Search

Objective: The petrosquamosal sinus (PSS) is an emissary vein that connects the transverse sinus and the external jugular vein. Recent studies have shown that a PSS can be identified on high resolution CT scan when it is contained within a bony canal. The persistent PSS is a potential risk of bleeding in middle ear surgery. The aim of this study is to determine the prevalence of the PSS in patients with chronic otitis media.Method: Between February 2011 and January 2012, 61 ears (47 patients) underwent CT scan before surgery for chronic otitis media. Patients younger than 10 years, showing congenital temporal bone anomaly, and having received prior ear surgeries, were excluded. The prevalence of persistent PSS was evaluated using CT scan. During the same period, 66 ears (33 patients) with peripheral facial palsy underwent CT scan. The frequency of a PSS was also examined in these patients.Results: Among the 61 ears with chronic otitis media, a PSS was detected in 12 ears on CT scan (20.0%). Among them, th...

Objective: The petrosquamosal sinus (PSS) is an emissary vein that connects the transverse sinus and the external jugular vein. Recent studies have shown that a PSS can be identified on high resolution CT scan when it is contained within a bony canal. The persistent PSS is a potential risk of bleeding in middle ear surgery. The aim of this study is to determine the prevalence of the PSS in patients with chronic otitis media.

Dural ateriovenous fistula (DAVF) is the acquired and progressive arteriovenous (AV) shunt disease on or between the dura matter, and its etiology is still controversial1-4. This disorder occurs not in the whole dura but at very specific locations. DAVF can be divided into two types based on the intervention of the drainage route and affected sinus; sinus type and non-sinus type. The sinus type has the shunt at the sinus wall or dural vein, and includes DAVF at the cavernous sinus (CS), transverse-sigmoid sinus (TS-SS), anterior condylor confluence (ACC), and superior sagittal sinus (SSS). The non-sinus DAVF has the shunt on the dura and directly drains into the pial veins, and includes tentorial, ethmoidal, craniocervical and spinal DAVF. However, even the sinus type DAVF ultimately changes to the isolated sinus with cortical reflux due to progressive sinus occlusion, similar to the non-sinus type. Such seemingly separated and complex pathogeneses of DAVF remain elusive.

Subdural empyema is a rare form of intracranial sepsis associated with high morbidity and mortality. The most frequent cause is extension of paranasal sinusitis through emissary veins or of mastoiditis through the mucosa, bone, and dura mater. Development of subdural empyema after pyogenic meningitis is known to be very unusual in adults. We report a rare case of fatal subdural empyema, an unusual complication of pyogenic meningitis. Our bitter experience suggests that subdural empyema should be borne in mind in patient with pyogenic meningitis who exhibit neurological deterioration.

Dural arteriovenous fistula (DAVF) can be separated into two types: DAVF which drains through an affected sinus (sinus type) and DAVF with direct reflux to the cortical vein (non-sinus type). The present report attempted to clarify the mechanism of formation and development of DAVF focusing on the emissary vein (EV) hypothesis. First, inflammation occurs at the penetrating point of the EV on the dura due to idiopathic or secondary causes. Local inflammatory reactions induce vessel dilatation and neovascularization, and subsequently create arteriovenous (AV) connections on the arteriole level. Although EV communicating with dural arteries might play a role as draining routes at first, they start to degrade due to compression of enlarged emissary arteries or to a hemodynamic shift to the drainage pathway of least resistance. Following the occlusion of drainage pathway through EV into the sinus or cortical veins may form, resulting in clinically detectable DAVF. The AV shunt then expands to the surrounding dura associated with recruitment of feeders from distant sites induced by expression of angiogenetic factors and a shift in the hemodynamic balance. In sinus type DAVF, the sinus is progressively compartmentalized and finally occludes due to thrombogenesis with activated coagulopathy or to hemodynamic hypertrophy of the sinus wall. This progression results in the mature, aggressive DAVF with drainage impairments. Previous mechanistic hypotheses focusing on sinus hypertension and sinus thromboses cannot explain the pathogenesis of non-sinus type of DAVF. Although the etiology of DAVF may be concerned by the thrombo-occlusive change of sinus, the unique theory presented in this report may enable an understanding of the common etiology of both types of DAVF.

Anomalous connections between an extracranial venous sac and intracranial dural sinuses through dilated diploic and emissary veins of the skull result in sinus pericranii (SP). In this study, two patients with the rare presentation of multiple, congenital SP with associated dural venous lakes and venous anomalies are described. In one patient, multiple SPs were located in the frontal, parasagittal region with an associated subcortical venous angioma; and, in the other, peritorcular and juxta–transverse–sigmoid sinus junction SP coexisted. The venous anomalies drained into venous lakes in close proximity to major sinuses. They also communicated with extracranial tributaries via interosseous veins leading to the development of venous hypertension that presumably caused pressure erosion of the skull. This may have been responsible for the pathogenesis of multiple subgaleal venous sacs of SP and may also lead to profuse hemorrhage, cortical venous thrombosis, or air embolism. Multiplicity, associated venous lakes, venous angioma, and a lateral location are unique presentations of SP. Sac excision, transcranial venous anastomotic channel blockage, and reinforcement/replacement of the underlying bone are the recommended modalities of treatment.

Le drainage veineux cérébral peut être évalué à partir de restes osseux par des mesures de diamètre des conduits des veines qui traversaient la boîte crânienne. Dans cette étude, nous proposons une méthode de moulage, avec un produit spécifique, destinée à préciser les dimensions de ces conduits veineux. Nous n’étudions qu’une partie de l’ancien cheminement veineux, la voie émissaire, sur un échantillon d’Hommes actuels. Cerebral blood drainage can be studied on bone remains by measuring the diameters of the canals of the veins which cross the cranium. In this study, we propose a methodology which uses a casting method with a specific material to define the measurements of these vein canals. Our study covers only a part of the original vein canal system, the emissary veins in a sample of modern humans.

