Difference between revisions of "Abducens nerve palsy"

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==Background==
 
==Background==
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*Also called 6th cranial nerve (CN VI)
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*Most common ocular nerve palsy
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*Innervates the ipsilateral lateral rectus muscle controlling eye abduction
 +
*Esotropia (eye moves inward) of the affected eye due to the unopposed action of the medial rectus muscle, innervated by the oculomotor nerve (CN III) <ref name="tint">Tintinalli JE, Kelen GD, Stapczynski JS, Ma, OJ, Cline DM, editors. Tintinalli’s Emergency Medicine. 7th ed. New York: McGraw-Hill; 2011. 763, 1037, 1546</ref>
  
Palsy of the abducens nerve, CN VI, is the most common ocular nerve palsy.  The abducens nerve innervates the ipsilateral lateral rectus muscle, controlling eye abduction. A palsy results in an esotropia of the affected eye due to the unopposed action of the medial rectus muscle.
+
===Causes===
 +
*Nuclear lesion
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**Congenital, [[MS|demyelinating]], [[CVA|ischemia]], traumatic
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*Inflammatory
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**[[Vasculitis]]
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**[[Sarcoidosis]]
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**[[Systemic lupus erythematosus]]
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*Infectious
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**[[Lyme disease]]
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**[[Syphilis ]]
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**[[Tuberculosis]]
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**[[Meningitis ]]
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*Orbital lesions
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**Neoplastic
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**Inflammatory
 +
**Infectious
  
 
==Clinical Features==
 
==Clinical Features==
 +
===History===
 +
*May complain of:<ref name="tint">Tintinalli JE, Kelen GD, Stapczynski JS, Ma, OJ, Cline DM, editors. Tintinalli’s Emergency Medicine. 7th ed. New York: McGraw-Hill; 2011. 763, 1037, 1546</ref><ref name="rosen">Marx JA, Hockberger RS, Walls RM, et al., eds. Rosen's Emergency Medicine: Concepts and Clinical Practice. Philadelphia, PA: Mosby/Elsevier; 2013</ref>
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*''[[Diplopia]]'' (frequent complaint) upon attempting lateral gaze and ''esotropia'' at rest
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**May have a ''head turn'' to help correct their diplopia
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*[[Vision loss]]
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*[[Hearing loss]]
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*Symptoms of [[vasculitis]], most commonly [[giant cell arteritis]] (headache, tenderness of the scalp, jaw claudication, reduced visual acuity, tinnitus, fever_
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*+/- history of [[diabetes]], [[hypertension]], [[stroke]], [[fever]], and [[headache]]
  
Patients with a CN VI palsy frequently present with diploplia and esotropia.
+
===Examination===
 +
*Excluding paresis of the other cranial nerves
 +
*Check ocular muscle movements
 +
*Check for papilledema
 +
*Test pupillary response
 +
*Test ocular motor nerves (CN III, IV, and VI)<ref name="oph">Yanoff M, Duker JS. Opthalmology. Mosby International Ltd; 2013</ref><ref name="eye">Gerstenblith AT. The Wills Eye Manual: Office and Emergency Room Diagnosis and Treatment of Eye Disease. Lippincott Williams and Wilkins</ref>
 +
**Trace a full H-pattern with finger and have the patient follow the finger only with their eyes
 +
**Patients with abducens nerve palsy are unable to move the affected eye laterally
 +
**In order to avoid diplopia, patients will turn their heads away from the lesion so that both eyes are looking sideways
 +
**Check deep tendon reflexes and strength to exclude corticospinal tract involvement
  
