Intracranial fatigable ptosis.

Two patients sought treatment for bilateral fatigable ptosis; one patient had a hematoma, and the other patient had an intracranial metastasis. Compression of the central caudal nucleus in the dorsal midbrain is proposed as the cause of this ptosis, and an alteration of central acetylcholine neurotransmission may contribute to ocular fatigability. Because symptoms that suggest fatigable ptosis can be similar to those that suggest ocular myasthenia gravis, a careful evaluation is necessary to avoid misinterpretation.