracranial arteries in 47 (17.4%) patients and a lack of signal in 19 (7%). Absence of sympathomimetic drug use [odds ratio (OR) 5.4, 95% confidence interval (CI) 1.8-16.0, P = 0.003) and female gender (OR 3.7, 95% CI 1.1-12.5, P = 0.03) were associated with false-negative results. A review of 16 studies showed a sensitivity of 88% and a specificity of 98% of TCD for confirming BD., Conclusions: The sensitivity of TCD for confirming BD may be lower than previously reported, but is probably similar to that of other non-invasive methods. The specificity of TCD is close to 100%. Uniform criteria are needed for the routine use of TCD as a confirmatory test for BD.

Objective: Cerebral blood flow tests have increasingly been advocated for the confirmation of brain death (BD). Angiography has been considered the gold standard in the diagnosis of BD but is invasive. We validated transcranial color Doppler ultrasonography (TCD) to confirm BD by comparing it to angiography., Patients and Methods: Forty patients experienced the clinical diagnosis of brain death due to head injury in 19 cases (47.5%), cerebral hemorrhage in 11 (27.5%), subarachnoid hemorrhage in 7 (17.5%), and cerebral infarction in 3 (7.5%). Blood pressure, heart rate, SPO2, and PCO2 were monitored throughout the study. Patients were excluded if episodes of hypoxia, arrhythmia, and hypotension occurred during examinations, or if the TCD was not technically feasible., Results: Both angiography and TCD confirmed BD in all patients. The agreement between the above methods to confirm BD was 100%. Angiography showed the absence of filling of intracranial arteries, while TCD revealed: (1) brief systolic forward flow or systolic spikes and diastolic reversed flow (50%); (2) brief systolic forward flow or systolic spikes and no diastolic flow (25%); (3) no demonstrable flow in a patient in whom flow had been clearly documented on a previous TCD examination (12.5%). Five patients required repeated TCD examinations, because of initial detection of a diastolic to-and-fro flow pattern. BD was confirmed by TCD in the above patients after 30 hours of clinical BD., Conclusion: TCD was a sensitive tool to diagnose BD, affording a reliable alternative examination to standard angiography.

Objective: To evaluate the validity of transcranial Doppler (TCD) in confirming brain death from various pathological conditions., Methods: An observational case-control study over a 2.5 year period, in which transcranial Doppler (TCD) examinations were done on 101 comatose patients for confirmation of brain death. Between October 2002 to May 2005, 44 clinically diagnosed brain death cases (29 male, 15 female; mean (SD) age, 46.5 (19.5) years; Glasgow Coma Scale (GCS) score, 3.0 (0.0)) and 57 controls (36 male, 21 female; age 48.1 (16.5) years; mean GCS, 4.9 (1.7)) were examined. Reverse diastolic flow, very small systolic spikes, or no signals were considered characteristic of cerebral circulatory arrest., Results: The sensitivity and specificity of TCD examination of both the basilar artery and the middle cerebral arteries (MCAs) in confirming brain death were 77.2% and 100%, respectively. The sensitivity of TCD-diagnosed brain death increased with elapsed time. There was a trend for the basilar artery to have greater sensitivity (86.4% v 77.2%), higher positive predictive value (90.5% v 85.1%), and fewer false negatives (14% v 23.7%) than the MCAs for diagnosing brain death (all NS). The consistency of the basilar artery and the MCAs for diagnosing brain death was significant (kappa=0.877, p<0.001 and kappa=0.793, p<0.001, respectively)., Conclusions: TCD can be a confirmatory tool for diagnosing brain death. The validity of TCD diagnosed brain death depends on the time lapse between brain death and the performance of TCD. TCD of both the basilar artery and the MCAs showed significant consistency in brain death diagnosis.

The role of transcranial Doppler sonography in diagnosis of brain death (a practical review). The authors summarize the most important technical and practical knowledge regarding transcranial Doppler sonography. The characteristic Doppler signs of the cessation of cerebral blood flow are demonstrated, such as: oscillating flow, systolic spikes and zero-flow. The relatively high sensitivity (93.3%) of the repeated transcranial Doppler measurements in brain death diagnosis is highlighted.

