Summary: Sobel et. al (2001)

Parkinson's disease is a disorder characterised by a progressive loss of neuronal structure or function. It has a primary influence on motor control, although Parkinson's disease may also affect both cognitive and sensory processing. Patients with Parkinson's disease have recognised olfactory impairments, however, Sobel et al. (2001) suggest that this is partly a sniffing impairment. Whereas olfaction integrates both sensory and motor information, sniffing is primarily a physical or motor action. Sobel et al. (2001) tested 40 people (20 with Parkinson's and 20 age-matched healthy controls) in four olfactory tests and found that people with Parkinson's disease at lower sniff airflow rate and volume, thus were impaired at sniffing. This suggests that sniffing is a vital component of human olfaction and is thus an important component of the olfactory impairment seen in Parkinson's disease patients.