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Oculomotor Nerve Palsy, Emergency Medicine

Basics

Description

- Typical presentation of a 3rd cranial nerve (CN) palsy: - Eyelid drooping - Blurred or double vision - Light sensitivity - May also have other neurologic signs/symptoms:

- Superior rectus: - Moves eye upward - Rotates top of eye toward nose - Slight adduction

- Inferior rectus: - Moves eye inferiorly - Rotates top of eye away from nose - Slight adduction

- Complete: Total loss of CN III function ( "down and out " ): - Compressive lesions: - Aneurysms - Tumors - Brainstem herniation with compression - Increased intracranial pressure

- Ophthalmologic exam: - Extraocular movements - Fundoscopic exam for papilledema - Ipsilateral and contralateral pupillary reaction - Ptosis - Diplopia - Chemosis or conjunctival injection - Tenderness - Visual acuity - Exophthalmos

- Pupil sparing lesion: - Ptosis - Globe is "down and out " - No elevation, depression, or adduction - Normal pupil exam - CN IV, V, VI intact - Usually no other neurologic signs/symptoms - Most commonly caused by ischemia in adults - Also consider giant cell arteritis and trauma

- Pupil-involving lesion: - Anisocria is present with a dilated pupil on affected side - Need to rule out compressive aneurysm

- Look for associated symptoms: - Extremity weakness - Changes in speech - Dysfunction of other CNs - Gait or coordination

- Intracranial tumor: Control increasing intracranial pressure - Inflammation and edema: Decrease with IV steroids. - Meningitis: - Rapid administration of IV antibiotics - IV steroids may be useful to decrease inflammatory response and edema

  • Typical presentation of a 3rd cranial nerve (CN) palsy:Eyelid droopingBlurred or double visionLight sensitivityMay also have other neurologic signs/symptoms:
  • CN III controls elevation, adduction and depression of the eye. This nerve also raises the lid and mediates pupillary constriction and lens accommodation:Medial rectus:Moves eye medially toward nose (adduction)Superior rectus:Moves eye upwardRotates top of eye toward noseSlight adductionInferior rectus:Moves eye inferiorlyRotates top of eye away from noseSlight adductionInferior oblique:Rotates top of eye away from noseSlight elevation and abductionLevator palpebrae superioris:
  • CN IV innervates the superior oblique:Moves eye down when looking mediallyRotates eye internally
  • CN VI innervates the lateral rectus:Moves eye laterally (abduction)Lesions categorized as:Complete vs. incompletePupil involving vs. pupil sparing
  • Complete: Total loss of CN III function ( "down and out " ):Compressive lesions:AneurysmsTumorsBrainstem herniation with compressionIncreased intracranial pressure
  • Incomplete: Partial loss of CN III function:Vascular infarction of vasa vasorum
  • Pupil involving:95 " 97% of compressive lesions (aneurysm, tumor, etc.) involve the pupilParasympathetic fibers sit peripherally in CN III
  • Pupil sparing:Ischemic injury to nerveDiabetics, uncontrolled hypertension

Etiology

  • Intracranial or orbital tumor
  • Aneurysm (particularly posterior communicating artery)
  • Trauma
  • Intracranial hemorrhage
  • Diabetes mellitus
  • Migraine headache
  • Infection, meningitis
  • Arteriovenous malformation or fistula
  • Cavernous sinus thrombosis
  • Neuropathy (e.g., myasthenia gravis, Guillain " Barre)
  • Collagen vascular diseases (e.g., sarcoidosis)
  • Idiopathic

Trauma is the most common cause of acquired oculomotor nerve palsies

Diagnosis

Signs and Symptoms

A careful history and physical exam are vital to narrow down the differential diagnosis

History

History is of utmost importance in determining cause:

  • Headache
  • Pupillary dilation
  • Eye pain
  • Diplopia
  • Blurry vision
  • History of long-standing diabetes mellitus
  • Head trauma, either recent or distant
  • Unintentional weight loss
  • Signs and symptoms of infection
  • Sudden onset of severe headache, meningeal signs, photophobia
  • Proptosis
  • Lid swelling

Physical Exam

  • Ophthalmologic exam:Extraocular movementsFundoscopic exam for papilledemaIpsilateral and contralateral pupillary reactionPtosisDiplopiaChemosis or conjunctival injectionTendernessVisual acuityExophthalmos
  • Pupil sparing lesion:PtosisGlobe is "down and out "No elevation, depression, or adductionNormal pupil examCN IV, V, VI intactUsually no other neurologic signs/symptomsMost commonly caused by ischemia in adultsAlso consider giant cell arteritis and trauma
  • Pupil-involving lesion:Anisocria is present with a dilated pupil on affected sideNeed to rule out compressive aneurysm
  • Incomplete, 3rd CN palsy:May have involvement of 1 or more extraocular muscle and may or may not involve pupil
  • Look for associated symptoms:Extremity weaknessChanges in speechDysfunction of other CNsGait or coordination

Essential Workup

CT/MRI of brain, orbit, sinuses

Diagnosis Tests & Interpretation

Lab

When indicated based on history and physical exam:

  • CBC with differential
  • ESR
  • Antinuclear antibodies, rheumatoid factor to evaluate for vasculitis
  • Lumbar puncture

