Search

We report magnetic resonance (MR), computed tomography (CT) and angiographic imaging of an unusual giant arachnoid granulation in the superior sagittal sinus in a man with headache and vertigo. Intrasinus pressure measurements revealed a significant pressure gradient across the lesion. MR imaging is useful to identify giant arachnoid granulation and dural sinus thrombosis, whereas dural sinus pressure measurement in certain cases of giant arachnoid granulations can be used to evaluate the lesion as the cause of the patient's symptoms.

Background: Oculomotor palsy is well known to be due to diabetes mellitus, or aneurysmal compression, or cavernous sinus lesion. Only few reports presented that arterial compression was the reason for oculomotor palsy., Case Description: We performed a surgical treatment for a 76-year-old man with left oculomotor palsy. During surgical clipping of the left IC-PC aneurysm, it became clear that the left IC-PC aneurysm had not been compressing the third cranial nerve. The left oculomotor nerve was being pinched between the arteriosclerotic PCA and the SCA. Microvascular decompression was carried out, and the oculomotor nerve palsy improved., Conclusion: Arteriosclerotic PCA and SCA may compress the oculomotor nerve. Microvascular decompression is effective in this type of oculomotor palsy.

Background and Purpose: The oculomotor cistern (OMC) is a small CSF-filled dural cuff that invaginates into the cavernous sinus, surrounding the third cranial nerve (CNIII). It is used by neurosurgeons to mobilize CNIII during cavernous sinus surgery. In this article, we present the OMC imaging spectrum as delineated on 1.5T and 3T MR images and demonstrate its involvement in cavernous sinus pathology., Materials and Methods: We examined 78 high-resolution screening MR images of the internal auditory canals (IAC) obtained for sensorineural hearing loss. Cistern length and diameter were measured. Fifty randomly selected whole-brain MR images were evaluated to determine how often the OMC can be visualized on routine scans. Three volunteers underwent dedicated noncontrast high-resolution MR imaging for optimal OMC visualization., Results: One or both OMCs were visualized on 75% of IAC screening studies. The right cistern length averaged 4.2 +/- 3.2 mm; the opening diameter (the porus) averaged 2.2 +/- 0.8 mm. The maximal length observed was 13.1 mm. The left cistern length averaged 3.0 +/- 1.7 mm; the porus diameter averaged 2.1 +/-1.0 mm, with a maximal length of 5.9 mm. The OMC was visualized on 64% of routine axial T2-weighted brain scans., Conclusion: The OMC is an important neuroradiologic and surgical landmark, which can be routinely identified on dedicated thin-section high-resolution MR images. It can also be identified on nearly two thirds of standard whole-brain MR images.

Background and Purpose: Large arachnoid granulations (AG) within the dorsal superior sagittal sinus (SSS) have been incompletely characterized and can be confused with pathology. This report reviews the characteristics of these anatomic structures to establish common imaging features that allow differentiation from pathology., Materials and Methods: Twelve cases of large AG in the dorsal SSS are presented, identified by MR imaging. Signal intensity characteristics, size, location, venographic appearance, and association with adjacent venous and osseous structures were documented., Results: A defect in the dura of the SSS was seen in all of the cases communicating with the subjacent subarachnoid space. The average size of the AG was 8.1 x 9.4 x 10.0 mm (range, 4-19 mm). Ten produced calvarial remodeling, and 11 were in the direct vicinity of the lambda. On T2-weighted images, all were hyperintense to the brain. On T1-weighted images, 8 were hypointense and 4 were hypointense with mixed areas of isointense signal intensity. All of the AGs were associated with cortical venous structures entering the sinus. On MR venography, AGs appeared as focal protrusions into the sinus, displacing, distorting, and narrowing the sinus lumen. Seven patients had headache without other visible cause on MR imaging, and 4 were initially interpreted as thrombosis or tumor., Conclusion: Large AGs can occur in the dorsal SSS. They are well-defined projections of the subarachnoid space into the sinus, can cause luminal narrowing and calvarial remodeling, and have typical signal intensity characteristics, position, and morphology differentiating them from other pathology. Association with patient symptoms is uncertain.

Gliomas are the most common infiltrative neoplasms of the optic nerve and can present as two distinct growth patterns: intraneural glial proliferation and perineural arachnoidal gliomatosis (PAG). It has been suggested that perineural arachnoidal gliomatosis is seen almost exclusively in the setting of neurofibromatosis type 1 (NF1). We describe a child with perineural arachnoidal gliomatosis occurring without neurofibromatosis type 1, supported by both radiographic and histological findings. A 4-year-old female without neurofibromatosis type 1 presented with rapidly progressive right-sided proptosis. Magnetic resonance imaging (MRI) revealed an enhancing fusiform intraconal lesion, which was hypointense on T1 and hyperintense on T2-weighted images: characteristic of perineural arachnoidal gliomatosis, the optic nerve was visualized coursing the tumor. Histopathologic study was consistent with perineural arachnoidal gliomatosis. Perineural arachnoidal gliomatosis can develop independent of neurofibromatosis type 1, as demonstrated by this case.

Background: Medulloblastoma is the most common malignant brain tumour in children. Despite recent advances, the prognosis in high risk patients remains poor. Further improvement in survival is dependent upon the development of strategies to attack the tumour more effectively, but with less toxicity. Intrathecal chemotherapy, is an ideal but currently underused method of directly targeting residual tumour within the area of resection and the leptomeningeal disease commonly associated with this tumour., Method: We describe the case of a 12 yr old child with metastatic medulloblastoma, who received intrathecal topotecan via a spinal catheter., Conclusion: This method represents a simple, safe and effective method of delivering an even and widespread distribution of drug within the cerebrospinal fluid (CSF) of the neuroaxis. With new agents being identified and others in the early stages of development, intrathecal chemotherapy may emerge as an important therapeutic option to consider when faced with such challenging cases.

