Granulomatosis With Polyangiitis of Spinal Dura Presenting With "Bottle Brush Sign" on 18 F-FDG PET/CT

ABSTRACT

A 72-year-old man with fever and weakness in both lower limbs underwent thoracolumbar MRI and 18 F-FDG PET/CT. The PET/CT scan revealed diffused FDG uptake along the spinal dura mater from T7 to S2 level like a "bottle brush." Pathologic examination after biopsy of spinal canal lesions manifested granulomatous inflammation. The blood test showed cytoplasmic antineutrophil cytoplasmic antibody (ANCA) and myeloperoxidase-ANCAs were positive, whereas the perinuclear ANCA was negative. Eventually, he was diagnosed with granulomatosis with polyangiitis.

Duraplasty using a combination of a pedicled dural flap and collagen matrix in posterior fossa decompression for pediatric Chiari malformation type 1 with syrinx

PURPOSE

In posterior fossa decompression for pediatric Chiari malformation type 1 (CM-1), duraplasty methods using various dural substitutes have been reported to improve surgical outcomes and minimize postoperative complications. To obtain sufficient posterior fossa decompression without cerebrospinal fluid-related complications, we developed a novel duraplasty technique using a combination of a pedicled dural flap and collagen matrix. The objective of this study was to describe the operative nuances of duraplasty using a combination of a pedicled dural flap and collagen matrix in posterior fossa decompression for pediatric CM-1.

METHODS

We reviewed the clinical and radiographic records of 11 consecutive pediatric patients who underwent posterior fossa decompression with duraplasty using a combination of a pedicled dural flap and collagen matrix followed by expansile cranioplasty for CM-1. The largest area of the syrinx and the size of the posterior fossa were calculated.

RESULTS

The maximum syrinx area was reduced by a mean of 68.5% ± 27.3% from preoperatively to postoperatively. Four patients (36.4%) had near-complete syrinx resolution (> 90%, grade III reduction), five (45.5%) had 50% to 90% reduction (grade II), and two (18.2%) had < 50% reduction (grade I). The posterior fossa area in the midsagittal section increased by 8.9% from preoperatively to postoperatively. There were no postoperative complications, including cerebrospinal fluid leakage, pseudomeningocele formation, or infection.

CONCLUSION

Duraplasty using a combination of a pedicled dural flap and collagen matrix in posterior fossa decompression is a promising safe and effective surgical technique for pediatric CM-1 with syrinx.

An Intraosseous Pterygopalatine Fossa Dural Arteriovenous Fistula

Intraosseous dural arteriovenous fistulas (DAVFs) are distinct in that the fistula is located within the bone rather than the dura through which the dural vessels pass. It has been stated that only fistulas within marrow should be considered as intraosseous DAVFs rather than DAVFs with traditional angioarchitecture that erode into bone or are located within a bony foramen. The ambiguity in the definition may have contributed to the oversight and scarcity of relevant cases reported in the literature. Three- or four-dimensional digital subtraction angiography is useful for determining the location of the fistula and developing treatment plans. We present an intraosseous DAVF around the pterygopalatine fossa using a transvenous approach.

Immune-Mediated Hypertrophic Pachymeningitis and its Mimickers: Magnetic Resonance Imaging Findings

Hypertrophic pachymeningitis (HP) is a rare and chronic inflammatory disorder presenting as localized or diffuse thickening of the dura mater. It can be idiopathic or an unusual manifestation of immune-mediated, infectious, and neoplastic conditions. Although some cases may remain asymptomatic, HP can lead to progressive headaches, cranial nerve palsies, hydrocephalus, and other neurological complications, which makes its recognition a fundamental step for prompt treatment. Regarding the diagnosis workup, enhanced MRI is the most useful imaging method to evaluate dural thickening. This article addresses the MR imaging patterns of immune-mediated HP, including immunoglobulin G4-related disease, neurosarcoidosis, granulomatosis with polyangiitis, rheumatoid pachymeningitis, and idiopathic HP. The main infectious and neoplastic mimicking entities are also discussed with reference to conventional and advanced MR sequences.

A selected case series of idiopathic hypertrophic pachymeningitis in a single center: Pathological characteristics and case-oriented review

Hypertrophic pachymeningitis (HP) is a relatively rare disease of the central nervous system characterized by local or diffuse fibrous thickening of the dura mater. At present, there is still insufficient research on the pathogenesis and treatment strategies of this disease. We reported a continuous case series of seven patients with idiopathic HP (IHP), and also details one case of immunoglobulin G4-related HP requiring surgical intervention. Early diagnosis and appropriate surgical intervention for IHP could prevent the progression of permanent neurological damage and spinal cord paraplegia.

IgG4-related hypertrophic pachymeningitis with chronic subdural haematoma

Hypertrophic pachymeningitis is a rare disorder of the dura mater of the spine or brain. It can be caused by inflammatory, infective or neoplastic conditions or can be idiopathic. We report a man with hypertrophic pachymeningitis and bilateral chronic subdural haematoma caused by IgG4-related disease. We highlight the diagnostic challenges and discuss possible underlying mechanisms of subdural haematoma formation in inflammatory conditions. Isolated IgG4-related hypertrophic pachymeningitis with chronic subdural haematoma is very rare; previously reported cases have suggested a possible predilection for men in their sixth decade, presenting with headache as the dominant symptom. Given the rarity and complexity of the condition, it should be managed in a multidisciplinary team setting.

A Three-Dimensional Anterior and Middle Cranial Fossa Model for Skull Base Surgical Training with Two Layers of the Colored Dura Mater

BACKGROUND

Adequate epidural procedures and anatomical knowledge are essential for the technical success of skull base surgery. We evaluated the usefulness of our three-dimensional (3D) model of the anterior and middle cranial fossa as a learning tool in improving knowledge of anatomy and surgical approaches, including skull base drilling and dura matter peeling techniques.

METHODS

Using a 3D printer, a bone model of the anterior and middle cranial fossa was created based on multi-detector row computed tomography data, incorporating artificial cranial nerves, blood vessels, and dura mater. The artificial dura mater was painted using different colors, with 2 pieces glued together to allow for the simulation of peeling the temporal dura propria from the lateral wall of the cavernous sinus. Two experts in skull base surgery and 1 trainee surgeon operated on this model and 12 expert skull base surgeons watched the operation video to evaluate this model subtlety on a scale of 1 to 5.

RESULTS

A total of 15 neurosurgeons, 14 of whom were skull base surgery expert, evaluated, scoring 4 or higher on most of the items. The experience of dural dissection and 3D positioning of important structures, including cranial nerves and blood vessels, was similar to that in actual surgery.

CONCLUSIONS

This model was designed to facilitate teaching anatomical knowledge and essential epidural procedure-related skills. It was shown to be useful for teaching essential elements of skull-base surgery.