Aim The objectives were to find the incidence and topography of the occipital emissary foramina in skulls of South Indian Region. Material and methods In the present study, 78 dried adult human skulls were examined. They were analyzed for the gross incidence and position of the occipital emissary foramen. The observations were made in the squamous part of the occipital bone from the posterior margin of the foramen magnum to the external occipital protuberance. Results From our observations, the occipital emissary foramen was present in 11 (14.1%) skulls. Left sided foramen was observed in 5 cases (6.4%), right-sided foramen in 4 (5.1%) and the median foramen was seen in 2 (2.6%) of the cases. Conclusion The occipital emissary vein is present in a small percentage (14.1%) of cases. It was also demonstrated that its location is variable as to left, right or midline. Its location was closer to the foramen magnum than to the external occipital protuberance in all the specimens. The morphology of this subject is important to the neurosurgeons and plastic surgeons. The knowledge is of importance in suboccipital craniotomies as this foramen transmits the occipital emissary vein and will keep awareness among the surgeons to avoid the excessive bleeding.

Publisher Summary This chapter discusses the epidemiology, etiology, pathogenesis, clinical features, diagnosis, and management of suppurative intracranial thrombophlebitis. Septic intracranial venous sinus thrombosis arises as a consequence of infection in the paranasal sinuses and less frequently following infections of the middle ear or mastoid. The most common isolate from the cases of septic intracranial venous thrombosis associated with pericranial infections is Staphylococcus aureus . Suppurative intracranial thrombophlebitis is most frequently the result of pericranial infection. The local infection causes septic thrombophlebitis of veins draining the infected area, with subsequent intracranial extension of the infected thrombus along emissary veins. The cavernous sinuses are the structures most frequently involved in septic venous sinus thrombosis. The transverse sinuses are the second most frequent intracranial venous sinuses to be involved by septic processes. The advent of magnetic resonance imaging (MRI) and then of computed tomography (CT) angiography and venography revolutionized diagnosis of both venous sinus and cortical vein thrombosis, such that MRI and CT venography are currently the diagnostic procedures of choice in detecting venous sinus thrombosis.

The orbitotemporal venous sinuses accompany the intracranial branches of the stapedial artery. These sinuses are large in primitive primates and drain the extensive territories supplied by the stapedial artery as well as the brain. The orbit is drained by a wide cranio-orbital sinus which empties into the postglenoid emissary vein. Also emptying into the postglenoid vein is the petrosquamous sinus. The latter diverts cerebral blood from the transverse sinus and also drains the temporalis muscle. Emptying into both the cranio-orbital and petrosquamous sinuses are meningeal tributaries, which drain the cranial side wall and the dura mater. The relatively small sinus communicans runs in the angle between the petrosal bone and the cranial side wall. It commences at the postglenoid vein and connects the distal end of the petrosquamous sinus to the pterygoid venous plexus. In humans, the orbitotemporal sinus system is greatly modified. Its remnants persist for the most part as “middle meningeal veins.” The system no longer drains the orbit, the temporal fossa, or the brain. The petrosquamous sinus becomes attenuated or obliterated along part or all of its length. The postglenoid vein vanishes. The cranio-orbital sinus is reduced in diameter and its connection to the orbit is feeble or absent. During development, the posterior end of the cranio-orbital sinus migrates inferiorly along the sinus communicans. In most individuals, this migration ceases at the foramen spinosum, site of the emissary vein of the sinus communicans. Meningeal tributaries are relatively large in humans, and drain principally into the cranio-orbital sinus or sphenoparietal sinus. The sphenoparietal sinus is an evolutionary novelty restricted to hominoids and is frequently developed in only Homo and Pongo. © Wiley-Liss, Inc.

The patient was involved in a traffic accident at the age of 1 and the left parieto-occipital scalp was contused without skull fracture. At the age of 5, an extracranial scalp mass was first noticed just beneath the multiple scalp scars. Angiography through the mass revealed that the extracranial mass cavity was connected to the superior sagittal sinus through the emissary veins. The mass located in the subgaleal, epiperiosteal space was totally resected and the connection with the intracranial sinus was closed with bone wax. Histologically, there were many capillaries and some large blood cavities with only one layered endothelium and connective tissue. Therefore, the mass was diagnosed as sinus pericranii and considered to be secondary to previous head trauma because: 1) The patient had a history of head trauma with considerably severe scalp injuries. 2) The extracranial blood sinus was located exactly beneath the traumatic scar. 3) There was no neoplastic tissue histologically. 4) No scalp mass was noticed before the traffic accident. 5) There was an elapsed time between the trauma and the growth of the mass. 6) No scalp nevus such as port-wine stain existed.

A retrosigmoid craniectomy was performed for acoustic neuroma during which bone wax was used to control emissary vein bleeding. Postoperatively the patient developed an extensive venous thrombosis due to wax in the sigmoid sinus from which she recovered. We discuss this rare complication of posterior fossa surgery.

The unique anatomical arrangement of blood vessels and sinuses in the human skull and the brain, the prevalence of a high density of skin appendages in the scalp, extracranial vessels of the scalp communicating with the brain via emissary veins and most importantly, the way that the scalp is used in Ayurvedic medical system in treating diseases associated with the brain show that a drug could be transcranially delivered and targeted to the brain through the scalp. The present study was to investigate by measuring the antinociceptive effect on rats whether the opioid analgesic methadone could be delivered and targeted to the brain by transcranial delivery route. A non aqueous solution of methadone base in sesame oil was used for the application on the scalp. Animal studies were carried out using six groups of male rats consisting of group 1, the oral control treated with distilled water 1 ml; group 2, the oral positive control treated with methadone hydrochloride solution 316.5 mug/ml; group 3, the negative control treated transcranially with the blank sesame oil 0.2 ml and three test groups 4, 5 and 6 treated with three different dose levels of the transcranial oil formulation of methadone base, 41.6 mug/0.2 ml, 104 mug/0.2 ml and 208 mug/0.2 ml, respectively. The antinociceptive effects were examined by subjecting the rats to the hot plate and tail flick tests. The two higher concentrations of the three transcranial methadone formulations yielded response vs time curves showing nearly equal maximum antinociceptive effects similar to that of the oral positive control. Maximum analgesic effect after transcranial administration was observed between 1st and 2nd h and declined up to 6th hour. The results indicate that the transcranial brain targeted delivery of methadone base in the form of an oil based non aqueous solution results in statistically significant antinociceptive effects under experimental conditions. Therefore, it is possible to deliver central nervous system drugs through the proposed transcranial route when suitably formulated.