Although arachnoid granulations (AGs) were already described by Antonio Pacchioni more than 300 years ago, two issues draw particular attention: first, the radiological features and differential diagnosis of the so-called giant AGs (GAGs) and second, their possible association with various disease processes. In order to evaluate the frequency, size and normal distribution of GAGs, an anatomical study of the dural sinuses was carried out. It involved all the autopsies performed during the period August 2002-February 2005 and included 651 cases: 306 females and 345 males, aged 13-99 years (mean 69 years). Grossly visible GAGs were identified in 24 cases: 7 females and 17 males, aged 45-92 years (mean 69 years). This is the largest population-based anatomical study on GAGs. It shows that GAGs, in general a rare finding (3.68%), are rather common in the adult population, especially in the elderly (aged >65 years) and that they can reach remarkable size (up to 2.5 cm and more in diameter). Giant AGs should be considered in the radiological differential diagnosis of intradural lesions, particularly those occurring in the transverse sinus of the elderly.

Leptomeningeal involvement in patients with CLL is relatively rare and the prognosis is usually considered to be poor. The authors reviewed all CLL patients treated in a tertiary referral center to assess the incidence and outcome of leptomeningeal involvement (LI) in CLL. They found an incidence of 1-2% of LI. Most of the patients with LI had a longterm survival, despite failure to clear the cerebrospinal fluid from tumor cells.

Object: Neuroradiology has become indispensable in detecting the pathophysiology in syringomyelia. Constructive interference in steady-state (CISS) magnetic resonance (MR) imaging can provide superior contrast at the sub-arachnoid tissue borders. As this region is critical in preoperative evaluation, the authors hypothesized that CISS imaging would provide superior assessment of syrinx pathology and surgical planning., Methods: Based on records collected from a database of 130 patients with syringomyelia treated at the authors' institution, 59 patients were prospectively evaluated with complete neuroradiological examinations. In addition to routine acquisitions with FLAIR, T1- and T2-weighted, and contrast-enhanced MR imaging series, the authors obtained sagittal cardiac-gated sequences to visualize cerebrospinal fluid (CSF) pulsations and axial 3D CISS MR sequences to detect focal arachnoid webs. Statistical qualitative and quantitative evaluations of spinal cord/CSF contrast, spinal cord/CSF delineation, motion artifacts, and artifacts induced by pulsatile CSF flow were performed., Results: The 3D CISS MR sequences demonstrated a contrast-to-noise ratio significantly better than any other routine imaging sequence (p < 0.001). Moreover, 3D CISS imaging can detect more subarachnoid webs and cavitations in the syrinx than T2-weighted MR imaging with less flow-void artifact. The limitation of 3D CISS imaging is a susceptibility to motion artifacts that can cause reduced spatial resolution. Lengthy acquisition times for axial segments can be reduced with multiplanar reconstruction of 3D CISS-generated sagittal images., Conclusions: Constructive interference in steady-state imaging is the MR sequence of choice in the preoperative evaluation of syringomyelia, allowing significantly higher detection rates of focal subarachnoid webs, whereas standard T2-weighted MR imaging shows turbulent CSF flow voids. Constructive interference in steady-state MR imaging enables the neurosurgeon to accurately identify cases requiring decompression for obstructed CSF. Motion artifacts can be eliminated with technical variations.

Wegener granulomatosis is an immune-mediated, systemic vasculitis with unknown etiology that can be seen in almost any anatomical site. Positivity for antineutrophil cytoplasmic antigene, which is a serological marker, and presence of granulomatous vasculitis in histopathologic specimens from the lesions are accepted as diagnostic. A case of Wegener granulomatosis whose presenting symptoms and signs are related to otologic and meningeal involvement of the disease is reported. Apart from atypical presentation, histopathological and serological findings from this patient remained negative throughout the course of the disease, and the diagnosis was made on the basis of clinical and secondary laboratory findings. We herewith discuss this unusual case in the light of relevant literature.

Background and Purpose: Defects at the skull base leading to spontaneous CSF rhinorrhea are rare lesions. The purpose of our study was to correlate CT and MR findings regarding the location and content of CSF leaks in 27 patients with endoscopic sinus surgery observations., Materials and Methods: Imaging studies in 27 patients with intermittent CSF rhinorrhea (CT in every patient including 10 examinations with intrathecal contrast, plain CT in 2 patients, and MR in 15 patients) were analyzed and were retrospectively blinded to intraoperative findings., Results: CT depicted a small endoscopy-confirmed osseous defect in 3 different locations: 1) within the ethmoid in 15 instances (53.6% of defects) most commonly at the level of the anterior ethmoid artery (8/15); 2) adjacent to the inferolateral recess of the sphenoid sinus in 7 patients including one patient with bilateral lesions (8/28 defects, 28.6%); 3) within the midline sphenoid sinus in 5 of 28 instances (17.9%). Lateral sphenoid defects (3.5 +/- 0.80 mm) were larger than those in ethmoid (2.7 +/- 0.77 mm, P < or = 0.029) or midsphenoid location (2.4 +/- 0.65 mm, P < or = 0.026). With endoscopy proven arachnoid herniation in 24 instances as reference, MR was correct in 14 of 15 instances (93.3%), CT cisternography in 5 of 8 instances (62.5%). Plain CT in 1 patient was negative., Conclusion: In patients with a history of spontaneous CSF rhinorrhea, CT was required to detect osseous defects at specific sites of predilection. MR enabled differentiating the contents of herniated tissue and allowed identification of arachnoid tissue as a previously hardly recognized imaging finding.

A desmoplastic infantile astrocytoma (DIA) is an extremely rare tumor that comprises a solid astrocytic tumor accompanied by a large cyst and involves the superficial cerebral cortex and leptomeninges in infants. The solid part of this type of tumor has been well described in various reports and books, but characteristics of the cystic portion have remained unclear. Because adequate resection is required to ensure a favorable prognosis, information about the cyst is very important for diagnostic purposes and surgical planning. The authors report on the clinical and histological features of the cyst in a case of a DIA. A 12-month-old boy presented with vomiting. Contrast-enhanced magnetic resonance imaging revealed a strongly enhancing single-lobed large cyst located in the deep white matter, under the solid part of the tumor attached to the dura mater of the left frontal lobe. Both the solid and cystic portions of the tumor were surgically removed. The border between the cyst wall and surrounding white matter was unclear. Histologically, the cyst wall was composed of gliosis representing a rough accumulation of reactive astrocytes, lymphocytes, and small capillary vessels in edematous parenchyma, but no tumor cells. The present case and previous reports suggest that the cyst does not contain tumor cells, even if strongly depicted on contrast-enhanced neuroimaging, and that a thickly enhancing cyst wall indicates gliosis with accumulation of numerous small vessels.

