What is the treatment for bilateral internuclear hemiplegia?

Treatment of Bilateral Internuclear Ophthalmoplegia

The treatment of bilateral internuclear ophthalmoplegia (INO) should be directed at the underlying cause, with magnetic resonance imaging (MRI) of the brain being essential for diagnosis and treatment planning.

Understanding Bilateral INO

Bilateral internuclear ophthalmoplegia is characterized by:

• Bilateral adduction impairment of the eyes
• Nystagmus in the abducting eye
• Caused by lesions in the medial longitudinal fasciculus (MLF) in the brainstem

Diagnostic Approach

1. Neuroimaging:

   • MRI of the brain with and without contrast is the gold standard for investigating INO 1
   • MR angiography should be considered to evaluate for vascular causes 1

2. Clinical Assessment:

   • Evaluate for focal neurologic findings that may indicate the underlying cause 2
   • Assess for signs of multiple sclerosis, stroke, or other conditions

3. Laboratory Testing:

   • Consider lumbar puncture if multiple sclerosis or infection is suspected

Common Causes and Targeted Treatment

1. Multiple Sclerosis (Most common cause in young adults)

• Treatment with corticosteroids for acute attacks
• Disease-modifying therapies for long-term management
• Consider plasma exchange or IVIG for severe cases 3

2. Ischemic Stroke (Common in older adults)

• Acute management:
  • Thrombolysis if within time window
  • Antiplatelet therapy
  • Blood pressure management
• Secondary prevention with antiplatelet or anticoagulation therapy 4, 5

3. Vertebral Artery Dissection

• Anticoagulation or antiplatelet therapy
• Close monitoring for progression of symptoms 1

4. Brainstem Tumors

• Neurosurgical consultation
• Radiation therapy or chemotherapy depending on tumor type

5. Infection

• Targeted antimicrobial therapy based on identified pathogen

Symptomatic Management

1. Visual Symptoms:

   • Prism glasses to alleviate diplopia
   • Eye patching for temporary relief of double vision
   • Vision therapy exercises

2. Associated Symptoms:

   • Management of neuropathic pain with gabapentinoids or tricyclic antidepressants if present 3
   • Physical therapy for any associated gait or balance issues

Monitoring and Follow-up

1. Regular neurological assessments to monitor progression or resolution
2. Follow-up MRI to evaluate response to treatment
3. Ophthalmological evaluation to assess improvement in ocular motility

Special Considerations

• In cases of vascular etiology, patients should be monitored for signs of progression or new infarcts 2
• When INO presents with intense headache, vascular causes should be strongly suspected 1
• Bilateral INO due to stroke is often localized to the infra-aqueductal region of the midbrain 5

Prognosis

The prognosis varies depending on the underlying cause:

• Multiple sclerosis: May improve with treatment of the acute attack
• Stroke: May show gradual improvement over weeks to months
• Vascular causes: Approximately one-third of bilateral INO cases have vascular etiology 1

Early diagnosis and prompt treatment of the underlying cause provide the best chance for recovery of ocular motility function and prevention of complications.