Impairment of olfaction (Hyposmia) or loss of smell (Anosmia) a characteristic and early feature of Parkinson’s disease. Recent data indicate that >95% of patients with Parkinson’s disease present with significant olfactory loss. Deficits in the sense of smell may occur years (usually reported 2-7 years) before clinical motor symptoms and can be used to assess the risk for developing Parkinson’s disease in otherwise asymptomatic individuals. People are usually not aware of their impairment in being able to smell
When combined with Symptoms of REM Behavior Sleep Disorder (Acting out your Dreams) and Constipation, there is an extremely high risk of developing Parkinson's Disease and is probably present at the beginning and well before the self reported 2-7 years.
Impaired sense of smell is found in 70-90% of those with Parkinson's Disease, specifically odor identification. Identification of Licorice, Coconut and Banana is especially impaired with the ability to smell Chocolate, Strawberry, Onion and others not affected. Parkinson's Patients can distinguish between odors but can not identify certain odors.

Vascular Parkinson's Disease, MPTP Induced Parkinson's, PARK2 Gene Mutation- Preserved sense of smell.

Progressive Supranuclear Palsy (PSP), Multi-System Atrophy (MSA), Corticobasal Ganglionic Degeneration (CBGD), PARK1 Gene Mutation, PARK8 Gene Mutation (excluding Asymptomatic Carriers)- Minimal loss of smell.

LRRK2 Gene Mutation-Impaired Sense of Smell

You might have impaired sense of smell and not know it like most people that do. If you notice a impaired sense of smell get tested and see a Neurologists that has done a fellowship in Movement Disorders (always ask if they have done a fellowship since some falsely advertise). Ask about DATScan Imaging that is able to tell when someone has a Parkinson's disorder before physical symptoms arise. Check out our blog on DATScan Imaging.