Management of Bilateral Sequential Abducens Nerve Palsy in a 73-Year-Old Patient
A comprehensive evaluation for underlying etiology is essential in bilateral abducens palsy, with neuroimaging required in this 73-year-old patient due to the high risk of serious underlying pathology with bilateral involvement. 1
Initial Diagnostic Evaluation
History and Examination
- Obtain detailed medical history focusing on:
- Onset and progression of diplopia (sequential involvement suggests potentially different etiologies)
- Presence of pain (may indicate inflammatory or vascular causes)
- Associated symptoms: headache, facial weakness, extremity weakness, jaw claudication, scalp tenderness
- Vascular risk factors: diabetes, hypertension, hyperlipidemia
- History of trauma, cancer, or recent infections
Essential Ophthalmic Examination
- Complete ophthalmic evaluation with emphasis on:
- Best-corrected visual acuity
- Check for afferent pupillary defect
- Color vision assessment
- Sensorimotor examination showing incomitant esotropia (typically worse at distance)
- Fundus examination for papilledema or optic atrophy (indicators of increased intracranial pressure)
- Assessment for abduction nystagmus
Laboratory Testing
- Blood pressure measurement
- Serum glucose and HbA1c
- If scalp tenderness or jaw claudication present:
- Erythrocyte sedimentation rate (ESR)
- C-reactive protein (CRP)
- Consider temporal artery biopsy if results suggest giant cell arteritis
Neuroimaging
- MRI brain with and without contrast is mandatory in bilateral abducens palsy 1
- Bilateral involvement significantly increases the likelihood of serious underlying pathology such as:
- Increased intracranial pressure
- Clival chordoma
- Meningeal process
- Demyelinating disease
- Neoplasm
Management Approach
Treat Underlying Cause
- Direct initial treatment to the primary etiology identified through workup
- Consider neuro-ophthalmology consultation, especially if giant cell arteritis is suspected
Symptomatic Management of Diplopia
Nonsurgical options (first-line):
- Occlusion therapy (patch, Bangerter filter, or satin tape on glasses)
- Temporary prism correction
- Botulinum toxin injection to medial rectus muscles to prevent contracture
Surgical management:
- Consider if deviation persists after 6 months from onset
- Options based on residual lateral rectus function:
- With some residual abducting force: medial rectus recession and lateral rectus resection
- With no abducting force: vertical rectus transposition procedures with medial rectus weakening
Special Considerations
Monitoring
- Close follow-up is necessary to determine if spontaneous resolution occurs
- In vasculopathic cases, lack of improvement within 4-6 weeks suggests need for neuroimaging
- If meningeal signs present (stiff neck with headache) or papilledema, consider lumbar puncture after neuroimaging
Surgical Technique Selection
- For severe cases with no abducting force, various vertical rectus transposition techniques may be used:
- Full-tendon or partial-tendon transfer
- Loop myopexy (reduces risk of anterior segment ischemia)
- Consider staging procedures to reduce ischemia risk
Prognosis
- Vasculopathic causes typically resolve within 6 months (one-third within 8 weeks)
- If no recovery by 6 months, approximately 40% demonstrate serious underlying pathology 1
- Pressure palsies generally show universal recovery
- Tumor-related palsies rarely improve without addressing the underlying cause
Pitfalls to Avoid
- Assuming bilateral involvement is merely an extension of common vasculopathic causes
- Failing to obtain neuroimaging in bilateral cases
- Delaying evaluation for giant cell arteritis when symptoms suggest this diagnosis
- Performing surgery before the deviation has stabilized (generally wait 6 months)
- Operating on all three rectus muscles simultaneously (risk of anterior segment ischemia)