Fourth nerve palsy
From Infogalactic: the planetary knowledge core
| Fourth cranial nerve palsy | |
|---|---|
Trochlear nerve
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| Classification and external resources | |
| Specialty | Lua error in Module:Wikidata at line 446: attempt to index field 'wikibase' (a nil value). |
| ICD-10 | H49.1 |
| ICD-9-CM | 378.53 |
| eMedicine | oph/697 |
| Patient UK | Fourth nerve palsy |
| MeSH | D020432 |
Fourth cranial nerve palsy is a condition that causes weakness or paralysis to the superior oblique muscle. This condition often causes vertical or near vertical double vision as the weakened muscle prevents the eyes from moving in the same direction together.
Because the fourth cranial nerve is the thinnest and has the longest intracranial course of the cranial nerves, it is particularly vulnerable to traumatic injury.
To compensate for the double-vision resulting from the weakness of the superior oblique, patients characteristically tilt their head down and to the side opposite the affected muscle.
When present at birth, it is known as congenital fourth nerve palsy.
