Brief review: The role of ancillary tests in the neurological determination of death

Brain death and the cervical spinal cord: a confounding factor for the clinical examination

“…[4][5][6][7] Only when confounding factors make the clinical examination of brainstem functions unreliable is an ancillary test required. [4][5][6][7][8][9][10][11] We report a case, and review the literature, to make the suggestion that upper cervical spinal cord injury is a common result of brain herniation, and a confounding factor in the clinical examination for BD. If unresponsive coma could be partly accounted for by the lack of ability to move the limbs, and if apnea could be attributed to absent respiratory muscle function, both due to upper cervical spinal cord injury, then clinical testing for BD is unreliable.…”

“…If unresponsive coma could be partly accounted for by the lack of ability to move the limbs, and if apnea could be attributed to absent respiratory muscle function, both due to upper cervical spinal cord injury, then clinical testing for BD is unreliable. 11 Many case reports in the setting of sudden brain herniation both with and without meningitis show that permanent or partially reversible cervical spinal cord injury can occur, and the clinical, autopsy and MRI findings suggest this is due to direct compressive injury to the spinal cord, its arterial supply and its venous drainage. [15][16][17][18][19][20][21][22][23][24][25][26][27][28] Furthermore, the autopsy series of BD show that high cervical spinal cord injury is a common finding (56-100% of cases), and most likely due to compression of the upper cervical spinal cord and its blood supply during cerebellar herniation.…”

“…[29][30][31][32][33][34][35] Fourth, in the setting of suspected BD, the spinal cord is rarely investigated or suspected to be affected when testing for limb movement to pain or apnea. [4][5][6][7][8][9][10][11] A final reason is that most patients are imaged with a CT scan of the brain, and this is often not adequate to show cerebellar herniation, and not inclusive of the upper cervical spinal cord. 43,44 To adequately show tonsillar herniation an MRI scan is required, and this is usually not done due to the hemodynamically unstable state of the patient.…”

“…4 High cervical spinal cord injury would be a confounding factor. 11 Other authors have written that the clinical testing to diagnose BD is done to show 'cerebral unresponsivity'; 5 'absence of the brainstem functions' 12 and 'loss of brainstem function; and signifies that breath as an essential element of life has vanished from man;' 13 or 'loss of the breath of life.' 14 We present a case and review the literature to argue that bedside testing cannot diagnose BD, because the cervical spinal cord is often injured and dysfunctional after cerebellar herniation, and therefore is a confounding factor.…”

The clinical criteria of brain death throughout the world: why has it come to this?

“…In Sweden, a cerebral angiogram has to be performed twice, with an adequate period of observation in between, documenting an absence of blood flow to the brain. Although the electroencephalogram is commonly recommended worldwide, in this issue Young et al 4 make compelling arguments against its use, in favour of tests that demonstrate the absence of intracerebral blood flow.…”