CN

Cranial Nerve I: Olfactory Nerve

Responsible for the sense of smell; innervates the olfactory epithelium in the nasal cavity.

Anosmia

Loss of smell, which can result from trauma, viral infections, or neurodegenerative diseases. (Affected Cranial Nerve: I - Olfactory Nerve)

Cranial Nerve II: Optic Nerve

Responsible for vision; innervates the retina of the eye.

Optic neuritis

Inflammation of the optic nerve often associated with multiple sclerosis, leading to vision loss or defects. (Affected Cranial Nerve: II - Optic Nerve)

Cranial Nerve III: Oculomotor Nerve

Controls eye movements and pupil constriction; innervates several extraocular muscles.

Ptosis

Drooping of the eyelid, often due to oculomotor nerve palsy.(Affected Cranial Nerve: III - Oculomotor Nerve)

Cranial Nerve IV: Trochlear Nerve

Controls the superior oblique muscle, which depresses and intorts the eye.

Vertical diplopia

Double vision when looking down, associated with trochlear nerve palsy. (Affected Cranial Nerve: IV - Trochlear Nerve)

Cranial Nerve V: Trigeminal Nerve

Responsible for facial sensory perception and motor functions like mastication. (Affected Cranial Nerve: V - Trigeminal Nerve)

Trigeminal neuralgia

Severe facial pain due to dysfunction of the trigeminal nerve.

Cranial Nerve VI: Abducens Nerve

Controls lateral rectus muscle to abduct the eye.

Inability to abduct eye

Typically seen in abducens nerve dysfunction, causing the eye to turn inward. (Affected Cranial Nerve: VI - Abducens Nerve)

Cranial Nerve VII: Facial Nerve

Controls facial expressions and provides taste sensation to the anterior 2/3 of the tongue.

Bell’s palsy

Sudden, unilateral facial weakness or paralysis due to facial nerve dysfunction. (Affected Cranial Nerve: VII - Facial Nerve)

Cranial Nerve VIII: Vestibulocochlear Nerve

Responsible for hearing and balance; composed of cochlear and vestibular branches.

Hearing loss

Loss of auditory perception, which can be sensorineural in nature.(Affected Cranial Nerve: VIII - Vestibulocochlear Nerve)

Cranial Nerve IX: Glossopharyngeal Nerve

Responsible for taste from the posterior 1/3 of the tongue and general sensation in the pharynx.

Dysphagia

Difficulty swallowing, often linked with glossopharyngeal nerve dysfunction. (Affected Cranial Nerve: IX - Glossopharyngeal Nerve)

Cranial Nerve X: Vagus Nerve

Involved in swallowing, voice production, and autonomic control of the heart and digestive tract.

Asymmetric uvula deviation

Occurs when the uvula deviates away from the lesion, indicating vagus nerve involvement. (Affected Cranial Nerve: X - Vagus Nerve)

Cranial Nerve XI: Accessory Nerve

Responsible for innervating the sternocleidomastoid and trapezius muscles.

Weak shoulder shrug

Indicative of accessory nerve dysfunction, often seen in neck trauma. (Affected Cranial Nerve: XI - Accessory Nerve)

Cranial Nerve XII: Hypoglossal Nerve

Controls tongue movements.

Tongue deviation

Occurs toward the side of the lesion when protruding the tongue. (Affected Cranial Nerve: XII - Hypoglossal Nerve)