UCL の研究者が主導した最近の研究では、COVID-19 に長くかかって無嗅覚症 (嗅覚喪失) を経験している人々は、嗅覚を回復した人や COVID-19 に感染したことがない人と比べて、異なる脳活動パターンを示すことがわかりました。 観察研究では MRI スキャンを使用し、長期にわたる COVID 嗅覚障害を持つ人々の脳活動の低下と、眼窩前頭皮質と前頭前皮質との間のコミュニケーション障害を発見しました。 この接続は、COVID 後に嗅覚を取り戻した人では損なわれませんでした。 調査結果は、長期にわたるCOVID無嗅覚症は、匂いが適切に処理されない脳の変化に関連している可能性があることを示唆していますが、臨床的に可逆的であるため、嗅覚トレーニングは脳がこの感覚を回復するのに役立つ可能性があります. この研究では、Covid無嗅覚症が長引いている人々の脳が、他の感覚領域との接続を強化することで代償している可能性があることも発見しました.
ユニバーシティ カレッジ ロンドン (UCL) の研究者が主導した新しい研究で、嗅覚の喪失に苦しんでいる長期にわたる COVID 患者は、脳の特定の領域で異なるパターンの活動を示していることがわかりました。
この研究では、MRIスキャンを使用して、嗅覚を失った長いCOVIDの人々、COVID感染後に嗅覚が正常に戻った人々、および陽性反応を示したことのない人々の脳活動を比較しました。[{” attribute=””>COVID-19.
Published in the journal eClinicalMedicine, the observational study found that people with long COVID smell loss had reduced brain activity and impaired communication between two parts of the brain that process important smell information: the orbitofrontal cortex and the pre-frontal cortex. This connection was not impaired in people who had regained their sense of smell after COVID.
The findings suggest smell loss, known as anosmia, caused by long COVID is linked to a change in the brain that stops smells from being processed properly. Because it’s clinically reversible, as shown in some subjects, it may be possible to retrain the brain to recover its sense of smell in people suffering the side effects of long COVID.
Dr. Jed Wingrove (UCL Department of Medicine) the lead author of the study, said: “Persistent loss of smell is just one way long COVID is still impacting people’s quality of life – smell is something we take for granted, but it guides us in lots of ways and is closely tied to our overall wellbeing. Our study gives reassurance that, for the majority of people whose sense of smell comes back, there are no permanent changes to brain activity.”
Joint senior author, Professor Claudia Wheeler-Kingshott (UCL Queen Square Institute of Neurology), said: “Our findings highlight the impact COVID-19 is having on brain function. They raise the intriguing possibility that olfactory training – that is, retraining the brain to process different scents – could help the brain to recover lost pathways, and help people with long COVID recover their sense of smell.”
Researchers say their findings also suggest that the brains of people with long COVID smell loss might be compensating for this lost sense by boosting connections with other sensory regions: their brains had increased activity between the parts of the brain that process smell and areas that process sight (the visual cortex).
“This tells us that the neurons that would normally process smell are still there, but they’re just working in a different way,” said Dr. Wingrove.
Professor Rachel Batterham (UCL Division of Medicine), also joint senior author of the study said: “This is the first study to our knowledge that looks at how brain activity changes in people with long COVID smell loss. It builds on the work we undertook during the first wave of the pandemic, which was one of the first to describe the link between COVID-19 infection with both loss of smell and taste.”
Reference: “Aberrant olfactory network functional connectivity in people with olfactory dysfunction following COVID-19 infection: an exploratory, observational study” by Jed Wingrove, Janine Makaronidis, Ferran Prados, Baris Kanber, Marios C. Yiannakas, Cormac Magee, Gloria Castellazzi, Louis Grandjean, Xavier Golay, Carmen Tur, Olga Ciccarelli, Egidio D’Angelo, Claudia A.M. Gandini Wheeler-Kingshott and Rachel L. Batterham, 2 March 2023, eClinicalMedicine.
DOI: 10.1016/j.eclinm.2023.101883
The study was funded by the National Institute for Health and Care Research (NIHR).