13 Dural Arteriovenous Malformation of the Major Venous Sinuses: An Acquired Lesion Mohammad Y. Chaudhary,1.2 Arteriovenous malformations of the dura are thought to be congenital. However, Ved P. Sachdev3 arteriographic investigations of four patients who, after a head injury, developed dural Soo H. Ch01 arteriovenous fistulae with features of congenital malformations suggest that these Imre Weitzner, Jr.1 abnormal communications may also be acquired. Thrombosis or thrombophlebitis in Smiljan Puljic2 the dural sinus or vein may be the primary event in their formation. The pathogenesis Yun Peng Huang 1 is probably " growth" of the dural arteries normally present in the walls of the sinuses during the organization of an intraluminal thrombus. This may result in a direct communication between artery and vein or sinus, establishing an abnormal shunt. Ultimate fibrosis of the sinus wall and intraluminal thrombus may be the factors responsible for the spontaneous disappearance of such malformations. Most dural arteriovenous malformations (AVMs) that involve th e major venous sinuses present either spontaneously or as incidental findings during arteriog­ raphy performed for other reasons. They occur predominantly in women over age 40 years [1]. The angiomatous network, multiple feeding arteries, numerous arteriovenous (A V) shunts, and occasional association with cerebral angiomas [2], as well as a few cases reported in children [3], suggest that these AVM s are congenital. Thrombosis of the draining sinus or vein is thought to be responsible for the occasional spontaneous disappearance of these lesions [4, 5]. Our experience with four patients who, after a head injury, developed dural AV fistulae with features of congenital malformations prompted a review of th e literature and this report. In two of our four cases, transverse and sigmoid sinus abnormalities were demonstrated angiographically before the AV fistulae devel­ oped. In case 3, angiography 2 years earlier for unrelated reasons was normal; no AV shunt was seen. Although in case 4, there was no angiographic evidence of a dural fistula before head injury, the posttrauma onset of symptoms and th e angiographic findings strongly suggested that this lesion had been acquired. Cases 1 and 3 were studied by serial angiography with selective internal, Received May 7, 1981 ; accepted after revision external, and common carotid injections, while stereo magnification serial an­ September 9, 1981. giography with selective and superselective catheterization of the feeding arteries Presented at the ann ual meeting of the Ameri­ was performed in cases 2 and 4. The first three patients were followed by can Society of Neuroradiology, Chicago, April periodic angiography for up to 4 years, and the AV shunts were seen to close 1981. spontaneously. ' Department of Radiology, Mount Sinai Hospi­ tal, New York, NY 10029. ' Department of Radiology, New York Medical Case Reports College, Westchester County Medical Center, Val­ halla, NY 10595. Address reprint requests to M. Case 1 Y. Chaudhary (present address). 3Department of Neurosurgery, Mount Sian i A 56-year-old woman was examined for head aches and dizzy spell s. Cerebral angiog­ Hospital , New York, NY 10029. raphy to rule out transient ischemic attacks was norm al (figs 1 A and 1 B). Control of her mild diabetes caused her headaches and dizzy spell s to disappear. AJNR 3:13-19, January / February 1982 0195-6108/ 82/ 0301-0013 $00.00 She was brought to the emergency room after a head injury 2 months later. She had a © American Roentgen Ray Society bruise over the right occipitomastoid area, was confused and disori ented, but she had no 14 CHAUDHARY ET AL. AJ NR:3, January / February 1982 neurologic defi cit. Wh en, after 1 week, her condition had not area and was bleeding from th e left ear. Skull films revealed a left improved, cerebral angiog raph y was perform ed, which showed a temporal fracture traversing th e mastoid air cells; a CT scan showed norm al arteri al phase. In th e ve nous phase, however, th e wall of th e bifrontal intracerebral hematomas. He improved graduall y with con­ ri ght sigmoid sinus was irregular and th e intern al jugul ar ve in (fig. servative treatm ent, but after 3 weeks he had a grand mal seizure. 