The changes on the MRI reflect reversible vasodilatation of migraine which has been reported1. In addition, there is mild ipsilateral arteriospasm. The vascular changes occur on the contralateral side to the hemiparesis. Speech was affected, suggesting that the main speech center is left sided in this patient.
No features to suggest stroke and no other cause for symptoms.
Symptoms resolved over 24 hours with no residual neurological deficit.