Assessment of Meningeal Lymphatics in the Parasagittal Dural Space: A Prospective Feasibility Study Using Dynamic Contrast-Enhanced Magnetic Resonance Imaging

OBJECTIVE

Meningeal lymphatic vessels are predominantly located in the parasagittal dural space (PSD); these vessels drain interstitial fluids out of the brain and contribute to the glymphatic system. We aimed to investigate the ability of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in assessing the dynamic changes in the meningeal lymphatic vessels in PSD.

MATERIALS AND METHODS

Eighteen participants (26-71 years; male:female, 10:8), without neurological or psychiatric diseases, were prospectively enrolled and underwent DCE-MRI. Three regions of interests (ROIs) were placed on the PSD, superior sagittal sinus (SSS), and cortical vein. Early and delayed enhancement patterns and six kinetic curve-derived parameters were obtained and compared between the three ROIs. Moreover, the participants were grouped into the young (< 65 years; n = 9) or older (≥ 65 years; n = 9) groups. Enhancement patterns and kinetic curve-derived parameters in the PSD were compared between the two groups.

RESULTS

The PSD showed different enhancement patterns than the SSS and cortical veins (P < 0.001 and P < 0.001, respectively) in the early and delayed phases. The PSD showed slow early enhancement and a delayed wash-out pattern. The six kinetic curve-derived parameters of PSD was significantly different than that of the SSS and cortical vein. The PSD wash-out rate of older participants was significantly lower (median, 0.09; interquartile range [IQR], 0.01-0.15) than that of younger participants (median, 0.32; IQR, 0.07-0.45) (P = 0.040).

CONCLUSION

This study shows that the dynamic changes of meningeal lymphatic vessels in PSD can be assessed with DCE-MRI, and the results are different from those of the venous structures. Our finding that delayed wash-out was more pronounced in the PSD of older participants suggests that aging may disturb the meningeal lymphatic drainage.

Spontaneous acute bleeding within subdural effusion from dural metastasis of gastric cancer: A case report

Dural metastases are uncommon findings and at diagnosis normally appear in disseminated stages of malignant tumors. Usually clinically silent, these could become symptomatic due to mass effect or after developing subdural collections. We present the case of a young woman recently operated from gastric cancer who presented consciousness deterioration and hemiparesis caused by subdural collection. During examination, the patient drastically worsens his neurological status due to an acute subdural bleeding within the subdural collection, which after pathological analysis was diagnosed of dural metastasis of gastric cancer. In malignancies associated with subdural collections it is important to suspect the coexistence of dural metastases and performing a contrast enhanced CT scan or Magnetic Resonance Imaging (MRI) may help in the diagnosis. If surgery is indicated, it is mandatory to evacuate the tumor and involved dura which causes the accumulation of fluid and to coagulate the external tumor membrane to avoid re-bleeding.

Low torcular Herophili position and large brainstem-tentorium angle in fetuses with open spinal dysraphism at 11-13 weeks' gestation

OBJECTIVE

To evaluate whether in fetuses with open spina bifida (OSB) the tentorium can be seen to be displaced downwards and vertically oriented by the time of the 11-13-week scan and whether this is reflected in an alteration of the brainstem-tentorium (BST) angle.

METHODS

The study population was recruited between 2015 and 2020 from three fetal medicine referral centers and comprised a control group and a study group of pregnancies with OSB. The control group was recruited prospectively and included singleton pregnancies with a normal sonographic examination after first-trimester combined screening for chromosomal abnormalities and normal outcome. The study group was selected retrospectively and included all cases with OSB between 2015 and 2020. All cases underwent detailed ultrasound assessment at 11 + 0 to 13 + 6 weeks' gestation. The position of the torcular Herophili (TH) was identified in the midsagittal view of the fetal brain with the use of color Doppler and was considered as a proxy for the insertion of the tentorium on the fetal skull. The BST angle was calculated in the same view and was compared between the two groups.

RESULTS

Sixty normal fetuses were included in the control group and 22 fetuses with OSB in the study group. In both groups, the BST angle was found to be independent of gestational age or crown-rump length (P = 0.8815, R²  = 0.0003861 in the controls, and P = 0.2665, R²  = 0.00978 in the OSB group). The mean BST angle was 48.7 ± 7.8° in controls and 88.1 ± 1.18°, i.e. close to 90°, in fetuses with OSB. Comparison of BST-angle measurements between the control group and cases with OSB showed a statistically significant difference (P = 0.0153). In all fetuses with OSB, the downward displacement of the TH and tentorium was clearly visible at the 11-13-week scan.

CONCLUSIONS

In fetuses with OSB, the BST angle is significantly larger than in normal controls, with the tentorium being almost perpendicular to the brainstem. This sign confirms the inferior displacement of the tentorium cerebelli with respect to its normal insertion on the occipital clivus as early as the first trimester of pregnancy and is useful in the diagnosis of Chiari-II malformation at this early stage. In fetuses with OSB, the low position of the tentorium and TH is clearly visible, even subjectively, at the 11-13-week scan. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Lymphoplasmacyte-rich meningioma in the central nervous system: An unusual case report

RATIONALE

Lymphoplasmacyte-rich meningioma (LPRM) is a rare meningioma characterized by significant infiltration of plasma cells and lymphocytes, and changes in the ratio of meningeal epithelial components. According to the World Health Organization, tumors of the central nervous system are classified as grade I tumors.

PATIENT CONCERNS

A 44-year-old man presented to our department with complaints of limb weakness accompanied by hand numbness. Half a month before admission, the patient's limb weakness worsened and he could not walk and raise his hands, with limb sensory disturbance and incontinence.

DIAGNOSIS

Magnetic resonance imaging of the head and cervical spinal cord showed a diffuse extramedullary mass creeping on the tentorium and skull base meninges along the clivus down to the sixth cervical spinal meninges. The cervical spinal cord was enveloped and pressed (Fig. 1A-C). Postoperative histopathological examination showed meningothelial areas admixed with lymphocytes and plasma cells (Fig. 2D-H), indicating that the mass was a LPRM.

INTERVENTION

Suboccipital craniotomy, C1 laminectomy, and C2-C6 laminoplasty were performed for this patient, and postsurgical pathology showed that the tumor was a LPRM with large amounts of lymphocytes and plasma cells.

OUTCOME

After 2 weeks of active treatment, the patient died of worsening pneumonia.

LESSONS

LPRM is a rare variant of meningioma, and it is more unusual that the lesions involve the intracranial dura mater and the entire cervical spinal meninges. So far, surgical resection has been the main treatment for LPRM, but according to its own characteristics of lymphoplasmacyte-rich, immunotherapy may become a new treatment option.

How I do it: paramedian supracerebellar transtentorial approach for a temporomesial glioma

BACKGROUND

Classical approaches to the temporomesial region (TMR) include transtemporal, transylvian, or subtemporal. The supracerebellar infratentorial, initially developed to access dorsolateral cavernomas, has of late shown its versatility to access areas around the central core. The TMR is one such area that can be accessed through this approach with the addition of a tentorial incision.

