Temporal Skull Base Research Articles

Supra Digastric Muscles Approach for Styloid Process Resection

Abstract Objective Eagle syndrome, categorized into classical styloid syndrome and stylocarotid syndrome, presents challenges in determining the optimal surgical approach for styloid process (SP) resection. While intraoral resection suffices for many cases, especially classical styloid syndrome cases, stylocarotid syndrome sometimes demands a transcervical resection due to its intricate spatial dynamics. We describe a step-by-step procedure for modified transcervical resection using a supra digastric muscle approach (SDMA) for SP, emphasizing anatomical precision. Methods and Results The approach is described in the case of a 60-year-old woman with acute cerebral infarction from left internal carotid artery dissection. Employing carotid artery stenting, we identified SP elongation as the underlying cause requiring transcervical resection to avoid stent damage. The operative procedure involves meticulous dissection via a linear skin incision, exposing key anatomical structures such as the sternocleidomastoid muscles, digastric muscles (DMs), and the transverse process of the atlas. Surgical corridor via supra DM space is an invaluable technique, offering the shortest distance to the SP without compromising nearby nerves. The SP, covered by muscles and ligaments, is carefully stripped off, enabling its amputation near the temporal skull base. The entire procedure is performed under a microscope to preserve surrounding nerves. Conclusion The SDMA is a simple and safe technique, offering enhanced anatomical precision and minimizing the risk of nerve damage.

Widespread distribution of lymphatic vessels in human dura mater remote from sinus veins.

Background and purpose: Previous experimental studies have shown that meningeal lymphatic vessels are located primarily along the walls of the dural sinus veins. Whether they are more widespread throughout human dura mater has presently not been characterized. The present study explored in humans whether meningeal lymphatic vessels may be identified remote from the sinus veins and whether they differ in the various location of dura mater. Methods: We included 15 patients who underwent neurosurgery, in whom dura mater was removed as part of the planned procedure. Tissue was prepared for immunohistochemistry using the lymphatic endothelial cell markers lymphatic vessel endothelial hyaluronan receptor 1 protein (LYVE-1), podoplanin and vascular endothelial growth factor receptor 3 (VEGFR3). Results: Lymphatic endothelial cell positive cells were found in dura mater at the posterior fossa (n = 8), temporal skull base (n = 5), frontal convexity (n = 1), and cranio-cervical junction (n = 1). They were most commonly seen remote from blood vessels, but also occurred along blood vessels, and seemed to be most abundant at the skull base. Conclusion: The present observations show that human lymphatic vessels are widespread in dura mater, not solely lining the dural sinuses.

Incidental findings involving the temporomandibular joint on computed tomography and magnetic resonance imaging.

The temporomandibular joint (TMJ) is frequently imaged in head and neck computed tomography (CT) and magnetic resonance imaging (MRI) studies. Depending on the indication for the study, an abnormality of the TMJ may be an incidental finding. These findings encompass both intra- and extra-articular disorders. They may also be related to local, regional or systemic conditions. Familiarity with these findings along with pertinent clinical information helps narrow the list of differential diagnoses. While definitive diagnosis may not be immediately apparent, a systematic approach contributes to improved discussions between clinicians and radiologists and better patient management.

Introducing the “Temporal Thumb Sign” in Pediatric Patients With New-Onset Idiopathic Seizures With and Without Elevated Cerebrospinal Fluid Opening Pressure

