The Olfactory Nerve: Anatomy and Pathology.

Area of Science:

• Neuroscience
• Otorhinolaryngology
• Radiology

Background:

• The human sense of smell (olfaction) is crucial for safety, emotion, and taste perception.
• Olfactory dysfunction, ranging from hyposmia to anosmia and parosmia, has gained recent attention due to the COVID-19 pandemic.
• Various conditions, including congenital disorders, trauma, infections, neoplasms, and post-operative changes, can affect the olfactory nerve.

Purpose of the Study:

• To review the normal anatomy of the olfactory nerve pathway.
• To highlight common conditions affecting the olfactory nerve and pathway.
• To discuss the role of imaging in evaluating olfactory disturbances.

Main Methods:

• Review of anatomical and pathological literature concerning the olfactory system.
• Discussion of imaging modalities used for olfactory pathway assessment, including Computed Tomography (CT) and Magnetic Resonance Imaging (MRI).
• Emphasis on CT for initial sinonasal pathology detection and MRI for detailed olfactory bulb and central olfactory projection area evaluation.

Main Results:

• Computed tomography is effective for identifying sinonasal pathologies, inflammatory processes, and bone tumors impacting olfaction.
• Magnetic resonance imaging with specialized protocols provides detailed assessment of the sinonasal compartment, anterior cranial fossa, olfactory bulb (volume, morphology, signal intensity), and central olfactory projections.
• A spectrum of diseases can compromise olfactory nerve function, necessitating comprehensive diagnostic approaches.

Conclusions:

• Olfactory pathways are susceptible to diverse pathologies affecting smell perception.
• CT and MRI are essential imaging tools for diagnosing the underlying causes of olfactory dysfunction.
• Understanding olfactory anatomy and pathology is critical for effective clinical management and diagnosis.