METHOD

The paramedian supracerebellar transtentorial approach (PSCTA) is described along with its advantages and limits compared to other approaches to treat TMR gliomas.

CONCLUSION

The PSCTA offers a basal panoramic view of the TMR without the need of retraction, cortical incision, and white matter transgression.

Intraspinal clear cell meningioma without dural attachment: A case report and literature review

RATIONALE

Clear cell meningioma (CCM) is one of the rarest but most aggressive forms of meningioma, with a tendency to occur at a high recurrence rate. Intraspinal CCM, especially the nondura-based type, is even rarer than the intracranial CCM.

PATIENT CONCERNS

We report a case of a 45-year-old woman who presented with a 1-month history of episodic pain in the lower back and in both thighs in the front side. Femoral nerve stretch tests were positive on both sides. Magnetic resonance imaging (MRI) demonstrated an intradural tumor at the L3 level, which was isointense on T1- and T2-weighted images (WI) and homogeneously enhanced on gadolinium-contrast T1 WI.

DIAGNOSES

The space-occupying lesion was pathologically confirmed as CCM.

INTERVENTIONS

During surgery, we found that the tumor adhered to a nerve root, without dural attachment. The nerve root was partially removed to achieve complete resection.

OUTCOMES

The pain disappeared after the operation. The 1 year follow-up MRI revealed no evidence of tumor recurrence or metastasis.

LESSONS

Nondura-based intraspinal CCM is easier to completely remove, and such complete removal should be achieved during the first operation. Although the recurrence rate of this particular type of meningioma appears to be lower than that of other types, close clinical and radiological follow-up is necessary.

Detection of Dural Metastases Before the Onset of Clinical Symptoms by 16α-[18F]Fluoro-17β-Estradiol PET in a Patient With Estrogen Receptor-Positive Breast Cancer

ABSTRACT

We offer an illustrative case about estrogen receptor (ER) imaging (also known as 16α-[18F]fluoro-17β-estradiol ([18F]-FES) PET) and the detection of metastatic lesions in the dural region. We present a case of a woman with ER-positive metastatic breast cancer and high [18F]-FES uptake in the dural region on PET imaging, without associated clinical symptoms. These lesions were missed on [18F]-FDG PET because of physiological [18F]-FDG uptake in the brain. This case highlighted some difficulties in the interpretation of imaging of brain metastases and demonstrated the added value of [18F]-FES PET imaging. [18F]-FES PET could be used to prove the presence of ER-positive metastases in the brain.

Limited Intradural Anterior Petrosectomy for Upper Basilar Aneurysms: A Technical Note

OBJECTIVE

The extradural anterior petrosectomy is a widely used skull base approach to the upper petroclival region, basilar trunk, and ventral pons. However, there is significant procedure-related morbidity and a complete petrosectomy is required, as the intradural structures are not in view at the time of drilling. We describe an intradural anterior petrosectomy for aneurysms of the basilar trunk and anterior inferior cerebellar artery with intraoperative photographs and artwork to illustrate the approach.

METHODS

A temporal craniotomy is made at the root of the zygoma and middle fossa floor. After opening dura, the trochlear nerve is identified at the tentorial edge. The tentorium is incised posterior to the trochlear nerve and the incision is carried forward across the cisternal segment of the trigeminal nerve toward V3 and the superior petrosal sinus. The petrous apex is identified and drilled lateral and posterior to V3 with a diamond bur. Intraoperative navigation is useful to confirm its location. Once posterior fossa dura is identified, the superior petrosal sinus may be safely cauterized and divided, connecting the tentorial incision with an incision in the posterior fossa dura, and exposing the upper basilar trunk and its branches. Additional bone is removed only as needed.

RESULTS

Two patients underwent successful treatment of a basilar trunk perforator and anterior inferior cerebellar artery aneurysm with a subtemporal approach and tailored intradural petrosectomy.

CONCLUSIONS

The intradural anterior petrosectomy allows limited drilling of the petrous apex and provides sufficient exposure of upper basilar artery aneurysms.

An immunohistochemical study of lymphatic elements in the human brain

Almost 150 papers about brain lymphatics have been published in the last 150 years. Recently, the information in these papers has been synthesized into a picture of central nervous system (CNS) "glymphatics," but the fine structure of lymphatic elements in the human brain based on imaging specific markers of lymphatic endothelium has not been described. We used LYVE1 and PDPN antibodies to visualize lymphatic marker-positive cells (LMPCs) in postmortem human brain samples, meninges, cavernous sinus (cavum trigeminale), and cranial nerves and bolstered our findings with a VEGFR3 antibody. LMPCs were present in the perivascular space, the walls of small and large arteries and veins, the media of large vessels along smooth muscle cell membranes, and the vascular adventitia. Lymphatic marker staining was detected in the pia mater, in the arachnoid, in venous sinuses, and among the layers of the dura mater. There were many LMPCs in the perineurium and endoneurium of cranial nerves. Soluble waste may move from the brain parenchyma via perivascular and paravascular routes to the closest subarachnoid space and then travel along the dura mater and/or cranial nerves. Particulate waste products travel along the laminae of the dura mater toward the jugular fossa, lamina cribrosa, and perineurium of the cranial nerves to enter the cervical lymphatics. CD3-positive T cells appear to be in close proximity to LMPCs in perivascular/perineural spaces throughout the brain. Both immunostaining and qPCR confirmed the presence of adhesion molecules in the CNS known to be involved in T cell migration.

Hypertrophic Pachymeningitis Related Brain Infarction in Synovitis-Acne-Pustulosis-Hyperostosis Osteomyelitis Syndrome

A 50-year-old woman with a history of synovitis-acne-pustulosis-hyperostosis osteomyelitis (SAPHO) syndrome was admitted for left unilateral neglect, dysarthria, and left hemiparesis. Brain MRI showed multiple infarctions in the territory of the right middle cerebral artery and gadolinium enhancement of the thickened frontotemporal dura mater on the right side. MR angiography showed significant narrowing of the cavernous segment of the right internal carotid artery. The right internal carotid artery stenosis was thought to originate from hypertrophic pachymeningitis associated with SAPHO syndrome. This is the first report of brain infarction due to internal carotid artery stenosis caused by hypertrophic pachymeningitis associated with SAPHO syndrome.

Thin Cervical Spinal Cord Between Ossifications of the Ligamentum Flavum and the Posterior Longitudinal Ligament: Case Report and Literature Review

BACKGROUND

Cervical ossification of the ligamentum flavum (OLF) is a rare condition; however, the coexistence of OLF and ossification of the posterior longitudinal ligament (OPLL) is extremely uncommon. These can exist simultaneously and cause thinning of the cervical spinal cord. Sufficient decompression, dural ossification, semispinalis dissection, and postoperative kyphosis were evaluated. We report the successful treatment of coexisting cervical OLF and OPLL.