BackgroundTemporal lobe changes, such as anterior temporal lobe meningoceles or encephaloceles, have been documented as possible epileptogenic foci in a subset of pediatric patients with seizures. In our study, we aim to analyze a different structural change in the temporal lobe, remodeling of the posterior temporal skull base by the inferior temporal gyrus called the “temporal thumb sign” (TTS), in pediatric patients presenting with new-onset seizures with or without elevated opening pressure (OP), patients presenting with confirmed diagnosis of idiopathic intracranial hypertension (IIH) without seizure presentation, and healthy controls. MethodsMagnetic resonance imaging scans of 163 pediatric patients were studied retrospectively for the presence of TTS. We analyzed the scans of 43 patients with elevated OP and confirmed IIH, 40 patients with elevated OP and new-onset idiopathic seizures, 40 patients with normal OP and new-onset idiopathic seizures, and 40 age- and sex-matched healthy controls. ResultsThe TTS was detected most frequently in patients with elevated OP and seizures at 72.5% compared with patients with IIH with no seizures and patients with normal OP and seizures (32.6% and 27.5%, respectively). The TTS had a frequency of 12.5% in the control group. The TTS had the highest combination of specificity and sensitivity (72.5% and 72.5%) in patients with seizures and elevated OP compared with patients with seizures and normal OP (P value < 0.001). ConclusionsOur results suggest the Kamali “temporal thumb sign” is a novel imaging feature that may be used as a sensitive and specific imaging finding associated with seizures and elevated OP in the pediatric population.

SAT-270 Priapism Secondary to Cabergoline

Background: Cabergoline and Bromocriptine are ergot derivative long-acting dopamine agonist that are very effective and well tolerated in patients with hyperprolactinemia. A rare and unwanted side effect of Bromocriptine is priapism, which has hardly ever been report in literature and it’s not cited under the medication insert. The underlying mechanism is not totally clear, but it is well known that dopaminergic pathways in the central nervous system are of importance for male sexual behavior and penile erection. Lesser is known about Cabergoline and priapism with only one case report in the literature (1). Clinical Case: A 65 yr old African American male with a past medical history significant for obesity, essential hypertension, and recent history of frontal headaches was found to have a pituitary macroadenoma. Brain MRI demonstrated 11 x 12 x 9 mm enhancing lesion within the right lateral sella turcica. The lesion extended laterally to abut the right cavernous ICA without vascular encasement or extension into the right temporal skull base. Prolactin level was 276.3 ng/mL (2.1-15.0 ng/mL). He was started on Cabergoline 0.5 mg weekly. 60 days after starting Cabergoline he presented to the ED with a painful penile erection lasting >12 hours. He did not take any Phosphodiesterase (PDE) inhibitors and had no other recent change in medications. He denied any history of sickle cell disease. His most recent dose of Carbergoline was the day prior to the ED visit. He was seen by a Urologist in the ED and confirmed to have a low flow Priapism and underwent aspiration of intracorporal bodies. He was discharged home on pseudoephedrine and pain medications. Carbergoline was discontinued. He has had no further episodes of Priapism since discontinuation of Cabergoline. Conclusion: The time between drug use and occurrence, absence of other offending medications or precipitating factors and no further priapism episodes once treatment was discontinued suggests a priapism as a rarely reported side effect of Cabergoline. (1)

Anterolateral thigh free flap in reconstruction of lateral skull base defects after oncological resection

PurposeEvaluation of the utility of the free anterolateral thigh flap reconstruction of the defects resulting from radical temporal bone resection in the management of lateral skull base malignancies in a single institution.MethodsAn analysis of 17 en bloc subtotal petrosectomies for removal of malignant tumours was performed. There were 12 squamous cell carcinomas, 4 basal cell carcinomas and 1 adenoid cystic carcinoma. The tumours were staged with the University of Pittsburgh TNM system. In all patients, the lateral temporal bone with the preservation of the petrous apex and carotid artery was performed. All patients had parotid gland resection. The post-resection defect was reconstructed with an ALT free flap.ResultsTumour radical resection and defect reconstruction with an ALT flap was achieved in all patients without intraoperative complications. The transplants were harvested as fasciocutaneous flaps, 11 perfused by musculocutaneous and 6 by septocutaneous perforators. The ALT flaps had a mean pedicle length of 8 cm (6–12 cm), and the flap size ranged between 6 × 15 cm and 15 × 30 cm. The flaps were supplied by nine facial, five occipital and three maxillary arteries. Recipient-site veins included eight internal jugular, seven facial, one retromandibular and one external jugular vein. All arterial pedicles were anastomosed in an end-to-end manner. The veins were anastomosed with interrupted sutures and in 11 cases with Synovis-Coupler® devices. All the flap transfers were performed successfully. Three patients experienced postoperative complications.ConclusionsThe ALT flap proved to be effective for covering large temporal skull base defects resulting from the radical removal of temporal bone malignancies. The functional and cosmetic results were acceptable with a low complication rate.

