Brain stem lesions: the oculomotor nerve nucleus in the brain stem is the "headquarters" where the "command" occurs, and the lesions in this part (such as tumor, infarction, bleeding, inflammation, etc.). ) will lead to ptosis.
Neurogenic: the oculomotor nerve emitted by the brain stem is similar to the "wire" that transmits "commands", and its damage can lead to ptosis. Common damages include pathological changes of oculomotor nerve itself (such as diabetic oculomotor nerve neuropathy and oculomotor neuritis), compression of nerve by adjacent tissues on oculomotor nerve conduction pathway (such as intracranial aneurysm and intracranial tumor), and inflammation of adjacent tissues on oculomotor nerve conduction pathway invading nerve (such as cavernous sinus syndrome).
Myogenic: Muscle weakness of levator palpebrae superioris and Miao Lei's meibomian muscle can lead to "command" being received but unable to be executed, leading to eye opening weakness, including myasthenia gravis (there is an obstacle at the signal conversion joint between nerve and muscle, which leads to the muscle receiving "command" unable to contract effectively), hyperthyroidism eye disease, mitochondrial myopathy, etc.
Aponeurotic ptosis: refers to ptosis caused by the aponeurotic defect of levator palpebrae caused by this etiology, and is the most common type of ptosis in clinical ophthalmology.
Mechanical ptosis: refers to eyelid diseases (such as neurofibroma, eyelid tumor, capillary hemangioma, senile eyelid skin relaxation, etc. ) causes eyelid tumors to increase, leading to ptosis.