CASE DESCRIPTION

A 70-year-old man had been experiencing weakness in the left knee and clumsiness in the left hand for 6 months. Hemiparesis was considered; however, magnetic resonance imaging revealed a cervical spinal lesion. Hence a spine surgeon diagnosed the patient with severe stenosis with OLF at the C2-C3 levels and OPLL at the C2-C4 levels. The patient presented with spastic gait and left-hand motor weakness. Computed tomography scan revealed the disappearance of the black line, indicating dural ossification surrounding the OLF. OPLL was observed in 61.5% of the C2 spinal canal. The K-line was (-); however, the alternative K-line between the C1 and C7 level was (+). Posterior laminectomy at the C2-C3 levels and laminoplasty at the C4-C7 levels with muscle preservation resulted in sufficient decompression. The patient's symptoms improved, and cervical alignment was maintained 2 years after surgery.

CONCLUSIONS

An alternative K-line comprised successful treatment for coexisting cervical OLF and OPLL. Surgeons must evaluate the severity of adhesion, damage of the paraspinal muscles, and necessity of posterior corrective surgery along with the patient's comorbidities and possible postoperative complications.

Parietal interhemispheric transfalcine transtentorial approach for posterior incisural space lesions: from the lab to the operative room

The operative approach to the posterior incisural space is challenging because of its deep location, the surrounding eloquent areas, and the intimate relationship with the deep veins. Several approaches have been proposed to manage the lesions in this region: supratentorial, infratentorial and a combination of them. Brain retraction, injury to the occipital lobe and corpus callosum, and venous bleeding are the principle drawbacks of these routes. We performed anatomical dissection study using 10 embalmed human cadaver specimens injected with colored latex exploring a different route, parietal interhemispheric transfalcine transtentorial (PITT). Then we used a PITT approach on two patients with posterior incisural space (PIS) lesions. The PITT approach led to successful and safe complete removal of PIS lesions in our cases. No complications were reported. The present approach could be a valuable option in case of PIS lesions, especially those associated with downward displacement of the deep venous complex; thanks to the gravity it reduce the complications related to the occipital lobe retraction and manipulation. Moreover, cutting the superior-anterior edge of the tentorium, the sub-tentorial space could be reached.

[Cerebellar haemorrhage after lumbar surgery with intraoperative dural tear]

In this case report, a 71-year-old female developed headache and nausea and signs of brain stem involvement following lumbar surgery with intraoperative dural tear. A CT scan showed cerebellar haemorrhage and hydrocephalus, and the patient was transferred to a neurosurgical department and treated with an external ventricular drainage, haematoma evacuation, and posterior fossa decompression. This case highlights the importance of swift diagnostics in patients developing neurological symptoms following lumbar surgery, as well as limiting any cerebrospinal fluid leakage following intraoperative dural tear.

Congenital interdural arachnoid cyst of the tentorium cerebelli

BACKGROUND

Intracranial interdural cyst is a rare lesion. The exact pathophysiology of these cysts remains unknown.

CLINICAL PRESENTATION

We report an infant with interdural cyst of the tentorium cerebelli. Although the cyst mimicked an arachnoid cyst on pre- and postnatal magnetic resonance images, lateral suboccipital craniotomy revealed the cyst within the tentorium. Fenestration on the infratentorial side was performed with successful results. Histologically, the inner surface of the cyst was lined with arachnoid cells.

CONCLUSION

We report detailed neuroradiological, intraoperative, and histological findings, and discuss the pathophysiology of the cyst in this case.

Superficial siderosis and intracranial hypotension syndrome following brachial plexus avulsion injury. A case of surgical treatment

Superficial siderosis (SS) is a slowly progressive neurodegenerative disorder caused by persistent or intermittent bleeding into the subarachnoid space. It leads to characteristic clinical and radiographic findings. Dural pathology is believed to be the most common identifiable etiology of SS. It has been suggested that dural tear may be the common pathology of both SS and intracranial hypotension syndrome. We present a patient with SS caused by posttraumatic duropathy that was associated with cerebrospinal fluid (CSF) hypotension headache. Patient was treated surgically with stabilization of neurological deficit and orthostatic headache improvement. It supports the speculated link between both entities and may confirm surgery being a reasonable approach in patients with SS.

Continuous dural suturing for closure of grade 3 leaks after tumor removal via an endoscopic endonasal approach

Cerebrospinal fluid (CSF) leakage is a major complication after extended endonasal transsphenoidal surgery (EETSS), which is commonly used in the treatment of anterior skull base tumors. Dural suturing and graded reconstruction are promising techniques to further decrease the incidence of postoperative CSF (poCSF) leakage. The effect of continuous dural suturing in endoscopic surgery was investigated in this retrospective study. A total of 79 EETSS patients were included; the procedures were performed for subdural tumor removal by a single endoscopic neurosurgical team. Comparisons were applied between patients who did and did not undergo endoscopic dural suturing after tumor removal. Multivariate logistic regression analysis was performed to identify variables that significantly influenced the incidence of poCSF leakage. In all, 79 adult patients developed Esposito's grade 3 intraoperative high-flow CSF leakage. Ten patients (12.7%) experienced poCSF leakage. One of the 36 patients who underwent intraoperative dural suturing developed poCSF leakage, compared with nine of 43 patients who did not undergo dural suturing (p = 0.016). Regression analysis showed that dural suturing could significantly decrease the incidence of poCSF leakage (p = 0.049, OR 0.108, 95% CI 0.013-0.899). Prophylactic lumbar drainage could also help decrease the CSF leakage rate. Dural suturing under endoscopy is a promising and effective method for application in skull base reconstruction after subdural skull base tumor removal. With future progress, lumbar drainage and even nasoseptal flap placement could be replaced in certain groups of patients undergoing EETSS.

A man in his fifties with variable weakness and difficulty in walking

BACKGROUND

An active man in his fifties was treated for atrial fibrillation with ablation. One week later he noticed variable weakness in his lower extremities. In the days that followed, his symptoms improved but could vary from day to day.

CASE PRESENTATION

On admission 3 months after the initial symptoms, he had spasticity and weakness in both lower extremities, with hyperreflexia and positive Babinski. Spinal fluid contained slightly elevated protein levels. Spinal MRI showed cord oedema and gadolinium enhancement over multiple spinal levels. Autoimmune myelitis was suspected, and he was treated with high dose steroids and rituximab. Due to lack of effect, repeated examinations were initiated. Information from his patient history regarding symptom exacerbation by walking or bending forward was emphasised. Repeated MRI showed unchanged spinal oedema and dilated peri- and intramedullary vessels. MRA and spinal digital DSA revealed a dural fistula at third lumbar level, with the left L3 radiculomedullary artery as the feed artery. The fistula was successfully ligated by the neurosurgeon.

INTERPRETATION

Spinal vascular lesions are rare and the diagnosis may be challenging due to atypical presentation. The case shows that detailed information from the patient history and thorough clinical investigation is of paramount importance to disclose this probably underreported condition.

