Rotten Fish And Shampoo Helped Doctors Understand Which Of The Patients Did Not Become A "vegetable"

Rotten fish and shampoo helped doctors understand which of the patients did not become a "vegetable"

It can be difficult for doctors to determine which patients will recover consciousness in the future after severe trauma, and which of them will remain in a vegetative state. Scientists have proposed a version of a simple test that helps solve this issue.

Photo: Quinn Dombrowski

Nature, the leading science journal, has published an article on the value of rotten fish odor in assessing patients with severe traumatic brain injury. Scientists report that pungent odors reveal signs of consciousness in people that do not respond to other stimuli.

It can be difficult for doctors to assess the condition of patients after severe craniocerebral trauma: to understand whether they have passed into a vegetative state or they retain a certain level of consciousness. They say about a vegetative state when, due to a violation of the brain, a person ceases to be aware of himself and the world around him.

To understand whether a person is responding to their surroundings, doctors usually ask them something or ask them to do something (for example, move a finger). But in people who are in the so-called state of minimal consciousness, the latter can "blink", therefore, they are often mistakenly attributed to a vegetative state.

A group of Israeli scientists decided to clarify whether it can be determined that a person has retained consciousness using olfactory tests. In theory, people should react to strong smells - we do this even in our sleep.

Scientists proceeded from the fact that the human brain in a non-vegetative state retains the ability to process information even when not in wakefulness.

The study authors followed 43 patients after traumatic brain injury who did not respond to sound and tactile stimuli for several weeks. For olfactory tests, scientists used strong smells - rotten fish or just fruit shampoo. During the experiments, they evaluated how much air the patients inhaled. It was assumed that the reduction in its volume in response to a pungent odor would indicate the protective reactions of the brain. For control, patients were allowed to sniff odorless air.

Research has shown that most patients in a state of minimal consciousness respond expressively to strong odors. Patients who remained in a vegetative state did not react to odor in any of the samples.

The most revealing results were for a group of 24 patients, whom doctors initially attributed to a vegetative state. Over time, 16 of them began to react to their surroundings (for example, to roll their eyes in response to visual stimuli), they were diagnosed with a state of minimal consciousness. 10 of these patients reacted strongly to odors throughout the study. But none of the patients who remained in the vegetative state showed reactions.

“If a person has no reaction to smells, we cannot say anything definite. But if a person has a reaction, it is very informative,”Anat Arzi of the Weisman Research Institute, co-author of the study, told New Scientist. She added that perhaps such a diagnosis could reduce the number of misdiagnoses.