Researchers from Israel’s Weizmann Institute have developed a process that contains a ‘sniff test’ in order to examine the likelihood of someone regaining consciousness; The initial four-year test period resulted in 100% accuracy.
Led by Dr. Anat Arzi, Israeli scientists at the Weizmann Institute have developed a method for testing the likelihood of someone to regain consciousness using a newfound ‘sniff test’. During the initial four-year test period, the test resulted in 100% accuracy, meaning that any patient who showed a response to the sniff test eventually regained consciousness.
The Weizmann Institute is located at the Loewenstein Rehabilitation Hospital in Ra’anana, Israel. Dr. Yaron Sacher, head of the Department of Traumatic Brain Injury Rehabilitation for the hospital, played a large role in the development of this test.
A few points that make this test unique from the get-go are:
1) It’s simple
2) It’s inexpensive
3) It’s convenient
Dr. Arzi explained, “The fact that the sniff test is simple and potentially inexpensive makes it advantageous. It can be performed at the patient’s bedside without the need to move them – and without complicated machinery.”
Acknowledging that it’s often difficult to determine whether an individual is conscious or not after they’ve suffered a significant brain injury, she explained, “Misdiagnosis can be critical as it can influence the decision of whether to disconnect patients from life-support machines. In regard to treatment, if it is judged that a patient is unconscious and doesn’t feel anything, physicians may not prescribe them painkillers that they might need.”
With the olfactory system (sense of smell) being the most important aspect of the brain as it relates to this test, the observation is that an individual’s nasal passages change in response to different odors. And for a healthy human being, any sort of response can take place in a state of unconsciousness, whether sleeping or not.
In the four-year study, over 40 different patients with brain injuries were involved. The researchers prepared different scent jars with items that ranged from hygienic products to rotten fish. The next step was for the researchers to measure how much air was actually being inhaled in response to the different odors. The patient would experience the odor of each jar ten times, varying in order each series.
The results were astounding! According to Dr. Arzi, “Astonishingly, all patients who were classified as being in a ‘vegetative state,’ yet responded to the sniff test, later regained consciousness, even if only minimal. In some cases, the result of the sniff test was the first sign that these patients were about to recover consciousness – and this reaction was observed days, weeks, and even months prior to any other signs.”
Adding to the success of the test, it not only revealed who was going to regain consciousness, but it also revealed who was likely to have a minimum of three more years of life with over 90% accuracy.
In an article done by the American Committee for the Weizmann Institute of Science, Dr. Arzi is recorded as stating, “In a well-known study, a patient diagnosed as being in a vegetative state following a car accident was scanned in an MRI machine. While in the scanner, the researchers asked the patient to imagine that she was playing tennis, and observed that her brain activity was similar to the brain activity of healthy people when they also imaged playing a tennis game. Suddenly, they realized: ‘hold on a minute, she’s there. She hears us and is responding to our requests. She simply has no way of communicating.”
Concluding her point, she added, “There are also known cases of people who were diagnosed as being in a vegetative state, but when they regained consciousness, they were able to recount in detail what was occurring while supposedly vegetative. Diagnosing the level of consciousness of a patient who has suffered a severe head injury is a major clinical challenge. The sniff test we have developed may provide a simple tool to tackle this challenge.”
Dr. Tristan Bekinschtein of the University of Cambridge’s Department of Psychology further praised this newfound method, stating, “When the sniff response is functioning normally it shows that the patient might still have some level of consciousness even when all other signs are absent. This new and simple method to assess the likelihood of recovery should be immediately incorporated in the diagnostic tools for patients with disorders of consciousness.”
As of 2019, Israel is home to four of the world’s top 200 research facilities, and the Weizmann Institute of Science is one of them.