The Olfactory Nerve: Anatomy and Pathology.

The human sense of smell is the unique sense through which the olfactory system can identify aromatic molecules within the air and provide a taste sensation. Still, also it plays an essential role in several other functions, warning about environmental safety and even impacts our emotional lives. Recently, olfactory impairment has become an issue of interest due to the COVID-19 pandemic. The dysfunction may vary from only reduced smell detection (hyposmia) to complete loss of it (anosmia) but also includes changes in the normal perception of odors (parosmia). Computed tomography and magnetic imaging resonance are the modalities of choice to evaluate the olfactory pathways. Computed tomography is the initial imaging modality for olfactory disturbances, allowing recognition of sinonasal pathologies, inflammatory processes, or bone-related tumors. Magnetic imaging resonance with dedicated protocols for olfactory disorders enables a detailed assessment of the sinonasal compartment and the anterior cranial fossa. Provides a better depiction of olfactory bulb volume, morphology and signal intensity, as well the status of signal intensity of the central olfactory projection areas. Several diseases can affect the olfactory nerve, such as congenital disorders, trauma, inflammatory or infectious diseases, neoplasms, and even post-operative involvement. This article aims to review the normal anatomy of the olfactory nerve pathway and highlight the spectrum of conditions that most commonly affect it.

The Trigeminal Nerve: Anatomy and Pathology.

The trigeminal nerve is the fifth cranial nerve and is a sensory-motor nerve that provides the innervation to the face with its three roots. The trigeminal nerve can be affected by several diseases, such as vascular conflict, congenital malformation, inflammatory or neoplastic diseases. Magnetic Resonance Imaging plays a crucial role in its evaluation. This article aims to review the trigeminal nerve anatomy, discuss the best magnetic resonance imaging techniques to evaluate each nerve segment, and demonstrate the imaging aspect of the diseases that most commonly affect it.

The Abducens Nerve: Anatomy and Pathology.

The abducens, or the sixth cranial nerve, is purely motor and runs a long course from the brainstem to the lateral rectus. Travels with the inferior petrosal sinus through the Dorello's canal before entering the cavernous sinus. Based on the location of an abnormality, other neurologic structures may be involved with the disturbs related to this nerve. This article aims to review the abducens nerve anatomy and demonstrates the imaging aspect of the diseases that most commonly affect it.