OBJETIVO: O cateterismo dos seios petrosos inferiores (SPI) ajuda a diferenciar as formas hipofisária e ectópica na síndrome de Cushing (SC). O objetivo desse trabalho é descrever a técnica empregada em nosso serviço, discutir a solução de dificuldades e verificar o índice de sucesso atingido. CASUÍSTICA E MÉTODO: Foram submetidos a cateterismo bilateral dos SPI 42 pacientes com SC, entre setembro de 2000 e setembro de 2005. As dificuldades para o posicionamento do cateter foram correlacionadas com as soluções empregadas. RESULTADOS: As variações anatômicas, a semelhança entre o SPI e a veia emissária do plexo basilar e a dificuldade de contrastar as estruturas a contrafluxo para localizá-las foram os principais problemas. Foram utilizados cateter pré-moldado, fio-guia semicurvo e dirigível, road-maping e venografia por injeção contralateral, além de critérios para diferenciar o SPI da veia emissária. Dos 84 SPI abordados, um apresentava trombose, e dos 83 possíveis, 80 (96,4%) foram cateterizados. Não se observaram complicações. CONCLUSÃO: A cateterização dos SPI pode ser feita na maioria dos pacientes. A identificação da veia emissária do plexo basilar e o uso de flebografia por injeção contralateral melhoraram o desempenho do método. PURPOSE: Inferior petrosal sinus catheterization and sampling for corticotropin dosage helps to differentiate hypophisary and ectopic forms of Cushing syndrome. The aim of this paper is to describe the technique used in inferior petrosal sinus catheterization in our service, emphasizing the solution found for frequent difficulties, and verify the success rate achieved. PATIENTS AND METHODS: Between September/2000 and September/2005, forty-two (eighty-four sinuses) patients were submitted to inferior petrosal sinus sampling. The difficulties for correct catheter positioning were identified and correlated with their solutions. RESULTS: Anatomical variations, similarity between IPS and emissary vein of the basilar plexus and unfavorable flow to the contrastation of the structures (retrograde catheterization) were the main problems. Using pre-shaped catheters, curved, steerable guide-wires, road-maping and venography by contalateral injection, besides criteria to differentiate IPS from the emissary vein. Of the 84 sinuses approached, one was thrombosed, and 80 (96.4%) of 83 possible were selectively catheterized. No clinical complication occurred. CONCLUSION: IPSC can be safe and successfully performed in most cases. The identification of the emissary vein of the basilar plexus and use of venography by contralateral injection, improved the method performance.

Detailed descriptions of the mastoid emissary veins (MEVs) and the foramina through which they travel are lacking in the literature. Therefore, the aim of our study was to explore and delineate the morphology, topography and morphometry of the MEV, mastoid foramen (MF) and occipital foramen (OF). One hundred cadaver heads and 100 dried human skulls were grossly examined The MF and OF varied from being absent to having as many as four small openings, each transmitting an emissary vein. The overall prevalence of MEV was 98% on the right and 72% on the left. The overall prevalence of OF was 7% on the right and 4% on the left. The mean length of the MEV from its point of origin to its point of termination was found to be 7.2 cm with a range of 3.8–11.8 cm. The mean diameter of the MEV at the mastoid emissary foramen was 3.5 mm with a range of 1.1–5.6 mm. In the majority of the cadavers (85%) it was observed that mastoid and occipital emissary veins formed a confluent venous system, while in the remaining 15%, they remained as single vessels. The MEV may be a significant source of bleeding during surgery of the skull base or middle ear, particularly during retrosigmoid and far-lateral approaches and detailed anatomical knowledge may help to prevent these complications. Endovascular treatment of dural arteriovenous fistulas is often extremely difficult due to limited access, however, the use of the MEV represents a unique and potentially valuable technique for accessing an isolated or inaccessible transverse or sigmoid sinus system.

Venous hypertension is emerging as a significant contributor to intracranial pressure in children with syndromic craniosysnostosis. This is associated with jugular foramen stenosis or atresia and with the development of collateral emissary veins. We demonstrate how computed tomography venography can document the prevalence of these emissary veins and how their visualisation plays an important role in operative planning.Patients with known syndromic craniosynostosis underwent computed tomography venography as part of their routine pre-operative evaluation. The venous drainage pattern was examined in these patients, with a special note of the presence of abnormal venous pathways.Eleven patients were recruited into the study from ages 3 months to 22 years. All had a diagnosis of syndromic craniosynostosis with six Crouzon's, four Pfeiffer's and one patient with Crouzon's and acanthosis nigricans. Nine of 11 patients had demonstrable evidences of transosseous venous drainage through an identifiable abnormal emissary vein. Four of 11 had a transosseous route as the main mechanism of drainage for the cerebral venous system.Patients with syndromic craniosynostosis often demonstrate abnormal venous anatomy, which can have serious consequences on craniofacial surgery, especially when a posterior decompression is being considered. Based on these findings, the authors assert that those children with some syndromic craniosynostosis being considered for surgery should undergo venographic studies as part of their pre-operative evaluation.