Object: The authors tested the hypothesis that patients with metastatic posterior fossa lesions (MPFLs) treated with resection have a higher risk of leptomeningeal disease (LMD) than those with MPFLs treated with stereotactic radiosurgery (SRS)., Methods: Between 1993 and 2004, 379 patients with MPFLs were treated with resection or SRS at The University of Texas M. D. Anderson Cancer Center. The authors' primary study outcome was the incidence of LMD, as diagnosed with cerebrospinal fluid cytological analysis and/or neuroimaging., Results: Resection was performed in 260 patients, whereas 119 patients underwent SRS. The median patient age was 56 years, 51% of patients were male, and 93% had a Karnofsky Performance Scale score>or=70. The most common primary cancers were those of the lung, breast, and kidney, as well as melanoma. Leptomeningeal dissemination of cancer occurred in 33 patients: 26 in the resection group and 7 in the SRS group (resection group: rate ratio [RR] 2.06, 95% confidence interval [CI] 0.89-4.75, p=0.09). Piecemeal tumor resection (137 cases) was associated with a significantly higher risk of LMD than en bloc resection (123 cases; RR 3.4, 95% CI 1.43-8.12, p=0.006) or SRS (RR 3.37, 95% CI 1.41-8.04, p=0.006), and there was no significant difference in the risk for LMD between en bloc resection and SRS (en bloc resection: RR 0.98, 95% CI 0.34-2.81, p=0.98). The multivariate RR and significance associated with piecemeal resection, however, were consistent, with a strong effect (RR 2.45, 95% CI 1.19-5.02, p=0.02) and no indication of biases associated with tumor size, location, or cystic/necrotic appearance., Conclusions: There is an increased risk of LMD after piecemeal resection of an MPFL. This increase, although clinically and statistically significant, is not as alarming as previously reported and is absent when en bloc removal is achieved. Further assessment of the role of resection in a controlled prospective setting is warranted.

Congenital muscular dystrophies with brain malformations, such as muscle-eye-brain disease, exhibit neural ectopias caused by overmigration of neurons. Such overmigration is evident in protein O-mannose beta-1,2-N-acetylglucosaminyltransferase (POMGnT1) knockout mouse, a model of muscle-eye-brain disease, caused by breaches in the pial basement membrane. We hypothesize that breaches in pial basement membrane disrupt the neural-meningeal boundary, resulting in ectopia of meningeal fibroblasts in the cerebral cortex and reactive gliosis. To test this hypothesis, the cerebral cortices of developing and adult POMGnT1 knockout mice were analyzed by immunostaining with cell-specific markers and by electron microscopy. The upper half of the cerebral cortex in the knockout mouse contained increased numbers of fibroblasts closely associated with capillaries. During development of the cerebral cortex in the knockout mice, breaches in pial basement membrane allowed emigration of overmigrated neurons into the developing pia-arachnoid, scattering its mesenchymal cells throughout the diffuse cell zone and resulting in ectopia of mesenchyme-derived fibroblasts in the upper half of the cortex. Glial fibrillary acidic protein (GFAP) immunostaining revealed that the upper half of the cerebral cortex in the knockout also contained increased numbers of cells with morphologies typical of reactive astrocytes compared with the wild type. Moreover, most of the GFAP-positive reactive astrocytes were in close contact with ectopic fibroblasts, suggesting that they were induced by the fibroblasts. Collectively, the data support the hypothesis that the cerebral cortex of POMGnT1 knockout mice is characterized by migration defects leading to disruption of the pia-arachnoid, ectopia of fibroblasts in the cortex, and reactive gliosis., ((c) 2007 Wiley-Liss, Inc.)

Isolated abducens nerve palsies associated with intracranial aneurysms have rarely been reported. Their association with anterior communicating artery (ACoA) is even rarer. Intracisternal clot formation and elevated intracranial pressure has been proposed to be the responsible mechanisms. Herewith, we report two cases of bilateral abducens palsies following ruptured ACoA aneurysms and speculated the possible mechanisms. Opening of Liliequist's membrane provides clinical improvement due to CSF release.

Objective: To evaluate leptomeningeal and subpial inflammatory responses of experimental Staphylococcus aureus bacteriemia following intraperitoneal and intravenous applications and to compare the inflammatory reactions in different regions of central nervous system., Material and Methods: Forty anesthetized rats were divided into four groups equal in number. The rats in group-I were given 1 ml suspension of Staphylococcus aureus intraperitoneally. Group-II was the control group of group I; it was administrated 1 ml 0.9% NaCl in water intraperitoneally. The rats in group-III were given the same amount of bacteria intravenously. Group IV was the control group of the group-III; it was administrated 1 ml 0.9% NaCl solution intravenously. The rats were sacrificed on the 21st day. Inflammatory changes of different regions of the central nervous system were examined under transmission electron microscopy. Statistical analysis was done by using variance analysis, Bonferroni, Tamhane post hoc, Student's t and univariate tests., Results: Thoracic and occipital regions were the most vulnerable zones. Increasing of collagen tissue was the most detected inflammatory change., Conclusion: This experimental model can be used for inducing subpial and leptomeningeal inflammations and it may be developed for investigations of pathogenesis of leptomeningitis during systemic infections.

Papilledema is an uncommon presentation of spinal cord processes. Spinal subdural abscess (SSA) is a rare site of post-operative infection. We report a patient who developed papilledema as the primary manifestation of a post-operative lumbar subdural abscess. A spinal abscess should be considered in the post-operative spinal surgery patient who develops papilledema in the setting of persistent back pain. The increased intracranial pressure associated with lumbar spinal cord abscess most likely results from a markedly elevated cerebrospinal fluid (CSF) protein or the disruption of CSF flow in the spinal cul-de-sac.