Imaging

  • MRI/MRA of brain and cerebral vessels particularly when pupil is involved
  • CT angiogram
  • Cerebral arteriogram: Has associated risk of neurologic morbidity and mortality
  • Doppler imaging for arteriovenous malformations, dural sinus thrombosis

Diagnostic Procedures/Surgery

  • Intraocular pressure to exclude glaucoma
  • Slit-lamp exam:Observe structural abnormalities of iris or anterior chamber

Differential Diagnosis

  • Intracranial infections
  • Malignancy
  • Vasculitis
  • Aneurysms
  • Myasthenia gravis
  • Botulism
  • Orbital infections
  • Trauma
  • Lens pathology
  • Retinal pathology
  • Glaucoma
  • MS

Consider congenital oculomotor nerve palsy

Treatment

Pre-Hospital

Without associated trauma, no specific pre-hospital care issues exist

Initial Stabilization/Therapy

  • Initial stabilization of trauma patient should concentrate on underlying injuries
  • Any patient with evidence of herniation should have the following measures to control intracranial pressure:Intubation using rapid-sequence induction and controlled ventilation to a PCO2 level of 35 " 40 mm HgElevate head of bed 30 °Mannitol

Ed Treatment/Procedures

  • Differentiation between incomplete and complete oculomotor or pupil-involving vs. pupil-sparing nerve palsy guides focus of ED treatment
  • All patients younger than 50 yr with any extent of 3rd nerve palsy should be evaluated for a compressive lesion
  • If pupil is involved, neuroimaging is indicated as well as consultation to determine cause
  • If pupil is spared and the patient has diabetes or other risk for an ischemic 3rd nerve, discharge is likely reasonable with outpatient follow-up:If partial sparing or patient does not have these risk factors, consultation and neuroimaging is indicated
  • Medication regimen determined by cause:Aneurysm:Control severe HTN.Decrease intracranial pressureControlled ventilationElevation of headMannitolIntracranial tumor: Control increasing intracranial pressureInflammation and edema: Decrease with IV steroids.Meningitis:Rapid administration of IV antibioticsIV steroids may be useful to decrease inflammatory response and edemaVasculitis and collagen vascular diseases: Decrease inflammatory cell infiltration with IV steroidsNeuropathy: Myasthenia gravis " edrophonium chloride test
  • Neurosurgical consultation as appropriate

MRI/MRA is indicated for all children with a 3rd nerve palsy

Medication

  • Ceftriaxone: 1 " 2 g (peds: 50 " 100 mg/kg) IV
  • Dexamethasone: 10 mg IV (peds: 0.15 " 0.5 mg/kg IV single dose in ED)
  • Edrophonium chloride: 5 " 8 mg IV (peds: 0.15 mg/kg IV; 1/10 test dose given 1st)
  • Mannitol: 1 g/kg IV (peds: Not routinely recommended)
  • Methylprednisolone: Adults/peds: 1 " 2 mg/kg IV single dose in ED

Follow-Up

Disposition

Admission Criteria

  • Complete oculomotor nerve palsy of any cause requires admission and emergency neurosurgical evaluation
  • Incomplete oculomotor nerve palsy with abnormal CT or MRI, abnormal lab studies, or other focal neurologic or constitutional symptoms should receive prompt neurologic consultation and imaging

Discharge Criteria

  • Incomplete oculomotor nerve palsy with negative CT or MRI, normal lab studies, and no other symptoms can be referred for urgent outpatient neurologic evaluation
  • Complete pupil-sparing oculomotor palsy in patients with risk factors for microvascular disease (i.e., diabetic) can receive outpatient neurologic workup

Followup Recommendations

If the patient is being discharged, prompt neurologic follow-up is required

Pearls and Pitfalls

  • Complete lesions must be assessed rapidly
  • Patients <50 yr old with any extent of CN III palsy should be evaluated for compressive lesions
  • If the pupil is involved, compressive lesions are often the cause and immediate MRI/MRA is indicated

Additional Reading

  • Bruce BB, Biousse V, Newman NJ. Third nerve palsies. Semin Neurol. 2007;27:257 " 268.
  • Chen CC, Pai YM, Wang RF, et al. Isolated oculomotor nerve palsy from minor head trauma. Br J Sports Med. 2005;39:e34.
  • Woodruff MM, Edlow JA. Evaluation of third nerve palsy in the emergency department. J Emerg Med. 2008;35:239 " 246.
  • Yanovitch T, Buckley E. Diagnosis and management of third nerve palsy. Curr Opin Ophthalmol. 2007;18:373 " 378.

Codes

ICD9

  • 378.51 Third or oculomotor nerve palsy, partial
  • 378.52 Third or oculomotor nerve palsy, total

ICD10

  • H49.00 Third [oculomotor] nerve palsy, unspecified eye
  • H49.01 Third [oculomotor] nerve palsy, right eye
  • H49.02 Third [oculomotor] nerve palsy, left eye
  • H49.03 Third [oculomotor] nerve palsy, bilateral
  • H49.0 Third [oculomotor] nerve palsy

SNOMED

  • 388980004 third cranial nerve weakness (disorder)
  • 3171005 Partial third nerve palsy (disorder)
  • 194119004 Total oculomotor nerve palsy (disorder)