A New Spinal Reflex Movement in Brain Death: Undulating Axial Trunk Torsion

Brain death is defined as the irreversible cessation of function of the brain, brain stem, and medulla oblongata, despite the persistent respiration and circulation supported by mechanical ventilation. The determination of brain death is important with outcome prediction and organ transplantations. Spinal reflexes can be seen in patients with brain death and created confusion about the diagnosis of brain death for patients’ families, which cause delay or refusal of deceased-donor organ donation. We present here a new dramatic spinal movement after tapping stimulation which should be recognized to avoid unnecessary testing and confusion for clinicians and family members. A 31-year-old woman presented with sudden severe headache to our hospital. Brain computed tomography (CT) revealed acute intraventricular hemorrhage. Her CT angiography showed a pseudoaneurysm at the end of left posterior pericallosal artery, puff-of-smoke collaterals at the M1 segment of right middle cerebral artery and at end of left internal carotid artery. A lumbar drainage was placed on the admission day. Two days later, her headache remained severe, and brain CT showed that her ventricular system was still filled with blood. An external ventricular drain was placed at the anterior horn of her right lateral ventricle. Six days later, she developed coma, and all her brain stem reflexes became absent. Brain CT showed increased intraventricular hemorrhage. Twenty days later, transcranial doppler and electroencephalogram proved brain death, and she passed the apnea test as well. All the procedures of brain death determination (clinical assessments and ancillary examinations) were conducted twice at an interval of 24 hours to confirm the death of brain. The timeline of her disease course and the results of relevant ancillary examinations were provided in Figures S1 through S3 and Table S1, SDC, https://links.lww.com/TP/C308. She was noted to have dramatic undulating axial trunk torsion and myoclonus in response to tapping stimulation at right shoulder (Figure 1). After tapping stimulation, the patient undulatingly twisted her abdomen towards the right with her chest and head moving to the left, and then she twisted her abdomen towards the left with her chest and head moving to the right. Myoclonus occurred after it and lasted for several seconds. Movements of undulating axial trunk torsion recurred in the end. The whole motor response to tapping stimulation lasted for about 10 seconds. This spinal reflex movement was seen for 8 days, from the 10th day after the absence of brain stem reflexes until 4 days after the confirmation of brain death when the patient was discharged upon request of family members.FIGURE 1.: Movement pattern. After tapping stimulation, the patient undulatingly twisted her abdomen towards the right with her chest and head moving to the left (①), and then she twisted the torso in the opposite way (②). Subsequently, myoclonus occurred (③), and movements of undulating axial trunk torsion repeated in the end.The exact mechanism for spinal reflexes in brain death remains unclear. These basic spinal reflex movements have been thought to be caused by modulatory afferents to these spinal cord centers and the absence of cortical inhibition.1 Some reflex movements evoked during the apnea test, such as Lazarus sign, might be due to hypoxic stimulation of cervical spinal cord neurons functionally isolated from rostral brain areas.2 Plantar flexion, myoclonus, triple flexion reflex, and pronator extension reflex are the common spinal reflexes in brain death.3 Lazarus sign is a rare complex movement consisting of bilateral arm flexion to chest, shoulder adduction, and hand crossing, which can be seen in 1.5% of brain-dead patients.4 Here, we reported another dramatic complex spinal movement of undulating axial trunk torsion which involves deep back muscles. The organ donation did not occur after determination of brain death due to the concern and refusal of family members. This reflex movement was not reported before and should be recognized to avoid uncertainty for families and failure in organ donation.5,6