Headache caused by craniospinal pressure dissociation in the Arnold-Chiari-syringomyelia syndrome.

Two patients with Arnold-Chiari malformation, associated with syringomyelia, are described. They presented with headache caused by coughing, sneezing and straining. The pathogenesis and diagnosis are discussed. The treatment of this condition consists in a fossa posterior decompression, in some cases followed by a syringoperitoneal or a syringosubarachnoid shunt.