Leah Croll, MD, Assistant Professor of Clinical Neurology at the Lewis Katz School of Medicine at Temple University, provided perspective for two HealthCentral articles – one about cluster headaches and one about status migrainosus. Cluster headaches are sudden, severe headaches that affect one side of the head and occur in periods of frequent attacks before disappearing for months or years between clusters. Status migrainosus is a type of intense migraine that lasts for more than 72 hours.