Intracranial calcifications under vitamin K antagonists or direct oral anticoagulants: Results from the French VIKING study in older adults

OBJECTIVES

The use of vitamin K antagonists (VKA) is associated with the onset of vascular and soft-tissue calcifications. Whether there are more intracranial calcifications under VKA remains unclear. The objective of this study was to determine whether the regular use of VKA in older adults was associated with an increased burden of intracranial calcifications compared with the use of direct oral anticoagulant (DOA).

STUDY DESIGN

Nineteen patients aged 70 years or more using VKA for more than 3 months and 19 controls (matched for age, gender and indication for anticoagulation) using DOA for more than 3 months were consecutively included in this study.

MAIN OUTCOMES MEASURES

The burden of intracranial calcifications was graded by an experienced neuroradiologist from 0 (no burden) to 3 (high burden) according to the quantity, size, intensity and confluence of calcifications on computed tomography scan of the brain. Age, gender, frontal assessment battery (FAB) score, hypertension, dyslipidaemia, carotid artery stenosis, kidney failure and indication for anticoagulation were investigated as potential confounders.

RESULTS

The 19 patients using VKA (median[IQR], 84years[7]; 10females) exhibited a greater burden of falcian calcifications than the 19 controls using DOA (respectively, 2[1] versus 1[2], P = 0.025). Overall, we found that using VKA was directly associated with the global burden of intracranial calcifications (β = 1.54, P = 0.049). No correlation was found with calcifications in sites other than the falx cerebri.

CONCLUSIONS

The use of VKA was associated with a greater burden of intracranial calcifications compared with the use of DOA, specifically in the falx cerebri. This finding may explain part of the neurocognitive morbidity met with VKA.

Preoperative radiographic clues for transdural disc herniation: could it be predictable?

BACKGROUND

Transdural disc herniation (TDH) is a rare event accounting for 0.3-1.5% of all disc herniation cases. Considering the risk of leakage of the cerebrospinal fluid from the dural defect after removal of TDH or incomplete removal, it is very important to recognize TDH before surgery. This study is a retrospective case analysis to analyze the imaging findings of seven cases and to construct a preoperative prediction model for TDH.

METHODS

Retrospective radiographic examination was performed among patients operated for TDH in two institutions from 2008 to 2018. The radiographic images were analyzed according to the following eight signs: including absence of dural tent, complete block of spinal canal, hawk-beak sign, double-layered lesion, increased distance between the dura and cauda equina, rim enhancement, dural tent enhancement, and epidural gas. To clarify the predictive ability of these radiographic signs, consecutive 131 surgically confirmed epidural disc herniation (EDH) patients for the last 2 years were set as a control group for TDH. The sum of radiographic findings was compared between TDH and EDH patients to determine the cutoff value.

RESULTS

There were 1 thoracic and 6 lumbar TDHs among 75 thoracic and 6674 lumbar disc herniation cases with an incidence of 1.33% and 0.09%, respectively. Dural tent (p = 0.000, odds ratio = 106.67), double-layered lesion (p = 0.000, odds ratio = 22.69), and distance between the dura and cauda equina (p = 0.007, odds ratio = 52.00) were statistically significantly different between TDH and EDH. According to the receiver operating characteristic curve, the cutoff value of 1.5 had 85.7% sensitivity and 90.8% specificity.

CONCLUSION

Preoperative imaging can be useful for TDH diagnosis. It is safe to consider the possibility of TDH in patients with more than two findings in the preoperative images.

Recurrent activity-induced headache associated with posttraumatic dural adhesion of the middle meningeal artery: A case report

BACKGROUND

The middle meningeal artery is surrounded by a plexus of afferent fibers shown to be involved in the progression of some forms of headache, especially migraine. Posttraumatic headache disorders sharing characteristics with migraine and involving the middle meningeal artery are not readily available in the literature.

CASE DESCRIPTION

This report describes a posttraumatic headache disorder in a middle-aged woman in which the causative factor proved to be a pathology of the left middle meningeal artery that resulted from trauma. Her pain could be triggered by moderate accelerative changes, occurring in the left frontotemporal region, and shared characteristics with migraine. Resection of a portion of the left middle meningeal artery has completely eliminated her pain syndrome.

CONCLUSION

This case further elucidates associations between the middle meningeal artery and headache. The presentation of posttraumatic headache sharing characteristics with migraine should suggest the possibility of a middle meningeal artery abnormality.

The myodural bridge complex defined as a new functional structure

PURPOSE

The connective tissue between suboccipital muscles and the cervical spinal dura mater (SDM) is known as the myodural bridge (MDB). However, the adjacent relationship of the different connective tissue fibers that form the MDB remains unclear. This information will be highly useful in exploring the function of the MDB.

METHODS

The adjacent relationship of different connective tissue fibers of MDB was demonstrated based upon three-dimensional visualization model, P45 plastinated slices and histological sections of human MDB.

RESULTS

We found that the MDB originating from the rectus capitis posterior minor muscle (RCPmi), rectus capitis posterior major muscle (RCPma) and obliquus capitis inferior muscle (OCI) in the suboccipital region coexists. Part of the MDB fibers originate from the ventral aspect of the RCPmi and, together with that from the cranial segment of the RCPma, pass through the posterior atlanto-occipital interspace (PAOiS) and enter into the posterior aspect of the upper cervical SDM. Also, part of the MDB fibers originate from the dorsal aspect of the RCPmi, the ventral aspect of the caudal segment of the RCPma, and the ventral aspect of the medial segment of the OCI, enter the central part of the posterior atlanto-axial interspace (PAAiS) and fuse with the vertebral dura ligament (VDL), which connects with the cervical SDM.

CONCLUSIONS

Our findings prove that the MDB exists as a complex structure which we termed the 'myodural bridge complex' (MDBC). In the process of head movement, tensile forces could be transferred possibly and effectively by means of the MDBC. The concept of MDBC will be beneficial in the overall exploration of the function of the MDB.

One Case Report of Cavernous Angioma in Posterior Sagittal Sinus

BACKGROUND

The Cavernous Angioma in Posterior Sagittal Sinus is exceedingly rare.

METHODS

We report for the case of a 10-year-old male patient who was diagnosed with Cavernous Angioma in Posterior Sagittal Sinus.

RESULTS

Our case is the second reported case of Cavernous Angioma in Posterior Sagittal Sinus in the world.

CONCLUSIONS

It is very rare for the cavernous hemangioma to occur in the sinus, preoperative conventional MR scan lacks specificity and easily leads to misdiagnosis. Head MR enhancement, MRBTI, and SWI can provide more useful diagnostic information. The final diagnosis depends on the pathology examination.

Diagnostic Importance of Axial Loaded Magnetic Resonance Imaging in Patients with Suspected Lumbar Spinal Canal Stenosis

OBJECTIVE AND BACKGROUND

To study the efficacy of lumbar (AL) magnetic resonance imaging (MRI) in patients with suspected lumbar spinal stenosis (LSS), with and without AL compression. Supine MRI is used in the assessment of patients with LSS. However, MRI findings may poorly correlate with neurologic findings because of the morphologic changes of the lumbar spinal canal between upright standing and supine positions. In patients without significant stenosis in routine lumbar MRI, by applying AL, MRI can show significant LSS.