A 14-year-old boy presented with a very rare meningioma in the posterior cranial fossa without dural attachment. Magnetic resonance imaging revealed a 3-cm, well-circumscribed, heterogeneously enhanced, round mass without dural tail sign in the right side of the posterior fossa. Right vertebral angiography revealed very faint tumor staining supplied by the right posterior inferior cerebellar artery. Total removal of the tumor was performed. Intraoperatively, the mass exhibited no attachment to the dura mater, cerebellar parenchyma, or choroid plexus, but was firmly attached to the arachnoid tissue near the foramen of Luschka. Histological and immunohistochemical studies established the diagnosis of meningothelial meningioma (World Health Organization grade I).

A 49-year-old woman presented with a rare atypical growth pattern of meningioma without evidence of dural attachment manifesting as chronic headache associated with transient paresthesia and left motor disorders. On admission, neurological examination showed no abnormalities. Magnetic resonance (MR) imaging revealed a right temporo-parieto-occipital lesion, which appeared to involve the subdural space and filling the cortical sulci. The lesion caused peritumoral white matter edema. The tumor appeared hypointense on T(1)-weighted and hyperintense on T(2)-weighted MR images, with homogeneous enhancement after contrast administration. A biopsy of the lesion was performed. Histological examination indicated that the lesion was a meningioma. Intraparenchymal meningiomas should be considered in the differential diagnosis of intraaxial lesions in patients of any age.

Arachnoid calcifications have been imaged on axial-CT and MRI. These often clinically asymptomatic deposits have been attributed to trauma, myelography (particularly with the use of oil-based contrast), subarachnoid hemorrhage, and spinal anesthesia. This report describes calcified arachnoid plaques in an 86-year-old male cadaver located in the dorsal thoracic level. A laminectomy from C4 to the lumbo-sacral junction was performed and the dura mater was transected and pinned aside. Three plaques between T2-T3, 3 at T7, 2 at T9 were noted. Plaques were 1.0 mm in thickness and ranged from 0.5 cm to 1.0 cm in diameter. The spinal cord or nerve roots were not displaced. The plaques stained positively with Von Kossa and Alizarin Red S staining, confirming that the deposits included calcium phosphate and calcium. Arachnoid calcifications are an incidental finding in cadavers and typically do not compress the spinal cord or nerve roots. However such plaques may be precursors to spinal arachnoid ossificans, a more serious condition that may cause spinal cord or nerve root compression., (Copyright 2006 Wiley-Liss, Inc.)

Background: Primary leptomeningeal astrocytomas are rare intracranial tumors. These tumors are believed to originate from cellular nests which migrate by means of aberration, ultimately settling in the leptomeningeal structure. They may occur in both solitary and diffuse forms. The literature reports only fifteen cases of solitary primary intracranial leptomeningeal astrocytomas., Case Presentation: The authors report the case of a seventy-eight year-old woman with a polycystic variant of a solitary primary intracranial leptomeningeal astrocytoma. The first neurological signs were seizures and aphasia. CT and MRI scans demonstrated a fronto-parietal polycystic tumor adherent to the sub arachnoid space. A left fronto-temporo-parietal craniotomy revealed a tight coalescence between the tumor and the arachnoid layer which appeared to wrap the mass entirely. Removal of the deeper solid part of the tumor resulted difficult due to the presence of both a high vascularity and a tight adherence between the tumor and the ventricular wall., Conclusion: A new case of a solitary primitive intracranial leptomeningeal astrocytoma of a rare polycystic variant is reported. Clinical, surgical, pathologic and therapeutic aspects of this tumor are discussed.

The morphology of the outer and inner membranes of traumatic chronic subdural hematomas (CSDHs) surgically removed from eight patients was investigated by scanning electron microscopy (SEM). Hematomas were divided into three groups based on time that had passed from the initiation of trauma to surgery. Structure of the CSDHs showed gradual morphological changes of the developing hematoma capsule. They initially included angiogenic and aseptic inflammatory reactions followed by progressive involvement of fibroblasts-proliferating and producing collagen fibrils. Numerous capillaries suggesting formation of new blood vessels were observed mainly in young hematomas removed between 15 and 21 days after trauma. In "older" hematomas (40 days after trauma), more numerous capillaries and thin-walled sinusoids were accompanied by patent, larger diameter blood vessels. Within the fibrotic outer membrane of the "oldest" hematoma capsules (60 or more days after trauma), especially in the area over the hematoma cavity, blood vessels were frequently occluded by clots. The results suggest dynamic changes in cellular and vascular organization of traumatic CSDH capsules paralleling the progression in hematoma age.

Objective: The aim of this study was to investigate the CD-31 and vonWillebrand factor (vWF) expressions and the cell morphological alterations ofarachnoid villus endothelium in different stages of animal hydrocephalus., Methods: Silicon oil was injected into the fourth ventricle of experimental canine for buildinghydrocephalus model. The post-injection ethology of the canine was observed, and thescoring of Tarlov n was performed. The magnetic resonance (MR) images of canineskulls were achieved for verification of hydrocephalus at 3 day, 2 weeks, and 12 Cweeks post-injection. The expressions of CD-31 and von Willebrand factor (vWF) inthe arachnoid villus endothelium cells at different stages of hydrocephalus werestudied by immunofluorescence histochemistry., Results: Experimental hydrocephalusanimal model was built up satisfactorily by injection of silicon oil. Experimentalcanines appeared the hydrocephalus symptoms and Tarlov scoring decrease. MRimages revealed progressive ventricular enlargement in different stages ofhydrocephalus. The immunofluorescence histochemistry staining showed that CD31 expressed positively in all the endothelium cells, including the endothelium cell of thevillus. The immunofluorescence histochemistry staining showed that the vWFexpression in the endothelium of the villus was diminished when compared to that innormal sinus wall. And in sub-acute and chronic hydrocephalus, the expression of vonWillebrand factor increased., Conclusions: The fourth ventricular injection of siliconoil may induce the hydrocephalus animal model. The expression of von Willebrandfactor in the endothelium cell of arachnoid villus increases during progressedhydrocephalus.

