What is the diagnosis and management for an adult patient with right eye ptosis and ophthalmoplegia, specifically an inability to look up and medially?

Right Eye Third Nerve Palsy: Diagnosis and Urgent Management

This presentation of right eye ptosis with inability to look up and medially is consistent with a right third nerve (oculomotor nerve) palsy, and the immediate priority is determining pupillary involvement to identify life-threatening compressive lesions, particularly posterior communicating artery aneurysm. 1, 2

Immediate Diagnostic Assessment

Critical First Step: Pupillary Examination

Examine the pupil in both bright and dim lighting to determine if this is pupil-involving or pupil-sparing third nerve palsy. 2, 3

• Pupil-involving (dilated pupil on right): This represents a neurosurgical emergency requiring urgent neuroimaging with MRI with gadolinium and MRA or CTA to rule out compressive lesions, especially posterior communicating artery aneurysm 1, 2, 3
• Pupil-sparing (normal pupil): If complete ptosis with complete motor dysfunction but normal pupil, the etiology is almost always microvascular secondary to diabetes, hypertension, or hyperlipidemia 2

Important Caveat About Pupil Assessment

Even in vasculopathic third nerve palsy, the pupil may be mildly involved, so you cannot be completely certain of microvascular etiology based on pupil-sparing alone—a compressive lesion might present this way 1. Recent evidence demonstrates that pupil-sparing third nerve palsy does not exclude a central brainstem lesion 4.

Neuroimaging Decision Algorithm

Proceed with urgent neuroimaging (MRI with gadolinium and MRA or CTA) if ANY of the following:

• Pupillary involvement (dilated pupil) 1, 2, 3
• Associated neurological symptoms (ataxia, tremor, hemiplegia, other cranial nerve palsies) 2, 3
• Papilledema or optic atrophy on fundus examination 2
• Age under 50 years without vascular risk factors 1
• Uncertainty about pupil status 1

If neuroimaging is normal, proceed with:

• Serologic testing for infectious diseases (syphilis, Lyme disease) 1, 3
• Lumbar puncture including glucose, protein, cell count, cytology, and culture 1, 3
• Consider acetylcholine receptor antibodies if variable/fatigable features suggest myasthenia gravis 2

If high suspicion for aneurysm despite normal MRA or CTA:

Proceed with catheter angiogram after brain MRI with and without contrast with specific attention to the third nerve 1

Differential Diagnosis Considerations

Other causes of third nerve palsy include:

• Tumors (meningioma, schwannoma, metastatic lesions) 1
• Trauma 1
• Subarachnoid hemorrhage 1
• Viral illnesses 1
• Demyelinating disease 1
• Leptomeningeal disorders 1
• Midbrain infarction (can present as pupil-sparing with partial involvement) 4

Myasthenia gravis as a masquerader:

If ptosis is variable and worsens with prolonged upward gaze, consider myasthenia gravis 2. Apply ice pack over closed eyes for 2 minutes—reduction of ptosis by approximately 2 mm is highly specific for myasthenia gravis 2.

Initial Management of Diplopia

While awaiting further recovery or definitive treatment:

• Complete ptosis: Many patients are not troubled by diplopia until the lid is elevated 1
• Botulinum toxin injection of opposing extraocular muscle or levator can temporize 1, 3
• Occlusion therapy: Eye patch, occlusive contact lens, or MIN lens (Fresnel, Inc.) for times when diplopia is most bothersome 1
• Prisms (press-on or ground-in) are often helpful while waiting for recovery or treating residual diplopia 1, 3
• Accommodation deficit: Prescribe uniocular progressive lenses or bifocals in younger patients 1

Surgical Management Considerations

Timing and approach:

Surgical management should be considered after 6-12 months if no further recovery is expected 3. Success depends on the amount of residual deficit 1.

For partial third nerve palsy with residual function:

• Residual exotropia with ability to adduct past midline responds well to lateral rectus recession combined with medial rectus resection (with or without adjustment), with or without vertical transposition 1
• Ipsilateral superior oblique weakening might reduce hypotropia and intorsion from inferior oblique weakness 1

For complete paralysis:

• Supramaximal lateral rectus recession, extirpation, or suturing to periosteum of lateral orbital rim 1
• Sometimes combined with nasal transposition of superior oblique toward medial rectus insertion or maximal medial rectus resection 1
• Nasal transposition of split lateral rectus to medial rectus insertion has shown some success 1

Critical surgical caveat:

Ptosis surgery should be tempered if Bell's response is extremely impaired, increasing the risk of exposure keratopathy 1. Patients treated surgically often require part-time occlusion or fogging contact lens for high-risk activities like driving due to persistent diplopia outside the region of binocular fusion 1.