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Objective Meningeal melanocytomas are low-grade primary melanocytic tumors with benign histological features and a favorable clinical prognosis. Transition from meningeal melanocytoma to primary melanoma of the central nervous system is exceptionally rare, with only 5 cases having been previously reported. Here, we discuss a case of malignant transformation of an intramedullary melanocytoma to primary melanoma and review the pertinent literature. Clinical presentation A 79-year-old woman presented with progressive paresis in the lower limbs followed by sphincter dysfunction. Magnetic resonance imaging scans disclosed an intramedullary lesion located at the T10-T11 level. Intervention The patient underwent subtotal resection of an intermediate-grade melanocytoma. Two years later, the tumor recurred locally, and the patient underwent additional surgery to remove the intramedullary mass. The histological findings of the tumor were consistent with an intramedullary malignant melanoma. Conclusion The malignant transformation of melanocytic tumors of the central nervous system may occur years after surgical treatment, and its incidence remains unknown. Emphasis should be placed on the importance of careful and continued follow-up monitoring of the tumor.

OBJECTIVE: Syringomyelia should be treated by reconstruction of the subarachnoid space and restoration of cerebrospinal fluid homeostasis. Direct intervention on the syrinx is a difficult choice and should be considered a rescue procedure. Data in the literature examining the various options are scanty, with generally unsatisfying results. We report our experience with shunting of the syrinx into the pleural space. METHODS: Twenty patients with syringomyelia refractory to cerebrospinal fluid flow restoration underwent a procedure for placement of a syringopleural shunt between 1998 and 2008. Modified Japanese Orthopaedic Association Scale scores and magnetic resonance imaging were available for each patient preoperatively and at the latest follow-up evaluation. A 2-tailed Wilcoxon signed-rank test was used for statistical analysis. Complications related to the operative procedure and to hardware failure were noted. RESULTS: Nineteen patients were available for follow-up with a mean duration of 37.5 (standard deviation, 31.1) months. The condition of 1 patient deteriorated, 2 remained stable, and the remainder improved. The overall mean improvement on the Modified Japanese Orthopaedic Association Scale was 19:5% (95% confidence interval, 8.5-30.5). The median improvement was 4 points on the 17-point scale. Results were statistically significant (P< 0.001). Follow-up magnetic resonance imaging showed syrinx collapse in 17 cases and marked shrinkage in 2 cases. Except for 1 case of meningitis followed by fatal pulmonary embolism, no significant complications were noted. CONCLUSION: A syrinopleural shunt should, in our view, be the syrinx diversion procedure of choice. More series of institutional experiences with a homogeneous approach would be helpful to verify this recommendation.

Objective To review our experience with the surgical management of craniovertebral junction malformations, focusing on the selection of surgical approach, management of the associated Chiari malformation, and postoperative instability. Methods During a 7-year period (May 2000-May 2007), 34 patients with a mean age of 55 years (age range, 32-75 years) underwent transoral surgery for fixed or nearly fixed ventral compression at the craniovertebral junction caused by basilar invagination and/or atlantoaxial dislocation. Chiari malformation was detected in 13 patients. The most common presenting signs were motor deficits (88%), followed by sensory loss (35%). All patients but one who had posterior stabilization performed elsewhere underwent single-stage anterior decompression and posterior occipitocervical fixation. Adjuncts to the transoral approach were tailored to the local anatomy (severity of basilar invagination, extent of mandibular excursion) found in each patient. Posterior fossa decompression was performed in 3 patients with Chiari malformation. Results Thirty-one patients were alive at the time of the last follow-up evaluation (average, 3.7 years; range, 0.5-7.5 years). Of the 28 surviving patients admitted with preoperative motor impairment, 24 patients (86%) improved at least 1 Nurick grade, whereas the grade did not change in 4 (14%) patients. There were 2 (6%) perioperative deaths, and 1 other patient died subsequently of causes unrelated to surgery. Surgical morbidity was 18% and included dural laceration, cerebrospinal fluid leak with meningitis, malocclusion, oral wound dehiscence, and occipital wound infection. Delayed instability occurred in 1 patient because of cranial settling of the C2 vertebral body. Conclusion Successful decompression of the abnormal craniovertebral junction requires extensive preoperative evaluation, appropriate tailoring of the operative approach, and an adequate learning curve. Transmaxillary approaches are useful adjuncts to the transoral approach in patients with severe basilar invagination or in cases of limited jaw mobility. Anterior decompression has been proven effective in relieving obstruction of the subarachnoid space at the foramen magnum in most patients with associated Chiari malformation.

