Migraine Aura without Headache:

A condition characterized by throbbing headaches which are preceded or accompanied by reversible symptoms that reflect cortical or brain stem dysfunction. The most common type of aura consists of a positive visual phenomenon, usually in the form of a scintillating scotoma. An aura may also take the form of other focal neurologic symptoms or signs, including loss of sensation or weakness in an extremity. In general, the aura precedes the headache by less than 60 minutes, develops over 4 minutes or longer, and has a duration of less than one hour. (From Adams et al., Principles of Neurology, 6th ed, p172; Cephalalgia 1988;8:Suppl 7:1-96)