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Purpose: This study aimed to examine the anatomical variations and morphometric characteristics of the sulci in the dural venous sinuses within the intracranial cavity, with a particular focus on sex differences and asymmetry. Methods: Thirty fixed cadaveric heads were used to measure the dimensions (length, width, and depth) and spatial relationships of the dural venous sinus sulci within the intracranial cavity, including the distance to the midline, distance to each other, and lateral margin of the skull. Comparisons were made between sexes and sides of the body. Results: A significant difference was observed in the length of the marginal sinus on the right side between sexes (p = 0.028). Various measurements, including the width of the transverse sinus, origin and insertion sites of the superior petrosal sinus, and distances between the sinuses and midline, showed statistically significant differences between the left and right sides (p < 0.05). Furthermore, the width of the inferior petrosal sinus and depth of the sigmoid sinus were notably higher on the right side (p < 0.05). Conclusion: The results suggest an asymmetric distribution of the sigmoid, superior/inferior petrosal, and transverse sinuses in terms of diameter and distance from the midline. Surgeons should consider these anatomical variations during procedures in this region. [ABSTRACT FROM AUTHOR]

Purpose: The precise location of the endolymphatic sac (ES) may be difficult during surgical approaches. This morphometric study aimed to determine the exact location of ES in adult human cadavers for the management of pathologies such as Meniere's disease. Methods: Twenty temporal bones of 10 adult cadavers (mean age: 70 ± 13.40 years, range: 45–92 years; sex: 4 males and 6 females) fixed with 10% formalin were bilaterally dissected to obtain numeric data about the location of ES. Results: Distances of ES to the posterior semicircular canal (PSC), Donaldson line (DL), sigmoid sinus (SS) and sinodural angle (SA) were found as 2.76 ± 1.18 (0.96–5.58) mm, 1.74 ± 1.13 (0.58–5.07) mm, 2.30 ± 1.09 (0.54–4.91) mm and 16.04 ± 3.15 (9.82–22.18) mm, respectively. In addition, the angle between the tangents passing through the cortical bone (CB) and SS was determined as 35.37°±11.32° (21.30°-60.58°). No statistical difference was found between right-left or male-female measurements (p > 0.05). Conclusion: DL, SS, and PSC are essential anatomical landmarks for determining the location of ES. The spatial location of SS, including its depth to the cortical bone and the distance to anteriorly located anatomical structures of the mastoid cavity consisting of the facial nerve and PSC, is believed to be underlined for ES surgery. Our data may be used as a database to further define the relationship between ES and adjacent anatomical structures (SS, PSC, etc.) during the application of surgical approaches. [ABSTRACT FROM AUTHOR]

Supratentorial craniotomy represents the upper part of the combined trans-tentorial or the supra-infratentorial presigmoid approach. In this study, we provide qualitative and quantitative analyses for the supratentorial extension of the presigmoid retrolabyrinthine suprameatal approach (PRSA). The infratentorial PRSA followed by the supratentorial extension craniotomy with dividing and removal of the tentorial strip were performed on both sides of 5 injected human cadaver heads (n = 10 sides). Quantitative analysis was performed for the surface area gained (surgical accessibility) by adding the supratentorial craniotomy. Qualitative analysis was performed for the parts of the brainstem, cranial nerves, and vascular structures that became accessible by adding the supratentorial craniotomy. The anatomical obstacles encountered in the added operative corridor were analyzed. The supratentorial extension of PRSA provides an increase in surgical accessibility of 102.65% as compared to the PRSA standalone. The mean surface area of the exposed brainstem is 197.98 (standard deviation: 76.222) and 401.209 (standard deviation: 123.96) for the infratentorial and the combined supra-infratentorial presigmoid approach, respectively. Exposure for parts of III, IV, and V cranial nerves is added after the extension, and the surface area of the outer craniotomy defect has increased by 60.32%. Parts of the basilar, anterior inferior cerebellar, and superior cerebellar arteries are accessible after the supratentorial extension. The supratentorial extension of PRSA allows access to the supra-trigeminal area of the pons and the lower part of the midbrain. Considering this surgical accessibility and exposure significantly assists in planning such complex approaches while targeting central skull base lesions. [ABSTRACT FROM AUTHOR]

In the present paper, we introduce a new subclass of normal- ized analytic and univalent functions in the open unit disk associated with Sigmoid function. Coeficient estimates, convolution conditions, convex- ity and some other geometric properties for functions in this class are investigated. Also, subordination and inclusion results are obtained. [ABSTRACT FROM AUTHOR]

Neuronavigation systems coupled with previously reported external anatomical landmarks assist neurosurgeons during intracranial procedures. We aimed to verify whether the posterior auricularis muscle (PAM) could be used as an external landmark for identifying the sigmoid sinus (SS) and the transverse-sigmoid sinus junction (TSSJ) during posterior cranial fossa surgery. The PAM was dissected in 10 adult cadaveric heads and after drilling the underlying bone, the relationships with the underlying SS and TSSJ were noted. The width and length of the PAM, and the distance between the muscle and reference points (asterion, mastoid tip, and midline), were measured. The PAM was identified in 18 sides (9 left, 9 right). The first 20 mm of the muscle length (mean 28.28 mm) consistently overlay the mastoid process anteriorly and the proximal half of the SS slightly posteriorly on all sides. The superior border was a mean of 2.22 mm inferior to the TSSJ and, especially when the muscle length exceeded 20 mm, this border extended closer to the transverse sinus; it was usually found at a mean of 3.11 mm (range 0.0–13.80 mm) inferior to the distal third of the transverse sinus. Superficial landmarks give surgeons improved surgical access, avoiding overexposure of deep neurovascular structures and reducing brain retraction. On the basis of our cadaveric study, the PAM is a reliable and accurate direct landmark for identifying the SS and TSSJ. The PAM could potentially be used for guiding the retrosigmoid approach. [ABSTRACT FROM AUTHOR]

Venous sinus thromboses (VSTs) are rare complications of neurosurgical procedures in the proximity of the dural sinuses. Surgery of the posterior cranial fossa (PCF) and particularly of the cerebellopontine angle (CPA) shows increased risk of VST. VST management is challenging because anticoagulant therapy must be balanced with the risk of postoperative bleeding. We performed a systematic review and meta-analysis to summarize the most important neuroradiologic and clinical aspects of VST after PCF/CPA surgery. We performed a comprehensive literature search to identify articles reporting data on VST after PCF/CPA surgery. We selected only comparative studies providing adequate neuroimaging assessing VST and a control group. We included 13 articles reporting 1855 patients. VST occurred in 251/1855 cases (estimated incidence, 17.3%; 95% confidence interval [CI], 12.4%–22.2%). Only presigmoid approach (odds ratio [OR], 2.505; 95% CI, 1.161–5.404; P = 0.019) and intraoperative sinus injury (OR, 8.95; 95% CI, 3.43–23.34; P < 0.001) showed a significant association with VST. VST-related symptoms were reported in 12/251 patients with VST (pooled incidence, 3.1%; 95% CI, 1%–5.2%). In particular, we found a significantly increased OR of cerebrospinal fluid leak (OR, 3.197; 95% CI, 1.899–5.382; P < 0.001) and cerebrospinal fluid dynamic alterations in general (OR, 3.625; 95% CI, 2.370–5.543; P < 0.001). Indications for VST treatment were heterogeneous: 58/251 patients underwent antithrombotics, with 6 treatment-related bleedings. Recanalization overall occurred in 56.4% (95% CI, 40.6%–72.2%), with no significant difference between treated and untreated patients. However, untreated patients had a favorable outcome. VST is a relatively frequent complication after PCF/CPA surgery and a presigmoid approach and intraoperative sinus injury represent the most significant risk factors. However, the clinical course is generally benign, with no advantage of antithrombotic therapy. [ABSTRACT FROM AUTHOR]