The aim of this study is to review our experience with the transoral surgical management of anterior craniovertebral junction (CVJ) lesions with particular attention to the decision making and to the indication for a consecutive stabilization. During 10 years (1998–2007), 52 consecutive patients presenting exclusively fixed anterior compression at the cervicomedullary junction underwent transoral surgery. Mean age was 55.85 years (range 17–75 years). Encountered lesions were: malformation (32 cases), rheumatoid arthritis (11 cases), tumor (5 cases) or trauma (4 cases). A total of 79% of patients presented with chronic/recurrent headache (cranial and/or high-cervical pain), 73% with varying degrees of quadrip aresis, and 29% with lower cranial nerve deficits. All of the patients but two, with posterior stabilization performed elsewhere, underwent synchronous anterior decompression and posterior occipitocervical fixation. Adjuncts to the transoral approach (Le Fort I with or without splitting of the palate), tailored to the local anatomy and to the extension of the lesions, were performed in seven cases. Follow-up ranged between 4 and 96 months. Of 35 patients with severe preoperative neurological deficits, 33 improved. The remaining 15 patients who presented with mild symptoms, healed throughout the follow-up. Perioperative mortality occurred in two cases and surgical morbidity in eight cases (dural laceration, cerebrospinal fluid leak with meningitis, malocclusion, oral wound dehiscence and occipital wound infection). Delayed instability occurred in one patient because of cranial settling of C2 vertebral body. A successful surgery achieving a stable decompression at the CVJ is an expertise demanding procedure. It requires accurate preoperative evaluation and, appropriate choice of decompression technique and stabilization instruments. Enlarged transoral approaches (despite higher morbidity) are a supportive means in cases of severe basilar invagination, cranial extension of the lesion or limited jaw mobility.

Posterior cranial fossa tumours, not involving the cerebellopontine angle cistern, are a rare cause of trigeminal neuralgia (TN). We describe a patient with a large paramedian tentorial meningioma associated with acquired Chiari malformation who presented with TN. Trigeminal pain resolved after gross total tumour resection and postoperative magnetic resonance images disclosed a minimal residual tumour in the torcular region as well as ascent of cerebellar tonsils. In this article, we investigate the physiopathological hypotheses for this unusual association with emphasis on the role of tonsillar prolapse as neuropathological basis of neuropathic pain in this patient.

The occurrence of subdural cerebrospinal fluid collections and ventricular dilatation (external hydrocephalus) after foramen magnum decompression is extremely rare. The authors report on a 37-year-old man who developed symptomatic subdural fluid collections (SFC) after uncomplicated foramen magnum decompression for Chiari I–syringomyelia complex. Postoperative magnetic resonance imaging revealed a supratentorial SFC with prominent midline shift. In addition, bilateral infratentorial SFCs extending supratentorially through the tentorial notch, pseudomeningocele and initial shrinkage of the syrinx were observed. Few days after evacuation of supratentorial collection, the patient experienced increasing headache and a computerized tomography scan demonstrated a contralateral subdural collection as well as ventricular dilatation. A programmable ventriculoperitoneal shunt was placed with resolution of supratentorial collection and progressive improvement of infratentorial collections and pseudomeningocele. Although previous reports described the occurrence of extra-axial fluid collections and hydrocephalus after foramen magnum decompression for Chiari malformation, to our knowledge, this is the only report of acute external hydrocephalus after foramen magnum decompression requiring urgent evacuation of SFC in order to reduce the mass effect.

Intracranial enterogenous cysts are an uncommon entity rarely found in the midline within the posterior cranial fossa. The occurrence of an enterogenous cyst in the cerebellopontine angle is exceptional. We present two new cases of cerebellopontine angle (CPA) enterogenous cysts and review the literature to clarify the diagnosis and the management of these lesions. Eighteen cases of CPA intradural enterogenous cysts have been reported to date, including the two cases presented in this article. All of them were symptomatic and underwent surgical treatment. After surgery, the symptomatic recurrence occurred in 31% of the patients, most of which had partial excision. Considering our patients and the published cases in the literature we suggest that the aim of surgery should be total removal of cyst and its content whenever possible. When partial resection of the cyst is performed, we recommend long-term clinical and neuroradiological follow-up.