 
==Differential Diagnosis==
 
==Differential Diagnosis==
 +
*''[[Elevated ICP|Increased intracranial pressure (ICP)]]'': Because of its position and intracranial length, increased ICP from any cause can lead to injury and dysfunction
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*''Vascular'': Aneurysm, central [[venous sinus thrombosis]]
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*''Inflammatory'': Post-[[viral syndrome|viral]], [[MS|demyelinating]], [[sarcoidosis]], [[giant cell arteritis]], Miller-Fisher Syndrome variant of [[Guillian-Barre Syndrome]]
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*''Neoplastic'': [[brain tumor|Lesions]] in the cerebellopontine angle. In children – pontine glioma
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*''Degenerative/deficiency'': [[vitamin B12 deficiency|Vitamin B deficiency]], [[Wernicke-Korsakoff syndrome]]
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*''Idiopathic'': Post-[[lumbar puncture]], status-post surgery involving head
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*''Infection'': [[Meningitis]], [[lyme disease]], [[syphilis]]
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*''Congenital'': Rare to find true congenital sixth nerve palsy
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*''Autoimmune'': [[Myasthenia Gravis]]
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*''[[head trauma|Trauma]]'': Especially if a torsional head motion or medial wall [[orbital fracture]] (with entrapment of the medial rectus muscle
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*''Endocrine'': [[diabetic neuropathy|Diabetic cranial mononeuropathy]] - the incidence of palsy in the 3rd, 6th, and 7th cranial nerves is significantly higher in patients with [[diabetes]]<ref name="tint">Tintinalli JE, Kelen GD, Stapczynski JS, Ma, OJ, Cline DM, editors. Tintinalli’s Emergency Medicine. 7th ed. New York: McGraw-Hill; 2011. 763, 1037, 1546</ref><ref name="rosen">Marx JA, Hockberger RS, Walls RM, et al., eds. Rosen's Emergency Medicine: Concepts and Clinical Practice. Philadelphia, PA: Mosby/Elsevier; 2013</ref> <ref name="oph">Yanoff M, Duker JS. Opthalmology. Mosby International Ltd; 2013</ref><ref name="eye">Gerstenblith AT. The Wills Eye Manual: Office and Emergency Room Diagnosis and Treatment of Eye Disease. Lippincott Williams and Wilkins</ref><ref>http://www.ncbi.nlm.nih.gov/pubmed/26314216</ref><ref>http://www.ncbi.nlm.nih.gov/pubmed/17157701</ref><ref>http://www.ncbi.nlm.nih.gov/pubmed/11555800</ref>
  
* Giant Cell Arteritis
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==Evaluation==
* Medial [[Orbital Fracture]] (with entrapment of the medial rectus muscle)
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===Work-up===
* ocular [[Myasthenia Gravis]]
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*Workup will depend on suspected etiology, may include
* Miller-Fisher Syndrome [[Guillian-Barre Syndrome]]
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**POC glucose
* Congenital Esotropia
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**CBC
 
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**BMP
==Diagnosis==
+
**ESR
 
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**Lyme titer
 +
**RPR (if suspect syphilis)
 +
**[[Lumbar puncture]] to exclude meningitis, Guillain-Barré
 +
**Antinuclear antibody test
 +
**[[CT head]]: exclude acute bleed or mass
 +
**[[brain MRI|MRI]]: indicated for brainstem findings on the exam and to exclude pontine glioma in children and in adults where the abducens nerve palsy does not improve<ref name="oph">Yanoff M, Duker JS. Opthalmology. Mosby International Ltd; 2013</ref><ref name="eye">Gerstenblith AT. The Wills Eye Manual: Office and Emergency Room Diagnosis and Treatment of Eye Disease. Lippincott Williams and Wilkins</ref>
  
 
==Management==
 
==Management==
 
+
*Treat by underlying etiology
 +
*Consider neuro/optho consult
 +
*Children: Can be treated with alternating patching to decrease probability of developing amblyopia in the affected eye
 +
*Adults: Lenses can be fogged with clear tape, paint, or nail polish to decrease diplopia. Neurology can prescribe Fresnel prisms as an alternative.
 +
*[[Giant cell arteritis]]: treat with [[prednisone]] or intravenous [[Methylprednisolone]].
  
