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 Egypt ( , ), officially the Arab Republic of Egypt, is a country spanning the Northeast Africa, northeast corner of Africa and Western Asia, southwest corner of Asia via the Sinai Peninsula. It is bordered by the Mediterranean Sea to northe ...

ian mummies). The phenomenon is named after

Lazarus of Bethany Lazarus of Bethany is a figure of the New Testament whose life is restored by Jesus four days after his death, as told in the Gospel of John. The resurrection is considered one of the miracles of Jesus. In the Eastern Orthodox Church, Lazarus i ...

, whom the Biblical Gospel of John says was raised from the dead by

Jesus Jesus (AD 30 or 33), also referred to as Jesus Christ, Jesus of Nazareth, and many Names and titles of Jesus in the New Testament, other names and titles, was a 1st-century Jewish preacher and religious leader. He is the Jesus in Chris ...

Causes

Like the knee jerk reflex, the Lazarus sign is an example of a reflex mediated by a

reflex arc A reflex arc is a neural pathway that controls a reflex. In vertebrates, most sensory neurons synapse in the spinal cord and the signal then travels through it into the brain. This allows for faster reflex actions to occur by activating spinal mo ...

—a neural pathway which passes via the

spinal column The spinal column, also known as the vertebral column, spine or backbone, is the core part of the axial skeleton in vertebrates. The vertebral column is the defining and eponymous characteristic of the vertebrate. The spinal column is a segmen ...

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. Some neurologists believe that hypoxia could lead to Lazarus sign but this theory lost strength as incidence of new cases in patients with normal oxygen level began to arise. 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 The sternum (: sternums or sterna) or breastbone is a long flat bone located in the central part of the chest. It connects to the ribs via cartilage and forms the front of the rib cage, thus helping to protect the heart, lungs, and major bl ...

. 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.

Occurrences

The phenomenon has been observed to occur several minutes after the removal of medical ventilators used to pump air in and out of brain-dead patients. It also occurs during testing for

apnea Apnea (also spelled apnoea in British English) is the temporary cessation of breathing. During apnea, there is no movement of the muscles of inhalation, and the volume of the lungs initially remains unchanged. Depending on how blocked the ...

—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 The American Academy of Neurology (AAN) is a professional society representing over 40,000 neurologists and neuroscientists. As a medical specialty society it was established in 1948 by A.B. Baker of the University of Minnesota to advance the a ...

. Occurrences of the Lazarus sign in intensive-care units have been mistaken for evidence of resuscitation of patients. They may frighten those who witness the movement, and have been viewed by some as miraculous events.

References

External links

Brain Death - Lazarus sign - Rare exuberant spinal reflex exclusively elicited per head flexion
{{DEFAULTSORT:Lazarus Sign Reflexes Signs of death Lazarus of Bethany

Causes

Occurrences

See also

References

External links