Background: The heart transplant is a treatment of the heart failure, which is not responding to medications, and its efficiency is already proved: unfortunately, organ donation is a limiting step of this life-saving procedure. To counteract heart donor shortage, we should screen aged potential donor hearts for initial cardiomyopathy and functionally significant coronary artery disease. Donors with a history of cardiac disease are generally excluded. Coronary angiography is recommended for most male donors older than 45 years and female donors older than 50 years to evaluate coronary artery stenoses. A simpler way to screen aged potential donor hearts for initial cardiomyopathy and functionally significant coronary artery disease should be stress echocardiography., Case Report: A marginal donor (A 57 year old woman meeting legal requirements for brain death) underwent a transesophageal (TE) Dipyridamole stress echo (6 minutes accelerated protocol) to rule out moderate or severe heart and coronary artery disease. Wall motion was normal at baseline and at peak stress (WMSI = 1 at baseline and peak stress, without signs of stress inducible ischemia). The pressure/volume ratio was 9.6 mmHg/ml/m2 at baseline, increasing to 14 mmHg/ml/m2 at peak stress, demonstrating absence of latent myocardial dysfunction. The marginal donor heart was transplanted to a recipient "marginal" for co-morbidity (a 63 year old man with multiple myeloma and cardiac amyloidosis, chronic severe heart failure, NYHA class IV). Postoperative treatment and early immunosuppressant regimen were performed according to standard protocols. The transplanted heart was assessed normal for dimensions and ventricular function at transthoracic (TT) echocardiography on post-transplant day 7. Coronary artery disease was ruled out at coronary angiography one month after transplant; left ventriculography showed normal global and segmental LV function of the transplanted heart., Conclusion: For the first time stress echo was successfully used in the critical theater of screening potential donor hearts. This method is enormously more feasible, less expensive, and more environmentally sustainable than any possible alternative strategy based on stress scintigraphy perfusion imaging or coronary angiography. The selection of hearts "too good to die" on the basis of bedside resting and stress echo can be a critical way to solve the mismatch between donor need and supply.

Radionuclide brain scintigraphy is a commonly performed examination for the confirmation of brain death. Although the absence of scintigraphically detectable flow of lipophilic tracers to the brain combined with the lack of uptake in the brain is considered consistent with brain death in the appropriate clinical scenario, the cause of death itself is usually not apparent on the scan. A case of bullet track and bullet visualization during a radionuclide brain death study with Tc-99m hexamethylpropyleneamine oxime (HMPAO) is described.

Background: The diagnosis of brain death is based on both clinical and laboratory findings. However, diagnosis of brain death is still contentious and reliable tests are required. Early recognition and declaration of the diagnosis is the main goal, which is important for discontinuation of life support and organ donation for transplantation. In order to achieve this goal, competent diagnostic procedures should be performed. In this paper the authors review the diagnosis of brain death in eight children from different age groups, with an emphasis on factors concerning the reliability, use and appropriate application time of Tc-99m-HMPAO single photon emission computed tomography (SPECT) in early diagnosis in infants and newborns., Methods: Eight patients who fulfilled the clinical criteria of brain death underwent Tc-99m HMPAO SPECT and electroencephalogram (EEG) monitoring., Results: All patients had electrocerebral silence on EEG recordings. Six patients showed lack of perfusion in cerebrum in their first SPECT, however, newborns needed a second image for a confirmed diagnosis., Conclusion: In infants, SPECT has a high reliability for confirmed diagnosis of brain death; however, in newborns the application time is important for an accurate diagnosis.

