The ethics of measuring and modulating consciousness: the imperative of minding time.

Using time as an over-arching metaphor, and drawing upon resources in the sciences, humanities, and the history of medicine, the author addresses the neuroethics of measuring and modulating consciousness. Static and evolving views of time dating to the Ancients are contrasted and applied to severe brain injury. These temporal worldviews are tracked progressively in the philosophies of Democritus and Heraclitus, Hippocrates and Galen, and the neurosurgeon, Wilder Penfield on into the modern era as they relate to current perceptions related to disorders of consciousness. These disorders, typified by the vegetative and minimally conscious states, can be viewed as either fixed and immutable or in flux depending upon social currents and scientific knowledge. Variable perspectives are examined in light of right-to-die cases involving permanently vegetative patients like Quinlan and Schiavo and contrasting "late" recoveries involving patients in the minimally conscious state. The author suggests that disorders of consciousness should not be viewed categorically as static entities but rather assessed as a reflection of a synchrony of time and biology that we are just beginning to understand. He stresses the relationship of temporality to clinical evaluation, diagnosis assessment, and prognostication and their association to new methods in functional neuroimaging. These time stamps have profound implications for systems of care and reimbursement mechanisms, which often mistakenly conflates futility with chronicity. This conflation is increasingly being challenged by patients who emerge from the minimally conscious state after conventional temporal expectations for improvement had transpired. These cases often referred to as "late emergences" point to the importance of better understanding the natural history of these conditions and the tempo of associated recoveries.