Alpha-synuclein Rt-quic and Neurologic Symptoms in Persons With idiOpathic anosMiA

Inclusion criteria with patients iOD: * Age 55 -75 years of age * Slowly progressing and non-fluctuating iOD * Able to give informed consent and to cooperate as evaluated by the PI Exclusion criteria with patients iOD: * Diagnosed with a neurodegenerative disease or major neurological/psychiatric condition. * Anosmia/hyposmia caused by sino-nasal disease (including chronic rhinitis and allergy), after trauma, infection, congenial, olfactory dysfunction due to surgery, or toxins/drugs affecting the olfactory function. * Olfactory dysfunction with response to systemic or local corticosteroids if tried * Severe nasal cavity abnormalities or infections. * Overt signs of dementia or PD * Current alcohol or drug abuse * Terminal illness * Diagnosed with neurodegenerative disease or major neurological/psychiatric condition. Inclusion criteria controls: * Age 55 -75 years of age * Able to give informed consent * Able to cooperate as evaluated by the PI Exclusion criteria controls: * Olfactory dysfunction on clinical test * Overt signs of dementia or PD * Severe nasal cavity abnormalities or infections. * Current alcohol or drug abuse * Diagnosed with neurodegenerative disease or major neurological/psychiatric condition.