To determine the role of the venous outflow restriction during human erection, we compared intracavernous pressure with deep dorsal vein pressure in 6 normal subjects during papaverine-induced erection and penile saline infusion. In addition, flows necessary to produce and maintain erection were measured in 10 cadavers before and after resection of the deep dorsal vein alone or together with ligation of the cavernous veins. Elongation of tunica albuginea was measured at the crural and mid portions of the penis. At rigidity there was complete blockage of the venous return through the emissary veins. The venous outflow through the cavernous veins was reduced but still persisted. The distention of the tunica albuginea was less important at the crural portion than at the distal portion and could explain why the cavernous veins were not blocked completely.

The “radiator” theory of brain evolution is proposed to account for “mosaic evolution” whereby brain size began to increase rapidly in the genusHomowell over a million yearsafterbipedalism had been selected for in early hominids. Because hydrostatic pressures differ across columns of fluid depending on orientation (posture), vascular systems of early bipeds became reoriented so that cranial blood flowed preferentially to the vertebral plexus instead of the internal jugular vein in response to gravity. The Hadar early hominids and robust australopithecines partly achieved this reorientation with a dramatically enlarged occipital/marginal sinus system. On the other hand, hominids in the gracile australopithecine throughHomolineage delivered blood to the vertebral plexus via a widespread network of veins that became more elaborate through time. Mastoid and parietal emissary veins are representatives of this network, and increases in their frequencies during hominid evolution are indicative of its development. Brain size increased with increased frequencies of mastoid and parietal emissary veins in the lineage leading to and includingHomo, but remained conservative in the robust australopithecine lineage that lacked the network of veins. The brain is an extremely heatsensitive organ and emissary veins in humans have been shown to cool the brain under conditions of hyperthermia. Thus, the network of veins in the lineage leading toHomoacted as a radiator that released a thermal constraint on brain size. The radiator theory is in keeping with the belief that basal gracile and basal robust australopithecines occupied distinct niches, with the former living in savanna mosaic habitats that were subject to hot temperatures and intense solar radiation during the day.

Introduction It is claimed that the tunica albuginea (TA) shares in the erectile mechanism by compressing the emissary veins passing through it. However, the TA does not contain smooth muscle fibers. Aim We investigated the hypothesis that TA lacks a contractile activity on the emissary veins passing through it. Methods Fourteen healthy male volunteers (mean age 35.2 ± 4.3 years) were studied. The electromyographic (EMG) activity of the TA and corpora cavernosa (CC) was individually recorded in the flaccid and erectile phases by EMG needle electrodes. Recording was performed in the upper, middle, and lower third of the TA and CC on one and then on the contralateral side. Main Outcome Measures The TA lacks a contractile activity on the emissary veins passing through it. Results The EMG of the CC in the flaccid phase recorded regular slow waves and random action potentials. The wave variables in the erectile phase exhibited a significant decrease ( P Conclusions Electric waves were recorded from the CC in the flaccid phase; wave variables decreased at erection. In contrast, the TA showed no electric waves in the flaccid or erectile phases. It appears that the TA acts as a CC covering sheet which expands passively at erection, and shares in compressing the subtunical venular plexus between it and the tumescent CC. Shafik A, Shafik AI, El Sibai O, and Shafik AA. Electrophysiologic activity of the tunica albuginea and corpora cavernosa: Possible role of tunica albuginea in the erectile mechanism.

The radiator hypothesis focuses on differential effects that natural selection had on the vascular physiology of hominins that occupied separate niches and the consequences for brain evolution in Paranthropus, Australopithecus, and Homo. Comparative studies of emissary foramina suggest that the network of cranial veins of the australopithecine ancestors of Homo began to increase in complexity in response to temperature constraints associated with occupying niches in thermally stressful habitats. This venous network subsequently became elaborated in Homo in conjunction with increasing brain size. Because physiologists have shown that emissary veins participate in selective brain cooling by delivering blood cooled at the head’s surface into the braincase, the radiator hypothesis postulates that the elaborate network of cranial veins contributed to the regulation of brain temperature as it coevolved with brain size during hominin evolution. The radiator hypothesis has been controversial for two basic reasons: First, it has implications for hominin phylogeny, which is always a contentious subject in paleoanthropology. Second, the subject of selective brain cooling in humans has been controversial within the physiological community. New findings are discussed that bear on selective brain cooling and the radiator hypothesis.

The objectives of the present study were to study the prevalence of the parietal emissary vein in adult South Indian population and to study the distance of foramen from the sagittal suture. There were 58 adult human skulls in the present study which were available at the anatomy department of our institution. The study included 116 parietal bones which have been observed macroscopically for the number, prevalence and topography of the emissary foramen. The emissary foramen was present in 83 parietal bones (71.5%) of the present study. It was present at the junction between the middle 1/3 and posterior 1/3 region of the parietal bone. The foramen was observed solitary in 73 parietal bones (62.9%), double in 8 bones (6.9%), and triple in 2 parietal bones (1.7%). The foramen was not observed in 33 parietal bones (28.4%). The bilateral absence of parietal emissary foramen was seen in 7 skulls (12.1%). It was absent unilaterally in 19 skulls (32.7%). The accessory foramina were seen in only 8 skulls (13.8%). The mean distance of the foramen from the sagittal suture was 6.7±2.9 mm and 6.8±2.8 mm on the right and left sides respectively. The prevalence of parietal emissary vein in the present study was 71.5%. The present study has observed important data about the morphology and morphometry of the parietal emissary vein in South Indian population. The identification of parietal emissary veins and accessory veins is important in the operation room to prevent the blood loss.

Study of foramen Vesalius and its clinical implications Foramen Vesalius also called as the emissary sphenoidal foramen is an inconstant foramen located anteromedial to the foramen ovale opening near the scaphoid fossa. An emissary vein passes through this foramen and communicates with the cavernous sinus. The purpose of this study is to evaluate to evaluate the incidence of the foramen Vesalius in dry human skulls and to analysis its clinical significance. The study sample consists of 50 dry human skulls available from the department of anatomy at Saveetha Dental College and Hospitals .the incidence of foramen Vesalius will be noted. Anatomical variations of foramen Vesalius can be explained due to developmental reasons. The detailed anatomical structure is required in clinical situations and surgery involving this foramen and the emissary veins passing through it.