Microsurgical and histological identification and definition of an interdural incision zone in the dorsolateral cavernous sinus.

The anatomy of the cavernous sinus is described controversially in a number of publications. In the present cadaveric study, the architecture of the dorsolateral wall of the cavernous sinus is studied microsurgically and histologically. Twenty cadaveric skulls have been dissected through a classical surgical frontotemporal approach. The temporal skull base was flattened and anatomical landmarks like the meningo-orbital band, superior orbital fissure, foramina rotundum, ovale, and spinosum were identified. Lateral of the trigeminal foramina, the dura was cut and the periosteal dural layer was separated from the meningeal layer, identifying an interdural zone. The length and the extent of this zone were evaluated. The dural architecture of the interdural incision zone was examined histologically. In all specimens, two dural layers lateral of the trigeminal foramina could be separated. The identified interdural incision zone extended in a length of 3.8-6.4 cm in the antero-posterior direction. The zone could be followed medially to the superior orbital fissure for 5.3 mm and lateral of the foramen spinosum for 6.4 mm. The separation of the dural layers allowed the approach to the superior border of the cavernous sinus through this interdural incision zone. The histological analysis of the interdural incision zone showed clearly the existence of two dural layers. The architecture of the temporal-fossa-dura allows the microsurgical separation of two meningeal dural layers through a length of 5-6 cm next to the trigeminal foramina. Opening this interdural incision zone allowed exploring the superior border of the cavernous sinus.

Epidural Anterior Petrosectomy with Subdural Visualization of Sphenobasal Vein via the Anterior Transpetrosal Approach

The drainage of the superficial middle cerebral vein (SMCV) is classified into four subtypes. The sphenobasal vein (SBV) drains from the SMCV to the pterygoid venous plexus at the temporal skull base. Epidural procedures in the standard anterior transpetrosal approach (ATPA) may damage the route of the SBV. We report a case in which modified surgical procedures via the ATPA were used to preserve the SBV. A 45-year-old male complained of right facial pain. Magnetic resonance (MR) images revealed a right cerebellopontine tumor suggestive of an epidermoid cyst. Right carotid angiography revealed that the SMCV drained into the pterygoid venous plexus via the SBV. The convexity dura mater of the temporal lobe was cut and the anterior part of the temporal lobe was retracted subdurally. The basal dura of the temporal lobe posterior to the SBV vein was visualized and cut subdurally. The posterior part of the temporal lobe was retracted epidurally. After dissecting, the dura mater medial to the greater petrosal nerve and to the edge of the petrous apex, the petrous apex was exposed and drilled out without injuring the SBV. The superior petrous sinus and the tentorium were cut. The tumor was compressed at the root exit zone of the trigeminal nerve. The tumor was removed grossly and totally. The modified ATPA (epidural anterior petrosectomy with subdural visualization of sphenobasal vein) is effective to preserve the SBV.