Background: Sigmoid sinus diverticulum/dehiscence (SSD) is one of the treatable causes of venous pulsatile tinnitus. It can be diagnosed using temporal bone computed tomography (CT) or magnetic resonance angiography/venography (MRA). In cases where patients find their symptoms intolerable, surgical treatment is typically preferred. Here, we have presented a novel surgical technique involving sigmoid sinus re-roofing and have analyzed its feasibility. Methods: Between January 2020 and July 2023, approximately 150 patients with pulsatile tinnitus were evaluated at two different tertiary hospitals. Of these, 12 patients were diagnosed with SSD, and seven underwent surgical treatment. Five patients were treated with tailored reroofing (TRR) of the sigmoid sinus and two with transmastoid resurfacing (MRS) of the sigmoid sinus. We compared the Korean tinnitus handicap inventory (K-THI) score, pure tone audiogram (PTA) threshold, and CT findings before and a month after surgeries for these two techniques. The operation time was also analyzed. Results: In TRR cases, the K-THI score reduced from 55.0 ± 31.4 preoperatively to 4.0 ± 3.0 postoperatively, and the SSD was well-repositioned and covered by a bone chip postoperatively. In MRS cases, the K-THI score reduced from 41.0 ± 9.9 preoperatively to 15.0 ± 21.2 postoperatively, and the SSD was well-covered with bone cement postoperatively. The average surgical time of five TRR and two MRS cases were 77.5 ± 32.5 and 174.0 ± 75.0 min, respectively. No complications were noted. Conclusions: Despite the insufficient number of cases, we noted that TRR requires a reasonable amount of time, involves a smaller incision, and may provide favorable outcomes compared to conventional MRS in cases of pulsatile tinnitus associated with SSD. [ABSTRACT FROM AUTHOR]

Background: Chorangioma are benign vascular tumors of the placenta that are nontrophoblastic in nature. The clinical importance of these tumors correlates with their size, with chorangioma larger than 4 cm being linked to complications for both the mother and the fetus. Case description: We present a rare case of 20-year-old primigravida female patient who presented to us at 35 weeks of gestation with a positive sickling test history and pain in the abdomen. Ultrasound showed a single live fetus with polyhydramnios, and a distinct hypoechoic lesion adjacent to the umbilical cord insertion site along the subchorionic plane of the placenta, suggestive of a chorangioma. Histopathological examination confirmed the placental chorangioma. The uniqueness of this case report lies in the presence of a hypoplastic left transverse sinus and sigmoid sinus following delivery without any fetal complications. However, such accidental diagnoses may cause a lot of complications during and after childbirth. Conclusion: It is crucial to implement routine and timely antenatal care to detect and manage potential complications effectively. [ABSTRACT FROM AUTHOR]

Background: Jugular foramen of human skull is one of the most interesting foramina. It is a complex bony canal, numerous vital structures, including nerves and vessels are transmitted through it. Most of the intracranial and extra cranial lesions of posterior cranial fossa might affect the structures in jugular foramen in addition to intrinsic abnormalities. It is very important foramen for neurosurgeons. Material and Methods: The present study was conducted in 72 adult dry skulls, which were collected for study in multiple medical and dental institutions in Karnataka. We have measured the jugular foramen - Anteroposterior diameter, Mediolateral diameter, the fossa width and depth of fossa. All these measurement with help of vernier callipers. All the measurements were taken bilaterally and expressed in Mean+SD. Results: We have observed that anteroposterior diameter was less than medial to lateral diameter. The anteroposterior diameter was ranged between 4 - 16 mm and medial to later diameter was 12 - 25mm. We have also seen about dome of jugular fossa, in 28(38.88%) skulls we have observed the presence of a prominent superior jugular bulb was present bilaterally. Depth of the fossa was measured. Most of the foramina were having depth between 5 and 20 mm. Conclusions: The present study concluded that the morphometric data and variations observed in the present study are of enormous value to neurosurgeons and otolaryngologists, while performing middle ear surgeries for various jugular foramen tumours. [ABSTRACT FROM AUTHOR]

In this study, we aimed to analyze the relationship of the sigmoid sinus (SS) with the external auditory canal, facial nerve, and mastoid cells from an anatomic point of view, to define the position of the SS during transmastoid, translabyrinthine, retrosigmoid (lateral suboccipital) approaches, in tympanomastoidectomy and posterior cranial fossa surgery. In this study, the morphologic structures associated with the sigmoid sinus were evaluated in cone beam computed tomography images taken between 2015 and 2022. The images of 68 men and 106 women, aged 18–65 years, obtained from the archive of Ankara University Faculty of Dentistry, Department of Oral and Maxillofacial Radiology were analyzed. The most common SS pattern was type II, with a rate of 60.8% (n = 209); the second was type III, with 20.6% (n = 71); and the least common was type I, with 18.6% (n = 64). Although the distance between the horizontal line passing through the external auditory canal and facial nerve and the anterior contour of the SS was highest in type I (right, 7.26 ± 1.62; left, 7.44 ± 0.97), it was lowest in type III (right, 4.40 ± 1.50; left, 4.84 ± 1.16) (P < 0.05). This study highlights the importance of the SS position in surgery, with special reference to otologic, neurotologic, and posterior cranial fossa surgery. To avoid intraoperative complications, each patient should be evaluated preoperatively by appropriate radiologic methods. [ABSTRACT FROM AUTHOR]

Background: Pulsatile tinnitus (PT) is a rare form of tinnitus that aligns with the heartbeat. It is typically brought on by lesions with significant vascularity, which produce aberrant sound conduction and increase the risk of mental health issues and hearing loss. Venous PT is more prevalent than arterial PT. Open procedures or interventional procedures can be used to treat PT. We present here a case of PT caused by venous luminal stenosis combined with jugular bulb (JB) malformation, which was improved by stenting and JB embolization. Case presentation: A 59-year-old woman presented with long-term tinnitus consistent with heart rhythm and hearing loss, accompanied by anxiety, insomnia, and depression. The results of brainMRV, CT, and DSA showed stenosis of the right sigmoid sinus and high jugular bulb (JB) with dehiscence of the JB wall. The patient saw a significant improvement in PT symptoms following sigmoid sinus stenting and spring coil embolization of the high JB, following the diagnosis of PT. The patient had no PT recurrence for the course of the 31-month follow-up period. Conclusion: In the present PT case, there was a simultaneous onset of the right sigmoid sinus stenosis and the high JB with the JB wall abnormalities. Sigmoid sinus stenting and spring coil embolization of high JBmay be a treatment for the PT, but the prevention of post-stenting complications is still an issue that requires great attention and needs further study. [ABSTRACT FROM AUTHOR]

