Idiopathic stabbing headache ( ISH) and ice cream headache occur due to paroxysmal firing of trigeminal pathways and a defect in pain control mechanisms. Any defect in pain control mechanisms appears to be localized to the affected areas. Therefore, we compared ISH and experimentally induced ice cream headache localizations in the same group of migraine sufferers to investigate similarities and differences between these headaches. The percentage of ice cream headache localizations restricted to 'in front of the vertex/ on the vertex' was 94%, while it was 45% for ISH. The percentage of ice cream headache occurrence behind the vertex was 6% and 55% for ISH. Due to the widespread distribution of ISH in the head, there might be irritation of various branches of the trigeminal nerve, while the restricted localizations of ice cream headache suggest irritation of a certain branch or branches of the trigeminal nerve, e. g. in the oropharynx. Either widespread or restricted irritation of trigeminal pathways causes either ISH or ice cream headache, in which intermittent deficits in central pain control mechanisms seem to be playing the key role. Copyright (C) 2004 S. Karger AG, Basel.