Board certified in neurology, Dr. Jonathan Fellus leads Advanced NeuroCare, LLC, a concierge medical practice that delivers superior neurodiagnostics and therapeutics. Dr. Jonathan Fellus and his colleagues offer a comprehensive assessment of different states of consciousness due to various underlying disorders. These include severe disorders of consciousness, like the vegetative state (now called the unresponsive wakefulness state) and minimally conscious state, both of which usually follow from being in a comatose state..
In the United States, roughly 2 percent of deaths follow a diagnosis of brain death, according government agencies. Brain death refers to an irreversible coma due to severe loss of brain function involving the most primitive part of the nervous system, the brainstem. The entire brain stops all basic function in the event of brain death, which in turn leads to a cessation in pulmonary and circulatory functions as well. The condition often occurs due to an acute catastrophic brain injury, but it must be tested for before someone is declared brain dead. This helps physicians rule out other conditions, like severe but reversible toxicity, extreme thyroid or glucose deficiency, or an overdose of tranquilizers or poisons.
Testing for brain death is done at least twice so that the chance of error is reduced--yet there are still variation from country to country. There are several different tests that are performed to adequately test for function. Basic brainstem responses are tested, assessing pupils, corneal sensitivity, and vestibular-ocular reflexes in addition to spontaneous breathing ability. All of these tests induce physical responses in a person, so failure to respond to them indicates that the brain has stopped functioning. In extremely rare cases (see the article authored by Dr. Fellus), brain death may be partially reversible, challenging the long-standing belief that brain death must, by definition, be 'irreversible'. Lately, some controversy has arisen due to the awareness that once brain death criteria are met, almost all such cases are rapidly removed from life support, recommended for organ donation; or individuals will die naturally--unable to maintain medical stability.
But while brain death clearly carries the worst prognosis, the public should understand how this state differs from coma, unresponsive wakefulness (UWS), and the minimally conscious states (MCS). In coma, the eyes are closed and there is no discernible evidence of awareness. In UWS, the eyes are open, some semblance of sleep-wake cycles return, yet there is still no demonstrable sign of awareness. Arousal may be present, but not meaningful awareness of the self or others. In the MCS, clear yet intermittent but unreliable or unsustainable behaviors indicate some sense of the person's awareness of self or of the 'outside world'. This last state has the best prognosis. Overall, the actual cause of severe disorders of consciousness will also determine the prognosis. A traumatic injury (such as from a car collision or sports impact) carries a much more favorable prognosis than a non-traumatic cause such as from asphyxiation, low blood sugar, or near-drowning.
In the United States, roughly 2 percent of deaths follow a diagnosis of brain death, according government agencies. Brain death refers to an irreversible coma due to severe loss of brain function involving the most primitive part of the nervous system, the brainstem. The entire brain stops all basic function in the event of brain death, which in turn leads to a cessation in pulmonary and circulatory functions as well. The condition often occurs due to an acute catastrophic brain injury, but it must be tested for before someone is declared brain dead. This helps physicians rule out other conditions, like severe but reversible toxicity, extreme thyroid or glucose deficiency, or an overdose of tranquilizers or poisons.
Testing for brain death is done at least twice so that the chance of error is reduced--yet there are still variation from country to country. There are several different tests that are performed to adequately test for function. Basic brainstem responses are tested, assessing pupils, corneal sensitivity, and vestibular-ocular reflexes in addition to spontaneous breathing ability. All of these tests induce physical responses in a person, so failure to respond to them indicates that the brain has stopped functioning. In extremely rare cases (see the article authored by Dr. Fellus), brain death may be partially reversible, challenging the long-standing belief that brain death must, by definition, be 'irreversible'. Lately, some controversy has arisen due to the awareness that once brain death criteria are met, almost all such cases are rapidly removed from life support, recommended for organ donation; or individuals will die naturally--unable to maintain medical stability.
But while brain death clearly carries the worst prognosis, the public should understand how this state differs from coma, unresponsive wakefulness (UWS), and the minimally conscious states (MCS). In coma, the eyes are closed and there is no discernible evidence of awareness. In UWS, the eyes are open, some semblance of sleep-wake cycles return, yet there is still no demonstrable sign of awareness. Arousal may be present, but not meaningful awareness of the self or others. In the MCS, clear yet intermittent but unreliable or unsustainable behaviors indicate some sense of the person's awareness of self or of the 'outside world'. This last state has the best prognosis. Overall, the actual cause of severe disorders of consciousness will also determine the prognosis. A traumatic injury (such as from a car collision or sports impact) carries a much more favorable prognosis than a non-traumatic cause such as from asphyxiation, low blood sugar, or near-drowning.