Dear Editor, The posterior condylar canal is located posterior to the occipital condyle and transmits the posterior condylar vein, one of the largest emissary veins in the retromastoid region.[1,6] This vein usually origins from superior bulb of the internal jugular vein or less frequently from the medial side of the distal portion of the sigmoid sinus and connect to the suboccipital venous plexus.[5,9] We report a patient with occipital bone fracture coursing through the posterior condylar canal causing thrombosis of posterior condylar vein with extension to internal jugular vein. To the best of our knowledge, thrombosis of posterior condylar vein with subsequent extension to major venous sinuses due to trauma has not been reported yet. A 50-year-old patient was brought to the emergency department following a fall from 15 steps. Initial head computed tomography (CT) scan demonstrated bilateral inferior frontal hemorrhagic contusions, traumatic subarachnoid hemorrhage in bilateral frontal and right temporal lobe, and linear occipital bone fracture extending to the posterior condylar vein on the right side. There was no extension of fracture line to the major dural venous sinuses. Subsequent CT venography (CTV) demonstrated thrombosis of right posterior condylar vein with extension to upper aspect of right internal jugular vein causing nonocclusive thrombosis [Figure 1]. Given the presence of hemorrhagic brain contusions and nonocclusive nature of thrombosis in the internal jugular vein, patient was not considered an appropriate candidate for anticoagulation and was managed conservatively. Follow-up CTV in 48 h demonstrated stable thrombosis with no extension. Figure 1 Axial CT scan demonstrates linear occipital bone fracture with extension to the right posterior condylar canal (a white arrow). Axial and sagittal oblique CT Venogram (b and c) demonstrate right condylar vein thrombosis (white arrow) with extension to ... Emissary veins connect the extracranial venous system with the intracranial venous sinuses. Although they are usually small in healthy people, they may enlarge in patients with increased intracranial pressure, in patients with high-flow vascular malformations or severe hypoplasia/aplasia or obstruction of the jugular veins. They may also serve as a conduit for retrograde spread of infection or tumors. Familiarity with major posterior fossa emissary veins is important to avoid misdiagnosis as abnormal findings and also to prevent surgical complications, which can result in intracranial hemorrhage, air embolism, and fatal increases in intracranial pressure.[7] The role of traumatic close head injuries as an important etiology of cerebral venous sinus thrombosis has been demonstrated in multiple studies.[2] Extension of skull fractures to venous sinuses had been reported in 10.4% and 13% of patients in two recent large studies.[3,8] Delgado Almandoz et al. demonstrated traumatic dural sinus thrombosis in 40.7% of patients with blunt head trauma with skull fractures extending to dural venous sinuses or jugular bulb, and more than half of those were occlusive.[3] In a more recent study, Rivkin et al. found thrombosis of at least one venous sinus or jugular bulb in 34.9% of patients (20.6% nonocclusive, 14.3% occlusive).[8] Fujii et al. also evaluated 97 patients with skull fractures crossing venous sinuses and found 22.4% of them to have thrombosis.[4] The indication for performing CTV in all of these studies was extension of skull fracture line to the major dural sinuses including superior sagittal sinus, transverse sinus, sigmoid sinus, or jugular bulb, and, to the best of our knowledge, traumatic thrombosis of posterior condylar vein with subsequent extension to major venous sinuses has not been reported yet. Development of venous sinus thrombosis in the setting of blunt trauma can result in poor clinical outcome resulting from multiple neurological complications including increased intracranial pressure, hemorrhagic venous infarctions, and increase in seizure frequency, with mortality rates as high as 50% for occlusive venous thrombosis.[3,4,8] Treatment of dural venous sinus thrombosis in the setting of trauma might be very challenging and only a small minority of patients with occlusive venous sinus thrombosis has been reported in prior studies.[3] In conclusion, in the setting of blunt head trauma, extension of the fracture lines to the posterior condylar canal can cause condylar vein thrombosis with secondary extension to major dural venous sinuses. Increase in awareness of this anatomical structure and routine CTV when there is extension of skull fracture line to the major dural sinuses is important for appropriate diagnosis.

Sinus pericranii is a rare abnormality that may appear as a midline nasofrontal mass. 1,2 This disorder consists of congenital or acquired anomalous connections between an extracranial blood-filled nodule and the intracranial dural sinuses through dilated diploic and emissary veins of the skull. 3 We report a case of sinus pericranii and present the findings on color Doppler ultrasonography (CDUS).

Background and purpose Three-dimensional (3D) contrast-enhanced magnetization-prepared rapid gradient-echo (MP-RAGE) sequence has been reported useful for evaluation of the intracranial venous structures. The purpose of this study is to assess the patterns of the major anastomotic veins on the lateral surface of the cerebrum using MP-RAGE sequence. Methods MP-RAGE images in consecutive 100 patients (200 sides) were reviewed by two neuroradiologists in consensus to evaluate drainage patterns of the superficial middle cerebral vein (SMCV), the vein of Labbe, and the Trolard vein. Results MP-RAGE images clearly depicted the major anastomotic veins and their draining vessel. The dominant vein was the Trolard vein in 12%, the vein of Labbe in 36%, SMCV in 38%, and all three veins in 14%. The vein of Labbe was entered the transverse sinus in 80% and superior petrosal sinus in 4%. Undeveloped type of the vein of Labbe was seen in 16%. The SMCVs were entered the sphenoparietal sinus in 57%, the cavernous sinus in 19%, and the emissary vein in 5%. Basal type of the SMCVs was seen in 3% and undeveloped type in 16%. It was difficult to differentiate the Trolard vein from other cortical veins, if it was not dominant. In the most cases with the dominant Trolard vein, it located at the level of the post central vein. Conclusion With MP-RAGE sequence, it is easy to identify the variation of the major anastomotic veins. Such information may be helpful to reduce the risk of damage on these important veins at surgery.

