“…In recent years, with the advent of such major advances in the technology of cerebral angiography as selective catheterisation, magnification, and subtration, a second type of arteriovenous communication has been recognised (Hayes, 1963;Takekawa and Holman, 1965;Mingrino and Moro, 1967;Clemens and Lodin, 1968a;Newton and Hoyt, 1968;Rosenbaum and Schechter, 1969;Newton and Hoyt, 1970;Taniguchi et al, 1971;Houser et al, 1972;Aminoff, 1973;Schlezinger and Schatz, 1973;Katsioris et al, 1974). These dural arteriovenous fistulae are 'low flow' communications between small meningeal branches of both the external and internal carotid arteries and basal venous sinuses, frequently the cavernous sinus or its tributaries.…”