Nonpharmacological approaches in the management of recurrent headache disorders and their comparison and combination with pharmacotherapy. Clinical Psychology Review, 6, 543-57 1. Gawel, M., Burkitt, M., & Rose, FC (1979). ‏ [books.google.com]

In 1955, Lippmann first characterized recurrent headaches resulting from prolonged ergotamine use ( Lippmann 1955 ). [medlink.com]

Concurrently, prophylaxis is initiated to suppress the recurrent headaches expected throughout the remaining cluster period; prophylaxis is continued for the expected duration of the cluster period and then tapered off. [aafp.org]

manifestations such as confusion, psychosis, convulsions, drowsiness, hemiplegia and peripheral neuropathy (Hokkanen et al. 1978; Horton and Peters 1982). [link.springer.com]