Sixth Cranial Nerve Palsy Management and Etiology

Etiology and Pathophysiology

The American Academy of Ophthalmology suggests that vascular disorders, particularly diabetes and hypertension, are the most common causes of 6th cranial nerve palsy, followed by trauma, neoplasm, increased intracranial pressure, and inflammatory or infectious processes 1, 2, 3
Diabetes mellitus is a common cause of 6th cranial nerve palsy in adults over 50, according to the American Academy of Ophthalmology 2
Hypertension is also a common cause of 6th cranial nerve palsy, as stated by the American Academy of Ophthalmology 2
Giant cell arteritis can cause 6th cranial nerve palsy, presenting with scalp tenderness and jaw claudication, as noted by the American Academy of Ophthalmology 5
Intracranial tumors can cause 6th cranial nerve palsy, particularly in pediatric patients, as reported by the American Academy of Ophthalmology 3
Clival chordoma can cause bilateral 6th cranial nerve palsy, often with abduction deficits, as described by the American Academy of Ophthalmology 3
Increased intracranial pressure can cause bilateral 6th cranial nerve palsies, associated with papilledema, as stated by the American Academy of Ophthalmology 3, 6

Patients with 6th cranial nerve palsy typically present with horizontal diplopia, worse at distance than near, as noted by the American Academy of Ophthalmology 2
Incomitant esotropia is a common finding in patients with 6th cranial nerve palsy, as reported by the American Academy of Ophthalmology 2, 5
Limited abduction of the affected eye is a characteristic sign of 6th cranial nerve palsy, as described by the American Academy of Ophthalmology 2, 3
Compensatory head turn toward the affected side is a common adaptation in patients with 6th cranial nerve palsy, as stated by the American Academy of Ophthalmology 2, 3

The American Academy of Ophthalmology recommends assessing for vasculopathic risk factors, such as diabetes and hypertension, in patients with 6th cranial nerve palsy 2
A complete ophthalmic evaluation, including best-corrected visual acuity, sensorimotor examination, and fundus examination, is essential in diagnosing 6th cranial nerve palsy, as stated by the American Academy of Ophthalmology 2, 3
Neuroimaging, such as MRI brain with and without contrast, is indicated in patients with 6th cranial nerve palsy, particularly those with other cranial neuropathies or signs of elevated intracranial pressure, as recommended by the American Academy of Ophthalmology 2, 5
Laboratory testing, including blood pressure, serum glucose, and hemoglobin A1c, is necessary to evaluate for underlying vasculopathic causes, as noted by the American Academy of Ophthalmology 2, 5

The American Academy of Ophthalmology suggests that treatment of the underlying cause is essential in managing 6th cranial nerve palsy, including control of diabetes and hypertension for vasculopathic causes 2
Observation is recommended for most vasculopathic palsies, as they often resolve spontaneously within 6 months, as stated by the American Academy of Ophthalmology 3
Symptomatic management of diplopia includes occlusion therapy, temporary prisms, and botulinum toxin injection to medial rectus, as described by the American Academy of Ophthalmology 1, 2, 5
Surgical management is indicated in patients with persistent deviation after 6 months from onset or stable angle of deviation for at least 3 months, as recommended by the American Academy of Ophthalmology 5