A 32 years old woman presents with a 13-year history of disabling, pounding pain over one temple that occurs a few times per month. She reports that the headaches come on gradually with nausea and sensitivity to light, and, when particularly severe, distort the vision in the ipsilateral eye. She says that her headaches can be triggered by lack of sleep, are worse with physical exertion, and are more common during menses. On a few occasions, headaches were preceded by the gradual appearance of a shimmering, zigzag line that enlarged, moved to the peripheral visual field and then faded away over 45 minutes. Untreated, they last for 2 days. Physical examinations are unremarkable. What potential sequelae do you need to be concerned about?