Upper and Lower Cluster Headache: Clinical and Pathogenetic Observations in 608 Patients

Abstract

Based on current anatomofunctional knowledge and on the most recent pathogenetic findings, we believe that changes in hypothalamic activity posteroinferiorly may lead to activation of the caudal part of the spinal trigeminal nucleus by way of the hypothalamus, midbrain, and trigeminal nerve fibers and consequently to activation of the trigeminovascular system with a different location in the two syndromes. More specifically, there seems to be a larger and more extensive involvement of the subnucleus caudalis in LS compared with US, where only its ventrocaudal portions are likely to be affected.