When a subway rider in new york used a choKEHold that ended up killing a 30-year-out homeless man, jordan neely, he was emblaying a technique that many neurologi sts warn is so dangerous that it should not be allowed in law enforcement.chokeholds or Strangleholds are known also as neck compressions, which involve applying pressure to both sides of the neck. They are allowed in some martial arts competitions, and certain US military personnel in ground-combat units may learn to apply chokeholds, and associative attested safe releases, in training. But in the past few years, police departments have increasingly banned the use of chokeholds, following events such as the deaths of Eric Garner and George Floyd. There are few data on how often police have used the holds, or what the consequences were Among the few studies is one reporting that officers in Spokane, Wash., used neck restraints 230 times in the eight years before May 2021, when Washington State banned them. While there were no fatalities recorded in the use of the holds by that department , neurologists say the dangers of neck compression are indisputable. Dr. Altaf Saadi, a neurologist at Massachusetts General Hospital, explained that chokeholds and strangleholds could kill or cause brain injuries in two ways. They can compress the trachea, pre venting the person from getting air into the lungs. And they can compress the carotid arteries, which are on either side of the neck, adjacent to the trachea. Seventy percent of the blood going to the brain passes through the carotids, Dr. Saadi said. If that blood flow is cut off in a chokehold or a stranglehold, some people can become unconscious in three to four seconds. If the flow continues to be restricted, a person can die within three to four minutes. If a person loses consciousness, that is an indication of possible injury to the brain, Dr. Saadi said. Even if the person does not lose consciousness, strokes and permanent brain damage, including cognitive impairment, can result from a chokehold. People with cardiovascular disease are especially susceptible to brain injury as a result of neck compression.In a paper published in 2020 in JAMA Neurology, Dr. Saadi and colleagues wrote, “The possibility of devastating repercussions is too high to merit the use of neck restraints in any circumstance.” The American Academy of Neurology came out firmly aga inst neck compression. In a position paper, the organization wrote that a mantra in its field is “time is brain,” meaning that brain tissue dies quickly when blood flow is stopped. The group notes that in strokes, when an area of the brain is deprived of blood, 1.9 million neurons die each minute before blood flow is restored. In a position statement, the group wrote that such techniques are “inherently dangerous in nature” and strongly encouraged all law enforcement personnel and policymakers “to classify neck restra ints, at a minimum, as a form of deadly force.” The group added a recommended prohibition of the technique “because there is no amount of training or method of application of neck restraints that can mitigate the risk of death or permanent profound neurologic damage with this maneuver. ”Oliver Whang contributed reporting.