What is the relationship between oculomotor (third cranial) nerve palsy and giant cell arteritis (GCA)?

From the Guidelines

Oculomotor nerve palsy in giant cell arteritis (GCA) is a medical emergency that requires immediate treatment with high-dose corticosteroids to prevent permanent vision loss. The relationship between oculomotor (third cranial) nerve palsy and giant cell arteritis (GCA) is well-established, with GCA being a potential cause of oculomotor nerve palsy due to granulomatous inflammation of medium and large arteries, including those that supply the oculomotor nerve 1.

Key Points to Consider

• GCA can present with both cranial and extracranial manifestations, including headaches, scalp tenderness, vision loss, and jaw claudication 1.
• Diagnosis of GCA is based on clinical presentation, pathologic abnormalities on temporal artery biopsy, and/or evidence of large vessel involvement on vascular imaging 1.
• Treatment of GCA typically involves glucocorticoids, with tocilizumab being an option for severe cases or to facilitate steroid tapering 1.
• The goal of treatment is to prevent permanent vision loss and other complications associated with GCA.

Treatment Approach

• High-dose corticosteroid therapy should be initiated immediately, with intravenous methylprednisolone 1000mg daily for 3 days, followed by oral prednisone 1mg/kg/day (typically 60-80mg daily) 1.
• After 2-4 weeks of high-dose therapy, a slow taper should begin, reducing by approximately 10% every 2 weeks, with close monitoring for symptom recurrence.
• Adjunctive therapy with tocilizumab (162mg subcutaneously weekly) should be considered in severe cases or to facilitate steroid tapering 1.

Monitoring and Prevention

• Patients require regular monitoring of inflammatory markers (ESR, CRP), blood glucose, blood pressure, and bone density.
• Calcium (1200mg daily) and vitamin D (800-1000 IU daily) supplementation along with bisphosphonates are recommended for osteoporosis prophylaxis during prolonged steroid use.

From the Research

Relationship between Oculomotor Nerve Palsy and Giant Cell Arteritis

• Oculomotor nerve palsy can be a rare initial manifestation of giant cell arteritis (GCA) 2, 3, 4
• GCA can present with acute painful third nerve palsy, mimicking the presentation of a microvascular cause 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, 3
• Isolated oculomotor nerve palsy in association with GCA is rare, but it is essential to consider GCA as a potential cause in patients over 50 years old with a new, refractory headache and cranial neuropathy 3

Treatment and Diagnosis

• High-dose oral prednisone can lead to rapid improvement in symptoms and signs of third nerve palsy caused by GCA 2
• Temporal artery biopsy is necessary to confirm the diagnosis of GCA 2, 5, 3
• Inflammatory markers, such as erythrocyte sedimentation rate (ESR) and c-reactive protein, can be elevated in GCA, but normal values do not rule out the diagnosis 3
• Corticosteroids remain the mainstay of treatment to prevent visual loss in GCA, with the type, dose, route, and duration of treatment being controversial 6