Delays in diagnosis of brain death have definite consequences for the organ retrieval and transplantation process. It is advisable to use accurate diagnostic methods. Transcranial Doppler sonography is a well-accepted technique for diagnosing cerebral circulatory arrest. However, in some cases, the access to the intracranial circulation via the temporal window is difficult. In 43 brain-dead patients we evaluated the rate of impossibility of insonation of middle cerebral artery using a temporal window and the usefulness of an orbital window for insonation of the carotid siphon. In 39 patients the usual protocol of insonation (temporal window and foramen magnum window) was sufficient to demonstrate cerebral circulatory arrest. In 10 patients, including all the cases in which it was impossible to use a temporal approach, the carotid siphon was successfully insonated, showing in all the cases the existence of a sonographic pattern compatible with cerebral circulatory arrest. It may be concluded that the use of an orbital window for exploring intracranial circulation by transcranial Doppler sonography can be a useful tool in cases of difficult sonic windows.

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.

Objective: To determine the reliability of radionuclide cerebral blood perfusion imaging in confirming brain death irrespective of continued heartbeat., Subjects and Methods: Twenty-eight patients (19 male and 9 female, aged 17-63 years) with severe brain injury and fully supported until the final cardiac asystole were included in the study. Two sets of clinical tests aimed at ascertaining brain death in each subject were performed separately for each case within an interval of 24 h. Dynamic, planar and single photon emission computed tomographic (SPECT) brain scintigraphy were also performed after intravenous administration of 550 MBq (15 mCi) technetium-99m hexamethyl propyleneamine oxime., Results: Following the clinical diagnosis of brain death, none of the patients was withdrawn from cardiopulmonary support or had any organ harvested. Dynamic, planar and SPECT imaging performed thereafter did not reveal any intracranial cerebral perfusion in any of the subjects, except in 1 patient where the initial scan showed posterior fossa activity that ceased, in a subsequent scan obtained after 24 h. All of the patients were declared dead only after the emergence of cardiac asystole., Conclusion: The findings indicate that radionuclide brain perfusion imaging is reliable, reproducible, noninvasive and simple to perform for the confirmation of brain death and as such we recommend it as an alternative to exhaustive neurophysiological tests and invasive catheter angiography., (Copyright 2004 S. Karger AG, Basel)

Background and Objective: The use of transcranial doppler (TD) for the assessment of critical neurological patients and brain death (BD) is steadily growing. In this study we describe the daily clinical practice around BD diagnosis and compare the usefulness of TD, including advantages and shortcomings, with that of other tests., Patients and Method: A series of 100 patients diagnosed of brain death is presented including the demographic and clinical data as well as the results of ancillary tests (CE)., Results: Fifty eight patients were males with a mean age of 46. The most frequent etiology of coma was spontaneous cerebral hemorrhage. Central nervous system depressants had been administered to 62 patients within a few hours prior to the diagnosis. When ancillary tests were performed, only 55% patients fulfilled the currently accepted clinical criteria for brain death. TD was performed in 44 patients and 80% of them showed a pattern supporting a brain death diagnosis. Definitive diagnostic tests were electroencephalogram (EEG) in 53% patients and TD in 35% of them. In ten cases, discrepancies were observed between the results offered by these tests., Conclusions: Transcraneal Doppler stands out as a safe, fast, inexpensive and bloodless method of assessment of the critical neurological patient and for BD diagnosis. It is the choice test in the presence of central nervous system depressant drugs, abuse of substances or coma of unknown etiology. The main limitations of this technique are the presence of extensive craniotomies and the absence of an adequate acoustic window.

