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The capacity for consciousness and the clinical diagnosis of brain death: are we using the correct gold standard?
... Rady. 1 The goal of our commentary was not to question the validity of the established criteria, but rather to offer an appraisal of available ancillary tests relative to the current definition of death by neurologic criteria (DNC) as accepted in 2021, as well as a necessary distinction between cerebral flow, perfusion, and function. 2, 3 We recognize the challenges and pitfalls associated with the use of neuroimaging and clinical examination for definitive determination of brain death, but they remain the only bedside tools available to the clinician. ...
At age 21, following a severe traumatic brain injury, Zack Dunlap was declared brain-dead according to the American Academy of Neurology guideline (Guideline) when he met the clinical criteria of brain death (minus apnea testing because of bradycardia) with technetium-99m diethylene-triamine-pentaacetate scintigraphy reported as showing no intracranial blood flow. His parents agreed to organ donation. During preparations for organ donation, Zack manifested a purposeful movement in response to a noxious stimulus made by his cousin. Following subsequent neurological recovery, he has returned to a normal life, holding steady employment and raising a family. During an interview, he reported that while in coma, he heard a doctor say that he was brain-dead and felt angry about it. His experience fits the phenomenon of cognitive-motor dissociation. Recently, Zack's medical records were made available to the first author. A critical review of the records uncovered a problem inherent in the logic of the Guideline algorithm regarding brain blood flow scintigraphy. This article discusses the lessons drawn from Zack's case, namely, that both the aforementioned problem and the occurrence of cognitive-motor dissociation in patients deemed to be brain-dead can pose a significant risk of a false-positive declaration of death.
In this paper, I review the case of Jahi McMath, who was diagnosed with brain death (BD). Nonetheless, ancillary tests performed nine months after the initial brain insult showed conservation of intracranial structures, EEG activity, and autonomic reactivity to the “Mother Talks” stimulus. She was clinically in an unarousable and unresponsive state, without evidence of self-awareness or awareness of the environment. However, the total absence of brainstem reflexes and partial responsiveness rejected the possibility of a coma. Jahi did not have uws because she was not in a wakefulness state and showed partial responsiveness. She could not be classified as a LIS patient either because LIS patients are wakeful and aware, and although quadriplegic, they fully or partially preserve brainstem reflexes, vertical eye movements or blinking, and respire on their own. She was not in an MCS because she did not preserve arousal and preserved awareness only partially. The CRS-R resulted in a very low score, incompatible with MCS patients. mcs patients fully or partially preserve brainstem reflexes and usually breathe on their own. MCS has always been described as a transitional state between a coma and UWS but never reported in a patient with all clinical BD findings. This case does not contradict the concept of BD but brings again the need to use ancillary tests in BD up for discussion. I concluded that Jahi represented a new disorder of consciousness, non-previously described, which I have termed “reponsive unawakefulness syndrome” (RUS).
In this paper, I reviewed the case of Jahi McMath who was diagnosed as being in brain death (BD). Nonetheless, ancillary tests, performed 9 months after initial brain insult, showed conservation of intracranial structures, EEG activity, and autonomic reactivity to “Mother Talks” stimulus. She was clinically in a state of unarousable and unresponsiveness, without evidence of awareness of self or environment, but full absence of brainstem reflexes, and partial responsiveness rejected the possibility of being in coma. Jahi was not a UWS, because she was not in a wakefulness state, and showed partial responsiveness. LIS patients are wakeful and aware, and although these cases are quadriplegic, they fully or partially preserve brainstem reflexes, vertical eye movements, and/or blinking, and respire by their own, rejecting the possibility of classifying her as a LIS patient. She was not a MCS because she did not preserve arousal, and only partially preserved awareness. The CRS-R resulted in a very low score, not corresponding with MCS patients. MCS patients fully or partially preserve brainstem reflexes, and usually breathe by their own. MCS has been always described as a transitional state between coma, UWS, but MCS has never been reported in a patient who has all clinical BD findings. This case doesn’t contradict the concept of BD, but brings again to discussion the needs of using ancillary tests in BD. I concluded that Jahi represented a new state of disorder of consciousness, non-previously described, that I have termed: “responsive unawake syndrome” (RUS).
In recent years, rapid technological developments in the field of neuroimaging have provided new methods for assessing residual cognition, detecting consciousness, and even communicating with patients who clinically appear to be in a vegetative state. Here, I highlight some of the major implications of these developments, discuss their scientific, clinical, legal, and ethical relevance, and make my own recommendations for future directions in this field.
This article clarifies some issues raised by Dr. Ariane Lewis in her recent “Current Opinion/Arguments” article on the case of Jahi McMath. Review of case materials. Jahi’s case most likely represents an instance of global ischemic penumbra (GIP) mimicking brain death (BD), with intracranial blood flow too low to support neuronal function or to be detected by radionuclide scan but sufficient to prevent widespread necrosis. Her MRI scan 9 months after the ischemic insult showed gross preservation of cortical and internal structures, incompatible with there ever having been a period of completely absent blood flow. Regarding Jahi’s alleged intermittent responsiveness, the set of videos, unsystematic as they are, constitutes convincing evidence that her movements in seeming response to command are not of spinal cord origin and are indeed voluntary responses, placing her in the category of minimally conscious state (MCS). In the absence of serial examinations by experts in MCS, the benefit of the doubt should be given. Unfortunately, her death on June 22, 2018, 4½ years after the diagnosis of BD, precludes such examinations. During those 4½ years, Jahi underwent menarche, with three documented menstrual periods, and ongoing pubertal development. Her case is an important example of false-positive diagnosis of BD, demonstrating the inability of current diagnostic standards to distinguish true BD from potentially reversible brain nonfunction due to GIP. The incidence of such mimicry is impossible to determine, because in most cases a BD diagnosis becomes a self-fulfilling prophecy.
Jahi McMath: a new state of disorder of consciousness
- C Machado