Background: The primary occurrences of meningiomas without attachment to the dura are rare. Clinical considerations and pathophysiologic mechanisms about these tumors have not been sufficiently explored, and a complete classification has not been accomplished., Case Description: A 16-year-old adolescent boy presented with epileptic seizure for 9 years. Neurologic deficits were not found on admission. Magnetic resonance imaging revealed a 25 x 23-mm mass lesion without dural attachment located in the parietooccipital region. The tumor was iso-intense on T1-weighted and hyperintense on T2-weighted images, and became clearly and heterogenously enhanced with gadolinium. During surgery, a right parietooccipital craniotomy revealed the tumor was completely buried in the sulcus occipitalis anterior. Total removal of the tumor was accomplished. Histologic examination indicated that the lesion was an atypical meningioma., Conclusion: According to sites of the tumor, supratentorial meningiomas without dural attachment are classified into 5 varieties, and posterior fossa meningiomas without dural attachment into 4 categories. Except for intraventricular ones, meningiomas without dural attachment predominantly occur in males. The average age is about 20 years younger than that of meningiomas in general. Fibroblastic meningiomas constitute the major subtype. Intraparenchymal or subcortical meningiomas should be considered as one type, which may arise from arachnoid cells of the pia mater within brain sulcus.

A 34-year-old woman with hyperthyroidism, who had been previously treated with propylthiouracil (PTU) is reported. She was admitted because of clumsiness in her left hand and abnormal behavior. A neurological examination demonstrated impairment of higher cortical function, and weakness and hyperreflexia of the left leg. An MRI scan with gadolinium enhancement showed pachyleptomeningeal thickening in the right frontoparietal lobe. Blood tests revealed a high MPO-ANCA titer of 122 EU (normal:<10 EU). After steroid administration, the neurological symptoms and the MRI findings improved markedly. This is the first report of PTU-induced cerebral pachyleptomeningitis associated with a high serum MPO-ANCA titer.

Arachnoid cysts are developmental anomalies usually diagnosed in childhood. The most important complications of arachnoid cysts are subdural haematomas and hygromas and intracystic haemorrhage. In our case we present a 7-year-old boy whose arachnoid cyst ruptured into the subdural space following a mild head injury and disappeared after draining the subdural haematoma by burr-holes.

Subarachnoid hemorrhage (SAH) may cause neurogenic pulmonary edema (NPE), and chylomicron metabolism may be destroyed in injured lungs. We aimed to investigate the effect of neurogenic pulmonary edema (NPE), if present, on the development of cerebral fat embolism. This study has been conducted on 20 rabbits. Experimental SAH has been applied to half of the animals by injecting homologous blood into the cisterna magna, and the remaining half was applied only isotonic saline solution in the same manner under general anesthesia. After 20 days, all animals were killed. Their lungs and brains were examined histopathologically. Six animals died of SAH between 16 and 20 days, and foamy hemorrhagic parenchymal lesions and intra-alveolar hemorrhage were observed in their lungs. Fat globules were abundantly found in cerebral arteries of six of all the non-surviving animals. But, minimal histopathological changes were found in the lungs and brains of the surviving animals. Cerebral fat embolism was detected in only one animal that was given isotonic solution. SAH may cause NPE and result in lung tissue destruction. Chylomicron metabolism may be disordered in the destructed lungs and leakage of chylomicrons into systemic circulation may be facilitated via destroyed lung barrier. These pathologic processes may lead to cerebral fat embolism.

A case of a 61-year-old female patient who presents with the clinical triad of normal pressure hydrocephalus (NPH), abnormal gait, urinary incontinence and dementia. On CT scanning, she is found to have a large arachnoid cyst which mimicked the syndrome of NPH. This is also the 60th published case of arachnoid cyst presenting over the age of 60.

Arachnoid granulations may expand the dural sinuses or inner table of the skull. Although usually incidental, giant arachnoid granulations that are of sufficient size to fill the lumen of a dural sinus and cause local dilation or filling defects can rarely cause symptoms due to sinus obstruction leading to venous hypertension. This 31-year-old man presented with a 3-month history of progressive bifrontal headaches and a giant arachnoid granulation at the posterior superior sagittal sinus. Intrasinus pressure measurements showed no significant pressure difference across the lesion to explain the headaches, which were then treated medically. Dural sinus pressure measurement, in certain cases of giant arachnoid granulations, can be used to exclude the lesion as the cause of the patient's symptoms.

Background: The effect of lumbar puncture needle bevel direction on the incidence of postdural puncture headache (PDPH) is somewhat controversial. We performed a meta-analysis of available trials to determine if bevel direction during lumbar puncture would influence the incidence of PDPH., Review Summary: Studies were identified primarily by searching the National Library of Medicine's PubMed database (1966 to November 29, 2004) and abstracts from several national meetings (American Society of Anesthesiology, International Anesthesia Research Society, American Society of Regional Anesthesia, Society of Obstetric Anesthesia and Perinatology) for terms related to needle and bevel direction. Inclusion criteria were assessment of the incidence of PDPH after lumbar puncture with a cutting needle (eg, Quincke, Tuohy), comparison of a "parallel" (bevel oriented in a longitudinal or cephalad to caudad direction) to "perpendicular" (bevel oriented in a transverse direction) orientation during needle insertion, randomized trials, and trials primarily in adult populations. Data on study characteristics and incidence of PDPH were abstracted from qualified studies and subsequently analyzed. The search resulted in 52 abstracts from which the original articles were obtained and data abstracted, with ultimately a total of 5 articles meeting all inclusion criteria. Insertion of a non-pencil-point/cutting needle with the bevel oriented in a parallel/longitudinal fashion resulted in a significantly lower incidence of PDPH compared with that oriented in a perpendicular/transverse fashion (unadjusted rates of 10.9% versus 25.8%; odds ratio = 0.29 [95% CI = 0.17-0.50])., Conclusions: Our meta-analysis indicates that with use of a cutting needle, insertion in a parallel/longitudinal fashion may significantly reduce the incidence of PDPH, although the reasons for this decrease are unclear.

