Hit your head, lose your sense of smell

Posted on July 24, 2019

It has been known that people who suffer major concussion may lose their sense of smell temporarily and develop affective problems, like anxiety and depression. Scientists found that this is true even for people who get minor concussion.

Minor incidents like falling off a bike with a helmet on, slipping on ice and hitting one’s head may provoke the same kinds of olfactory and anxiety problems. A team led by Université de Montréal neuropsychologists compared 20 hospital patients who had mild concussions to 22 who suffered from broken limbs but had no concussion. Within 24 hours of their accident, just over half of those with mild concussions had a reduced sense of smell, versus only 5 per of the patients with broken bones. A year later, although their sense of smell was back to normal, the first group of patients had significantly more anxiety than the control group.

Identifying the problem of persistent loss of smell and anxiety after injury indicates the severity of the injury – the first step to getting personalized treatment. Physicians should also educate their patients so that they check whether symptoms crop up in the weeks following their accident. This raises awareness, the more people being told to watch for signs of olfactory loss and anxiety, the easier it will be for doctors to respond.

A year later, the patients were sent a follow-up questionnaire and a set of scratch-and-sniff booklets. By comparing the two groups of patients' results in the day following their injury and 12 months later, the researchers were able to determine that most who'd lost their sense of smell gained it back within six months of their accident.

What did not significantly diminish, however, were their symptoms of anxiety: thoughts that made them worry, difficulties to relax, and sudden feelings of panic. About 65 per cent of the concussed patients reported such symptoms.


Source material from Science Daily