 
==Disposition==
 
==Disposition==
 
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*Dispo appropriate to etiology
 +
*Truly isolated cases: often benign, can be followed up by neurologist for serial exams
 +
*Surgery: If patient does not improve within 6 months after treatment and serial check-ups, surgery may be required<ref name="oph">Yanoff M, Duker JS. Opthalmology. Mosby International Ltd; 2013</ref><ref name="eye">Gerstenblith AT. The Wills Eye Manual: Office and Emergency Room Diagnosis and Treatment of Eye Disease. Lippincott Williams and Wilkins</ref>
  
 
==See Also==
 
==See Also==
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==References==
 
==References==
<references/>
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{{Reflist}}
  
[[Category:Ophtho]]
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[[Category:Ophthalmology]]
[[Category:Neuro]]
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[[Category:Neurology]]
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[[Category:Symptoms]]

Latest revision as of 15:39, 23 October 2019

Background

  • Also called 6th cranial nerve (CN VI)
  • Most common ocular nerve palsy
  • Innervates the ipsilateral lateral rectus muscle controlling eye abduction
  • Esotropia (eye moves inward) of the affected eye due to the unopposed action of the medial rectus muscle, innervated by the oculomotor nerve (CN III) [1]

Causes

Clinical Features

History

Examination

  • Excluding paresis of the other cranial nerves
  • Check ocular muscle movements
  • Check for papilledema
  • Test pupillary response
  • Test ocular motor nerves (CN III, IV, and VI)[3][4]
    • Trace a full H-pattern with finger and have the patient follow the finger only with their eyes
    • Patients with abducens nerve palsy are unable to move the affected eye laterally
    • In order to avoid diplopia, patients will turn their heads away from the lesion so that both eyes are looking sideways
    • Check deep tendon reflexes and strength to exclude corticospinal tract involvement

Differential Diagnosis

Evaluation

Work-up

  • Workup will depend on suspected etiology, may include
    • POC glucose
    • CBC
    • BMP
    • ESR
    • Lyme titer
    • RPR (if suspect syphilis)
    • Lumbar puncture to exclude meningitis, Guillain-Barré
    • Antinuclear antibody test
    • CT head: exclude acute bleed or mass
    • MRI: indicated for brainstem findings on the exam and to exclude pontine glioma in children and in adults where the abducens nerve palsy does not improve[3][4]

Management

  • Treat by underlying etiology
  • Consider neuro/optho consult
  • Children: Can be treated with alternating patching to decrease probability of developing amblyopia in the affected eye
  • Adults: Lenses can be fogged with clear tape, paint, or nail polish to decrease diplopia. Neurology can prescribe Fresnel prisms as an alternative.
  • Giant cell arteritis: treat with prednisone or intravenous Methylprednisolone.

Disposition

  • Dispo appropriate to etiology
  • Truly isolated cases: often benign, can be followed up by neurologist for serial exams
  • Surgery: If patient does not improve within 6 months after treatment and serial check-ups, surgery may be required[3][4]

See Also

External Links

References

  1. 1.0 1.1 1.2 Tintinalli JE, Kelen GD, Stapczynski JS, Ma, OJ, Cline DM, editors. Tintinalli’s Emergency Medicine. 7th ed. New York: McGraw-Hill; 2011. 763, 1037, 1546
  2. 2.0 2.1 Marx JA, Hockberger RS, Walls RM, et al., eds. Rosen's Emergency Medicine: Concepts and Clinical Practice. Philadelphia, PA: Mosby/Elsevier; 2013
  3. 3.0 3.1 3.2 3.3 Yanoff M, Duker JS. Opthalmology. Mosby International Ltd; 2013
  4. 4.0 4.1 4.2 4.3 Gerstenblith AT. The Wills Eye Manual: Office and Emergency Room Diagnosis and Treatment of Eye Disease. Lippincott Williams and Wilkins
  5. http://www.ncbi.nlm.nih.gov/pubmed/26314216
  6. http://www.ncbi.nlm.nih.gov/pubmed/17157701
  7. http://www.ncbi.nlm.nih.gov/pubmed/11555800