Fibromuscular dysplasia of arteries: a spastic phenomenon?

Arterial fibrodysplasia is principally observed in renal and carotid arteries: the disease is a systemic, acquired one related to ischemia of the muscular cell of the media, by obstruction of the vasa-vasorum. Its histological identification in very rare cases of spastic arteries in cases of chronic ergotamine or methysergide intoxication lead me to consider that fibrodysplasia could be due to chronic, repeated, discontinuous and subobstructing spasms, favoured by the various etiological co-factors already known.