Scientists discover link between minor concussion and loss of smell

New study led by team of neuropsychologists from the Université de Montréal confirm that even minor concussion in people may cause a temporary loss of smell, in addition to leading to other problems such as anxiety and depression.

Tumbling on ski slopes, hitting one’s head, slipping on ice, falling off a bike with a helmet on, were some of the minor accidents listed by researchers that can trigger olfactory and anxiety problems among individuals.

For the study, scientists examined 20 hospital patients who underwent mild concussions and 22 others who had broken limbs, but did not suffer concussion. It was found that within 24 hours of their accident, only over half of the people suffered from a reduced sense of smell, in comparison to 5% of patients who had broken bones. Moreover, it was observed, their sense of smell was back to normal after a year, however the first group of patients suffered from more anxiety than the control group.

“A lot of people will suffer a mild concussion at some point in their life, so realizing they have trouble smelling is the first step to telling their doctor about it,” according to lead author Fanny Lecuyer Giguère. Giguère completed her doctoral thesis in neuropsychology supervised by UdeM associate professor of psychology Johannes Frasnelli. “It’s important that patients report any loss of smell, because it’s not something their general practitioner or emergency-room physician normally asks about.”

Giguère visited hospital patients in the alpine ski resort between December 2016 and February 2017 in order to examine the patient’s capacity to identify smells. It was observed that almost all of those who had mild concussions had experienced a skiing accident. All of these patients, including those who suffered fractures, but no concussions were examined.

With the help of scented ‘Sniffin’ Sticks’- felt-pen tips, the patients were asked to identify the synthetic odours like those of garlic, roses, solvent and cloves. A year later, the patients were asked to respond to a questionnaire, in addition to a set of scratch-and-sniff booklets.

After comparing results between the two groups of patients, on the day of accident and 12 months later, the experts were able to determine that the patients were able to gain their sense of smell within six months of their accident.

However, scientists observed that 65% of the patients had symptoms of anxiety which did not diminish as easily, they especially faced problems while relaxing, had sudden feelings of panic and anxiety. Further study in the research will thus allegedly examine the link between anxiety and olfaction.