METHODS

This study included 103 consecutive patients (188 disc levels) who presented with neurogenic claudication with and without low back pain. AL was performed using a nonmagnetic compression device for 5 minutes. T1- and T2-weighted axial and sagittal sequences were obtained during AL applied to the spine. The dural sac cross-sectional area (DSCA) appeared to be narrow at each disc level of L4-5 to L5-S1 in all patients and was measured using T2-weighted images in routine supine and AL images.

RESULTS

The groups included patients with a reduction in the DSCA (>15 mm²) according to patient age and DSCA in routine spine MRI. The mean DSCA of the disc levels without and with AL were 138 mm² and 123 mm², with a mean difference of 15 mm² at L4-5, 134 mm² and 125 mm² and a mean difference of 9 mm² at L5-S1, respectively.

CONCLUSIONS

The use of AL MRI in patients with clinically suspected LSS could reduce the risk of misdiagnosis of stenosis, leading to inappropriate treatment.

C3 segmental vertebral artery diagnosed by computed tomography angiography

Extremely rarely, the vertebral artery (VA) enters the subarachnoid space via the intervertebral space of the C2-3 vertebrae. We have identified three cases with this anomalous VA in the literature. We report here another case involving aberrant VA penetration of the dura at the C2-3 vertebral level diagnosed by computed tomography (CT) angiography. A 71-year-old-woman with memory disturbance underwent brain CT and CT angiography. The right VA was aberrant and penetrated the dura at the C1-2 vertebral level. On the left side, the VA penetrated the dura at the C2-3 vertebral level. To our knowledge, this anomalous VA is the first case of C3 segmental VA diagnosed by CT angiography. To prevent VA injury, it is important to identify this variation before performing a posterior fusion of the cervical vertebrae.

Cerebrospinal fluid rhinorrhea in a bilateral frontal decompressive craniectomy patient caused by strenuous activity: A case report

RATIONALE

Iatrogenic cerebrospinal fluid (CSF) rhinorrhea in a bilateral frontal decompressive craniectomy patient triggered by strenuous sport is rare. To the best of our knowledge, no similar case has yet been reported.

PATIENT CONCERNS

Herein, we report a case of CSF rhinorrhea in a 37-year-old man. He had previously suffered a traumatic brain injury in a traffic accident, and a subsequent bilateral frontal decompressive craniectomy operation was performed. Based on the frontal skull defect peculiarity, strenuous exercise may have caused drastic CSF pressure waves to tear the dura mater of the anterior skull base, resulting in CSF rhinorrhea.

DIAGNOSES

The thin-slice computerized tomography (CT) images revealed a frontal skull defect and the open frontal sinus. In addition, in the opened frontal sinus, low-density liquid-filled areas were visible.

INTERVENTIONS

During surgery, the torn dura was carefully repaired, and the frontal sinus was filled with temporal muscle, fascia, and fibrin glue. A simultaneous cranioplasty was performed.

OUTCOMES

The patient was followed-up postoperatively for 12 months to date without rhinorrhea recurrence. Recovery was uneventful.

LESSONS

Patients with skull defects should avoid strenuous sports, and cranioplasty should be performed as early as possible in order to decrease the likelihood of a dural tear and prevent the occurrence of CSF leakage. After cranioplasty, the skull should be restored to a closed state to reduce the damaging effects of CSF waves during movement. It is important to maintain normal intracranial pressure to reduce the recurrence rate of CSF rhinorrhea.

Degrees of Diaphragma Sellae Descent during Transsphenoidal Pituitary Adenoma Resection: Predictive Factors and Effect on Outcome

This study is aimed to classify degrees of diaphragma sellae (DS) descent into sella turcica according to the surgical field block caused by the descent and to construct predictive imaging criteria for the degree of descent, and in addition, to determine whether there is any correlation between the degree of DS descent and the operative outcome (in the form of cerebrospinal fluid leak and/or presence of residual tumor). Totally, 72 patients were enrolled in our study. Their clinical and radiological data as well as the high definition videos of operations were retrospectively reviewed. The degree of DS descent during the operation was classified into five degrees according to surgical field block caused by the descent. We investigated the correlation between these five degrees and the clinical findings, radiological findings as well as the surgical outcomes. We found that the most important determining factors of DS descent degree were the volume and the height of the tumor portion above diaphragma opening. On the other hand, the total tumor volume, the maximum tumor height and the morphological pattern according to Wilson's system (modified from Hardy) had no statistically significant correlation with DS degree of descent. Presence of residual tumor on postoperative magnetic resonance images was significantly correlated with Wilson's classification and with supradiaphragmatic tumor height. On the other hand, cerebrospinal fluid leak showed no statistically significant difference between variable degrees of DS descent. Volumetric data of the tumor portion above the diaphragma opening are more important than morphological data for prediction of surgical field block caused by descended DS. While DS prolapse significantly increases the difficulty of the operative procedure, residual tumor presence is mainly dependent on morphological classification, especially cavernous sinus invasion.

Transforaminal Endoscopic Excision of Intradural Lumbar Disk Herniation and Dural Repair

BACKGROUND

Intradural disk herniation is a rare entity with <0.3%-1% of all disk herniations and at an L2-L3 level even rarer. The dural defects repairs on ventral aspect are technically challenging and may not be possible after durotomy, so many authors have placed fascia, muscle, or plugging by the hemostatic material. The surgical treatment of intradural disk herniation is usually posterior open surgery with formal durotomy to remove the disk fragments with good to fair results. Poorer outcome occurs in late-presenting cases.

CASE REPORT

We report on a 78-year-old man who presented with spontaneous low back pain and bilateral buttock pain aggravated for 1 month with severe walking difficulty without bowel and bladder symptoms. Magnetic resonance imaging revealed disk herniation at the L2-L3 level. He underwent a transforaminal endoscopic removal of intradural disk fragments via the original rent in the anterolateral aspect of the dura, and sealing was performed with dural patch and Gelfoam without any lumbar drain. The patient's symptom significantly improved postoperatively with muscle power improved to grade 5 on day 1 with no cerebrospinal fluid leakage, and he was mobilized with a lumbar orthosis on the first postoperative day. Postoperative and at 6-month follow-up, magnetic resonance imaging revealed adequate decompression and successful sealing of the ventral dural defect.

CONCLUSIONS

To our knowledge, this is the first case of transforaminal endoscopic treatment of intradural disk herniation at an L2-L3 level in which good clinical outcomes were obtained and maintained until recent follow-up of 8 months.

Visualizing protoporphyrin IX formation in the dura tail of meningiomas by mass spectrometry imaging

BACKGROUND

The advantages of 5-aminolevulinacid (5-ALA)-induced fluorescence-guided surgery in meningiomas are increasingly discussed. In this context, despite detectable tumor tissue in histopathologial analyses, no fluorescence was shown at the dura tail using the standard operating microscope. Thus, 5-ALA metabolism in this surgically important site remains unknown but needs to be elucidated when further evaluating indications of fluorescence-guided surgery in meningiomas.

