Anosmia
August 18th, 2017
Overview
Smell is uncommonly assessed in the cranial nerve exam, and rarely assessed comprehensively. It is important to remember that loss of sense of smell is an early sign of Parkinson's disease; it can also occur in certain other neurologic conditions or simply due to nasal blockage.
How to Elicit
- Ask the patient whether their sense of smell has been abnormal recently. Ask them to close their eyes and present common smells such as hand sanitizer, coffee, peppermint etc. and ask the patient to identify them.
Causes of Anosmia
- Mechanical anosmia - inflammation of nasal mucosa, blockage of nasal passages
- Olfactory anosmia - blunt trauma, frontal lobe damage, meningitis, neurosyphillis
- Parkinson's disease
- Congenital anosmia
Interpretation
- Complete loss of olfactionReceptor damage, olfactory nerve / bulb damage
- Inability to identify / match odoursDamage to frontal lobe / temporal lobe / amygdala
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