Background: Although the clinical examination and documentation of the clinical signs of brain death are very uniform, there are significant differences in the guidelines for using technical confirmatory tests to corroborate the clinical signs. The current study examined the utility of transcranial Doppler ultrasonography (TCD) for confirmation of brain death., Methods: After 19 patients were excluded from the study because of lack of bone window or because an apnea test could not be performed because of desaturation, 100 patients (61 patients with clinical brain death, and 39 control patients with Glasgow Coma Score<5) were included in the study. The following TCD findings were accepted as confirmatory of brain death when they were found bilaterally or in at least three different arteries for at least 3 minutes within the same examination: (1) brief systolic forward flow or systolic spikes and diastolic reverse flow, (2) brief systolic forward flow or systolic spikes and no diastolic flow, or (3) no demonstrable flow in a patient in whom flow had been clearly documented in a previous TCD examination., Results: The sensitivity and specificity of the first TCD examination for confirmation of brain death were 70.5% and 97.4%, respectively. Eighteen patients with clinical brain death required repeat TCD examinations because of detection of forward systolo-diastolic flow or a diastolic to-and-fro flow pattern, which were not confirmatory for the diagnosis of brain death. Brain death was confirmed ultrasonographically in 12 of 18 patients in a second examination after 12.6 +/- 8.3 hours of clinical brain death, in 2 patients in a third TCD examination, and in 1 patient in a fourth examination. Three clinically brain-dead patients had died before the diagnosis was confirmed by repeat TCD examinations. The sensitivity of TCD reached 100% in our study population after the fourth examination., Conclusion: The sensitivity of TCD is increased with repeat examinations and should be repeated in cases in which systolo-diastolic forward flow is demonstrated after the first TCD. TCD may prolong or shorten the time to declaration of brain death. The necessity of demonstrating cerebral circulatory arrest in patients with clinical brain death is debatable.

The concept of "brain death" was introduced to medicine in the second half of the 20th century, when technological advancements began to allow sustaining cardiorespiratory functioning of the body in the absence of brain function. Although physicians generally agree that a patient can be declared brain dead when the loss of brain function is total and irreversible, different approaches have been taken to define what constitutes brain death. A thorough clinical examination is essential to the diagnosis. The role of confirmatory tests differ among countries in the world but generally are indicated when a specific part of the clinical examination cannot be performed or is deemed unreliable. Under certain circumstances, confirmatory tests can be used to shorten the clinical observation. Of the confirmatory tests recommended by the American Academy of Neurology and the American Academy of Pediatrics, cerebral scintigraphy is a safe, reliable, and widely available alternative. Once the radiopharmaceutical is properly compounded, cerebral scintigraphy can be performed rapidly and can be interpreted in a straightforward manner. It is tolerant of metabolic aberrations and pharmacologic intoxicants. It is not affected by electrical interference, and the presence of skull defects or scalp trauma do not preclude its performance. The radiopharmaceuticals used in scintigraphy have no deleterious effects on potential donor organs. Cerebral radionuclide angiography has been highly sensitive. Either cerebral planar scintigraphy or cerebral scintitomography with Tc-99m hexamethylpropyleneamineoxime also are highly sensitive, but, in addition, appear to be 100% specific.

Objective: Complex sets of movements of the extremities can be seen in patients with brain death (BD), and are typically observed during apnea testing or removal of ventilatory support (also called the Lazarus sign). We here describe brain-dead patients who had not shown previous movements, even during apnea testing, but presented complex spinal reflexes during transcranial Doppler (TCD) examination elicited by neck flexion., Methods: We performed a prospective TCD study of patients with the clinical diagnosis of BD., Results: Four (2.5%) of 161 brain-dead patients presented complex spinal reflexes exclusively during TCD examination. TCD showed vertebro-basilar circulatory arrest in all four. Their systolic blood pressure was significantly lower than that of brain-dead patients not presenting movements during TCD examination., Conclusions: Hypotension and mechanical stimulation play a role in the pathophysiology of complex spinal reflexes present in BD, which are not exclusively seen in terminal hypoxia. Intensive care personnel and neurologists who perform TCD to confirm BD should be aware of these movements.

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 persistence of intracranial telediastolic flow using TDS. In those cases, it is advisable to use other tests to confirm the clinical diagnosis of BD.

The criteria for the confirmation of brain death (BD) using transcranial Doppler ultrasonography (TCD) state that flow should not be observed in the internal carotid artery (ICA). In 94 brain-dead patients examined by TCD, 19 (20%) had flow in the ICA despite cerebral circulatory arrest. There was no difference in the clinical characteristics of patients with or without isolated flow in the ICA. Shunting of blood from the ICA into the external carotid system or the arrest of blood flow at a higher level than the carotid siphon may explain our findings. Our results show that the current TCD criteria can result in a high rate of false negatives. We suggest that the TCD criteria for the diagnosis of brain death should be reviewed.

