• Genetics
• cerebellar degeneration
• cerebellar ataxia
• neurogenetics
• neuropathy

The cerebellum is classically considered a primary motor control organ with specific roles in coordination and motor learning. Functional imaging experiments in humans have indicated cerebellar involvement in a host of additional functions such as attention, cognition and, more recently, olfactory processing.1 ,2

Olfactory dysfunction is present in a number of common neurodegenerative disorders such as Alzheimer's disease (AD) and idiopathic Parkinson's disease (PD) as well as disorders that primarily affect the cerebellum such as spinocerebellar (SCA) and Friedreich's ataxia (figure 1).3–8 Olfactory dysfunction can be measured in three main domains: olfactory detection threshold, identification and discrimination.9 Simple detection of odours is believed to be more dependent on the peripheral olfactory system, while identification and discrimination require more activation of the central olfactory structures and have more cognitive components.9 Olfactory testing may be useful in differentiating AD from …