Background: We have previously presented an alternative method for surgical decompression of intracranial arachnoid cysts. This minimally invasive method, with insertion of an internal shunt from the cyst to the subdural compartment, seemed to be an efficient and simple, and hence promising technique. The aim of the present study was to investigate the long-term results of this procedure., Methods: This study is a questionnaire-based retrospective study that includes 31 adult patients (>18 years) who were operated on in our department for an arachnoid cyst in the temporal fossa or overlying the frontal convexity with the internal shunt technique between April 1990 and October 2003. Follow-up ranged from 15 months to 14.8 years (mean = 8.2 years)., Results: Of the patients, 83% were asymptomatic or had insignificant complaints at follow-up. A total of 17% reported no reduction of the preoperative complaints. No patient experienced worsening of the symptoms. The cyst was no longer visible on postoperative radiologic examinations in 37% of the patients. In 37%, the postoperative fluid volume was less than 50% of the original volume. In 13%, the cyst volume was reduced but the postoperative volume was greater than 50% of the original cyst volume. Thus, the cyst was unchanged in only 13% of the patients. There was no correlation between volume reduction and clinical improvement. A complication (subdural hygroma or hematoma) occurred in 7 patients, all with temporal cysts, leading to reoperation in 4. None of the complications caused permanent neurologic deficits or invalidity. Seven patients were reoperated on because of suspected or established treatment failure., Conclusions: The internal shunt technique is a relatively simple, safe, and efficient alternative method for treatment of arachnoid cysts. It should be considered a valuable alternative in the treatment of arachnoid cysts.

Background: Choroid plexus papillomas are typically considered benign lesions, but histology is not always predictive of their behavior. These tumors can metastasize anywhere along the neuraxis and may be intraventricular, subarachnoid, or intraparenchymal. We present 2 cases that illustrate the wide diversity with which choroid plexus papillomas can disseminate., Case Descriptions: The patient described in case 1 had a primary fourth ventricular choroid plexus papilloma that produced diffuse cystic subarachnoid and leptomeningeal lesions. Patient 2 also had a primary fourth ventricular tumor but with subsequent suprasellar and spinal drop metastases. Patient 1 was treated with temozolomide, resulting in regression of symptoms including headache and dizziness. Patient 2 has been treated with several modalities, including radiation therapy and chemotherapy, with slowing of symptom progression., Conclusions: Variations of choroid plexus papilloma dissemination include intraventricular, subarachnoid, and leptomeningeal nodules or cystic lesions, and intraparenchymal locations. There is no consensus on the most effective treatment for choroid plexus papilloma metastases; surgical resection, chemotherapy, and radiation therapy may all yield benefits. The prognosis for patients with disseminated choroid plexus papilloma can range from prolonged stable disease and symptoms to death within months.

Background: There are few reports on the outcome of surgical treatment of TGN without vascular compression., Methods: Between 1984 and 2004, 668 patients underwent MVD for TGN. In 21 patients (3.1%), vascular compression was absent. The surgical strategy in these cases involved the following: (1) dissection and exposure of the entire trigeminal nerve root; (2) slight neurapraxia with bipolar tips at the trigeminal nerve root; and (3) isolation of trigeminal nerve with Teflon sponge fragments., Results: The patients' (female/male, 20:1) ages ranged from 33 to 77 years. Their right side was the most frequently involved (61.9%). Their mean duration of pain before treatment was 7.6 years (range = 1-20 years). At surgical exploration, vascular compression or anatomical abnormalities were absent in 15 patients (71.4%), arachnoidal thickening was present in 5 (23.8%), and fiber dissociation of the trigeminal nerve was present in 1 (4.8%). Mean follow-up after surgery was 17.7 months (range = 4-65 months). Immediate relief from pain occurred in all 21 patients. On Kaplan-Meier analysis, recurrence was maintained at 14.8% for 12, 24, and 36 months, increasing to 43.2% at 48 months. Permanent hypoesthesia was present in 6 patients (28.6%), whereas loss of corneal reflex was observed transiently in 1 (4.8%). Motor function of the trigeminal nerve was intact in all patients. No other complication was found., Conclusion: The proposed surgical plan of standard MVD plus slight trigeminal nerve root neurapraxia is a safe and effective management option for TGN without vascular compression.

We report a 66-year-old woman with a presyrinx state due to adhesive arachnoiditis. She had a history of subarachnoid hemorrhage one year ago. She became aware of gait disturbance and abnormal sensation at the chest 6 months ago. Neurological examination revealed weakness of the both lower extremities and sensory disturbance below the T6 level. MR images of the thoracic spine revealed swelling of the thoracic cord at the T3-4 level, with an intramedullary hyperintensity on T2 weighted images (WI) and hypointensity on T1-WI. The intramedullary hypointensity on T1-WI was less than the CSF intensity. In addition, the thoracic cord lower than T5 level was compressed by an arachnoid cyst in the spinal canal. The preoperative diagnosis was the presyrinx state due to adhesive arachnoiditis. An operation for detachment of arachnoidal adhesion and restoration of CSF flow pathway was performed. After one month from the operation, neurological findings were improved. Postoperative MR images revealed improvement of swelling of the thoracic cord and intramedullary abnormal intensity. The arachnoid cyst in the spinal canal was decreased in the size. The presyrinx state is recently recognized condition before the formation of syringomyelia and that is known to resolve with proper treatment. We wish to emphasize we could prevent a progression to syringomyelia by a proper treatment for the presyrinx state.

In this report, we present a case of non-traumatic intradiploic arachnoid cyst in a 65 year-old woman with a slow growing swelling in the right frontotemporal region without a history of head trauma, which was diagnosed intra-operatively. Extradural intracranial location of non-traumatic arachnoid cyst is a rare clinical entity with a few reported cases in the literature. Characteristic features of non-traumatic intradiploic arachnoid cysts are also described in this mini-review article.

