History of head trauma or olfactory loss before Covid-19 infection History of surgery or brain tumor Patient examination or CT scan in patients is beneficial for olfactory conduction disorder History of similar treatments with olfactory training Neurodegenerative diseases that cause olfactory disorders such as Parkinson's and Levy Buddy disease

History of head trauma or olfactory loss before Covid-19 infection History of surgery or brain tumor Patient examination or CT scan in patients is beneficial for olfactory conduction disorder History of similar treatments with olfactory training Neurodegenerative diseases that cause olfactory disorders such as Parkinson's and Levy Buddy disease