Article
Clinical Neurology
Masanori Sawamura, Hirotaka Onoe, Hideo Tsukada, Kaoru Isa, Hodaka Yamakado, Shinya Okuda, Masashi Ikuno, Yusuke Hatanaka, Shigeo Murayama, Norihito Uemura, Tadashi Isa, Ryosuke Takahashi
Summary: This study established a nonhuman primate model of Lewy body diseases (LBDs) and found that alpha-Syn pathology propagates from the olfactory bulb, resulting in atrophy of the olfactory bulb and reduced cerebral glucose metabolism in LBDs.
MOVEMENT DISORDERS
(2022)
Article
Clinical Neurology
Cecilia Tremblay, Geidy E. Serrano, Anthony J. Intorcia, Lucia Sue, Jeffrey R. Wilson, Charles H. Adler, Holly A. Shill, Erika Driver-Dunckley, Shyamal H. Mehta, Thomas G. Beach
Summary: The decline of olfactory function is frequently observed in aging. This study found that tau pathology is commonly observed in the olfactory bulb of normally aging individuals, but it does not independently contribute to age-related olfactory decline. Further involvement of the brain seems to be necessary for age-related olfactory impairment.
Article
Neurosciences
Ulas Ay, Zerrin Yildirim, Emel Erdogdu, Ani Kicik, Esin Ozturk-Isik, Tamer Demiralp, Hakan Gurvit
Summary: During the progression of Lewy pathology in Parkinson's disease, the involvement of the amygdala occurs relatively early. This study aimed to investigate the volumetric differences between the nuclear and sectoral subdivisions of the amygdala in the cognitive impairment continuum of PD, revealing their potential role in PD-CI diagnosis.
COGNITIVE NEURODYNAMICS
(2023)
Article
Medicine, General & Internal
G. Pagano, K. I. Taylor, J. Anzures-Cabrera, M. Marchesi, T. Simuni, K. Marek, R. B. Postuma, N. Pavese, F. Stocchi, J. -P. Azulay, B. Mollenhauer, L. Lopez-Manzanares, D. S. Russell, J. T. Boyd, A. P. Nicholas, M. R. Luquin, R. A. Hauser, T. Gasser, W. Poewe, B. Ricci, A. Boulay, A. Vogt, F. G. Boess, J. Dukart, G. D'Urso, R. Finch, S. Zanigni, A. Monnet, N. Pross, A. Hahn, H. Svoboda, M. Britschgi, F. Lipsmeier, E. Volkova-Volkmar, M. Lindemann, S. Dziadek, S. Holiga, D. Rukina, T. Kustermann, G. A. Kerchner, P. Fontoura, D. Umbricht, R. Doody, T. Nikolcheva, A. Bonni
Summary: The study found that prasinezumab had no meaningful effect on global or imaging measures of Parkinson's disease progression and was associated with infusion reactions.
NEW ENGLAND JOURNAL OF MEDICINE
(2022)
Article
Cell Biology
Penglai Liu, Cheng Gao, Jing Wu, Tingting Wu, Ying Zhang, Changyu Liu, Changcheng Sun, Anan Li
Summary: This study investigates the role of the lateral entorhinal cortex (LEC) and the posterior piriform cortex (PPC) in aversive olfactory learning. The findings suggest that LEC is involved in the acquisition of negative odor value, while PPC is involved in the memory-retrieval phase. Inhibition of LEC CaMKIIa+ neurons affects fear encoding, fear memory recall, and PPC responses to a conditioned odor, providing evidence for the involvement of LEC CaMKIIa+ neurons in negative valence encoding.
Article
Clinical Neurology
Tommaso Schirinzi, Daniela Maftei, Francesco M. Passali, Piergiorgio Grillo, Henri Zenuni, Davide Mascioli, Riccardo Maurizi, Laura Loccisano, Martina Vincenzi, Anna Maria Rinaldi, Massimo Ralli, Stefano Di Girolamo, Alessandro Stefani, Roberta Lattanzi, Cinzia Severini, Nicola B. Mercuri
Summary: This study outlines the dynamics of the prokineticin-2 pathway in relation to the clinical-pathological features of Parkinson's disease by examining olfactory neurons of patients. The results show that prokineticin-2 expression is increased in Parkinson's disease and is directly correlated with the severity of motor symptoms. Additionally, the accumulation of oligomeric alpha-synuclein is associated with prokineticin-2 protein levels. These findings support prokineticin-2 as a potential target for Parkinson's disease and validate the use of olfactory neurons to reflect pathological changes of the disease.
ANNALS OF NEUROLOGY
(2023)
Article
Behavioral Sciences
Kohei Takahashi, Minoru Tsuji, Osamu Nakagawasai, Soh Katsuyama, Lihua Hong, Kazuya Miyagawa, Kazuhiro Kurokawa, Atsumi Mochida-Saito, Hiroshi Takeda, Takeshi Tadano
Summary: This study found that the acetylcholinesterase inhibitor donepezil (DNP) can prevent olfactory dysfunction and reduce alpha-synuclein aggregation through enhancing autophagy in a mouse model of reversible olfactory impairment. These findings have important implications for preventing olfactory dysfunction associated with Alzheimer's disease.
