Diseases of the fourth cranial (trochlear) nerve or its nucleus in the midbrain. The nerve crosses as it exits the midbrain dorsally and may be injured along its course through the intracranial space, cavernous sinus, superior orbital fissure, or orbit. Clinical manifestations include weakness of the superior oblique muscle which causes vertical DIPLOPIA that is maximal when the affected eye is adducted and directed inferiorly. Head tilt may be seen as a compensatory mechanism for diplopia and rotation of the visual axis. Common etiologies include CRANIOCEREBRAL TRAUMA and INFRATENTORIAL NEOPLASMS.

Descriptor ID	D020432
MeSH Number(s)	C10.292.850
Concept/Terms	Trochlear Nerve Diseases Trochlear Nerve Diseases Trochlear Nerve Disease Trochlear Neuropathy Neuropathies, Trochlear Neuropathy, Trochlear Trochlear Neuropathies Trochlear Nerve Disorders Trochlear Nerve Disorder Cranial Nerve IV Diseases Fourth Cranial Nerve Diseases Superior Oblique Myokymia Superior Oblique Myokymia Myokymia, Superior Oblique Myokymias, Superior Oblique Superior Oblique Myokymias Superior Oblique Palsy, Neurogenic Superior Oblique Palsy, Neurogenic Neurogenic Superior Oblique Palsy Fourth Cranial Nerve Palsy Fourth Cranial Nerve Palsy Trochlear Nerve Palsy Palsies, Trochlear Nerve Palsy, Trochlear Nerve Trochlear Nerve Palsies Fourth Nerve Palsy Fourth Nerve Palsies Palsies, Fourth Nerve Palsy, Fourth Nerve

Below are MeSH descriptors whose meaning is more general than "Trochlear Nerve Diseases".

Below are MeSH descriptors whose meaning is related to "Trochlear Nerve Diseases".

Below are MeSH descriptors whose meaning is more specific than "Trochlear Nerve Diseases".