Objective: To review clinical outcomes in patients referred for confirmation of brain death by (99m)Tc-labelled exametazime scintigraphy and to assess any tangible benefit., Design and Setting: A retrospective casenote review in the intensive care unit and nuclear medicine department of a tertiary-level acute care hospital., Patients and Participants: 66 consecutive patients, in whom a clinical diagnosis of brain death was not possible, undergoing (99m)Tc-labelled exametazime scintigraphy from February 1993 to March 2002, and for 56 of whom casenotes were available for review., Measurements and Results: Brain death was confirmed in 77% on the basis of absent supratentorial and infratentorial uptake. Where brain death was not confirmed, a normal scan was seen in 30%, the remainder showing patchy reduced infratentorial and/or supratentorial uptake. All patients with the scintigraphic appearance of brain death subsequently died. Even when brain death could not be confirmed, 11 of 13 patients died soon afterwards. Two patients with normal brain scintigraphy regained consciousness and survived for an extended period. When brain death was not confirmed by scintigraphy, elapsed time to certification of death was longer (44.7 vs. 7 h) and organ donation was less common even when a subsequent clinical diagnosis was made., Conclusions: The results indicate that patient prognosis remains poor regardless of the findings on (99m)Tc-labelled exametazime scintigraphy, but that the scan result influences the elapsed time to withdrawal of therapy or organ donation, providing a significant cost benefit, and occasionally a long-term survivor is seen.

Background and Purpose: The Doppler waveform patterns of loss of diastolic flow, appearance of retrograde diastolic flow, or no detectable flow in the cerebral arteries suggest significantly abnormal cerebral blood flow (CBF). A retrospective study was performed to show that significantly abnormal CBF alone, without clinical criteria, is not necessarily specific to brain death in the young pediatric population., Patients and Methods: Forty-seven pediatric patients, from newborn to 4 years of age, were found to have significantly abnormal CBF, including 7 patients with loss of diastolic flow, 28 with retrograde diastolic flow, and 23 with no detectable cerebral flow on serial Doppler sonographic examinations. Their clinical data and sonographic results were collected and analyzed., Results: Forty-two patients died, a few of whom had only transient improvement of cerebral flow. All of the patients with no detectable cerebral flow expired. Five patients survived with or without sequelae. Their underlying conditions that caused increased intracranial pressure were treated by medical and/or surgical intervention, and diastolic reversal of CBF corrected within 1 day in all 5., Conclusions: Although no detectable flow is a lethal sign, pediatric patients with loss or reversal of diastolic flow may survive with prompt and effective treatment. Using Doppler ultrasound to diagnose cerebral circulatory arrest should be done with caution in pediatric patients.

Background: The aim of this study is to evaluate the value ofTc-99 HMP AO cerebral SPECT imaging to confirm brain death in patients with complex spinal automatism., Methods: Fifteen patients (8 female, 7 male) aged between 1,5-48 years showing spinal movements within 24-72 hours after brain death were examined with Tc-99 HMPAO cerebral SPECT., Results: All patients demonstrated empty skull on Tc-99 HMPAO images and no contradictory case was ob- served between standard clinical criteria and SPECT study., Conclusion: Non-invasive brain SPECT study is valuable to diagnose and confirm brain death with spinal automatism in adults and children. Key words: Tc-99 HMPAO SPECT, brain death, spinal automatism

Objective: To create an experimental organ donor model and validate it by ultrasound evaluation of intracranial blood flow velocity., Material and Method: Ten white New Zealand rabbits were assigned to either a control group or an experimental group. Brain death was induced in the experimental group by way of severe cranial hypertension. A diagnosis of brain death was based on physical examination and velocity of intracranial blood flow determined by transcranial doppler ultrasonography. Physical and ultrasound examinations were performed on all animals at baseline and at the time of the experiment., Results: Physical examination and intracranial blood flow velocity were normal in the control group animals at baseline and during the study. The findings were also normal for the experimental group animals at baseline. After provocation of intracranial hypertension, we observed signs of brain death (absence of response to pain stimulus in one cranial par absence of brainstem reflexes, and apnea) in the experimental animals, and the velocity of flow in arteries at the base of the skull acquired the waveform known as sharp systolic peaks, which are characteristic of cerebral circulation failure., Conclusions: The results of physical examination and ultrasonography in this study provide adequate validation of this experimental model of brain death and demonstrate that transcranial doppler ultrasonography is useful for diagnosing brain death in the rabbit.

