Effects of increasing the intracranial blood volume in cluster headache patients and controls

Eleven patients with episodic cluster headache in period, five patients out of period and six controls were studied concerning the effects of an increase of the intracranial blood volume by tilting. Common carotid artery (CCA) blood flow was similar in all three groups at baseline and during tilting. CCA diameters were similar at baseline and increased during tilting in all three groups, indicating that tilting caused an increase in the extra- and intracranial blood volume. Unilateral pain or sympathetic dysfunction did not appear during tilting in the patients out of period or in the controls. In four of eight studied patients with cluster headache in period, unilateral miosis and ptosis appeared during tilting. Two of these four patients developed intense unilateral pain, while the other two did not report any pain. Four other patients developed slight unilateral pain but no sympathetic dysfunction during tilting.