We report a case with rare complication of cerebral venous thrombosis, as well as an incomplete response, after sigmoid sinus resurfacing surgery for pulsatile tinnitus (PT). A 24-year-old female patient with PT originating from the sigmoid sinus underwent sigmoid sinus resurfacing surgery. The tinnitus was immediately resolved, but it recurred with headache 5 days after surgery. A cerebral venous thrombosis was identified and treated, but PT persisted, although its frequency and loudness decreased. Sigmoid sinus resurfacing surgery is a safe and effective method to treat PT, but in some patients, it can cause serious complications and/or persistent tinnitus. In our patient, factors such as changes in blood viscosity due to warfarin intake or increased blood flow due to weight loss may have influenced the persistence of the tinnitus. It is important to identify the various associated factors and the weight of each of these factors to provide more tailored treatment of PT for individual patients in the future and to reduce complications and increase the effectiveness of sigmoid sinus resurfacing surgery. [ABSTRACT FROM AUTHOR]

The exhaustive information regarding the types of trigeminal pore (TP) or trigeminal impression (TI), internal acoustic opening (IAO), and related surgical approaches is lacking in the literature. Therefore, this study is performed to further elucidate the types of TP or TI, IAO, and the relationships with critical surgical landmarks in the skull base. Trigeminal impression (TI) and internal acoustic opening (IAO) found in 11 dry skulls, 24 right temporal bones, and 25 left temporal bones were examined on both sides to define their relationship to each other and nearby structures. The age and sex of these bones were not identified. Besides these, 77 skulls were examined by radiologic imaging methods. These skulls were identified by gender. According to test results, there was a significant difference between the left and right internal acoustic opening in the case of horizontal dimension (HD). The left HD-IAO is bigger than the right one. In addition, right HD-IAO, vertical dimension (VD) of right internal acoustic opening, left HD-IAO, and left VD-IAO values differed significantly in male and female patients. Investigating the relationship of TI and IAO with relevant structures suggests that surgical approaches involving the TP and IAO indicated that surgical approaches considering the TI and IAO variations may be used in the development of surgical processes and primary surgical interventions. [ABSTRACT FROM AUTHOR]

Objective: Cerebral venous sinus thrombosis (CVST) is one of the rare and severe complications of coronavirus disease 2019 (COVID-19) vaccines. CVST has also been reported to develop into dural arteriovenous fistula; however, there were no reports of dural arteriovenous fistula associated with COVID-19 vaccine-induced cerebral venous sinus thrombosis. Here, we describe a rare case of a transverse-sigmoid sinus dural arteriovenous fistula followed by CVST due to COVID-19 vaccination. Case Presentation: A 70-year-old patient presented with headache five days after receiving a second dose of COVID- 19 vaccine. MRI showed a CVST in the superior sagittal sinus, left transverse sinus, and left sigmoid sinus. His headache improved after the administration of anticoagulant therapy. Six months later, a similar headache recurred, and cerebral angiography demonstrated a dural arteriovenous fistula in the left transverse sigmoid sinus and convexity dural arteriovenous fistulas in the left parietal cortex. The patient was treated twice with two sessions of transarterial embolization, and the shunts were completely occluded. His symptoms improved, and he was discharged with a modified Rankin Scale score of 0. Conclusion: Dural arteriovenous fistula can develop after CVST in association with COVID-19 vaccination. [ABSTRACT FROM AUTHOR]

The mastoid foramen (MF) is located on the mastoid process of the temporal bone, adjacent to the occipitomastoid suture or the parietomastoid suture, and contains the mastoid emissary vein (MEV). In retrosigmoid craniotomy, the MEV has been used to localize the position of the sigmoid sinus and, thus, the placement of the initial burr hole. Therefore, this study aimed to examine the exact location and variants of the MF and MEV to determine if their use in localizing the sigmoid sinus is reasonable. The sample in this study comprised 22 adult dried skulls (44 sides). MF were identified and classified into five types based on location, prevalence, whether they communicated with the sigmoid sinus and exact entrance into the groove of the sigmoid sinus. The diameters and relative locations of the MF in the skull were measured and recorded. Finally, the skulls were drilled to investigate the course of the MEV. Additionally, ten latex-injected sides from human cadavers were also dissected to follow the MEV, especially in cases with more than one vein. We found that type I MFs (single foramen) were the most prevalent (50%). These MFs were mainly located on the occipitomastoid suture; only one case on the right side was adjacent to the parietomastoid suture. Type II (paired foramina) was the second most prevalent (22.73%), followed by type III (13.64%), type 0 (9.09%), and type IV (4.55%). The diameter of the external opening in a connecting MF (2.43 ± 0.79) was twice that of a non-connecting MF (1.14 ± 0.56). Interestingly, on one side, two MFs on the external surface shared a single internal opening; the MEV bifurcated. MFs followed three different courses: ascending, almost horizontal, and descending. Regardless of how many external openings there were for the MF, these all ended at a single opening in the groove for the sigmoid sinus. For cadaveric specimens with multiple MEVs, all terminated in the sigmoid sinus as a single vein, with the more medial veins terminating more medially into the sinus. Based on our study, the MF/MEV can guide the surgeon and help localize the deeper-lying sigmoid sinus. Knowledge of this anatomical relationship could be an adjunct to neuronavigational technologies. [ABSTRACT FROM AUTHOR]

This study was conducted to evaluate the anatomical and clinical features of Trautman's triangle (TT) and to better understand the possible surgical corridor for other surgical approaches involving the petroclival region, especially the presigmoid retrolabyrinthine approach. In this study, morphological analysis of structures related to TT was performed from cone beam computed tomography images of 134 female and 206 male individuals aged 18–65 years. The TT area was observed as 5.6% (n = 19) type I, 63.2% (n = 215) type II, and 31.2% (n = 106) type III. It was determined that 87.6% of the sigmoid sinus (SS) was lateral to the posterior semicircular canal and 12.4% was medial. It was determined that the TT area showed a positive correlation with petrous slope and a negative correlation with mastoid aeration. In other words, as the TT area increased, the petrous inclination angle also increased, but the mastoid aeration decreased. It was also found that the TT area was associated with the location of the SS and the largest TT area (164.84 ± 42.29 mm2) was observed in the posteriorly located SS. The relationship between TT and SS, petroclival angle, mastoid aeration, and subarcuate fossa has a very dynamic structure. Understanding the variations and clinical significance of these structures in the petroclival region is critical in determining the surgical approaches to be applied and understanding the etiology of vestibular system diseases. [ABSTRACT FROM AUTHOR]

Background: Main anatomical landmarks of retrosigmoid craniotomy are transverse sinus (TS), sigmoid sinus (SS), and the confluence of both. Anatomical references and guidance based on preoperative imaging studies are less reliable in the posterior fossa than in the supratentorial region. Simple intraoperative real-time guidance methods are in demand to increase safety. Methods: This manuscript describes the localization of TS, SS, and TS-SS junction by audio blood flow detection with a micro-Doppler system. Conclusion: This is an additional technique to increase safety during craniotomy and dura opening, widening the surgical corridor to secure margins without carrying risks nor increase surgical time. [ABSTRACT FROM AUTHOR]

