Differential Diagnosis for Unilateral Upper Eyelid Droop
- Single most likely diagnosis
- Ptosis due to senile levator aponeurosis dehiscence or disinsertion: This condition is a common cause of unilateral upper eyelid droop, especially in older adults, due to the weakening or detachment of the levator aponeurosis from the tarsus.
- Other Likely diagnoses
- Horner's syndrome: Characterized by ptosis, miosis, and anhidrosis, Horner's syndrome can cause unilateral eyelid droop due to disruption of the sympathetic nerves supplying the eye.
- Third cranial nerve (oculomotor nerve) palsy: This condition can lead to ptosis, among other symptoms like diplopia and pupil dilation, due to weakness or paralysis of the muscles controlled by the oculomotor nerve.
- Myasthenia gravis: An autoimmune disorder that can cause fluctuating muscle weakness, including eyelid droop, which may be unilateral or bilateral.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Cavernous sinus thrombosis or tumor: Although rare, these conditions can cause third cranial nerve palsy and subsequent ptosis, and are medical emergencies requiring prompt treatment.
- Aneurysm of the posterior communicating artery: Compression of the third cranial nerve by an aneurysm can lead to ptosis and other symptoms, and is a potentially life-threatening condition if ruptured.
- Pituitary apoplexy: A medical emergency where a pituitary tumor undergoes hemorrhage or infarction, potentially causing third cranial nerve palsy and ptosis.
- Rare diagnoses
- Chronic progressive external ophthalmoplegia (CPEO): A mitochondrial disorder that can cause progressive weakness of the external eye muscles, including the levator palpebrae superioris, leading to bilateral or unilateral ptosis.
- Oculopharyngeal muscular dystrophy: A rare genetic disorder characterized by progressive muscle weakness, including eyelid droop, typically starting in adulthood.
- Congenital ptosis: Although typically bilateral, some cases of congenital ptosis may present unilaterally due to abnormalities in the development of the levator palpebrae superioris muscle or its innervation.