Prodromes of classic migraine were retrospectively studied from the records of 325 patients as regards their type, number, duration, frequency and sidedness in relation to the headache phase. We conclude:
1. Prodromes can affect any of the senses, but most commonly affect the visual field.
2. When more than one prodrome was present, the most common combinations were: Visual + Sensory for two prodromes; visual + sensory + speech for three prodromes; and visual + sensory + speech + motor for four prodromes,
3. Duration and Frequency of prodromes vary widely.
4. A definite statement about sidedness of headache in relation to prodrome could not be made.
We feel a prospective study of prodromes is necessary to examine prodrome phenomena in greater detail.