Introduction: Throughout the world, is fully accepted that a person is dead when brain death exists. In most situations, neurological criteria permit the diagnosis of brain death, but in some instances, as when high-dose barbiturate therapy has been used, confirmatory testing are required by law., Clinical Case: We report the case of a 17 year-old women who suffered high-dose barbiturate therapy due to post traumatic intracranial hypertension. During the period of the barbiturate infusion and until six days after the suppression of this therapy, neurological exploration and EEG findings seem to confirm brain death, while transcranial Doppler (TCD) study remained normal., Conclusions: TCD is a fast, simple and accurate confirmatory testing in the determination of brain death and its findings are not affected by high-dose barbiturate therapy. We think that TCD must be present in all hospitals where mechanical ventilation and support of patients are carried out.

The purpose of these guidelines is to assist nuclear medicine practitioners in recommending, performing, interpreting, and reporting the results of brain perfusion SPECT studies using Tc-99m radiopharmaceuticals and brain metabolism PET studies using F-18 fluorodeoxyglucose (FDG). These guidelines have been adapted and extended from those produced by the Society of Nuclear Medicine (Juni et al., 1998) and the European Association of Nuclear Medicine by a Belgian group of experts in the field trained in neurology and/or nuclear medicine. Some indications are not universally approved (e.g. brain death), but largely supported by the literature. They have been included in these guidelines in order to provide recommendations and a standardised protocol.

Introduction: The Real Ordinance 2070/1999 meant an important modification in the legislation, when including transcranial Doppler (TCD) in explorations to confirm the clinical diagnosis of brain death (BD). Habitually for their employment in the diagnosis of BD, we look for blood flow signal from the middle cerebral arteries (MCA) and the basilar artery (BA)., Objectives: To check the effectiveness of the TCD like test of BD, looking for both middle cerebral arteries (MCA) and both intracranial vertebral arteries (VA), instead of the BA, and taking as Gold Standard cerebral scintigraphic techniques., Patients and Methods: . We present 25 patients diagnosed clinically with BD; on these TCD was carried out to confirm BD. Later on we proceeded to carry out cerebral scintigraphic techniques in all these cases. As statistical tool the test of c2 is used with confidence interval of 95%., Results: In 24 of the 25 cases, the TCD was effective in confirming the diagnosis of BD. In the remaining patient, a false positive result was obtained, since the TCD didn't reveal flow in the infratentorial compartment, as contrary to the cerebral scintigraphic techniques which showed the presence of residual flow at this level; this residual flow disappeared in 36 hours. This patient was hemodynamically unstable during TCD exploration., Conclusions: In our results the TCD obtains a reliability of 100% when confirming the absence of blood flow in the supratentorial compartment; nevertheless the false positive result obtained at the infratentorial level, warns us to be cautious in accepting the flow from the VA as a test of absence of flow at the infratentorial compartment, especially in those patients with hemodynamic instability.

Unlabelled: An infant with intrauterine brain death accompanied by pulmonary hypoplasia is reported. The fetus was delivered after 36 weeks gestation, 5 weeks after fetal movements ceased. The child died 4 h after birth. Pulmonary hypoplasia and remote brainstem necrosis associated with multicystic encephalomalacia were found at autopsy., Conclusion: These findings suggest that damage to brainstem respiratory centres had led to pulmonary hypoplasia through the absence of fetal respiratory movement.