Introduction: Once the underlying pathology has been identified, pulsatile tinnitus (PT) can be treated successfully with surgical or interventional management. However, some patients experience residual or recurrent symptoms following initially successful surgical treatment, and require revision surgery or additional procedures. Here, we report a case series of patients who had undergone revision surgery or interventional treatment, and suggest possible ways of minimizing the need for revision. Methods: Between January 2014 and March 2023, a total of seven subjects underwent revision surgery or interventional treatment for persistent or recurrent PT after initial surgical treatment. Demographic data, reasons for revision, and changes in symptoms before and after revision were analyzed retrospectively. Temporal bone computed tomographic angiography images were reviewed to identify the causes and reasons for revision. Results: Of the seven subjects, six underwent sigmoid sinus (SS) resurfacing/reshaping due to ipsilateral diverticulum (Div) or dehiscence (Deh), and one underwent jugular bulb (JB) resurfacing due to a high-riding JB with bony Deh. Of the five subjects who underwent revision SS surgery due to recurrent SS-Div or SS-Deh, three showed marked resolution of PT, while the other two showed partial improvement of the symptoms. One subject who underwent revision JB resurfacing, and another who underwent additional transarterial embolization for a concurrent ipsilateral dural arteriovenous fistula, reported marked improvement of PT. Discussion: The possibility of recurrence should be taken into account when performing surgical intervention in patients with PT. The likelihood of recurrence can be minimized through a comprehensive evaluation to identify possible multiple etiologies, and through the use of durable materials and appropriate surgical methods. [ABSTRACT FROM AUTHOR]

Intracranial dermoid cysts are rare dysembryonic tumors of benign nature. These are uncommon in adults. If present, they are usually located in the midline or along the lines of embryonic fusion. The posterior fossa region is an infrequent site. Extradural or interdural locations are even more rare. In this case report, the authors report a laterally located large posterior fossa right cerebellar convexity interdural and extradural dermoid cyst over the sigmoid sinus. It was managed by totally extradural maximum possible safe decompression with microneurosurgical technique. The authors share their experience of addressing this rare pathology at the rarest location with unusual imaging findings. [ABSTRACT FROM AUTHOR]

Background: Asterion is the junction of lambdoid, parietomastoid, and occipitomastoid sutures. In traditional anatomy teaching, it is believed that asterion sits over the transverse-sigmoid sinus junction (TSSJ). It is a significant surgical landmark for the placement of a burr hole in the retrosigmoid approach. Objective: The purpose of this study was to evaluate the asterion's accuracy as a TSSJ-specific external surgical landmark in the Indian population. Materials and Methods: 16 human dried skulls were obtained from the Department of Anatomy, AIIMS, New Delhi. The point of TSSJ was taken between the two lips and just posterior to the entry of the superior petrosal sinus. Asterion internally was localized with the help of a geometrical divider. The x- horizontal/ anterior and y- vertically superior (+)/ inferior (-) distances were measured from asterion (internally) to the TSSJ by a digital vernier caliper. Results: The mean horizontal distance (x) of the left side asterion & TSSJ was 10.3±1.0mm whereas the vertical distance (y) ranged between +2 to -4.3 mm. The mean horizontal distance (x) of the right side asterion & TSSJ was 13.5±1.4mm whereas the vertical distance (y) ranged between +3 to -4.2 mm. Conclusion: Asterion is not a reliable landmark for TSSJ in Indian skulls. The TSSJ with respect to asterion was found on average 10mm and 13.5mm anterior on the left and right side respectively, and mostly inferior (average 4.2mm) in 75% of the skulls. The TSSJ was closer to the asterion on the left side in comparison with the right side. However, further studies with a larger sample size will be needed to evaluate the population-specific relation of asterion with the TSSJ. [ABSTRACT FROM AUTHOR]

Background: The degree of mastoid pneumatization of the temporal bone (TB) has been implicated in the pathogenesis of TB diseases and surgical implications, and planning of a few otologic surgeries. However, there is lack of consensus in the classification of the degree of pneumatization. This study aimed to suggest a simple, quick, and less-burden classification system for assessing and rating the degree of pneumatization by comparing two levels of TB computed tomographs (CTs) using the SS as a reference in an inter-observer assessment among otologists. Methods: This was a randomized pilot survey among otologists. A questionnaire consisting of different axial CTs of TB taken at two levels: the level of malleoincudal junction (MIJ) and the level of lateral semicircular canal (LSCC), with different pneumatization patterns, was used to assess participants' impressions of the degree of pneumatization. The terms "hypo-," "moderate," "good," and "hyper-" pneumatization were listed as options to rate their impressions on the degree of mastoid pneumatization of the TB images using the SS as a reference structure. Likert scale was used to assess their level of agreement or disagreement with using SS as a reference in evaluating mastoid pneumatization. Results: Participants who correctly rated images taken at the level of LSCC according to their respective degree of pneumatization were significantly higher (p < 0.05) regardless of their year of experience compared to those that correctly rated corresponding images taken at the level of MIJ. A 76% positivity in their level of agreement with the use of sigmoid sinus in evaluating mastoid pneumatization was observed on the Likert-scale chart. Conclusion: Findings from this study suggest that evaluating air cells around the SS at the level of LSCC on CTs could be easier in assessing and classifying the degree of mastoid pneumatization. [ABSTRACT FROM AUTHOR]

Objective To highlight the advantages and disadvantages of the combined translabyrinthine (TL) and classic retrosigmoid (RS) approaches. Design Retrospective chart review. Setting National tertiary referral center for skull base pathology. Participants Twenty-two patients with very large cerebellopontine angle tumors were resected using the combined TL-RS approach. Main Outcome Measures Preoperative patient characteristics including age, sex, and hearing loss. Tumor characteristics, pathology, and size. Intraoperative outcome: tumor removal. Postoperative outcomes included facial nerve function, residual tumor growth, and neurological deficits. Results Thirteen patients had schwannoma, eight had meningioma, and one had both. The mean age was 47 years, mean tumor size was 39 × 32 × 35 mm (anterior–posterior, medial–lateral, craniocaudal), and mean follow-up period was 80 months. Tumor control was achieved in 13 patients (59%), and 9 (41%) had residual tumor growth that required additional treatment. Seventeen patients (77%) had postoperative House–Brackmann (H-B) facial nerve function grades I to II, one had H-B grade III, one H-B grade V, and three H-B grade VI. Conclusion Combining TL and RS approaches may be helpful in safely removing large meningiomas and schwannomas in selected cases. This valuable technique should be considered when sufficient exposure cannot be achieved with the TL or RS approach alone. [ABSTRACT FROM AUTHOR]