Objective: Prostate cancer is a well known cause of spinal column metastases; however, an intradural location is extremely rare. It is considered to be a type of leptomeningeal spread. Cerebral seeding has usually occurred by the time of presentation. Due to a poor prognosis, surgery is rarely indicated, and controversially discussed., Patient and Results: We review the known cases of spinal leptomeningeal prostate cancer spread, including our patient, who developed paraparesis over 6 weeks, 3 years after prostate cancer was diagnosed. Following surgical decompression and resection, the patient additionally received radiation therapy of the spinal meninges and antihormonal treatment. 6 months after surgery, the patient is still ambulatory with a good quality of life., Conclusion: Spinal leptomeningeal metastases occur at a late stage of systemic disease, and the prognosis is generally poor. In the literature, outcomes after surgery are reported as devastating, with mortality and morbidity rates of up to 20% and 60%. The aim of surgery is to relieve pain, preserve or even restore neurological function, and reveal histology if uncertain. This may be achieved by debulking the tumor without placing the patient at an unacceptably high risk. Surgery should be performed in selected cases of spinal leptomeningeal metastases, in patients who are still ambulatory with controlled systemic disease, and should be followed by adjuvant therapy.

Background: Leptomeningeal metastasis is discovered at autopsy in approximately 5% of patients with systemic cancer. Until recently with the introduction of magnetic resonance imaging (MRI), premorbid diagnosis was extremely difficult. In particular, initial spinal fluid cytology is diagnostic in less than 50% of autopsy-verified patients, although repeated spinal fluid examinations may increase the yield significantly. Leptomeningeal metastasis in metastatic prostate cancer has been reported in only 14 patients previously., Case Description: We recently studied such a patient and were able to establish a correct diagnosis based solely on the MRI and the presence of an elevated cerebrospinal fluid (CSF) prostate-specific antigen (PSA). Only 3 previous patients with leptomeningeal prostate metastasis have undergone CSF PSA evaluations., Conclusion: We believe that, in such patients, the combination of MRI and CSF studies can overcome the lack of sensitivity of CSF cytology.

Introduction: Spinal extradural arachnoid cysts are an uncommon cause of neural compression in children. Even more uncommon is the association of such cysts with spina bifida occulta., Material: Two girls, 12 and 8-years-old, presented with left leg pain, deteriorating gait, clinical signs of left L5 and S1 root compression, without bladder or bowel symptoms. The first patient had left foot drop. The second patient had muscle wasting and smaller left foot with pes cavus. Radiographs showed spina bifida occulta of S1 in both. MRI revealed an extradural cyst at the S1 level, indenting the thecal sac and the L5 and S1 roots. At operation in both patients a large arachnoid cyst arising from a small dural defect in the axilla of the left S1 root was compressing and displacing it and the dural sac. It was removed and the defect was repaired. The first patient improved with complete recovery of the foot drop. An MRI at 12 months showed no cyst recurrence. The second patient made good recovery initially, but at 10 months developed recurrent symptoms. An MRI scan showed recurrence of the cyst with root compression. On repeat exploration a different dural defect was identified in a more anterior position and was repaired., Discussion: The coexistence of extradural arachnoid cyst and corresponding bifid spinal segment has not been described previously. It raises the suspicion that the dural defect giving rise to the arachnoid cyst may be due to segmental dural dysgenesis in the context of the dysrhaphic neuroectodermal malformation.

Object: Endoscopic fenestration has been recognized as an accepted treatment choice for patients with symptomatic arachnoid cysts. The success of this procedure, however, is greatly influenced by individual cyst anatomy and location as well as the endoscopic technique used. This review was conducted to assess what variables influence the treatment success for different categories of arachnoid cysts., Methods: Thirty-three consecutive patients who underwent endoscopic fenestration for treatment of an intracranial arachnoid cyst were identified from a prospective database. The surgical indications and techniques were reviewed, and surgical success rates and patient outcomes were assessed. Specific examples of each cyst category are included to illustrate the technical aspects of endoscopic cyst fenestration. Endoscopic fenestration of arachnoid cysts was successful when judged by cyst decompression, and symptom resolution was noted in 32 (97%) of 33 cases. The one patient with short-term treatment failure underwent a successful repetition of the operation. There were no surgery-related morbidities or deaths., Conclusions: Arachnoid cysts are a relatively benign pathological entity that can be managed by performing endoscopically guided cyst wall fenestrations into the ventricular system or cerebrospinal fluid-containing cisterns. Proper patient selection, preoperative planning of endoscope trajectory, use of frameless navigation, and advances in endoscope lens technology and light intensity combine to make this a safe procedure with excellent outcomes.

Background: The purpose was to analyse the clinical and radiological findings, and management approaches used in 30 consecutive cases of traumatic epidural haematoma of nonarterial origin treated at one centre., Method: Medical records for 30 patients surgically treated for epidural haematoma of nonarterial origin between 1997 and 2003 were reviewed. Epidural haematoma of nonarterial origin was diagnosed based on computed tomography (CT) and the bleeding source was confirmed intra-operatively. Admission status, outcome, fracture location, haematoma location/size/volume, and additional intracranial pathology were among the data noted. Two groups were formed for analysis: venous sinus bleeding (group 1) and other venous sources (group 2)., Findings: The 30 cases accounted for 25% of the total number of traumatic epidural haematomas (n = 120) treated during the same period. The epidural haematomas of nonarterial origin locations were transverse sigmoid sinus (n = 11; 36.7%), superior sagittal sinus (n = 6; 20%), venous lakes (n = 5; 16.6%), diploë (n = 5; 0.16%), arachnoid granulations (n = 2; 6.7%), petrosal sinus (n = 1; 3.3%). There were 12 postoperative complications in 9 patients: recurrence (n = 4; 13.3% of the 30 total), pneumonia (n = 4; 13.3%), meningitis (n = 2; 6.7%), hydrocephalus (n = 1; 3.3%) and subdural effusion (n = 1; 3.3%). All recurrence cases were re-explored. Six (20%) patients died. Glasgow Outcome Scale (GOS) scores (mean follow-up 13.3 +/- 7.8 months) revealed 22 (73.3%) patients with favourable results (GOS 4-5) and 8 (26.7%) had poor results (GOS 1-3)., Conclusions: Cases of epidural haematoma of nonarterial origin differ from the more common arterial-origin epidural haematomas with respect to lesion location, surgical planning, postoperative complications, and outcome. Epidural haematoma of nonarterial origin should be suspected if preoperative CT shows a haematoma overlying a dural venous sinus or in the posterior fossa and convexity. The sinus-origin group had a high frequency of fractures which crossed the sinuses, and this might be diagnostically and surgically useful in such cases.