Glial Heterotopia of Sphenoid in Association with a Patent Sternberg's Canal presenting with Meningitis

ABSTRACTEctopic glial tissue, presenting at various sites of body is a rare embryonic developmental anomaly. Very few cases are reported in adults, most being incidentally detected, revealed only by histopathological findings. One of the rarest locations is the sphenoid sinus.We present here the case of a middle aged female, presenting with spontaneous cerebrospinal fluid (CSF) rhinorrhea and meningitis. With the radiological finding of a soft tissue density in sphenoid sinus with erosion of left temporal skull base, she underwent lateral craniotomy, with excision of the mass and middle cranial fossa floor repair. Histopathology revealed a heterotopic glial tissue. Peroperative finding of a well-defined defect in the lateral wall of an extensively pneumatized sphenoid showed typical features of a patent Sternberg's canal.This case could be a living proof for the existence of this rare developmental anomaly. A persisting Sternberg's canal should be considered as the source of spontaneous CSF leaks with or without lesions in sphenoid sinuses with extensive lateral pneumatization. Most of the cases may be treated with an extended endoscopic approach. Extreme lateral lesions like this would benefit most from a craniotomy approach for proper closure of skullbase defect. Three years after successful surgery, she remains symptom free.How to cite this articleSuma R, Jeena KJ, Pavithran VM, Govindan A, Ramachandran K. Glial Heterotopia of Sphenoid in Association with a Patent Sternberg's Canal presenting with Meningitis. Int J Otorhinolaryngol Clin 2014;6(2):81-83.

Glial Heterotopia of Sphenoid in Association with a Patent Sternberg's Canal presenting with Meningitis

ABSTRACT Ectopic glial tissue, presenting at various sites of body is a rare embryonic developmental anomaly. Very few cases are reported in adults, most being incidentally detected, revealed only by histopathological findings. One of the rarest locations is the sphenoid sinus. We present here the case of a middle aged female, presenting with spontaneous cerebrospinal fluid (CSF) rhinorrhea and meningitis. With the radiological finding of a soft tissue density in sphenoid sinus with erosion of left temporal skull base, she underwent lateral craniotomy, with excision of the mass and middle cranial fossa floor repair. Histopathology revealed a heterotopic glial tissue. Peroperative finding of a well-defined defect in the lateral wall of an extensively pneumatized sphenoid showed typical features of a patent Sternberg's canal. This case could be a living proof for the existence of this rare developmental anomaly. A persisting Sternberg's canal should be considered as the source of spontaneous CSF leaks with or without lesions in sphenoid sinuses with extensive lateral pneumatization. Most of the cases may be treated with an extended endoscopic approach. Extreme lateral lesions like this would benefit most from a craniotomy approach for proper closure of skullbase defect. Three years after successful surgery, she remains symptom free.

CT and Magnetic Resonance Imaging Findings of Lipomatous Hemangiopericytoma of Skull Base: A Case Report

Hemangiopericytomas were described as tumors arising from the pericytes of Zimmermans, which are modified smooth muscle contractile cells surrounding the capillaries (1). Hemangiopericytoma is a rare tumor with an incidence of less than 1% of all central nervous system (CNS) tumors. In addition, hemangiopericytoma is an aggressive tumor with malignant potential and tends to recur and occasionally metastasize, mainly to the bone, lung, and liver (2). However, hemangiopericytomas with a significant lipomatous component were first introduced into literature in 1990. Later, Nielsen et al. (3) coined the term, lipomatous hemangiopericytoma (LHPC), as a pathologically distinct entity. Folpe et al. (4) reported LHPC that occurred in adults, primarily in the deep soft tissues of the leg and in the retroperitoneum. This entity, arising from the skull base has not yet been documented on magnetic resonance (MR) imaging. We experienced a surgically proven LHPC of the temporal skull base within a 44-year-old woman.

