From the Guidelines
In cases of suspected 3rd cranial nerve (CN) palsy due to giant cell arteritis (GCA), immediate high-dose corticosteroid therapy is essential to prevent vision loss and other complications, as recommended by the 2021 American College of Rheumatology/Vasculitis Foundation guideline for the management of GCA 1.
Significance of 3rd CN Palsy in GCA
The presence of 3rd CN palsy in GCA is a medical emergency, as it can lead to vision loss and other serious complications. The 2021 guideline conditionally recommends initiating treatment with IV pulse glucocorticoids (GCs) over high-dose oral GCs for patients with newly diagnosed GCA with threatened vision loss, which includes those with 3rd CN palsy 1.
Treatment Approach
The treatment approach for 3rd CN palsy due to GCA involves:
- Initiating high-dose corticosteroid therapy, such as intravenous methylprednisolone 1000 mg daily for 3 days, followed by oral prednisone 1 mg/kg/day (typically 60-80 mg daily) 1
- Obtaining a temporal artery biopsy within 1-2 weeks to confirm the diagnosis, but not delaying treatment while waiting for biopsy results 1
- Monitoring the patient closely for symptom improvement and potential steroid side effects
- Gradually tapering the prednisone dose over several months, with a typical tapering schedule reducing the dose by 10% every 2 weeks, individualized based on the patient's response
Rationale
The rationale for this approach is that GCA is an inflammatory condition affecting medium and large arteries, including those supplying the eye and brain. Corticosteroids rapidly suppress this inflammation, potentially preventing irreversible damage to the oculomotor nerve and preserving vision. The high initial dose and prolonged tapering are necessary due to the risk of relapse if treatment is discontinued too quickly.
Key Considerations
- The optimal duration of therapy with GCs for GCA is not well established and should be guided by the patient’s values and preferences 1
- For patients with GCA who experience disease relapse with symptoms of cranial ischemia, adding a non-GC immunosuppressive agent and increasing the dose of GCs may be recommended 1
From the Research
Significance of 3rd Cranial Nerve Palsy in Giant Cell Arteritis
- The 3rd cranial nerve palsy is a rare initial manifestation of Giant Cell Arteritis (GCA) 2
- GCA can present with acute painful third nerve palsy, mimicking the presentation of a microvascular cause 2
- The third nerve palsy often improves rapidly after steroid treatment is started 2
- The presence of GCA symptoms or elevated inflammatory markers in a patient older than 50 years with an acute third nerve palsy should prompt initiation of high-dose steroid treatment and temporal artery biopsy 2
Diagnostic Criteria and Management
- Diagnostic criteria for GCA include clinical criteria and temporal artery biopsy 3
- Management of GCA involves high-dose corticosteroids, with the goal of preventing visual loss 3
- The most reliable and sensitive parameters to regulate and taper down steroid therapy are the levels of erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) 3
Treatment and Prognosis
- Corticosteroids may be considered in the treatment of cryptogenic cranial neuropathy, once other possible aetiologies have been excluded 4
- Interleukin-6 (IL-6) is a biologic marker of disease activity in GCA, and plasma IL-6 levels are more sensitive than ESR for indicating disease activity 5
- Low-dose aspirin may decrease the rate of visual loss and cerebrovascular accidents in patients with GCA 6