A 44-year-old man presented with a rare case of idiopathic hypertrophic cranial pachymeningitis manifesting as generalized seizure. Neuroimaging and pathological examinations showed the typical features of hypertrophic cranial pachymeningitis. Tuberculosis was a possible cause based on the positive purified protein-derived skin test, but the origin of the disease was not confirmed by further examinations. Cerebral angiography showed total occlusion of the dural sinuses with development of the emissary veins. Histological examination of the dura showed thickening of the fibrous tissue with rare inflammatory cells, suggestive of the extremely long duration of the disease. The diagnosis was idiopathic hypertrophic cranial pachymeningitis, but was treated only with anticonvulsants. The disease did not progress during follow up of 3 years. Idiopathic hypertrophic cranial pachymeningitis may have various causes related to unusual forms of infectious or autoimmune disorders.

Cochlear implants have transformed the treatment of sensorineural hearing loss. They have few major complications. The authors describe the case of a man fitted with a cochlear implant who suffered a postoperative subdural haematoma. The haematoma is thought to have been caused by bleeding from emissary veins opened by the drill passages used to anchor the sutures for the receiver/stimulator. The authors have abandoned tie down sutures in cochlear implants, preferring an appropriately deep well with squared-off rims, which would secure the implant in place. They have had no further complications of this nature.

Prior to computed tomography (CT), plain skull radiographs were often the first study in the patient with suspected central nervous system disease [1]. Subtle clues to the intracranial contents could be discerned by the presence of calcification, skull erosion, and signs of increased intracranial pressure, as with demineralization of the sellae or an increase in the size of mastoid emissary veins, as well as by recognition of diseases primarily affecting the osseous structure of the skull in the form of sclerotic and/or lytic lesions (Fig. 29.1). CT revolutionized the radiologist’s ability to see the intrinsic structure of the skull in cross-section. This has decreased the demand for skull x-rays. Magnetic resonance imaging (MRI) has further decreased the demands for skull films, by showing the intracranial contents even more exquisitely than CT. Today, the skull radiograph plays a relatively limited role in the evaluation of the pediatric patient. Except in the evaluation of trauma, craniosynostosis, and known genetic diseases affecting the cranial structures, the skull x-ray tends to be a procedure that follows the recognition of its need on the basis of another examination, such as CT, MRI, or the radionuclide study.

upper eyelids (figure, A, arrows). She was seen by doctors who applied topical mydriatic drops, and examined her eyes thoroughly, but found nothing unusual, and made a working diagnosis of an allergic reaction. 3 days later, the patient developed a headache and consulted an orthopaedic specialist and a practitioner of alternative medicine, neither of whom made a specific diagnosis. On day 6, she presented to our hospital. Her medical history was unremarkable and she was not prone to headaches. Blood pressure, body temperature, and routine blood tests were in the normal range. The patient had a body mass index of 32·2. We did a neurological examination and found slightly exaggerated left-sided tendon jerks. A contrastenhanced angio-CT showed thrombosis of the sagittal superior sinus and both transverse sinuses (figure, B, arrows). We diagnosed an aseptic cerebral venous thrombosis, and gave her intravenous heparin. The eyelid oedema decreased the following day (figure, C) and a second ophthalmic examination showed bilateral papilloedema (figure, D). Tests for thrombophilia were negative. Following 6 months of oral anticoagulation, the veins partially recanalised. Eyelid oedema is a typical finding in cases of septic thrombosis of the cavernous sinus, but can also occur with aseptic thrombosis of the sagittal sinus. The venous drainage from the eyelids via the venae ophthalmicae into the cavernous sinus is probably impaired by elevated intracranial pressure as well as by the compensatory elevated flow in the emissary veins, through the diploe into the veins of the forehead. In this case the eyelid oedema preceded the more common symptoms of cerebral venous thrombosis—namely headache, neurological signs, and papilloedema, by a few days. Clinical Picture

The atlas of a 52-year-old male Japanese cadaver, which had been removed and macerated, presented a bilateral unknown bone bridge forming a foramen (Case 1). The bone bridge connected the ponticulus lateralis (PL) and posterior (PP) to form an oval foramen between the superior roots of both ponticuli. The atlas of a 69-year-old male Japanese cadaver was found to have similar variations in situ (Case 2). In this case, the right bone bridge connected the superior root of the incomplete PL and the inferior root of the also incomplete PP to form a long ellipsoid foramen opening medially. The medial opening of the foramen was closed by a ligamentous connective tissue in situ. The condylar emissary vein passed this complete foramen to join the cervical epidural venous plexus. The similar bilateral foramen in case 1 was supposed to pass the same vein as in case 2. The bone bridge between the two ponticuli and the resulting foramen mentioned above have not been described previously, as far as we know. We propose that these structures be called the ponticulus interponticularis atlantis and the foramen atlantoideum interponticulare, respectively.

Fourteen cadaver specimens (28 sides) and twelve dry human skulls (24 sides) were used to study the anatomic relationships between bony, neurovascular and foraminal landmarks in the floor of the middle fossa in preparation for performing the extradural subtemporal keyhole approach to the sphenocavernous region. The interforaminal distance was largest between the foramina rotundum (FR) and ovale (FO) and was smallest between the FO and foramen spinosum (FS). The largest angle between exit foramen was the FR to FO. The greater superficial petrosal nerve (GSPN) was always found to overlie and run parallel to the petrous internal carotid artery, however, its location over the artery and its separation from it by bone was variable. With a subtemporal "keyhole" placed above the posterior zygomatic root (PZR), a 0 degrees endoscope allowed easy visualization of the middle meningeal artery (MMA) and the mandibular nerve (V 3 ) however, a 30 degrees endoscope was more useful for visualizing the maxillary nerve (V 2 ) and the ophthalmic nerve (V 2 ). With a sphenoidotomy performed between V 1 and V 2, the 30 degrees endoscope was found to be the most useful for visualizing the carotid siphon and the contralateral wall of the sphenoid sinus, while the 70 degrees endoscope was the most useful for visualizing of the floor of the sella and the walls of the sphenoid sinus. Two venous concerns with respect to performing endoscopic approaches to the region were identified: a fibrous layer overlies a heavy venous plexus that encircles the petrous carotid artery, and the foramen Vesalius, which transmits a large emissary vein draining the cavernous sinus, was identified medial to the FO in 30 % of our dissected sides.

