Fourth nerve palsy
Revision as of 10:59, 6 September 2015 by Neil.m.young (talk | contribs)
Background
- Trochlea innervates superior oblique muscle
- Intorts, depresses and abducts the globe
- Most common cause of vertical diplopia
Etiology
- Head trauma [1]
- Mechanisms that increase IOP
- Practically never involved by aneurysm
- Herpes zoster opthalmicus
- Meningitis
- Diabetic neuropathy
- Lupus/Sjogren syndrome
Clinical Features
- Vertical diplopia[2]
- Worse on downward gaze and gaze away from affected muscle
- Head-tilt
- Tilt typically away from affected side
- May be easier to evaluate on old photos
Differential Diagnosis
- Head trauma (adult)
- Herpes Zoster Ophthalmicus
- Lupus
- Sjogrens
- Stroke
- Third nerve palsy
- Abducens nerve palsy
Diagnostic Evaluation
- Rule out acute causes including CVA, trauma, herpes zoster
Management
- Address any acute causes
- May require surgical correction
Disposition
- Determined by etiology and clinical condition
See Also
External Links
Medscape: Trochlear Nerve Palsy