Microvascular decompression (MVD) is a widely adopted neurosurgery in treating cranial nerve diseases providing long-term pain relief. Improving surgical techniques has been a focus of recent studies. Venous structures such as the sigmoid sinus are essential to protect, and whose risk of destruction during surgery increases with size. The medical records of patients who went through MRI ahead of MVD surgery between Dec 2020 and Dec 2021 were reviewed. Section area of sigmoid sinus calculated from the MRI plane of auditory nerve showed a right dominance of the sinus. The improved method concerning the relationship between affected side and the dominant sigmoid sinus offered a better bone window and surgical field by planning the operation incision in advance. Intraoperative adjustment of the bone flap was avoided, and the risk of destructing the sigmoid sinus was reduced. [ABSTRACT FROM AUTHOR]

HypothesisWe hypothesize patient-specific flow models to be an adequate in vitro surrogate to allow for characterization of pulsatile tinnitus (PT) that affects three to five million Americans.BackgroundPT, rhythmic sounds without an extracorporeal source that patients appreciate, can be caused by aberrant blood flow in large cerebral veins near the cochlea. To investigate the sound production mechanism, we created 3D printed flow models based on patient-specific cerebral venous anatomies.MethodsMagnetic resonance angiography datasets from two patients with PT were used to generate patient-specific 3D printed flow models. A flow circuit connecting the patient-specific models to a pulsatile, continuous flow pump simulating cardiac cycle was created. Sound recordings were made along the surface of the models using an electronic stethoscope. Peak-to-rms amplitude, and area under the power spectral density (PSD) curve values were computed to evaluate the sound measurements. Wilcoxon rank sum test was used to statistically determine the differences in measurements between the patient-specific models.ResultsIn patient-1, the recordings (peak-to-rms) from the internal jugular vein stenosis of baseline model (4.29 ± 1.26 for 146 samples) were significantly louder (p

Abstract Hypothesis The parietal notch is a reliable surface landmark of the sigmoid sinus at the sinodural angle. Background Currently no surface landmark approximates the anterior border of the sigmoid sinus. Additionally, the temporal line may not accurately identify the tegmen near the sinodural angle. This study examines the reliability of the parietal notch as a surface landmark of the sigmoid sinus at the sinodural angle. Methods Forty‐seven cadaveric temporal bones were used to identify the parietal notch by two observers. The parietal notch and sinodural angle were labeled with radiopaque markers, mounted on foam, and CT imaged in the axial plane. The horizontal and vertical distances between the labeled landmarks were measured using PACS software. Results The parietal notch location was identified in 43/47 specimens. The notch was posterior to the sinodural angle in 90.6% and superior in 65% of the specimens. The average horizontal and vertical distance between the two landmarks was 6.1 mm (SD = 5.4) and 0.8 mm (SD = 8.7), respectively. In 60% of the specimens the parietal notch was within 6 mm of the sinodural angle in the horizontal dimension. Conclusions The parietal notch is identified in most temporal bones. It also approximates the anterior boarder of the sigmoid sinus and level of the tegmen due to its proximity to the sinodural angle. The parietal notch helps to define the posterosuperior margins of a mastoid dissection and may assist surgeons during mastoid surgery.

To evaluate the outcomes in patients of vascular tinnitus managed at our institute. The clinical data of all patients diagnosed with pulsatile tinnitus from January 2014 to April 2022 and managed at AIIMS, Bhubaneswar, was retrospectively reviewed. The diagnosis, treatment and outcomes were analyzed. A 6-year literature review was performed from March 2015 to April 2021. Our series discusses managing eleven cases of vascular tinnitus with varied aetiology and their outcomes. Out of the eleven cases, eight patients underwent surgical or radiological intervention, and seven had complete resolution of symptoms. Of the eleven patients, three had partial resolution. The 6-year literature review revealed sigmoid and transverse sinus as the most common causative anatomical sites for pulsatile tinnitus. Amongst those who received an intervention, 83.56% of the patients had complete resolution of symptoms. Vascular tinnitus can be cured if the exact vessel causing it is localized. Clinical suspicion is based on the character of tinnitus and patient history. A careful evaluation of the head and neck sites for any vascular anomaly that can cause pulsatile tinnitus must be done. Radiology demonstrates treatable causes of it. It delineates the aberrant anatomical variations that can lead to this disturbing aetiology. Treatable causes are best addressed, and pathology should be taken care of. A multidisciplinary team comprising ENT surgeons, audiologists and interventional radiologists must identify and treat the pathology. [ABSTRACT FROM AUTHOR]

Purpose: The objective of this study was to evaluate our 12-year experience in treating Borden type III transverse-sigmoid sinus (TSS) dural arteriovenous fistulas (DAVFs) and discuss the technical aspects of ipsilateral and contralateral transvenous embolization (TVE) approaches. Methods: We retrospectively reviewed charts of consecutive patients with TSS DAVF treated with multimodal treatment between April 2008 and March 2020. The baseline patient characteristics, imaging data, details of procedure, data sets of sinus pressure monitoring, and clinical results were systematically collected. Results: Of 44 patients with TSS DAVF who were treated during study periods, 23 patients of Borden type III were extracted. Among the 23 patients, 18 with transfemoral TVE were included for analysis. TVE was performed using an ipsilateral approach in 8 patients and a contralateral approach in 10. Pressure monitoring data revealed that initial mean sinus pressure (43.5 mmHg vs. 29.5 mmHg; P = 0.033), maximum sinus pressure during the procedure (69.0 mmHg vs. 40.5 mmHg; P = 0.011), and sinus pressure gradient (22.5 mmHg vs. 5.5 mmHg; P = 0.021) were significantly higher in the ipsilateral approach group. The complete obliteration rate by primary embolization was 94% in our cohort with the recurrence rate of 5.6% with a median follow-up period of 57 months. Conclusion: Our study showed the durability of TVE for patients with Borden type III TSS DAVF. TVE performed via the contralateral approach might prevent a potentially dangerous increase in intraprocedural sinus pressure and cortical venous reflux. [ABSTRACT FROM AUTHOR]

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Purpose: During retrosigmoid craniotomy, the mastoid emissary vein (MEV) can be a source of considerable bleeding during the operation, especially when the larger diameter MEV or sigmoid sinus is torn. In this study, we evaluated the relevant structure of the MEV for their anatomy and applied the data in surgery to summarize their clinical significance. Methods: The posterior craniocervical regions of 15 silicon-injected Chinese human cadaver specimens were dissected to expose the MEV and adjacent structures. Fifty-one patients who were scheduled to undergo retrosigmoid craniotomy were selected. All patients underwent preoperative routine CT of the head. The relevant data were collected on cadaveric anatomy and CT. Eventually, all patients underwent retrosigmoid craniotomy and the MEV was observed during the operation. Results: In cadaver specimens, the prevalence of the MEV was 90.0%. It originated from the middle and lower parts of the posterior wall of the sigmoid sinus and extended in the posterior direction in the mastoid process, usually having 1–2 external openings (86.7%) and only 1 internal opening. The intraosseous courses of the MEV were classified as straight and curved. The straight type accounted for 57.9%, and the curved type for 42.1%. The mean diameter of the MEV was 1.84 ± 0.85 mm, and the straight length of the MEV inside the mastoid process was 11.93 ± 3.58 mm. In 16.7% and 6.7% of all cadaver specimens, the MEV diameter was greater than 2.5 and 4 mm, respectively. In 51 patients (bilateral), routine head CT scan showed the MEV in 49.0% of the patients, and the MEV diameter was greater than 2.5 and 4 mm, respectively, in 17.6% (18/102) and 3.9% (4/102) of the cases. During surgery (unilateral) in the 51 patients, 48 had the MEV and 3 had no MEV. None of the patients had sigmoid sinus tears or massive bleeding. Conclusion: In the process of retrosigmoid craniotomy, detailed anatomical knowledge of the MEV, well-planned CT scan, and meticulous microsurgical techniques are key for successful operation, which can reduce the occurrence of complications. [ABSTRACT FROM AUTHOR]

