Computerized axial tomography in brain death.

Abstract

SUMMARY Two patients with the diagnosis of brain death were evaluated with computerized axial tomography (CAT). After intravenous infusion of 30% Conray there was no visualization of the intracranial vasculature (circle of Willis). The second patient also had an isoelectric EEC A third patient with an intracerebral lesion similar to the other cases but without diagnosis of brain death, showed good visualization of the circle of Willis. Therefore, contrast-enhanced CAT scans can be used as another diagnostic aid to confirm brain death.AN ISOELECTRIC electroencephalogram is one of the means by which brain death is confirmed. Lack of cerebral artery perfusion at arteriography has also been recognized as a neurodiagnostic sign of brain death. In the following 2 cases the lack of cerebral artery perfusion on contrast-enhanced computerized axial tomography (CAT) scan also confirmed brain death. Patient 1A 75-year-old hypertensive woman experienced a severe headache associated with vomiting 30 minutes prior to becoming unconscious. Blood pressure was 210/120, pulse 60/min. Brain stem reflexes were absent. The patient was flaccid and unresponsive to all stimuli. Supportive respiratory devices were used for 30 minutes after the patient went into respiratory arrest. An isoelectric electroencephalogram was recorded the following day and CAT scanning was performed after infusion of 300 ml of 30% Conray at the rate of 25 ml/min for the first 6 minutes and 12 ml/min for the next 12. The first horizontal cut, designed to transect the circle of Willis, was scanned after 150 cc had been infused. The preinfusion scan revealed an extensive thalamic hemorrhage with intraventricular extension.The contrast-enhanced scan confirmed this but failed to visualize the circle of Willis ( fig. 1). Patient 2A 47-year-old male complained of severe headache on the morning of hospital admission. BP was 170/90, pulse 80/min. He was semicomatose and responsive to painful stimuli only. Right hemiparesis was evident. There was nuchal rigidity. A spinal tap revealed CSF pressure of 450 mm of water and bloody spinal fluid.

Confirmation of brain death diagnosis: A study on French practice

“…Several reasons could explain this result. This method, described for this indication in 1978 [12,13], has benefited from advances in imaging techniques that make it quick and easy to perform. More recent studies showed that a score evaluating the lack of opacification of 7 intracranial vessels allowed confirming cerebral circulatory arrest with high specificity but low sensitivity [6,14].…”

“…Eighty-two out of 188 ICUs filled out the questionnaire (a response rate of 44% [10][11][12][13][14][15][16][17][18]. The number of brain dead patients admitted per ICU each year was 11 [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22].…”

“…The number of brain dead patients admitted per ICU each year was 11 [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22]. [4-20%]; P < 0.01).…”

“…Twenty percent of other ICUs followed a protocol [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29]. The combination of these two reasons was chosen by 35% of respondents.…”

Dynamic Computed Tomography of Cerebral Circulatory Arrest

“…The findings on IVDCT in CCA are in some ways more straightforward and in other ways more complex than past reports would indicate [19][20][21][22]. CT is sufficiently contrast sensitive to detect minor amounts of intracranial intravascular contrast media that would be otherwise missed during conventional angiography.…”