olfaction & Alzheimer's disease

Epidemiology

• men with Alzheimer's disease (AD) more likely to have olfactory dysfunction than women

Pathology

• worse visuospatial functioning associated with olfactory dysfunction
• the primary olfactory cortex is the only primary cortex affected early during the course of Alzheimer's disease.
• olfactory bulb & olfactory tract effected as early as entorhinal cortex
• olfactory bulb & olfactory nerve involvement begins in Braak stage 2

Diagnostic procedures

• UPSIT odor test may predict development of AD inpatients with mild cognitive impairment (MCI) & correlate with measures of amyloid plaques* & neurofibrillary tangles (see UPSIT)

* seems inconsistent with Braak staging

Radiology

• olfactory bulb volume may serve as a preclinical marker for adults at risk for developing Alzheimer's disease later in life

Notes

• also see anatomic predilection of Alzheimer's pathology

Additional terms

• Alzheimer's disease (AD)
• olfaction (smell)
• Pennsylvania smell identification scale (UPSIT)