Carotid cavernous fistulas (CCFs) are a rare but debilitating entity that may present with orbital or cerebral venous hypertension. CCFs may pose diagnostic and management pitfalls for clinicians as they can initially be misdiagnosed as primary orbital pathology or nonarteriovenous shunting-related cavernous sinus pathology. Furthermore, the resolution of pulsatile tinnitus could be an ominous sign in patients with untreated dural arteriovenous fistula. We describe a case of a 56-year-old male who presented with progressive right eye proptosis, congestion, decreased visual acuity, limited duction, exophthalmos, and pulsatile tinnitus. The patient had poor response to antibiotics and steroids. Magnetic resonance imaging brain showed significant inflammation involving the right orbit and atypical enhancement of the basal frontal lobe adjacent to the orbit. Cerebral angiography revealed an indirect right CCF and right sigmoid sinus thrombosis with stenosis of the right internal jugular vein. No clear predisposing factor was identified. Given the rapidly progressive nature of the condition, the patient successfully underwent endovascular treatment with transvenous approach to preserve flow in the internal carotid artery while ensuring occlusion of the fistula. A triad of proptosis, eye congestion, and signs of turbulent flow such as tinnitus or orbital bruit should raise suspicion for CCF. An interesting feature in this patient is that CCF may have occurred secondary to sigmoid sinus thrombosis with accompanying small cortical vein drainage. Our case highlights the importance of early recognition and timely intervention to ensure the resolution of orbital hypertension-related symptoms in rare cases of CCFs. [ABSTRACT FROM AUTHOR]

There are many studies on the effects of temporal bone anatomical variations on a mastoid pneumatization. Considering the effects of the anatomic variations on mastoid pneumatization, it is considered that many anatomic variations may affect graft success rates and postoperative hearing threshold gains. We aimed to evaluate the effects of various anatomic variations on postoperative hearing gains among patients undergoing tympanoplasty. This retrospective cohort study conducted in a tertiary-care university hospital. This study enrolled 57 patients who underwent primary type 1 tympanoplasty operation using the temporal muscle fascia. The patients were divided into two groups as those with an anteriorly located sigmoid sinus (group 1), and no anatomic variation (group 2). Airway gain values at the frequency range of 250 Hz–8000 Hz and pure tone average (PTA) value were calculated preoperatively and at postoperative sixth month. The gains attained by the patient groups with anatomic variations were compared with group 2. There were significant differences between Group 1 and Group 2 in terms of the airway frequencies of 250, 500, 2000, 4000 Hz, and PTA value. We detected a lesser postoperative hearing gain in patients with an anteriorly located SS. We believe that anatomic variations that may affect middle ear and mastoid cavity may also affect postoperative hearing gain. [ABSTRACT FROM AUTHOR]

To assess the safety, time consumption and presumed postoperative complications of posterior repositioning in cases with bilateral anterior displaced sigmoid sinus (ADSS) having cochlear implant surgery. Cases with bilateral ADSS were included. A cortical bone chip was harvested. Sinus plate was drilled thin and removed, ADSS was repositioned posteriorly and secured by the bone chips. The procedure was completed using the standard posterior tympanotomy (PT) technique. Follow up was done both clinically and by computed tomography (CT). Out of 632 cases operated upon in more than 7 years, only 7 cases had Bilateral ADSS (1.1%) of which 5 were females (71.45%). The average age was 8.2 ± 12 (6 children and an adult). No intraoperative bleeding was encountered in any of the 7 cases. The average operative time was 103.6 ± 9.7 min. No minor nor major complications were detected in all 7 cases. To keep the advantages of PT, repositioning of ADSS in bilateral cases can be done safely with a reasonable increase in the average operative time. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to examine the anatomical variations and morphometric characteristics of the sulci in the dural venous sinuses within the intracranial cavity, with a particular focus on sex differences and asymmetry., Methods: Thirty fixed cadaveric heads were used to measure the dimensions (length, width, and depth) and spatial relationships of the dural venous sinus sulci within the intracranial cavity, including the distance to the midline, distance to each other, and lateral margin of the skull. Comparisons were made between sexes and sides of the body., Results: A significant difference was observed in the length of the marginal sinus on the right side between sexes (p = 0.028). Various measurements, including the width of the transverse sinus, origin and insertion sites of the superior petrosal sinus, and distances between the sinuses and midline, showed statistically significant differences between the left and right sides (p < 0.05). Furthermore, the width of the inferior petrosal sinus and depth of the sigmoid sinus were notably higher on the right side (p < 0.05)., Conclusion: The results suggest an asymmetric distribution of the sigmoid, superior/inferior petrosal, and transverse sinuses in terms of diameter and distance from the midline. Surgeons should consider these anatomical variations during procedures in this region., Competing Interests: Declarations. Ethical approval: All procedures conducted in this study involving human participants adhered to the ethical standards of the Bahcesehir University Clinical Research Ethics Committee, as approved by the ethics committee of the Bahcesehir University Faculty of Medicine (protocol ID: 2022-17/02 and approval date: November 16, 2022), and were in accordance with the 1964 Helsinki Declaration and its subsequent amendments or comparable ethical standards. Consent to participate: Not applicable. Consent to publish: Not applicable. Informed consent: Not applicable. Statement of research involving human participants and animals: The study was approved by the Bahcesehir University Clinical Research Ethics Committeeand certify that the study was performed in accordance with the ethical standards as laid down in the 1964 Declaration of Helsinki and its later amendments or comparable ethical standards. Conflicts of interest: The authors declare that they have no conflicts of interest., (© 2024. The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.)

