Diffuse cerebral swelling following head injuries in children: the syndrome of “malignant brain edema”

Abstract

The commonest initial computerized tomography (CT) finding in head-injured children is bilateral diffuse cerebral swelling. Cerebral blood flow and CT density studies suggest that this swelling is due to cerebral hyperemia and increased blood volume, not to edema. The clinical history, course, and outcome of 63 children with this CT pattern are reviewed. Fourteen children had a Glasgow Coma Scale score of greater than 8; all made a complete recovery and follow-up CT scans were normal. Forty-nine children had Glasgow Coma Scale scores of 8 or less. Fifteen had a history of a lucid period following the initial unconsciousness. One of these children died of delayed brain swelling, the others recovered well with minimal neurological deficit. Thirty-four children were rendered immediately and continuously unconscious. There was a high incidence of second lesions on the CT scan, 50% of this group developed intracranial hypertension and five died. All of the others were in coma for periods ranging from weeks to months. Follow-up CT scans showed an extracerebral collection with a density of cerebrospinal fluid in 27% of the patients, and ventriculomegaly with large sulci in 35%, whereas this pattern was seen only once in those with a lucid period. The difference between those with and without a lucid period is related to the degree of primary diffuse impact injury to the white matter.

Cerebral Blood Flow and Autoregulation After Pediatric Traumatic Brain Injury

“…Traumatic brain injury can cause flow-metabolism uncoupling, resulting in cerebral ischemia (CBF less than cerebral metabolic demand) or cerebral hyperemia (CBF in excess of CMRO 2 ) [66,67]. Adult TBI studies demonstrate that CBF reduction early after injury increases regional cerebral ischemia [68,69].…”

“…However it is difficult to know which patient will be at risk for either hyperemia or ischemia unless point of care examination of the relationship between CBF and CMRO 2 occurs. Examination of CBF after pediatric TBI during the 1980s concluded that cerebral hyperemia was responsible for the frequently observed diffuse brain swelling [66,82,83]. However, recent studies suggest age and gender differences in CBFV.…”

“…Additionally, cerebral autoregulation is not a static condition and may deteriorate in patients with initially intact autoregulatory capacity. Since, theoretically, augmenting MAP in the hyperemic brain could result in cerebral hemorrhage [66,81,106], these data question whether empirically increasing MAP to prevent cerebral ischemia in the presence of unilaterally impaired cerebral autoregulation and cerebral hyperemia may potentially be harmful.…”

Delayed, Transient Neurological Deterioration After Mild Head Injury. Case Report.

“…7,8,25,27,29) Post-traumatic hyperemia can be divided into malignant and benign types depending on the association with intracranial hypertension. 4,[12][13][14][15]19,23,26,27) Analysis of intracranial pressure and cerebral blood flow in 59 patients with moderate or severe head injuries showed that the median duration of hyperemia associated with intracranial hypertension was longer (median 6 days, range 1-14 days) than that of hyperemia without intracranial hypertension (median 2.5 days, range 0-5 days). 12) Our findings indicate that certain cases of mild head injury may represent a more delayed or prolonged hyperemia phase linked to a favorable outcome.…”

Pediatric Neurocritical Care

“…The mechanisms underlying this phenomenon are not fully understood [43]. Although initially attributed to increased cerebral blood flow (CBF) and vascular engorgement [44,45], better characterization of CBF in healthy and injured children has shown a more heterogeneous cerebrovascular response to injury in pediatric patients [46]. Cerebral hypoperfusion is likely the dominant derangement and there may be a greater risk of hypoperfusion following injury in the youngest victims [47][48][49][50].…”