1 C) was not opacified , in dicating th rombosis or thrombophl ebitis. Cerebral angiograph y confirmed th e bifrontal intracerebral avas­ She recovered completely, but 6 months later returned to th e cular masses and, in addition, showed a dural AV fi stula in th e wall hospital complaining of tinnitus and a bu zz in g noise in her ri ght ear. of th e right lateral sinu s (figs. 3B-30) draining into a cortical ve in . Au scultation revealed an audible bruit over th e right mastoid region. Review of the right common carotid arteri ogram obtained during Cerebral angiograph y showed multiple dural AV fi stulae supplied a workup for headaches 2 years earli er was norm al (fig. 3 A) . In th at by th e occipital and middle meningeal branches of th e right extern al study no AV shunt was seen. Becau se th e pati ent was in poor carotid artery (figs. 10-1 E) . condition, he was treated conservati ve ly and improved graduall y. A At surgery, the menin geal branches of th e occipital artery and repeat CT scan 8 weeks later revealed th at th e hematomas had th e mastoid emissary ve in were li gated extracranially. Postopera­ been replaced by areas of decreased attenuation. An giog raphy 2 ti ve ly, her complaints of tinnitus and buzz in g noise behind her ri ght years after th e patient was discharg ed showed th e fi stula had ear disappeared, but, on auscultati on, bruit was still audible. A closed spontaneously (fig . 3E) . repeat angiog ram showed th at AV shunts were still present but fl ow through th em had decreased (fig. 1 F) . Follow-up arteri og raph y a Case 4 year later (n ot illustrated) showed th at th e right middle meningeal art ery was no longer supplyin g th e fi stulous communications. In­ A 66-year-old man with a left acoustic neurinoma had a complete stead, th e arteri al supply from the transosseous and oth er menin­ hearing loss on th e left and slight facial asymmetry, with minimal geal branches of the occipital and th e ascending pharyngeal arter­ left facial droop. He also had slight weakness of hi s ri ght arm th at ies appeared to have increased. Th e major ve nous flow at this time he attributed to a head injury 3 years earli er, at whic h time he was was noted to be via th e condyloid and oth er emissary ve in s into th e unconscious for 3 days. CT and cerebral angiograph y confirmed a paravertebral ve nous plexus. The intern al jugular ve in opacificati on mass lesion in the left cerebell opontine angle. was delayed, suggesting stenosis or occlu sion in th e reg ion of th e Left extern al carotid arteriography also revealed a dural AV fi stul a jugular bulb. in th e wall of th e superior sagittal sinu s in th e falx (figs. 4A-4F) . At She returned to th e hospital again 3 years after her first ad mi ssion surgery, all of the meningeal feeders were ligated and th e dura complaining of ri ght occipital headaches. Ri ght common, extern al, excised. Surprisingly, after surgery, strength in his right arm in­ and intern al carotid arteri ography showed th at the fi stulous com­ creased. He was readmitted to the hospital 3 months later and th e munications had disappeared spontaneously (fig. 1 G) . Th e ri ght mass lesion in th e left cerebellopontine angle, which proved to be sigmoid sinus was abnorm al; its lumen was narrowed and its wall an acousti c neurinoma, was successfully removed. An angiog ram irregular, particularl y at the site of th e previous fi stulous communi­ at this time showed the dural AV shunt had not recurred. cation (fig. 1 H). The patient was treated conservati ve ly, and her headaches improved with medication. Discussion Case 2 Normal Arterial Supply of th e Dural Walls of th e Venous Sinuses A 50-year-old male constru cti on worker was ad mitted to th e hospital after a head injury th at caused him to lose consciousness In considering the pathogenesis of these malformations, for 15 min . He was confused but neurolog ically intact on admission. a brief review of the normal arterial supply of the dura walls Skull films showed diastasis of th e ri ght lambdoid al suture, but a of the great venous sinuses may be useful. The dura mater computed tomography (CT) scan was norm al. After 3 weeks, he is highly vascular, especially in the region of the great had not improved and was increasin gly disori ented. CT was re­ venous sinuses. The middle meningeal artery normally ends peated, and compression and blunting of th e frontal horn of the left in the anterior and posterior paramedian meningeal lateral ve ntricle were evident. branches, which run along the insertion of the dural wall of Th ese findings prompted bilateral common carotid arteri og raph y, the superior sagittal sinus at the convexity, as far as the whic h revealed a left frontopari etal subdural hematoma and an AV fi stula in th e scalp on th e ri ght side (figs. 2A and 2B). The subdural cribiform plate anteriorly, and to the foramen magnum pos­ hematoma was evacuated, and it was decided to evaluate th e scalp teriorly.