METHOD

We here present the spatially resolved identification of protoporphyrin IX (PpIX) in sphenoid ridge meningioma cryosections from a patient who underwent fluorescence-guided microsurgery using molecular imaging analysis by matrix-assisted laser desorption/ionization tandem mass spectrometry (MALDI-MS/MS).

RESULTS

Despite a strong fluorescence of the main tumor, no fluorescence could be detected at the dura tail using the standard operating microscope (blue-light, 405 nm). However, histopathological analyses clearly showed meningioma tissue. Remarkably, MALDI-MS/MS analysis revealed PpIX formation also at the non-fluorescing dura tail. However, no PpIX was detected in the tumor free dura mater.

CONCLUSION

MALDI-MS/MS visualized a selective accumulation of PpIX within the tumor tissue including the dura tail. Thus, absence of fluorescence in the dura tail as visualized by the operating microscope is not caused by the lack of PpIX formation.

Clinical relation among dural adhesion, dural ossification, and dural laceration in the removal of ossification of the ligamentum flavum

BACKGROUND CONTEXT

Dural laceration frequently occurs during surgery in patients with ossification of the ligamentum flavum (OLF), mainly because of dural adhesion (DA) and dural ossification (DO) between the ligamentum flavum and the dura mater. However, the radiological predictive factors of DA in OLF have rarely been reported.

PURPOSE

The objective of this study was to determine the preoperative radiological signs for predicting intraoperative DA in OLF by using preoperative magnetic resonance imaging (MRI) and computed tomography (CT).

STUDY DESIGN

This is a retrospective study.

PATIENT SAMPLE

This study included 182 patients who underwent decompressive laminectomy and OLF removal from 2005 to 2014.

OUTCOME MEASURE

Demographic data, preoperative neurologic status, surgical procedure and results, and intraoperative and postoperative complications were analyzed. Clinical outcome was assessed with the Japanese Orthopaedic Association score.

MATERIALS AND METHODS

Depending on the morphologic appearance of OLF in preoperative radiographs, we aimed to investigate the prevalence of intraoperative DA and DO. We used the following factors of representative classifications: (1) surface appearance, (2) "double-layer" or "tram-track" sign, (3) cross-sectional area of the stenosed level, (4) Sato classification as axial classification, (5) Kuh classification as sagittal classification, and (6) high-signal-intensity change on T₂-weighted MRI.

RESULTS

Intraoperative evidence of DA was observed in 52 patients (29%), and DO was observed in 23 patients (13%). Twenty-seven patients (15%) had dural laceration during surgery. Statistically, DA was closely associated with the non-uniform type of surface appearance (odds ratio 5.396, p=.001) and with the presence of either a double-layer sign or a tram-track sign (odds ratio 11.525, p<.001). In the preoperative CT and MRI, 21 out of 23 patients with DO showed a "double-layer sign" or a "tram-track sign."

CONCLUSIONS

This study identified two predictive factors of DA in OLF, which were the non-uniform surface appearance and the presence of a double-layer sign or a tram-track sign. The presence of DO in OLF was closely associated with a double-layer sign or a tram-track sign in the preoperative radiological images.

Lumbosacral osteosarcoma with dural spread, skip lesions and intravascular extension: A case report

Primary osteosarcoma of the spine is indeed rare and only several sporadic cases have been reported. It tends to occur in a slightly older age group than those with appendicular skeleton tumours. We present here an unusual case of aggressive lumbosacral osteosarcoma in a young teenager complicated by extensive dural spread, skip lesions and intravascular extension. Although a histopathological examination is mandatory to establish the diagnosis, this case emphasises the need of imaging to ascertain the full extent of disease spread especially in deciding the type of treatment to be instituted and to evaluate the response to the treatment.

Sequential spinal and intracranial dural metastases in gastric adenocarcinoma: A case report

Dural metastasis from primary gastric adenocarcinoma has been rarely reported, and its prognosis is very poor because it frequently leads to acute subdural hematoma. Here, we describe a case with sequential spinal and cranial dural metastases from gastric adenocarcinoma without subdural hematoma. A 43-year-old woman with gastric adenocarcinoma and well-controlled peritoneal carcinomatosis presented with back pain, right radiating leg pain, left facial palsy, and hearing loss. Magnetic resonance imaging of the spine and brain revealed dural masses at the lumbosacral junction with invasion to the L5 and S1 nerve roots and at the skull base with invasion to the internal auditory canal. She was treated with local radiotherapy, and her pain and neurologic symptoms improved after palliative radiotherapy. This is the first reported case of dural metastases of gastric adenocarcinoma of the spine and skull base but with a relatively indolent course and without subdural hematoma.

Dural sac area is a more sensitive parameter for evaluating lumbar spinal stenosis than spinal canal area: A retrospective study

Narrowing of the dural sac cross-sectional area (DSCSA) and spinal canal cross-sectional area (SCCSA) have been considered major causes of lumbar central canal spinal stenosis (LCCSS). DSCSA and SCCSA were previously correlated with subjective walking distance before claudication occurs, aging, and disc degeneration. DSCSA and SCCSA have been ideal morphological parameters for evaluating LCCSS. However, the comparative value of these parameters is unknown and no studies have evaluated the clinical optimal cut-off values of DSCSA and SCCSA. This study assessed which parameter is more sensitive.Both DSCSA and SCCSA samples were collected from 135 patients with LCCSS, and from 130 control subjects who underwent lumbar magnetic resonance imaging (MRI) as part of a medical examination. Axial T2-weighted MRI scans were acquired at the level of facet joint from each subject. DSCSA and SCCSA were measured at the L4-L5 intervertebral level on MRI using a picture archiving and communications system.The average DSCSA value was 151.67 ± 53.59 mm in the control group and 80.04 ± 35.36 mm in the LCCSS group. The corresponding average SCCSA values were 199.95 ± 60.96 and 119.17 ± 49.41 mm. LCCSS patients had significantly lower DSCSA and SCCSA (both P < .001). Regarding the validity of both DSCSA and SCCSA as predictors of LCCSS, Receiver operating characteristic curve analysis revealed an optimal cut-off value for DSCSA of 111.09 mm, with 80.0% sensitivity, 80.8% specificity, and an area under the curve (AUC) of 0.87 (95% confidence interval, 0.83-0.92). The best cut off-point of SCCSA was 147.12 mm, with 74.8% sensitivity, 78.5% specificity, and AUC of 0.85 (95% confidence interval, 0.81-0.89).DSCSA and SCCSA were both significantly associated with LCCSS, with DSCSA being a more sensitive measurement parameter. Thus, to evaluate LCCSS patients, pain specialists should more carefully investigate the DSCSA than SCCSA.

