What to do if extraocular muscles (EOMs) are not intact and the left eye is not moving?

Management of Non-Intact Extraocular Movements with Left Eye Immobility

If the left eye is not moving, this represents a potential cranial nerve palsy or mechanical restriction requiring urgent evaluation to rule out life-threatening causes, particularly if the pupil is involved, which demands immediate neuroimaging to exclude posterior communicating artery aneurysm. 1

Immediate Clinical Assessment

Critical History Elements

• Speed of onset: Acute onset suggests vascular or compressive etiology versus gradual onset 1
• Associated symptoms requiring urgent attention: 1
  • Pupillary changes (dilated pupil is concerning for aneurysm)
  • Ptosis (suggests third nerve involvement)
  • Diplopia pattern and direction
  • Neurologic symptoms: ataxia, tremor, hemiplegia, vision loss
  • Trauma history (even if patient doesn't recall—occult fractures occur) 1
  • Bradycardia, nausea, vomiting (oculocardiac reflex indicating muscle entrapment—life-threatening) 1, 2

Essential Physical Examination

• Pupillary examination in bright and dim illumination: Pupil involvement versus pupil-sparing determines urgency and etiology 1
• Complete motility assessment: 1
  • Versions (both eyes together)
  • Ductions (each eye individually)
  • Cover-uncover and alternate cover testing
  • Forced duction testing to distinguish restriction from paresis 1
• Ptosis assessment: Complete versus incomplete ptosis 1
• Fundus examination: Look for papilledema or optic atrophy 1
• Proptosis measurement: Use exophthalmometry 1, 2
• Visual acuity and confrontational fields 2

Diagnostic Algorithm Based on Findings

If Third Nerve Palsy Pattern (Down-and-Out Eye Position)

Pupil-Sparing (Normal Pupil) with Complete Ptosis and Complete Motility Loss:

• This is almost always microvascular disease (diabetes, hypertension, hyperlipidemia) 1
• However, if partial muscle involvement or incomplete ptosis exists, you cannot assume microvascular cause—proceed to neuroimaging 1
• Obtain MRI with gadolinium and MRA or CTA 1

Pupil-Involving (Dilated or Sluggish Pupil):

• This is a medical emergency—compressive lesion must be ruled out urgently 1
• Posterior communicating artery aneurysm is the primary concern 1
• Immediate neuroimaging: MRI with gadolinium and MRA or CTA 1
• If high suspicion persists despite normal MRA/CTA, proceed to catheter angiogram 1
• Other differential: meningioma, schwannoma, metastatic lesions, trauma, subarachnoid hemorrhage, viral illness (including COVID-19), demyelinating disease 1

If Sixth Nerve Palsy Pattern (Inability to Abduct)

• Evaluate for microvascular disease versus increased intracranial pressure 1
• Neuroimaging indicated if atypical features present 1

If Mechanical Restriction Suspected

Trauma History:

• CT scan (not MRI) if any concern for metallic foreign body 1, 3
• Look for orbital fracture with muscle entrapment 1
• White-eyed blowout fracture with oculocardiac reflex requires urgent surgical repair 1
• Forced duction testing confirms restriction 1

Thyroid Eye Disease Pattern:

• Typically hypotropia with esotropia (inferior and medial rectus involvement) 1
• Fixation duress: brow elevation and eyelid retraction on attempted upgaze 1
• CT or MRI shows tendon-sparing muscle enlargement 1

Urgent Neuroimaging Indications

• Any pupil involvement 1
• Partial muscle involvement with pupil-sparing 1
• Incomplete ptosis with pupil-sparing 1
• Associated neurologic signs 1
• Trauma with suspected entrapment 1
• Oculocardiac reflex (bradycardia, nausea, vomiting) 1, 2

If Neuroimaging is Normal

• Serologic testing: syphilis, Lyme disease 1
• Consider lumbar puncture: glucose, protein, cell count, cytology, culture 1

Initial Management While Awaiting Workup

For Diplopia Management

• Complete ptosis often eliminates diplopia until lid is elevated 1
• Occlusion (eye patch, occlusive contact lens, or MIN lens) 1
• Botulinum toxin to antagonist muscles can temporize 1
• Press-on prisms may help after partial recovery 1

Common Pitfalls to Avoid

• Never assume microvascular cause if pupil is involved—this is aneurysm until proven otherwise 1
• Never assume microvascular cause if incomplete ptosis or partial muscle involvement, even with normal pupil 1
• Do not miss oculocardiac reflex signs—this is life-threatening and requires urgent surgical intervention 1, 2
• Do not order MRI if metallic foreign body suspected—use CT instead 1, 3
• Do not delay imaging in pupil-involving third nerve palsy—hours matter for aneurysm 1

Timing Considerations

• Pupil-involving third nerve palsy: Immediate imaging (within hours) 1
• Oculocardiac reflex with entrapment: Immediate surgical repair 1, 2
• White-eyed blowout fracture: Urgent repair 1
• Microvascular third nerve palsy: Observation for 3-6 months for spontaneous recovery 1