Differential Diagnosis for Sudden Diplopia
- Single most likely diagnosis
- Microvascular cranial nerve palsy (e.g., third cranial nerve palsy): This is a common cause of sudden diplopia, often related to diabetes, hypertension, or atherosclerosis, which can cause a temporary disruption in the blood supply to the cranial nerves controlling eye movement.
- Other Likely diagnoses
- Thyroid eye disease: Autoimmune conditions like Graves' disease can cause inflammation and swelling of the tissues around the eye, leading to misalignment of the eyes and sudden diplopia.
- Myasthenia gravis: An autoimmune disorder that affects the neuromuscular junction, causing fluctuating muscle weakness, including the muscles controlling eye movement, which can lead to sudden diplopia.
- Orbital or periorbital trauma: Blunt trauma to the orbit or surrounding areas can cause diplopia due to damage to the extraocular muscles, nerves, or bones.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Aneurysm or arteriovenous malformation (AVM): A sudden onset of diplopia can be a warning sign for a life-threatening condition like an aneurysm or AVM, which requires immediate medical attention.
- Stroke or cerebral vasculitis: Diplopia can be a presenting symptom of a stroke or cerebral vasculitis, which can have severe consequences if not promptly treated.
- Increased intracranial pressure: Conditions like idiopathic intracranial hypertension or a space-occupying lesion can cause diplopia due to increased pressure on the cranial nerves.
- Rare diagnoses
- Wernicke's encephalopathy: A rare but serious condition caused by thiamine deficiency, which can lead to sudden onset of diplopia, among other symptoms.
- Tolosa-Hunt syndrome: A rare condition characterized by inflammation of the cavernous sinus or superior orbital fissure, causing diplopia and other symptoms.
- Ocular myositis: Inflammation of the extraocular muscles, which can cause diplopia and other eye movement abnormalities.