The emissary veins are residual connections between intra-cerebral veins and their extra-cranial drainage. Mastoid emissary vein is a rare but definite entity which if not diagnosed preoperatively could be a cause of severe hemorrhage at the time of surgery which may prove to be life threatening. These veins may vary in size from that of a mere thread to that of a wax match or 1/8th–3/8th of an inch. We report one such case of a giant mastoid emissary vein which was opened while operating on mastoid and caused profuse bleeding which could only be controlled by surgical pack.

Tinnitus is an annoying symptom that affects approximately 10% of the population. Unfortunately, in more than 60% of patients, even an extensive workup may not lead to diagnosis, partly because of the diverse causes of the symptom. The imaging protocol study should therefore be adapted to the history of the patient, and each imaging study should underline which etiologies it may exclude. Imaging studies should only be performed after a careful clinical examination and otoscopy. Some characteristic clinical findings are suggestive of such etiologies as pulsed synchronous tinnitus or positional tinnitus, varying with the venous pressure. History of associated neurological deficits, nerve palsies, trauma, ischemic attacks, and visual disturbance (in overweight women) may modify the imaging protocol. Study of the brain and the cervical vessels should always be included to rule out a benign intracranial hypertension. Path and size of the internal carotid artery should be systematically described with regard to the size of the jugular vein and presence of emissary veins. Objective pulsatile tinnitus and tinnitus in children always need a careful imaging study.

Objective and importance Patent foramen ovale (PFO) has been suggested as a potential source of paradoxical embolism. A higher prevalence of PFO in ischemic stroke of unexplained cause has been recognized. Brain abscesses are commonly associated with a contiguous focus of infection, hematogenous spread from a distant focus, or cranial trauma. However, no predisposing factors, including a distant focus with unknown cause, are identified in approximately 15 to 30% of reported cases. Clinical presentation We encountered two patients with brain abscess presumably caused by dental infections. Both patients displayed PFO, through which right-to-left atrial contrast shunting was revealed by transesophageal echocardiography. Although the radiological location of the abscesses suggested hematogenous spread as a cause, the patients had no arteriovenous shunting other than the PFO, despite exhaustive investigations for a potential infectious route. The patients displayed no definite focal orofacial inflammatory signs during the postoperative course despite diagnosis of pyorrhea alveolaris or periodontitis. Intervention In Patient 1, the abscess was aspirated stereotactically, and in Patient 2, the abscess disappeared radiologically after high-dose antibiotic treatment. Conclusion The mechanism of brain abscess formation putatively related to PFO should be different from that related to common dental sepsis. Analysis of these cases suggested that infectious embolism from a latent or even identifiable focus through the PFO may be an underrecognized cause of brain abscess, in contrast to simple seeding of the brain via transit of the infecting bacteria through the valveless emissary veins.

In this chapter we analyze the intracranial venous system in a craniofugal fashion: from deep, to cortical, to dural. The supratentorial compartment will be studied first, followed by the infratentorial level. The relevant embryological information needed is included in each section. The developmental venous anomalies (DVAs, so-called venous angiomas) will serve as a model for the venous variations. This will facilitate our understanding of variability and permit us to predict the different possible variants for the cerebral venous patterns.

The supply to the skull base and the brain depends on the parasellar arterial system. The parasellar region is lateral to the sella turcica and includes the cavernous region with its extradural venous plexus. In many species the branchial arteries give rise to the cerebral feeders. These arteries originate from a network of arterial channels (rete) lateral to the sella; this rete is later replaced by the intracavernous internal carotid artery or carotid siphon. The carotid-basilar anastomoses will determine, through their regression, the presence and role of these potential sources of supply to the brain. As seen in Chap. 3, the carotid-basilar arteries include the internal carotid artery but also the branches of the external carotid artery. Table 5.1 Foramina of the sellar and perisellar regions and their neurovascular contents Foramina of the sellar and perisellar regions Neurovascular contents Pharyngohypophyseal canal (inconstant) Capsular branch (sinusal) Optic canal Optic nerve Ophthalmic artery Superior orbital fissure III IV VI V1 Autonomic nervous system Deep recurrent ophthalmic artery Ophthalmic vein Recurrent meningeal, recurrent tentorial, or meningo-ophthalmic artery depending on the variant Foramen rotundum V2 Emissary vein Artery of the foramen rotundum Foramen ovale V3 Vm Emissary vein Cavernous branch of the accessory meningeal artery Arnold’s foramen (inconstant) Superficial and deep minor petrosal nerves, emissary vein Foramen of Vesalium (inconstant) Emissary vein Cavernous branch of the accessory meningeal artery (maxillary dominance) Foramen lacerum Internal carotid artery Pericarotid autonomic nervous system Carotid branch of the ascending pharyngeal artery Vidian nerve and artery Mandibular artery Foramen spinosum (inconstant) Middle meningeal artery Open image in new window Fig. 5.1 The venous drainage of the base of the skull, seen from above and from the side. The cavernous confluent is demonstrated with its tributaries and drainage. SOV, Superior ophthalmic vein; SSV, superficial sylvian vein; DSV, deep sylvian vein; VFO, vein of the foramen ovale; SPS, superior petrosal sinus; IPS, inferior petrosal sinus; TOS, transverse occipital sinus; VFR, vein of the foramen rotundum

The authors describe the clinical and radiological findings in a case of non-syndromic craniosynostosis affecting multiple sutures, in which the intracranial venous drainage was grossly anomalous. Investigation by magnetic resonance imaging and angiography revealed that almost all of the intracranial venous blood was draining from the dural sinuses transosseoussly via enlarged emissary veins to the external jugular veins and the vertebral veins. Although present, both internal jugular veins were small. This discovery represented a contraindication for the vault expansion surgery that had been recommended as treatment for the patient's raised intracranial pressure, and it has important implications for the management of all types of craniosynostosis.

