Rosen & Barkin's 5-Minute Emergency Medicine Consult (489 page)

Trauma is the most common cause of acquired oculomotor nerve palsies

DIAGNOSIS

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

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
  

• 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
    
• 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 weakness
    
  • Changes in speech
    
  • Dysfunction of other CNs
    
  • Gait or coordination
    

CT/MRI of brain, orbit, sinuses

When indicated based on history and physical exam:

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

• 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
  

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

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

Consider congenital oculomotor nerve palsy

TREATMENT

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

• 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 PCO
    ₂
    level of 35–40 mm Hg
    
  • Elevate head of bed 30°
    
  • Mannitol
    

• 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 pressure
      
    • Controlled ventilation
      
    • Elevation of head
      
    • Mannitol
      
  • 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
      
  • Vasculitis and collagen vascular diseases: Decrease inflammatory cell infiltration with IV steroids
    
  • Neuropathy: Myasthenia gravis—edrophonium chloride test
    
• Neurosurgical consultation as appropriate
  

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

• 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

• 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
  

• 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
  

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

• 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
  

• 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

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

BASICS