Epidural anterior petrosectomy with subdural visualization of sphenobasal vein via the anterior transpetrosal approach—technical case report

The drainage of the superficial middle cerebral vein (SMCV) is classified into four subtypes. The sphenobasal vein (SBV) drains from the SMCV to the pterygoid venous plexus at the temporal skull base. Epidural procedures in the standard anterior transpetrosal approach (ATPA) may damage the route of the SBV. We report a case in which modified surgical procedures via the ATPA were used to preserve the SBV. A 45-year-old man complained of right facial pain. Magnetic resonance images revealed a right cerebellopontine tumor suggestive of an epidermoid cyst. Right carotid angiography revealed that the SMCV drained into the pterygoid venous plexus via the SBV. The convexity dura mater of the temporal lobe was cut and the anterior part of the temporal lobe was retracted subdurally. The SBV was visualized from the subdural side. The basal dura mater of the temporal lobe posterior to the SBV was cut and the posterior part of the temporal lobe was retracted epidurally. After dissecting the dura mater medial to the greater petrosal nerve and to the edge of the petrous apex, the petrous apex was exposed and drilled out without injuring the SBV. The superior petrous sinus and the tentorium were cut. The tumor compressed the root exit zone of the trigeminal nerve. The tumor was grossly totally removed. The modified ATPA (epidural anterior petrosectomy with subdural visualization of the SBV) is effective in preserving the SBV.

Gliosarcoma with bone infiltration and extracranial growth: case report and review of literature

Gliosarcoma is a relatively rare and highly malignant brain tumor consisting of both a glioblastoma and a mesenchymal component. Because of the natural barrier of the dura mater, that prevents intra or extradural neoplasm dissemination, cases of penetration of the dura and cranium by gliosarcomas without previous surgery or radiation are very rarely reported. We report an unusual case of gliosarcoma that involved the temporal skull base and the dura without antecedent radiation or surgery, although the lesion traversed the dura without radiologic or gross interruption of the dura. Remarkable in our case is the initial integrity of cerebral parenchyma. Follow-up revealed a tumorous infiltration of the temporal lobe almost one year after initial diagnosis. Thus the origin of the gliosarcoma in our case seemed to be extradural in the temporal skull base. Furthermore, this report demonstrates that extensive multi-modality treatment might be effective in patients with gliosarcomas and poor prognostic factors, for example unmethylated MGMT status.

Endoscopic Transnasal Transmaxillary Transpterygoid Approach to the Parapharyngeal Space: An Anatomic Study

The aim of this study was to assess the feasibility of an endoscopic approach to the parapharyngeal space through a transnasal route. For this purpose, an anatomic study was conducted. The target area was studied separately on each side in 4 adult cadaver heads. To simulate actual endoscopic surgery, the dissection was performed thoroughly under the rigid endoscope. The surgical steps and extent of surrounding tissue resection necessary for the approach were evaluated. Both the pre- and poststyloid compartments could be exposed with restricted sacrifice of the surrounding tissue around the pterygoid process. Adding a wide sphenoidotomy and subpetrous bone resection, the surgical exposure could be extended at the medial temporal skull base including the medial infratemporal fossa. Although its usefulness has to be further verified in the clinical setting, the present results of the anatomic dissection indicate the potential of the approach to become a novel technique for treatment of a lesion in the parapharyngeal space.

Consequences of Preoperative Evaluation of Patterns of Drainage of the Cavernous Sinus in Patients Treated Using the Anterior Transpetrosal Approach

Extradural procedures in an anterior transpetrosal approach (ATPA) may interrupt the route of drainage from the superficial middle cerebral veins (SMCVs) and the cavernous sinus (CS) to the pterygoid venous plexus at the temporal skull base. Patterns of drainage of the SMCV and the CS and the results of surgery were examined in 12 patients with petroclival lesions treated using the ATPA between 2000 and 2008. The angiographic patterns of drainage of the SMCV were examined in 22 sides of the 12 patients. The SMCV drained into the sphenoparietal sinus in 12 sides, the sphenobasal veins in 4 sides, and the cortical veins in 6 sides. The patterns of drainage of the CS were examined on 12 sides in which the SMCV drained into the sphenoparietal sinus. The CS drained into the inferior petrosal sinus (IPS) in 7 sides and equally into the pterygoid plexus and IPS in 3 sides. The CS drained mainly into the pterygoid plexus in 2 sides of 2 patients, who both suffered temporal lobe swelling postoperatively. The pattern of venous drainage of the CS must be considered in planning surgical approaches to petroclival lesions. In patients with a well-developed pterygoid plexus, surgical interruption of this drainage route may be a cause of injury of the temporal lobe.

