Head And Neck - Clinical Significance

Front 1

Pterion

Back 1

The bones at the pterion are thin and easily broken in a blow to the side of the head.
Just deep to the pterion are the branches of the middle meningeal artery that are easily ruptured, causing intracranial bleeding.

Front 2

Anosmia

Back 2

Loss of smell.
Often associated with head injuries in which the cribiform plate is fractured, rupturing the olfactory nerves as they pass through it.

Front 3

Visual field defects - Lesion of optic nerve

Back 3

Blind in eye.

Front 4

Visual field defects - Lesion of optic tract

Back 4

Loss of half the visual field in each eye.
Right - left temporal, right nasal
Left - right temporal, left nasal

Front 5

Visual field defects - Lesion of optic chiasm

Back 5

Loss of peripheral vision.
Result of pituitary tumor, aneurysm of internal carotid artery.

Front 6

Vestibulocochlear nerve lesion

Back 6

Often affect both divisions of the nerve.

Front 7

Meniere's syndrome

Back 7

Excess fluid in the inner ear.
Causes tinnitus, hearing impairment, and vertigo.

Front 8

Lesion of the vestibular division

Back 8

Often through viral infection or head trauma.
Results in vertigo, dizziness, nausea, vomiting.

Front 9

Lesion of the cochlear division

Back 9

Results in loss or impairment of hearing.

Front 10

Lesion of IV and VI

Back 10

Abnormal positioning of the eye.

Front 11

Lesion of XI

Back 11

Often caused by penetrating neck injury.
Result in weakness of head rotation and shrugging, winged scapula.

Front 12

Lesion of XII

Back 12

Often caused by skull base injury or pathology.
Atrophy of the tongue muscles on affected side; deviation towards affected side. Impaired speech and ingestion.

Front 13

Horner's syndrome

Back 13

Lesion of sympathetic pathway.
Symptoms: constricted pupil that does not react to light, ptosis (loss of Mueller's muscle), anhydrosis (loss of facial sweating on affected side).