Third Nerve Palsy: A Case of Bilateral Eyelid Ptosis, Normal Pupils, and Vertical Diplopia With Multiple Intracranial Lesions

Bilateral eyelid ptosis presents a rare and diagnostically challenging clinical scenario, particularly when accompanied by multiple intracranial lesions. We present the case of a 68-year-old woman with bilateral ptosis, vertical diplopia, and progressive confusion. Imaging revealed a dorsal midbrain lesion and bilateral frontal lobe masses. Clinical examination ruled out common causes of ptosis, such as myasthenia gravis and muscular dystrophies. The patient's constellation of symptoms, bilateral ptosis without pupillary involvement and vertical diplopia, localized the lesion to the midbrain rather than the cortex. This case highlights the importance of integrating clinical examination with neuroimaging to refine localization in challenging presentations of cranial nerve pathology.