Pigmented villonodular synovitis of the temporomandibular joint: a rare tumor of the temporal skull base

Musculoskeletal tumors are not usually encountered at the skull base. Benign lesions such as cholesterol granuloma, cholesteatoma, fibrous dysplasia, and Paget disease are common examples of such tumors arising from the bone of the cranial base. The authors report a case involving an adult male patient with the rare finding of pigmented villonodular synovitis of the temporomandibular joint. This case is reported as an example of another lesion to consider in the differential diagnosis. Due to the complexity of the anatomy at the cranial base, radical resection as recommended for the usual sites of occurrence in major joints is problematic. Because of the reported high recurrence rates at other sites, as radical excision as possible with vigilance for recurrence is recommended.

Synovial Chondromatosis of the Temporomandibular Joint With Intracranial Extension -Case Report-

A 52-year-old man presented with an extremely rare case of synovial chondromatosis in the temporomandibular joint (TMJ) with extension into the middle cranial fossa manifesting as swelling and exacerbation of pain. He had a long history of right TMJ disorders. Computed tomography and magnetic resonance imaging showed a mass in the right TMJ with extension into the intracranial part through the destroyed temporal skull base. The preoperative diagnosis was chondrosarcoma or osteosarcoma. The patient underwent surgery via combined trans-zygomatic temporal skull base and pre-auricular approaches and the mass was totally removed. Histological examination found an enormous number of closely packed loose bodies of various sizes, consisting of hyaline chondrocytes. The histological diagnosis was synovial chondromatosis. This rare lesion is difficult to discriminate from chondrosarcoma, so total removal is essential for correct diagnosis and cure.

Boundaries of the Cleavage Plane between the Temporal Dura Stratum Meningeale and Periostale

Introduction: The dura mater consists of two layers which are usually crosslinked to an inseparable sheet. At the level of the lateral middle skull base, those layers diverge allowing a cleavage plane between the stratum meningeale and periostale. We wanted to describe precisely the boundaries of that plane at the lateral temporal skull base and the structures that can be reached by separating these two layers.

Giant intracerebral choroid plexus calcification

While small calcifications of the choroid plexus are frequent, a large, single intracerebral calcification originating from the choroid plexus is rare. This report presents a 27-year-old woman who was admitted because of right temporal headache which had persisted for months. There was no neurological deficit. Computed tomography demonstrated a mass of calcium density measuring approximately 3 x 3 x 4 cm in the right temporal region, extending to the temporal skull base and to the rostral edge of the petrous bone. At surgery a very hard, poorly vascularised tumour originating from the choroid plexus of the temporal horn of the right lateral ventricle was completely removed. Histological workup yielded the diagnosis of a markedly calcified choroid plexus with no indication of neoplasia or inflammation. Physiological intracranial calcifications resulting from local tissue dystrophy are usually incidental. In the case presented here, a large intracerebral choroid plexus calcification was detected in a patient presenting with episodes of severe headache. The potential pathogenetic mechanism is discussed.

Arachnoid cyst of middle cranial fossa and ipsilateral subdural haematoma: Diagnostic and therapeutic implications in three cases

We describe three cases of arachnoid cyst of the middle cranial fossa with associated intracystic and subdural haematomas. In all of the patients the diagnosis was made before surgical treatment. No bleeding could be attributed to ruptured bridging veins. In two cases the source of bleeding was identified at the interface between the dura mater and the outer membrane at the temporal skull base. We suggest that, even if wide outer membrane membranectomy is probably not indicated, careful coagulation of the membrane at the skull base is necessary to avoid bleeding within the cyst.