BEHAVIOURAL BRAIN RESEARCH
(2023)
Article
Otorhinolaryngology
Eslam Hamed Elsayed Abdou, Hisham Atef Ebada, Mohammed Abdelbadie Salem, Mahitab Mohamed Rashad Ghoneim, Fatma Sherif, Elsharawy Kamal
Summary: This study analyzed the clinical and imaging findings in patients with COVID-related olfactory dysfunction and investigated possible mechanisms. The results showed that 57.3% of patients had edema in the olfactory cleft, while only 15.5% had radiological evidence of sinusitis. The most probable mechanism of COVID-related olfactory dysfunction is virus spread and damage to the olfactory epithelium and pathways.
AMERICAN JOURNAL OF RHINOLOGY & ALLERGY
(2023)
Article
Clinical Neurology
Marina Friesen, Stephanie Ziegler-Waldkirch, Milena Egenolf, Paolo D'Errico, Christina Helm, Charlotte Mezo, Nikolaos Dokalis, Daniel Erny, Natalie Katzmarski, Romina Coelho, Desiree Loreth, Marco Prinz, Melanie Meyer-Luehmann
Summary: The study shows an age-dependent increase in Aβ load in the olfactory bulb of APP-transgenic mice, which correlates with worsening olfactory performance. The presence of α-syn significantly reduces Aβ deposits and improves olfactory function in the mice.
Article
Clinical Neurology
Norihito Uemura, Jun Ueda, Toru Yoshihara, Masashi Ikuno, Maiko T. Uemura, Hodaka Yamakado, Masahide Asano, John Q. Trojanowski, Ryosuke Takahashi
Summary: This study aimed to investigate the clinicopathological contribution of alpha-Syn spread from the olfactory bulb in PD. The results showed that alpha-Syn preformed fibril injections induced more widespread pathology in transgenic mice, affecting the olfactory pathway and limbic system, leading to hyposmia, anxiety, and memory loss.
MOVEMENT DISORDERS
(2021)
Article
Neurosciences
Fabrizio Esposito, Mario Cirillo, Rosa De Micco, Giuseppina Caiazzo, Mattia Siciliano, Andrea Gerardo Russo, Caterina Monari, Nicola Coppola, Gioacchino Tedeschi, Alessandro Tessitore
Summary: This study analyzed the neural connectivity in the central olfactory system of individuals with persisting olfactory impairment due to COVID-19. The results showed that both the structural and functional connectivity were significantly increased in previously infected subjects compared to the control group. Greater residual olfactory impairment was associated with more segregated processing within certain regions. These findings suggest a characteristic brain connectivity response to residual hyposmia related to COVID-19.
HUMAN BRAIN MAPPING
(2022)
Article
Otorhinolaryngology
Xiang Liu, Jiayu Huang, Peng Tian, Junwu Hu, Laiquan Zou
Summary: This study developed and validated a simple and effective self-reported olfactory dysfunction questionnaire (SODQ) for the initial screening of clinical olfactory disorders in China. The final version of SODQ consisted of 10 items with one factor, showing excellent test-retest reliability and convergent validity with the T&T olfactory test. The SODQ has the potential to effectively screen for clinical olfactory disorders from a subjective perspective.
Article
Allergy
Alfred B. Addison, Billy Wong, Tanzime Ahmed, Alberto Macchi, Iordanis Konstantinidis, Caroline Huart, Johannes Frasnelli, Alexander W. Fjaeldstad, Vijay R. Ramakrishnan, Philippe Rombaux, Katherine L. Whitcroft, Eric H. Holbrook, Sophia C. Poletti, Julien W. Hsieh, Basile N. Landis, James Boardman, Antje Welge-Lussen, Devina Maru, Thomas Hummel, Carl M. Philpott
Summary: Through systematic review and expert discussion, members of the Clinical Olfactory Working Group overwhelmingly recommended olfactory training as a management option for postinfectious olfactory dysfunction, while no one recommended the use of monocycline antibiotics. The diagnostic role of oral steroids was discussed, with some group members in favor of vitamin A drops as a treatment option. Further research is needed to confirm the efficacy of other therapeutic options.
JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY
(2021)
Article
Medicine, Research & Experimental
David T. Liu, Maha Sabha, Michael Damm, Carl Philpott, Anna Oleszkiewicz, Antje Haehner, Thomas Hummel
Summary: The study found that the presence of parosmia is associated with clinically relevant recovery in olfactory discrimination and identification function in patients with PIOD receiving olfactory training, with patients who have lower baseline olfactory function being more likely to show significant improvements.
Article
Biology
Keerthana Chithanathan, Fang-Ling Xuan, Miriam Ann Hickey, Li Tian
Summary: Compared to wildtype mice, 5 x FAD mice exhibited enhanced anxiety as early as 2 months old and showed increased pro-inflammatory cytokines in the olfactory bulb. The microglial activation and morphological changes were more prominent in the olfactory bulb of 2-month-old 5 x FAD mice. In the frontal cortex, pro-inflammatory cytokines were upregulated at a later stage (5-6 months old).