Case Report: We describe the clinical, radiological and pathological findings of concurrent, congenital leptomeningeal arteriovenous malformation with hemangioma diagnosed in a newborn by prenatal and immediately postnatal magnetic resonance imaging. Vascular abnormalities were accompanied by massive arachnoidal cell hyperplasia reminiscent of meningioma., Conclusion: To the best of our knowledge, this is the first case of such a lesion reported in the literature.

Objective: To clarify the pathogenesis of leptomeningeal amyloidosis in familial amyloidotic polyneuropathy amyloidogenic transthyretin Y114C (FAP ATTR Y114C)., Methods: The authors analyzed eight FAP ATTR Y114C patients. Six patients showed CNS symptoms associated with leptomeningeal amyloidosis. To examine the function of the blood-CSF barrier and blood-brain barrier (BBB), the authors performed CSF and MRI studies. The authors also performed a histopathologic study of autopsy specimens to examine the distribution of amyloid deposition in the CNS., Results: CSF study showed high total protein concentrations and increased albumin CSF/serum concentration quotients (Qalb; an indication of blood-CSF barrier function). MRI with gadolinium (Gd) revealed enhancement from brainstem to spinal cord. Serial brain MRI studies with FLAIR images after Gd administration showed Gd leakage into the subarachnoid space (two patients). These findings suggested the blood-CSF barrier and BBB dysfunctions. Constructive interference in steady state (CISS) three-dimensional Fourier transformation (CISS-3DFT) sequence analysis demonstrated amyloid-induced funiculus structures joining the spinal cord and dura mater (one patient). Histopathologic study revealed intense amyloid deposition in leptomeninges, vessel walls, and parenchyma in spinal cord and the brain. These distributions of amyloid deposition are unique compared to other TTR related leptomeningeal amyloidosis., Conclusions: Patients with familial amyloidotic polyneuropathy amyloidogenic transthyretin Y114C had CNS disorders related to amyloid deposition in leptomeninges, vessel walls, and parenchyma in spinal cord and the brain. The pathogenesis of CNS disorders may reflect disruption of the blood-CSF barrier and blood-brain barrier by amyloid deposition.

The authors determined the levels of vascular endothelial growth factor (VEGF) and urokinase-type plasminogen activator (uPA) in the CSF of patients with leptomeningeal metastases (LM; n = 53), cancer patients without LM (n = 18), and subjects without malignancy (n = 25). Median levels of uPA and VEGF were significantly higher in patients with LM, supporting the hypothesis that angiogenesis contributes to LM. VEGF was negatively correlated with survival in patients with LM, suggesting its use as a prognostic factor.

Background and Purpose: CSF enhancement on MR images after intravenous administration of gadolinium chelate, which mimics subarachnoid hemorrhage, has been reported. The purpose of this study was to determine whether CSF enhancement can be seen on serial MR images following administration of contrast material in patients with transthyretin-related familial amyloid polyneuropathy (FAP) and to assess other ancillary MR findings., Methods: We serially studied T1-weighted and fluid-attenuated inversion recovery (FLAIR) images of the brain before, immediately after, and 3, 6, and 24 hours after contrast administration in 6 patients with genetically confirmed transthyretin-related FAP. By consensus, 2 radiologists assessed the presence, degree, and extent of enhancement of the CSF, leptomeninges, brain parenchyma, and other structures. Statistical analysis was performed to define the difference of the enhancement between the 2 MR imagings., Results: In 3/6 patients with cysteine-for-tyrosine substitutions at position 114 (Tyr114Cys mutations), marked CSF enhancement was observed on the FLAIR images at 3 and 6 hours and on T1-weighted images at 3 hours after contrast administration. Although there was no significant difference between the 2 MR imagings, leptomeningeal enhancement for these 3 patients was evident only on FLAIR images. The labyrinth and vitreous body was also enhanced on postcontrast delayed MR images of these 3 patients. These enhancements were not observed in the other 3 patients with Val30Met mutation. In none of the 6 patients did images demonstrate parenchymal enhancement of the brain., Conclusion: In FAP patients with Tyr114Cys mutations, contrast material can leak into the CSF. This finding may depend on the subtype of FAP and be more evident with FLAIR images. The enhancement of the leptomeninges, labyrinth, and vitreous body was also seen in the patients.

This unusual mixed glioneuronal neoplasm of the spine resembling central neurocytoma is only the second reported example of a neoplasm of this type involving the spinal cord and is, seemingly, the first to present with diffuse leptomeningeal dissemination and communicating hydrocephalus. This 15-month-old boy presented with somnolence, bilateral sixth nerve palsy, and lower-extremity weakness and was found to harbor a primary neoplasm within the thoracic spine and associated syrinx, widespread leptomeningeal dissemination, and communicating hydrocephalus. The patient underwent cerebrospinal fluid shunt placement, thoracic laminectomy for tumor debulking and biopsy, chemotherapy, and radiation therapy to the neuraxis. Immunohistochemically, the tumor was marked by evidence of mixed glial (glial fibrillary acidic protein-positive) and neuronal (synaptophysin-positive) differentiation. Mitotic activity was inconspicuous. No areas of vascular proliferation, necrosis, or marked nuclear pleomorphism were noted. Mixed glioneuronal neoplasms are a heterogeneous group of tumors whose biological potential remains incompletely defined. The present case illustrates the reality that some of these neoplasms can be clinically aggressive, despite comparatively bland histological features. The authors' goal is to acquaint neurosurgeons with the expanding spectrum of mixed glioneuronal neoplasms and with the potential of some of these lesions to pursue an aggressive clinical course.