Background and Objective: Recently, we have shown, by using localized in vivo phosphorus-31 magnetic resonance spectroscopy (31P MRS) of the anterior left ventricular wall, that brain death (BD) is not associated with reduced myocardial energy status. In this study, we applied ex vivo 31P MRS of the entire heart to study the effects of BD on the energy status of the feline donor heart following explantation., Methods: We used cats (6 BD and 6 controls [C]) in a 26-hour protocol. After 2 hours of preparation, we induced BD by filling an intracranial balloon at t = 0 hour. At t = 6 hours, the hearts were arrested with St. Thomas' Hospital cardioplegic solution, explanted, and stored in the same solution at 4 degrees C in a 4.7 Tesla magnet for 17 hours. Subsequently, the hearts were reperfused in the Langendorff mode at 38 degrees C for 1 hour. The first 5-minute 31P MRS spectrum was obtained 1 hour after crossclamping the aorta; we obtained subsequent spectra every hour during storage and every 5 minutes during reperfusion. At the end, the hearts were dried and weighed. Phosphocreatine (PCr), gamma-adenosine triphosphate (gamma-ATP), inorganic phosphate (Pi), and phosphomonoesters (PME), were expressed per g dry heart weight. The intracellular pH (pH(i)) and the PCr/ATP ratio were calculated., Results: During storage, we identified a significant but similar decrease of pH(i), PCr/ATP ratio, and PCr in both groups. During reperfusion, pH(i) and PCr/ATP ratio recovered similarly in both groups, whereas the recovery of PCr in the BD group was significantly lower (p < 0.05). The Pi and PME increased in both groups during storage but to a lesser extent in the BD group (p < 0.05). This difference disappeared during reperfusion. The gamma-ATP was already significantly lower in the BD group at the onset of storage, and this remained so throughout storage and reperfusion (p < 0.05 vs C). Contractile capacity was lost in all hearts, except for 1 heart in the BD group., Conclusion: Brain death-related failure of the energetic integrity of the feline donor heart becomes apparent only when using 31P MRS during ischemic preservation and subsequent reperfusion.

Initially introduced in the early 1980's, transcranial Doppler followed by transcranial Doppler sonography were used in neurosurgical units for management and follow-up of intracranial vasospasm in patients with subarachnoid hemorrhage. This imaging technique, more sensitive and less invasive than catheter angiography, also proved to be of value for diagnosis of intracranial atherosclerosis, management of patients with head trauma, and evaluation of collateral flow through the circle of Willis. Doppler US would also allow prediction of the risk of symptomatic embolic events through monitoring of HITS. Evaluation of the middle cerebral arteries during carotid occlusion testing is useful for evaluating the need for particular revascularization techniques. Finally, Doppler imaging is useful to assess patients with possible brain death. A recent advance in Doppler imaging is the ability to provide a three-dimensional projection (3D Doppler) of the intracranial arteries enabling improved detection and evaluation of stenoses involving the circle of Willis and improved characterization of intracranial aneurysms. These new applications benefit from the use of US contrast agents and harmonic US imaging.

Transcranial doppler ultrasonography (TCD) is a noninvasive monitoring tool which allows imaging of blood flow velocities in intracranial blood vessels. It is safe, portable, easy to perform and provides accurate information regarding underlying physiology which may help to guide therapy in critically ill neurologic patients. It has significantly contributed to the management of vasospasm related to subarachnoid hemorrhage in the neurologic intensive care unit. TCD is also helpful in the early diagnosis of a variety of complications that can occur in patients with head injury such as vasospasm, elevated intracranial pressure and disordered cerebral autoregulation. Careful performance of the test and experienced interpretation can identify TCD waveforms indicative of cerebral circulatory arrest, an ancillary finding used for the diagnosis of brain death. TCD is likely to play a larger role in evaluation of the patient in the future because of its safety, portability and ability to define moment-to-moment changes in cerebral blood flow velocities and cerebral blood flow.