A recent estimate of the number of men in the United States suffering with complete erectile dysfunction is 10 to 20 million. When partial erectile dysfunction is included, the estimate jumps to 30 million.1 Age-specific prevalence is estimated to be 5% at age 40, increasing to 15% to 25% by age 65. In clinical series, the ratio of organic to psychologic male sexual dysfunction also varies with age: 70% of patients under 35 years of age have a psychogenic cause, and 85% of patients over 50 years of age have organic impotence.2 Patient accounts of coital frequency similarly vary with age: 75% of men in their seventh decade report having coitus once monthly, and 37% of patients 60 to 69 years old describe having weekly coitus.

In 1992, I composed a talk called “Fact or Fiction” regarding vascular impotence. In that presentation, I prepared slides with various points that needed to be questioned. One of the statements was “Veno-occlusive dysfunction is a major single entity cause of impotency”. I posed that statement for reflection. We were beginning to discover, at that time, that although veno-occlusion is an extremely important part of the male erectile cycle it is not truly a venous disorder responsible for veno-occlusive dysfunction. The faulty veno-occlusion is, in fact, a reflection of an underlying healthy cavernosa tissue with a structurally intact trabecular system, an intact arterial in-flow system, and an uncompromised elastic tunica albuginea.

Sir, We read with great interest the excellent review by Agid and Farb [1] describing the association between the development of mastoid air cell effusions with dural sinus thrombosis. The authors pointed out that it was likely that a mastoid effusion was a secondary rather than a primary event due primarily to occlusion of the emissary vein draining the mastoid sinus. We would like to add supportive evidence to their theory by means of an unusual sequence of imaging events that we recently encountered at our institution. A 23-year-old woman with a history of migraine underwent computed tomography (CT) of the head to exclude a space-occupying lesion as a cause of her headaches. Her CT scan was normal. In particular, there was no evidence at this stage of a dural sinus thrombosis. Of note, her mastoid air cells showed no abnormality (Fig. 1). Lumbar puncture and other investigations were all normal at this stage. She had no other medical problems, but was taking the combined oral contraceptive pill. The patient was discharged with a diagnosis of migraine, but re-presented with a recurrent headache and vomiting 10 days later. A repeat CT examination at this stage demonstrated clear evidence of a dural sinus thrombosis as well as a newly developed ipsilateral mastoid effusion (Fig. 2). Magnetic resonance venography (MRV) further confirmed thrombosis of the lateral and superior saggital sinus (Fig. 3). The patient was anticoagulated andwas discharged 10 days following admission. The aetiology of the dural sinus thrombosis in this case was felt to be related to a combination of the oral contraceptive pill and dehydration from excessive vomiting. It is likely that the development of the lateral sinus component of the thrombus occluded the emissary vein from the mastoid sinus, resulting in the effusion. The presence of an initial normal CT indicated either the lack of a dural thrombus at this stage or possibly the presence of a small or early undetectable dural thrombus. In either case, the

Dear Editor, We appreciate the critical review by colleagues from Turkey and their valuable contribution for the discussion of the subject. In response to their letter, wewould like to point out some aspects of the article “Dural sinus and internal jugular vein thrombosis complicating a blunt head injury in a pediatric patient” [1]. Regarding the figures of the article, the noncontrast computed tomography (CT) showing hypodensity on the right cerebral hemisphere consistent with edema and hyperdensity area at the sigmoid sinus suggestive of dural venous sinus thrombosis was not represented, so the reference on “Figure 1” is misplaced. On “Figure 2”, the thrombus is visible on transverse/sigmoid sinus junction on the axial image. For optimal visualization of transverse, sigmoid, and internal jugular vein thrombosis, it would require multiple images on the coronal, sagittal, and axial planes. Although not ideal, the three-dimensional volume image was an attempt to represent the extension of the thrombosis. The CT images on this letter may elucidate their doubts and understanding of the case (Fig. 1). The colleagues also questioned our hypothesis on the formation of the thrombus. We agree that their hypothesis proposed for the case reported is plausible; however, we are faced with a “chicken-egg” dilemma where the triggering factor will remain uncertain and of little relevance. In our opinion, the prevailing situation in the generation of the thrombus is the multifactorial setting (release of thromboplastin, sinus compression by intracranial edema or bleeding, intramural hemorrhages, extension of injured emissary veins, and trauma to the endothelial lining), independent of the precipitating factor. Finally, there is no doubt on the value of CT and magnetic resonance venography as a diagnostic study in cerebral venous sinus thrombosis. We are aware that the CT scan has its limitations in evaluating parenchymal brain injury and bears the potential risks of the ionizing radiation in the pediatric population. However, we should not ignore the fact that a well-justified CT scan may exceed its risk and have a favorable impact. In the trauma setting or when dealing with severely compromised patients where time may dictate the outcomes, the CT scan provides fast and sufficient information to guide the patient management [2].

A 16-year-old girl presented to our clinic with right-sided tongue atrophy and fasciculations of 1-year duration. Enlargement of the outer opening of the hypoglossal canal was revealed by conventional and computed tomography of the skull. Magnetic resonance imaging disclosed an enlarged venous system extending from the jugular vein to the internal jugular vein on the right, with low signal density suggestive of a flow void. A right-sided occipital craniotomy was performed. When the hypoglossal canal was opened, an enlarged emissary vein compressing the hypoglossal nerve was identified. This is the first reported case of unilateral tongue atrophy and an enlarged hypoglossal canal due to an enlarged emissary vein.