A case of idiopathic hypertrophic pachymeningitis presenting with chronic headache and multiple cranial nerve palsies: A case report

RATIONALE

Idiopathic hypertrophic pachymeningitis (IHP) is a rare condition, characterized by a chronic fibrosing inflammatory process usually involving either the intracranial or spinal dura mater, but rarely both. Here, we report a rare case of IHP affecting both the intracranial and spinal dura mater. We also discussed the diagnosis, management, and outcome of IHP.

PATIENT CONCERNS

We reviewed the case of a 60-year-old woman presenting with chronic headache, multiple cranial nerve palsies and gait disturbance. Magnetic resonance imaging (MRI) of her head revealed thickened and contrast-enhanced dura in the craniocervical region as well as obstructive hydrocephalus and cerebellar tonsillar herniation. The patient had a suboccipital craniectomy and posterior decompression through C1 plus a total laminectomy. The dura was partially resected to the extent of the bony decompression, and a duroplasty was performed.

DIAGNOSES

Microscopic examination of the surgically resected sample showed chronic inflammatory changes, lymphoplasmacytic cell infiltration, fibrous tissue hyperplasia, and hyaline degeneration. Blood tests to evaluate the secondary causes of hypertrophic pachymeningitis (HP) were unremarkable.

INTERVENTIONS

Steroid was used to treat suspected IHP.

OUTCOMES

Postoperatively, the patient showed gradual improvement in her headache, glossolalia, and bucking. Prior to discharge, a follow-up MRI showed improvement of the dura mater thickening.

LESSONS

IHP is a chronic inflammatory disorder of the dura mater that usually causes neurological deficits. Clinical manifestations of IHP, MRI findings, and laboratory abnormalities are the essential components for making an accurate diagnosis. When the radiological or laboratory evaluation is uncertain, but neurological deficits are present, a prompt surgical approach should be considered. Postoperative steroid therapy and close observation for recurrence are necessary to ensure a good long-term outcome.

Anatomical localization of the cavernous sinus dural fistula by 3D rotational angiography with emphasis on clinical and therapeutic implications

BACKGROUND AND PURPOSE

Carotid cavernous sinus dural arteriovenous fistulas (CSDAVFs) are presumed to be located within the walls of the cavernous sinus, however the exact fistulous site has not yet been studied by angiographic or anatomical methods. The present study aimed to localize CSDAVFs with the help of 3D rotational angiography (RA) and correlated the observations with clinical and angiographic findings.

MATERIALS AND METHODS

The CSDAVFs were categorized as dural, extradural or osseous based on the site of convergence of feeders into the venous sac. Extradural CSDAVFs were further subcategorized into posteromedial, posterolateral and anterior subtypes, depending on proximity to a possible venous plexus. This classification was correlated with various clinical presentations and angiographic subtypes.

RESULTS

Thirty-seven patients were included in the final analysis. The sac was identified in all the patients and the mean sac size of the fistula was small (<4mm). Dural type was associated with exclusive cortical venous drainage. Extradural anterior CSDAVF showed tendency towards younger age predilection. Extradural posterolateral CSDAVF was more often associated with initial oculomotor nerve palsy and this observation was statistically significant. Discordancy between the location of the fistula and the side of clinical affection was observed in midline fistulas such as osseous CSDAVF and posteromedial type of extradural CSDAVF.

CONCLUSIONS

CSDAVF is a heterogeneous vascular disorder involving the sphenoclival bone, extradural space and dura, homologous to the epidural-dural shunts of vertebra with a common clinical presentation of orbital manifestations. Preoperative localization of the fistula could explain enigmatic observations and potentially simplify its interventional management.

Reuse of a Reversed "Bone Pad" to Perforate Incompletely Penetrated Burr Holes Created by Automatic-Releasing Cranial Perforators

BACKGROUND

It can be difficult to make complete burr holes using a perforator with automatic releasing systems in cases of a soft diploe or thick calvarial bone.

OBJECTIVE

To demonstrate the utility of a flipped "bone pad" (BP) in recovery of penetration failure when using an automatic releasing perforator.

METHODS

For craniotomy or ventricular drainage, the first step is to make 1 or more burr holes using a craniotome. Neurosurgeons sometimes incompletely penetrate the skull using the latest tools. As a countermeasure for such cases, we have developed a simple and practical method. When making a perforation using a high-speed perforator, a round bone piece we call the BP is formed just above the dura. We pulled the BP from a completed burr hole, and placed the reversed BP in position at the bottom of the incompletely perforated burr hole. The BP acted as a new hard surface, preventing the automatic releasing system from activating, and allowed the burr hole to be completed by the craniotome without the need for additional tools.

RESULTS

With this technique, we have successfully completed 6 out of 7 imperfectly perforated burr holes using a perforator with an automatic releasing system. There were no technique-related complications, such as plunging or dural laceration.

CONCLUSIONS

The method has the advantage that the BP can be obtained without drilling an additional burr hole, and can be completed without the need for increasing cost, time, or instrument usage.

[A case of superficial siderosis ameliorated after closure of dural deficit detected by MRI-CISS (constructive interference in steady state) imaging]

A 64-year-old male developed headache, dizziness, and difficulty hearing, two years after an operation for chronic subdural hematoma due to head injury. These symptoms gradually worsened over the following 15 years. As he showed bloody cerebrospinal fluid (CSF) and marginal hypointensity on the surface of the brain and spinal cord on T₂/T₂*-weighted MRI, he was diagnosed with superficial siderosis (SS), although the source of the bleeding was unclear and anti-hemorrhagic drugs were ineffective. When he was admitted to our hospital, neurological examination disclosed horizontal gaze-evoked nystagmus, severe bilateral hearing loss, scanning speech, and limb and truncal ataxia. CISS (constructive interference in steady state) MRI detected a dural defect at the Th2-3 level on the anterior side of the spinal canal. On operation, a 2 mm × 6 mm size dural defect with blood clots was found at the Th2-3 level. After closure of the dural defect, bloody CSF became transparent, and his persistent headache, dizziness, and hearing impairment improved. Brain and whole spine MRI, especially CISS imaging, should be considered for detecting the source of bleeding in intractable cases of SS.

Diagnostic Clue of Meningeal Melanocytoma: Case Report and Review of Literature

In this report, the patient was pre-diagnosed as meningioma before surgery, which turned out to be meningeal melanocytoma. Hence, we will discuss the interpretation of imaging and neurological statuses that may help avoid this problem. A 45-year-old man had increasing pain around the neck 14 months prior to admission. His cervical spine MR imaging revealed a space-occupying, contrast-enhancing mass within the dura at the level of C1. The neurologic examination revealed that the patient had left-sided lower extremity weakness of 4+, decreased sensation on the right side, and hyperreflexia in both legs. Department of Neuroradiology interpreted CT and MR imaging as meningiom. The patient underwent decompression and removal of the mass. We confirmed diagnosis as meningeal melanocytoma through pathologic findings. Afterwards, we reviewed the patient's imaging work-up, which showed typical findings of meningeal melanocytoma. However, it was mistaken as meningioma, since the disease is rare.