What is the treatment for 3rd (third) nerve palsy?

Treatment for Third Nerve Palsy

Treatment of third nerve palsy is directed first toward identifying and managing the underlying cause, followed by symptom-directed management of diplopia and ptosis, with surgical intervention reserved for cases showing no further recovery after 6-12 months. 1

Initial Management Strategy

Determine Etiology First

The treatment approach hinges on whether the palsy is pupil-sparing or pupil-involving, as this determines urgency and underlying cause 1, 2:

• Pupil-sparing palsy with complete ptosis and complete motility dysfunction typically indicates microvascular disease (diabetes, hypertension) and can be observed with expectation of spontaneous recovery within 3 months 1, 3
• Pupil-involving palsy requires urgent neuroimaging (MRI with gadolinium and MRA or CTA) to rule out compressive lesions, particularly posterior communicating artery aneurysm 1, 2
• If neuroimaging is normal, proceed with serologic testing for infectious diseases (syphilis, Lyme) and consider lumbar puncture 1

Address Vascular Risk Factors

For microvascular causes, manage underlying diabetes, hypertension, and hyperlipidemia, as these are the primary risk factors 1, 3

Non-Surgical Management

Observation Period

• Complete ptosis often eliminates diplopia complaints until the lid is elevated, so many patients tolerate this well initially 1
• Most microvascular cases recover spontaneously within 3 months, with recovery rates of 85.2% showing at least partial improvement 3, 4

Temporary Diplopia Management

When diplopia is bothersome, use these temporizing measures while awaiting recovery 1, 2:

• Botulinum toxin injection into antagonist extraocular muscles or the levator muscle 1
• Occlusion therapy: eye patch, occlusive contact lens, or MIN lens (Fresnel) for activities where diplopia is most problematic 1
• Prisms (press-on or ground-in) following partial recovery, though the incomitant nature limits effectiveness outside primary gaze 1
• Accommodation aids: uniocular progressive lenses or high-placed bifocals for younger patients with accommodation deficits 1

Surgical Management

Timing and Indications

Surgery should be considered after 6-12 months if no further recovery is expected, with goals being reconstruction of alignment, improvement of binocular vision, or reduction of diplopia 1, 2

Surgical Approach for Partial Third Nerve Palsy

For residual exotropia with ability to adduct past midline 1:

• Lateral rectus recession combined with medial rectus resection (with or without adjustment), with or without vertical transposition 1
• Ipsilateral superior oblique weakening or anterior intorting fiber weakening to reduce hypotropia and intorsion from inferior oblique weakness 1
• Contralateral eye recession with or without posterior fixation to expand binocular single vision field 1

Surgical Approach for Complete Third Nerve Palsy

Complete paralysis requires more aggressive intervention 1:

• Lateral rectus weakening is typically required: supramaximal recession, extirpation, or suturing to lateral orbital rim periosteum 1
• Nasal transposition of split lateral rectus to medial rectus insertion has shown notable success, performed unilaterally or bilaterally 1
  • Safest when split ends placed within 4mm of medial rectus to reduce choroidal effusion risk 1
  • Easiest when no prior lateral rectus recession performed 1
  • Avoid if aberrant regeneration with secondary innervation present 1
• Alternative techniques: superior oblique nasal transposition toward medial rectus insertion or maximal medial rectus resection for tethering effect 1
• Botulinum toxin augmentation with supramaximal lateral rectus recession and medial rectus resection 1

Ptosis Surgery Considerations

Temper ptosis surgery if Bell's response is extremely impaired due to increased exposure keratopathy risk 1

Postoperative Expectations

• Postoperative prism correction often required for fusion in primary or reading position 1
• Patients frequently have significant diplopia outside the binocular fusion region and may benefit from part-time occlusion or fogging contact lens for high-risk activities like driving 1
• Patients with concomitant brain or brainstem injury may have central fusion disruption and be unable to fuse despite satisfactory alignment 1

Important Caveats

Giant Cell Arteritis Screening

In patients over 50 years with acute third nerve palsy, scalp tenderness, temporal tenderness, or jaw claudication, consider giant cell arteritis and initiate high-dose steroids with temporal artery biopsy, as third nerve palsy can be the initial manifestation 1, 5

Aberrant Regeneration

Avoid split lateral rectus transposition if aberrant regeneration is present, as this involves secondary innervation of extraocular muscles 1

Specialist Referral

Diagnosis and management require expertise in neuro-ophthalmology and adult strabismus, with orthoptists providing valuable assistance under ophthalmologist supervision 1