Background: Although the asterion has long been used as a skeletal surface marker of the transverse-sigmoid sinuses junction (TSSJ) point in the retrosigmoid approach, abundant evidence shows that the relationship between asterion and TSSJ point varies greatly. In recent years, new technologies have been developed, such as neuronavigation and three-dimensional volume rendering imaging, that can guide in exposing the TSSJ point individually. However, they are not only expensive but also difficult to apply in emergency surgery.Objective: To introduce a quick, practical, and low-cost new method for locating the TSSJ point precisely.Methods: In this retrospective before-after study, the test group located the TSSJ point with our new method during a 6-month period, while the control group used asterion as a surface landmark to estimate the TSSJ during the preceding 6 months. The primary outcome is the immediate exposure rate of the TSSJ point by the initial burr hole.Results: There were 60 patients in both control and test groups as no significant difference in the general clinical characteristics of both groups were observed. The new three-step method significantly increased the TSSJ exposure rate by initial burr hole compared with the control group (96.67% vs. 53.33%, P = 0.0002). Moreover, the total bone loss and craniotomy duration were significantly reduced by the new method. Incidence of sinus injury (10% vs. 6.6%), post-operation infection (3.33% vs. 3.33%), and CSF leakage (3.33% vs. 0%) were similar.Conclusions: The novel three-step approach accurately locates TSSJ points in retrosigmoid craniotomy, reduces bone defects, saves time, and does not increase the risk of sinus injury, infection, and CSF leakage. [ABSTRACT FROM AUTHOR]

Introduction  Proposed landmarks to predict the anatomical location and trajectory of the sigmoid sinus have varying degrees of reliability. Even with neuronavigation technology, landmarks are crucial in planning and performing complex approaches to the posterolateral skull base. By combining two major dependable structures—the asterion (A) and transverse process of the atlas (TPC1)—we investigate the A-TPC1 line in relation to the sigmoid sinus and in partitioning surgical approaches to the region. Methods  We dissected six cadaveric heads (12 sides) to expose the posterolateral skull base, including the mastoid and suboccipital bone, TPC1 and suboccipital triangle, distal jugular vein and internal carotid artery, and lower cranial nerves in the distal cervical region. We inspected the A-TPC1 line before and after drilling the mastoid and occipital bones and studied the relationship of the sigmoid sinus trajectory and major muscular elements related to the line. We retrospectively reviewed 31 head and neck computed tomography (CT) angiograms (62 total sides), excluding posterior fossa or cervical pathologies. Bone and vessels were reconstructed using three-dimensional segmentation software. We measured the distance between the A-TPC1 line and sigmoid sinus at different levels: posterior digastric point (DP), and maximal distances above and below the digastric notch. Results  A-TPC1 length averaged 65 mm and was posterior to the sigmoid sinus in all cadaver specimens, coming closest at the level of the DP. Using the transverse-asterion line as a rostrocaudal division and skull base as a horizontal plane, we divided the major surgical approaches into four quadrants: distal cervical/extreme lateral and jugular foramen (anteroinferior), presigmoid/petrosal (anterosuperior), retrosigmoid/suboccipital (posterosuperior), and far lateral/foramen magnum regions (posteroinferior). Radiographically, the A-TPC1 line was also posterior to the sigmoid sinus in all sides and came closest to the sinus at the level of DP (mean, 7 mm posterior; range, 0–18.7 mm). The maximal distance above the DP had a mean of 10.1 mm (range, 3.6–19.5 mm) and below the DP 5.2 mm (range, 0–20.7 mm). Conclusion  The A-TPC1 line is a helpful landmark reliably found posterior to the sigmoid sinus in cadaveric specimens and radiographic CT scans. It can corroborate the accuracy of neuronavigation, assist in minimizing the risk of sigmoid sinus injury, and is a useful tool in planning surgical approaches to the posterolateral skull base, both preoperatively and intraoperatively. [ABSTRACT FROM AUTHOR]

Introduction: We hypothesized that the cranial phenotype influences the shape of the posterior cranial fossa and the relative position of the sigmoid sinus. Materials and methods: The topography of the sigmoid sinus was studied on 26 magnetic resonance venograms and 35 embalmed cadavers by morphometric analysis, dissection, and photo modeling techniques. Results: The data show that the transverse diameter of the posterior cranial fossa correlates positively with the laterolateral diameter of the skull. The majority of cases with the low-anterior position of the sigmoid sinus were recorded in the brachycephalic group (82%), while the high-posterior localization of the sigmoid sinus was typical for the dolichocephalic patients (63%). The results of the ANOVA test confirm the significance of differences. Conclusions: The shape of the skull reflects the morphology of the posterior cranial fossa and influences the topographic characteristics of the sigmoid sinus that must be considered in the selection of surgical approach to the inner ear and pontocerebellar angle. [ABSTRACT FROM AUTHOR]

Hypothesis: The parietal notch is a reliable surface landmark of the sigmoid sinus at the sinodural angle. Background: Currently no surface landmark approximates the anterior border of the sigmoid sinus. Additionally, the temporal line may not accurately identify the tegmen near the sinodural angle. This study examines the reliability of the parietal notch as a surface landmark of the sigmoid sinus at the sinodural angle. Methods: Forty‐seven cadaveric temporal bones were used to identify the parietal notch by two observers. The parietal notch and sinodural angle were labeled with radiopaque markers, mounted on foam, and CT imaged in the axial plane. The horizontal and vertical distances between the labeled landmarks were measured using PACS software. Results: The parietal notch location was identified in 43/47 specimens. The notch was posterior to the sinodural angle in 90.6% and superior in 65% of the specimens. The average horizontal and vertical distance between the two landmarks was 6.1 mm (SD = 5.4) and 0.8 mm (SD = 8.7), respectively. In 60% of the specimens the parietal notch was within 6 mm of the sinodural angle in the horizontal dimension. Conclusions: The parietal notch is identified in most temporal bones. It also approximates the anterior boarder of the sigmoid sinus and level of the tegmen due to its proximity to the sinodural angle. The parietal notch helps to define the posterosuperior margins of a mastoid dissection and may assist surgeons during mastoid surgery. [ABSTRACT FROM AUTHOR]

Objective  Structural anomalies of the jugular foramen (JF) and adjacent structures may contribute to development of pulsatile tinnitus (PT). The goal of this study was to assess anatomical variants in the ipsilateral JF region in patients with PT and to explore possible predisposing factors for PT. Methods  One hundred ninety-five patients with PT who underwent CT angiography and venography of the temporal bone were retrospectively analyzed. Anatomic variants including dominance of the ipsilateral JF, bony deficiency of the sigmoid sinus and internal carotid artery canal, high riding or dehiscent jugular bulb, dehiscence of the superior semicircular canal, tumors in the JF region, or cerebellopontine angle were assessed. Results  Of 195 patients with PT, the prevalence of a dominant JF on the ipsilateral side of patients with PT was 67.2%. Furthermore, the dominant JF demonstrated a significant correlation with the presence of ipsilateral PT (p  < 0.001). No anatomical variants were present in 22 patients (11.3%), whereas in patients with structural variants, bony deficiency of the sigmoid sinus was most common (65.6%), followed by high riding (54.9%) or dehiscent jugular bulb (14.4%). Dehiscent internal carotid artery canal (3.1%) and superior semicircular canal (4.1%) were occasionally identified, while arteriovenous fistula, arterial aneurysm and tumors arising from the JF region or cerebellopontine angle were rarely encountered. Conclusion  Structural abnormalities of the JF and adjacent structures may predispose to the development of PT. Knowledge of these anatomical variants in the JF region may help establish a clinical strategy for addressing PT. [ABSTRACT FROM AUTHOR]