The medical records of all brain dead patients (n = 228) at the Hospital for Sick Children, Toronto from January 1990 to December 1999 were reviewed. A radionuclide cerebral blood flow study (RCBFS) as a supportive and confirmatory test was performed on 27 patients and the clinical diagnosis of brain death was confirmed on all of them. A RCBFS was performed on 10 out of 27 patients because full clinical evaluation could not be performed due to severe facial injuries or cervical injuries. A RCBFS was performed on 17 patients who underwent a full clinical evaluation, of which 15 cases were due to uncertainty in the clinical etiology of the deep coma and 2 cases were due purely to the need to persuade the family. In recent years, RCBFS was not used as extensively on patients who underwent a full clinical evaluation, reflecting social acceptance and a higher level of clinical certainty in diagnosing brain death in children. This study supports the opinion that brain death can be accurately diagnosed in pediatric patients with clinical criteria alone and confirmatory tests are not necessary in most cases.

In this study, we investigated the blood flow velocity changes in orbital arteries by using Doppler sonography in eight patients with brain death. Peak-systolic and end-diastolic velocities and resistive indices of the ophthalmic and central retinal arteries were evaluated. We observed the absence or reversal of end-diastolic blood flow in these arteries. To our knowledge, this finding has not been previously reported to be associated with brain death.

Objective: To evaluate whether a negative atropine test (i.e., increase in heart rate of less than 3% after intravenous administration of 3 mg atropine) correctly predicts circulatory arrest in the fossa posterior during craniocaudal herniation in patients with primary supratentorial lesions., Material and Methods: Prospective, observational clinical study., Setting: Two surgical intensive care units in a university hospital., Patients: In 45 consecutive patients with suspected brain death, an atropine test (AT) and a transcranial Doppler sonography were performed simultaneously and, if necessary, repeatedly., Measurements and Results: Forty-four patients fulfilled the typical criteria of a supratentorial and infratentorial circulatory arrest as the atropine test became negative. In one patient, who had undergone a decompressive craniectomy for uncontrollable intracranial pressure 4 h prior to the AT testing, we found a negative AT in the presence of an antegrade supratentorial and infratentorial flow., Conclusion: A negative atropine test indicates a circulatory arrest in the fossa posterior in patients with primary supratentorial lesions and craniocaudal herniation. In patients with brain-stem lesions, however, a negative atropine test does not unequivocally indicate a circulatory arrest.

Diagnosis of brain death requires definite evidence of an acute CNS catastrophe and exclusion of complicating medical conditions that may confound clinical assessment. Acute CNS catastrophe may be due to direct ("primary") brain damage (e.g., intracerebral hemorrhage, severe concussion, brain tumors), or indirect ("secondary") brain damage (e.g., cerebral hypoxia following cardio-pulmonary resuscitation). The cardinal findings in brain death are coma, absence of brainstem reflexes, and apnea. Persistence of these clinical signs determines brain death. In Germany, the intervals of a repeat clinical evaluation are at least 12 hours in patients with primary, and at least 72 hours in those with secondary brain damage. Electroencephalographically documented absence of electrical activity for at least 30 minutes or by means of transcranial Doppler ultrasonography or isotope angiography documented intracranial circulatory arrest also confirm brain death. Under such conditions, a repeat clinical evaluation is unnecessary in patients with clinical brain death signs. First of all, brain death is a clinical diagnosis. Confirmatory tests are not mandatory in most situations. In Germany, confirmatory tests are required in newborns, infants below the age of 2 years, and patients with infratentorial brain damage.

Background: The accuracy of the clinical diagnosis of brain death has never been established., Methods: Seventy-one consecutive clinically brain dead patients were studied retrospectively. Inclusion criteria were complete cessation of brain function with profound coma of known cause, complete absence of brain stem reflexes, and apnea, all persisting for a least 6 hours. A formal apnea test with a documented Pco2 of > 60 mm Hg was required. All evaluations were done by experienced neurosurgery or neurology resident or staff physicians. The clinical diagnosis was compared with the results of radionuclide angiography and with the clinical course and final outcome., Results: Seventy patients had no arterial blood flow on radionuclide angiography. One blood flow study was considered to have yielded a false-negative result. No patient recovered or survived., Conclusions: The clinical diagnosis of brain death is highly reliable when made by experienced examiners using established criteria. In this study, the accuracy was 100%.