Sixth nerve palsy: Difference between revisions
 
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==Background==
==Background==
[[File:Gray785.png|thumb|Figure showing the mode of innervation of the recti lateralis from CNII.]]
[[File:Capture2.PNG|thumbnail|Right eye]]
[[File:Extraocular muscle actions and innervation.png|thumb|Eye movements by extra-ocular muscles and cranial nerve innervation]]
*Also called 6th cranial nerve (CN VI) or abducens nerve palsy
*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) <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
**Congenital, [[MS|demyelinating]], [[CVA|ischemia]], traumatic
*Inflammatory
**[[Vasculitis]]
**[[Sarcoidosis]]
**[[Systemic lupus erythematosus]]
*Infectious
**[[Lyme disease]]
**[[Syphilis ]]
**[[Tuberculosis]]
**[[Meningitis ]]
*Orbital lesions
**Neoplastic
**Inflammatory
**Infectious


==Clinical Features==
==Clinical Features==
[[File:Abducens palsy.jpg|thumb|Limitation of abduction of the right eye when looking to the right.]]
[[File:PMC3663068 kjo-27-219-g002.png|thumb|Paresis of the abducens nerve (demonstrated in the right eye when looking to the right).]]
===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>
*''[[Diplopia]]'' (frequent complaint) upon attempting lateral gaze and ''esotropia'' at rest
**May have a ''head turn'' to help correct their diplopia
*[[Vision loss]]
*[[Hearing loss]]
*Symptoms of [[vasculitis]], most commonly [[giant cell arteritis]] (headache, tenderness of the scalp, jaw claudication, reduced visual acuity, tinnitus, fever_
*+/- history of [[diabetes]], [[hypertension]], [[stroke]], [[fever]], and [[headache]]


Patients with a CN VI palsy frequently present with '''diplopia''' and '''esotropia'''.  They may have a '''head turn''' to help correct their diplopia.
===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
*''Vascular'': Aneurysm, central [[venous sinus thrombosis]]
*''Inflammatory'': Post-[[viral syndrome|viral]], [[MS|demyelinating]], [[sarcoidosis]], [[giant cell arteritis]], Miller-Fisher Syndrome variant of [[Guillian-Barre Syndrome]]
*''Neoplastic'': [[brain tumor|Lesions]] in the cerebellopontine angle. In children – pontine glioma
*''Degenerative/deficiency'': [[vitamin B12 deficiency|Vitamin B deficiency]], [[Wernicke-Korsakoff syndrome]]
*''Iatrogenic'': Post-[[lumbar puncture]], status-post surgery involving head
*''Infection'': [[Meningitis]], [[lyme disease]], [[syphilis]]
*''Congenital'': Rare to find true congenital sixth nerve palsy
*''Autoimmune'': [[Myasthenia Gravis]]
*''[[head trauma|Trauma]]'': Especially if a torsional head motion or medial wall [[orbital fracture]] (with entrapment of the medial rectus muscle
*''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
==Evaluation==
* Medial [[Orbital Fracture]] (with entrapment of the medial rectus muscle)  
===Work-up===
* ocular [[Myasthenia Gravis]]
*Workup will depend on suspected etiology, may include
* Miller-Fisher Syndrome [[Guillian-Barre Syndrome]]
**POC glucose
* Congenital Esotropia
**CBC
* Meningitis
**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
**[[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
*CBC
*Consider neuro/optho consult
*BMP
*Children: Can be treated with alternating patching to decrease probability of developing amblyopia in the affected eye
*Accucheck
*Adults: Lenses can be fogged with clear tape, paint, or nail polish to decrease diplopia. Neurology can prescribe Fresnel prisms as an alternative.
*CT/MRI Brain
*[[Giant cell arteritis]]: treat with [[prednisone]] or intravenous [[Methylprednisolone]].
*ESR
*Lyme Titer
*RPR


==Disposition==
==Disposition==
 
*Dispo appropriate to etiology
Dispo appropriate to etiology, consult either Neuro or Ophtho.
*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==
Line 38: Line 95:


==References==
==References==
<references/>
{{Reflist}}


[[Category:Ophtho]]
[[Category:Ophthalmology]]
[[Category:Neuro]]
[[Category:Neurology]]
[[Category:Symptoms]]

Latest revision as of 20:44, 28 July 2021

Background

Figure showing the mode of innervation of the recti lateralis from CNII.
Right eye
Eye movements by extra-ocular muscles and cranial nerve innervation
  • Also called 6th cranial nerve (CN VI) or abducens nerve palsy
  • 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

Limitation of abduction of the right eye when looking to the right.
Paresis of the abducens nerve (demonstrated in the right eye when looking to the right).

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
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