Normal Cerebral Radionuclide Angiogram in a Child with Electrocerebral Silence

Abstract

Pediatric neurologists agree that the determination of brain death in children, and especially retarded children, is difficult and that the criteria used in adult brain death may not be sufficient in pediatric cases. An unusual case of sustained electrocerebral silence on electroencephalogram (EEG) in a three-year-old retarded comatosed child with preserved intracerebral perfusion documented by a series of cerebral radionuclide angiograms (CRAG) is presented. The EEG showing electrocerebral silence represents loss of cerebrum (cortex) function (Barlow 1976). This absence of cortical function is demonstrated even though intracranial circulation is shown to be intact. We believe that the correlative studies presented accurately document a discordance between apparent loss of cortical function in a child as indicated by electrocerebral silence in the face of preserved cerebral blood flow. It is suggested that when evaluating brain death in retarded children with known cerebral atrophy, special emphasis should be placed on the CRAG and that the EEG should be read with caution.

Ancillary Testing in Brain Death

“…38 Cases of electrocerebral silence with preserved cerebral blood flow have also been reported. 39,40 Conversely, persistence of EEG activity has been described in patients thought to meet clinical criteria for brain death. 41 Additional limitations are that EEG is vulnerable to most of the same confounders as physical examination; it is not available 24 hours per day at many centers; and it is sometimes contaminated by electrical signals recorded from elsewhere in the intensive care unit environment (►Table 2).…”

“…As with other methods of assessing brain blood flow, some authors have speculated that skull defects or decompressive craniectomy may contribute to the scenario where there is some persistence of flow despite a clinical examination that is otherwise consistent with brain death. 39,92 In some cases, TCD patterns consistent with loss of brain blood flow may slightly precede complete loss of brain function. 83,93,94 Nevertheless, there are very few false-positive cases of brain death reported in the literature.…”

Brain Tissue Oxygenation in Children Diagnosed With Brain Death

“…When brain death occurs, CBF is expected to be absent, causing cerebral ischemia and irreversible cessation of brain function. Yet rarely, CBF to the cortex may continue after brain death has occurred [14,15]. However, we are unaware of any cases of return of brain stem function after a clinical diagnosis of brain death with continued CBF.…”

Normal Cerebral Radionuclide Angiogram and Electrocerebral Silence in the Presence of Severe Cerebral Atrophy

“…Current efTorts to establish uniform criteria for brain death determination in children make the recent report of Blend et al (3) particularly timely. The evaluation of the accuracy and limitations of the ancillary tests used to determine cerebral death have been one ofthe major points of controversy.…”