Lazarus sign
Encyclopedia
The Lazarus sign or Lazarus reflex is a reflex
movement in brain-dead or brainstem failure
patients, which causes them to briefly raise their arms and drop them crossed on their chests (in a position similar to some Egypt
ian mummies).
The phenomenon is named after the Biblical character Lazarus of Bethany
, whom Jesus
is described as having raised from the dead in the Gospel of John
.
Like the knee jerk reflex, the Lazarus sign is an example of a reflex mediated by a reflex arc
– a neural pathway
which passes via the spinal column but not through the brain. As a consequence the movement is possible in brain-dead patients whose organs have been kept functioning by life-support machines, precluding the use of complex involuntary motions as a test for brain activity. It has been suggested by neurologists studying the phenomenon that increased awareness of this and similar reflexes "may prevent delays in brain-dead diagnosis and misinterpretations."
The reflex is often preceded by slight shivering motions of the patient's arms, or the appearance of goose bumps
on the arms and torso. The arms then begin to flex at the elbows before lifting to be held above the sternum. They are often brought from here towards the neck or chin and touch or cross over. Short exhalations have also been observed coinciding with the action.
The phenomenon has been observed to occur several minutes after the removal of medical ventilator
s used to pump air in and out of brain-dead patients to keep their bodies alive. It also occurs during testing for apnea
– that is, suspension of external breathing and motion of the lung muscles - which is one of the criteria for determining brain death used for example by the American Academy of Neurology
.
Occurrences of the Lazarus sign in intensive-care units have been mistaken for evidence of resuscitation of patients. They have also frightened patients and nurses, and been incorrectly-viewed as miraculous
events.
Reflex
A reflex action, also known as a reflex, is an involuntary and nearly instantaneous movement in response to a stimulus. A true reflex is a behavior which is mediated via the reflex arc; this does not apply to casual uses of the term 'reflex'.-See also:...
movement in brain-dead or brainstem failure
Brain stem death
Brain Stem Death is a clinical concept, implying an irreversibly unconscious patient, with irreversible apnea and irreversible loss of brain stem reflexes. The concept defines the core physiological basis for neurological diagnosis of death in the United Kingdom and elsewhere...
patients, which causes them to briefly raise their arms and drop them crossed on their chests (in a position similar to some Egypt
Ancient Egypt
Ancient Egypt was an ancient civilization of Northeastern Africa, concentrated along the lower reaches of the Nile River in what is now the modern country of Egypt. Egyptian civilization coalesced around 3150 BC with the political unification of Upper and Lower Egypt under the first pharaoh...
ian mummies).
The phenomenon is named after the Biblical character Lazarus of Bethany
Lazarus of Bethany
Lazarus of Bethany, also known as Saint Lazarus or Lazarus of the Four Days, is the subject of a prominent miracle attributed to Jesus in the Gospel of John, in which Jesus restores him to life four days after his death...
, whom Jesus
Jesus
Jesus of Nazareth , commonly referred to as Jesus Christ or simply as Jesus or Christ, is the central figure of Christianity...
is described as having raised from the dead in the Gospel of John
Gospel of John
The Gospel According to John , commonly referred to as the Gospel of John or simply John, and often referred to in New Testament scholarship as the Fourth Gospel, is an account of the public ministry of Jesus...
.
Like the knee jerk reflex, the Lazarus sign is an example of a reflex mediated by a reflex arc
Reflex arc
A reflex arc is a neural pathway that controls an action reflex. In higher animals, most sensory neurons do not pass directly into the brain, but synapse in the spinal cord...
– a neural pathway
Neural pathway
A neural pathway, neural tract, or neural face, connects one part of the nervous system with another and usually consists of bundles of elongated, myelin-insulated neurons, known collectively as white matter...
which passes via the spinal column but not through the brain. As a consequence the movement is possible in brain-dead patients whose organs have been kept functioning by life-support machines, precluding the use of complex involuntary motions as a test for brain activity. It has been suggested by neurologists studying the phenomenon that increased awareness of this and similar reflexes "may prevent delays in brain-dead diagnosis and misinterpretations."
The reflex is often preceded by slight shivering motions of the patient's arms, or the appearance of goose bumps
Goose bumps
Goose bumps, also called goose flesh, goose pimples, chill bumps, chicken skin, funky spots, Dasler Bumps, chicken bumps or the medical term cutis anserina, are the bumps on a person's skin at the base of body hairs which may involuntarily develop when a person is cold or experiences strong...
on the arms and torso. The arms then begin to flex at the elbows before lifting to be held above the sternum. They are often brought from here towards the neck or chin and touch or cross over. Short exhalations have also been observed coinciding with the action.
The phenomenon has been observed to occur several minutes after the removal of medical ventilator
Medical ventilator
A medical ventilator can be defined as any machine designed to mechanically move breatheable air into and out of the lungs, to provide the mechanism of breathing for a patient who is physically unable to breathe, or breathing insufficiently....
s used to pump air in and out of brain-dead patients to keep their bodies alive. It also occurs during testing for apnea
Apnea
Apnea, apnoea, or apnœa is a term for suspension of external breathing. During apnea there is no movement of the muscles of respiration and the volume of the lungs initially remains unchanged...
– that is, suspension of external breathing and motion of the lung muscles - which is one of the criteria for determining brain death used for example by the American Academy of Neurology
American Academy of Neurology
The American Academy of Neurology is a professional society for neurologists and neuroscientists. As a medical specialty society it was established in 1949 by A.B. Baker of the University of Minnesota to advance the art and science of neurology, and thereby promote the best possible care for...
.
Occurrences of the Lazarus sign in intensive-care units have been mistaken for evidence of resuscitation of patients. They have also frightened patients and nurses, and been incorrectly-viewed as miraculous
Miracle
A miracle often denotes an event attributed to divine intervention. Alternatively, it may be an event attributed to a miracle worker, saint, or religious leader. A miracle is sometimes thought of as a perceptible interruption of the laws of nature. Others suggest that a god may work with the laws...
events.