Seeing Double: Finding the Cause of Diplopia
Seeing Double: Finding the Cause of Diplopia
Tamhankar MA, Biousse V, Ying GS, et al
Ophthalmology. 2013;120:2264-2269
Diplopia is a frightening, disconcerting experience for patients. Attempting to identify the cause of diplopia can be a similarly anxiety-filled endeavor for clinicians. An isolated cranial nerve palsy (a mononeuropathy) can range from a relatively benign, self-limited complication of vascular disease to a life-threatening emergency. Hypertension and diabetes are the common culprits for microvascular palsies. A handful of other conditions such as tumors, aneurysms, and giant cell arteritis can also produce diplopia.
The possibility of uncovering a critical systemic origin of the patient's symptoms argues for routine neuroimaging of patients with a mononeuropathy, although a microvascular complication is the most likely cause of cranial nerve palsies in patients older than 50 years. There has been much discussion about the necessity of neuroimaging patients with isolated neuropathies, and conclusions from major studies are conflicting. Before the routine use of MRI, the imaging modalities for evaluating cranial nerve palsies were risky, expensive, or both. With the incorporation of MRI into routine medical practice, imaging has become much safer and cost-effective.
Although most isolated mononeuropathies are ischemic in nature in older patients, some patients will benefit from early neuroimaging. The question is, which patients should be imaged?
Isolated Third, Fourth, and Sixth Cranial Nerve Palsies From Presumed Microvascular Versus Other Causes: A Prospective Study
Tamhankar MA, Biousse V, Ying GS, et al
Ophthalmology. 2013;120:2264-2269
The Phenomenon Known as "Double Vision"
Diplopia is a frightening, disconcerting experience for patients. Attempting to identify the cause of diplopia can be a similarly anxiety-filled endeavor for clinicians. An isolated cranial nerve palsy (a mononeuropathy) can range from a relatively benign, self-limited complication of vascular disease to a life-threatening emergency. Hypertension and diabetes are the common culprits for microvascular palsies. A handful of other conditions such as tumors, aneurysms, and giant cell arteritis can also produce diplopia.
Is Neuroimaging Indicated?
The possibility of uncovering a critical systemic origin of the patient's symptoms argues for routine neuroimaging of patients with a mononeuropathy, although a microvascular complication is the most likely cause of cranial nerve palsies in patients older than 50 years. There has been much discussion about the necessity of neuroimaging patients with isolated neuropathies, and conclusions from major studies are conflicting. Before the routine use of MRI, the imaging modalities for evaluating cranial nerve palsies were risky, expensive, or both. With the incorporation of MRI into routine medical practice, imaging has become much safer and cost-effective.
Although most isolated mononeuropathies are ischemic in nature in older patients, some patients will benefit from early neuroimaging. The question is, which patients should be imaged?