Duplications and fenestrations of the internal jugular vein (IJV) are rare anatomic variations. There were previously found mostly unilateral fenestrated internal jugular veins, either empty, or traversed by the spinal accessory nerves. It was documented the computed tomography angiogram of a 65 year-old female patient and bilateral high fenestrations of the IJVs were found. On both sides, the superior ends of the fenestrations were in the jugular foramina. On the right side the fenestration had 3.8 cm length and was located in front of the transverse processes of the first two cervical vertebrae. On the opposite side the fenestration had 1.5 cm length and was antero-lateral to the transverse process of the atlas vertebra. On both sides the antero-medial arms of the fenestrations received the inferior petrosal sinuses and anterior condylar veins. Such highly placed fenestrations of the IJVs should be carefully documented either preoperatively, or prior to central venous access. [ABSTRACT FROM AUTHOR]

INTRODUCTION: In Tympanosclerosis and Chronic Suppurative Otitis Media (CSOM) surgery; the presence of anteriorly located sigmoid sinus (ALSS), high jugular bulbus (HJB) and carotid artery dehiscence may provide a basis for undesired morbid and / or mortal complications. Therefore, it is important to evaluate these anomalies radiologically before the operation. In our study, we aimed to compare the findings of Temporal Bone Computed Tomography (TBCT) in terms of the frequency and radiological features of ALSS, HJB and carotid artery dehiscence in patients with tympanosclerosis and CSOM. METHODS: In our study, TBCT of patients who were diagnosed with 30 tympanosclerosis and 30 CSOM between March 2017 and March 2019 and therefore operated on were therefore retrospectively analyzed. RESULTS: While HJB was detected in 8 (26.6%) of patients with CSOM, it was present in 11 (36.6%) of patients with tympanosclerosis. While ALSS was detected in 14 (46.6%) patients with CSOM, it was present in 21 (70%) of patients with tympanosclerosis. According to our findings, the frequency of HJB, ALSS and bilateral occurence in tympanosclerosis cases, was higher than CSOM, although it was not statistically significant. While none of the patients with CSOM had carotid artery dehiscence, 2 of the patients with tympanosclerosis had carotid artery dehiscence. DISCUSSION AND CONCLUSION: As a result, HJB and ALSS were detected in significant numbers in our study. Therefore, we think that TBCT examination and preoperative evaluation are necessary in order to avoid possible complications, especially in cases with tympanosclerosis with higher frequency of ALSS, HJB and carotid artery dehiscence.

Abstract Background Intracranial venous hypertension has been associated with a few cases of meningioma secondary to compression of the venous sinus. This is the rare case of small meningioma involving the sigmoid sinus leading to intracranial venous hypertension mimicking venous thrombosis. Case presentation A 39-year-old woman suffered visual dysfunction due to bilateral papilledema. Noncontrast head computed tomography (CT) showed no intracranial space-occupying lesions or hydrocephalus. Cerebrospinal fluid examination revealed high opening pressure. Various image inspections such as three-dimensional CT angiography, magnetic resonance imaging, and cerebral angiography demonstrated a small 2.5-cm lesion causing subtotal occlusion of the dominant right sigmoid sinus. No improvement of clinical manifestations was observed after medical treatment for 6 months, so right presigmoid craniectomy was performed. Operative findings revealed that the tumor was located predominantly involving the sigmoid sinus. The pathological diagnosis was fibrous meningioma. Postoperative fundoscopic examination showed improvement of bilateral papilledema. Conclusions We treated a patient presenting with intracranial hypertension due to a small meningioma involving the sigmoid sinus. This unusual case suggests that early surgical strategies should be undertaken to relieve the sinus obstruction.

Background: Sigmoid sinus is an area of interest for anatomists, neurosurgeons, and radiologists. Different procedures such as mastoidectomy, thrombectomy in the sigmoid, and transverse sinus thrombosis have realized the need of proper morphological knowledge of the sigmoid sinus and its variations and their important relations. Therefore, the present study was conducted to report the prevalence of various nonmetrical attributes of the sigmoid sulcus in dry human skulls in India. Methodology: This study was conducted on 224 human skulls in which sex and origin were not known and these were taken from the departmental osteology laboratory. Interior of the skull base at the area of the sigmoid sulcus was carefully observed for the presence of any osseous projection on its anterior or posterior lips such as crest, plate, or bars. Shape, position, and side of projection were noted and frequency was calculated in percentage. Results: Out of 224 skulls, 80% of the sigmoid sulci showed one or other form of bony features. A total prevalence of 43.08% was observed for crests, whereas plates showed lesser frequency (28.57%) on the anterior lip of the sigmoid sulcus. Bony bars were the least common (9.14%) features, but were characteristically located at the angle region of the sigmoid sulcus. In 16.74% of skulls, sigmoid sulcus was shallow. Conclusion: Occurrence of bony attributes in the form of plates, crests, and bridges along the course of the sigmoid sulcus is quite high and shows frequent variability in location and laterality, which may adversely affect the morphology of the sigmoid sinus.

Objective  To evaluate the clinical characteristics and present surgical outcomes of transtemporal venous decompression technique in the treatment of pulsatile tinnitus (PT). Study Design  This is a prospective cohort study. Setting  This study was done at the tertiary private neurotologic skull base clinic. Participants  The primary author, between March 2012 and February 2013, evaluated 55 patients with the complaint of PT. Seven out of the 55 patients were diagnosed with severe, unrelenting idiopathic pulsatile tinnitus (IPT), and were placed into the study. These seven patients had temporal bone computed tomography, magnetic resonance imaging, arteriogram, videonystagmography, electrocochleography, and lumbar puncture based on the symptoms. All the seven patients underwent transtemporal venous decompression surgery. Main Outcome Measure  Resolution of PT was determined as the primary outcome measure. Results  Six out of seven patients had complete resolution of their PT immediately after surgery and at 3 to 4 years follow-up. One patient developed intracranial hypertension after 3 months requiring ventriculoperitoneal shunt, which resolved PT as well. No complications occurred. Conclusion  A significant subset of the PT patient population has known reversible causes. The more common includes conductive hearing loss, superior canal dehiscence, benign intracranial hypertension, jugulosigmoid venous anomalies, stapedial myoclonus, etc. There exists a subset of patients who have IPT. Transtemporal venous decompression is a surgical technique that can be employed to give patients with IPT long-term relief. [ABSTRACT FROM AUTHOR]

Abstract Background The top of the mastoid notch (TMN) is close to the transverse-sigmoid sinus junction. The spatial position relationship between the TMN and the key points (the anterosuperior and inferomedial points of the transverse-sigmoid sinus junction, ASTS and IMTS) can be used as a novel method to precisely locate the sinus junction during lateral skull base craniotomy. Methods Forty-three dried adult skull samples (21 from males and 22 from females) were included in the study. A rectangular coordinate system on the lateral surface of the skull was defined to assist the analysis. According to sex and skull side, the data were divided into 4 groups: male&left, male&right, female&left and female&right. The distances from the ASTS and IMTS to the TMN were evaluated on the X-axis and Y-axis, symbolized as ASTS&TMN_x, ASTS&TMN_y, IMTS&TMN_x and IMTS&TMN_y. Results Among the four groups, there was no significant difference in ASTS&TMN_x (p = 0.05) and ASTS&TMN_y (p = 0.3059), but there were significant differences in IMTS&TMN_x (p