Dissections of intracranial arteries are rare and occur most commonly in the vertebrobasilar system.1 Isolated dissecting aneurysms of the posterior cerebral artery (PCA) are very uncommon. We report a case of subarachnoid haemorrhage (SAH) heralded by a 3-month history of diplopia due to dissection of the right PCA documented with digital subtraction angiography (DSA), magnetic resonance imaging (MRI) and angiography (MRA). The patient was treated conservatively, with a good outcome. A 58-year-old male farm worker was found unconscious in the countryside and admitted to hospital. His medical history was unremarkable except for treated arterial hypertension and diplopia for 3 months. On admission, he had a Glasgow Coma Scale (GCS) score of 14 and a complete right third-nerve palsy. Vision and corneal reflexes were normal. A computed tomography scan showed diffuse SAH and intraventricular haemorrhage with hydrocephalus (fig 1A). Soon after arrival, he became less responsive and underwent temporary external ventricular drainage. DSA disclosed a fusiform dilatation of the P1–P2 segment of the right PCA with a focal “blister”, suggesting a dissecting aneurysm (fig 1B). Figure 1 Computed tomography scan at admission showing extensive subarachnoid haemorrhage (SAH) (A). Digital subtraction angiography (DSA; anteroposterior projection) showing a fusiform ectasia of the P1–P2 segment of the right posterior cerebral artery (PCA) with a …

Tumour-to-tumour metastasis is a rare pathological entity. Meningioma is the most common intracranial tumour to host metastases, the majority of which arise from breast and lung cancers. We present the first report of a colonic cancer metastasis within an intracranial meningioma.A 76-year-old woman presented with a one month history of partial seizures. Her medical history included resection of an adenocarcinoma of the descending colon followed by adjuvant chemotherapy 1 year before our evaluation. Magnetic resonance imaging revealed a homogeneously enhancing lesion in the right frontal convexity.A well capsulated tumour attached to the frontal dura was surgically removed. The pathological examination demonstrated a mixture of fibrous meningioma and colloid adenocarcinoma. Possible explanations for the development of a cohesive chimeric mass of composite pathology are investigated.

We report on an extremely rare case of a paravertebral thoracic mesothelial cyst in a young woman who presented with dorsal radiculopathy affecting the T5 dermatome. The patient underwent a standard transthoracic intercostal approach with removal of the cyst. During the operation, the T5 intercostal neurovascular bundle was found firmly attached to the lesion elucidating the origin of the radicular pain. To our knowledge, this is the first report of radiculopathy due to a paravertebral mesothelial cyst. Although highly unusual, paravertebral mesothelial cyst should be considered in the differential diagnosis for lesions inducing dorsal radicular pain.

✓Developmental venous anomalies (DVAs) are often associated with intracranial cavernous malformations (CMs). The frequency of this association and the observation of de novo CMs located near a known, preexisting DVA raise speculations as to the possible etiopathogenetic relationship between the two. In this article, the authors review the recent literature dealing with the potential etiopathogenetic, prognostic, and therapeutic implications of the association between DVAs and CMs.

The authors report on an unusual case of a congenital tethered cervical spinal cord in young man who presented with progressive tetraparesis. Neuroradiological evaluation of the spine revealed a discrete exophitic cervical spinal cord mass with a stalk of tissue that extended from the mass and terminated in the muscle tissue. The patient underwent a laminectomy with intradural exploration. A stalklike lesion was discovered and excised. Pathological examination showed that the stalk was formed of hamartomatous tissue. The patient improved following surgery, which suggested that tethering of the cervical spinal cord was responsible for his symptoms.

Dear Editor,Dermoid cysts are rare congenital slow growing neoplasmsaccounting for less than 1 % of intracranial tumors [2].Dermoid cysts confined to the lateral wall of the cavernoussinus are extremely unusual and clinical symptoms general-ly occur late in the course of tumor growth, due to localirritative effects of the space-occupying lesion. The mostcommon clinical presentation results from involvement ofthe cranial nerves contained in the lateral wall of the cav-ernous sinus. Accordingly, while trigeminal nerve dysfunc-tion, oculomotor and trochlear nerve palsies with dermoidorigin have been widely described [1, 5], isolated abducensnerve deficit, to the best of our knowledge, has not beenpreviously reported.A 37-year-old man presented with a 1-week history ofprogressive diplopia. On the first examination, a remarkablelimitation in abduction in his right eye was observed (Fig. 1).Magneticresonanceimaging(MR)demonstratedacysticovalshaped lesion in the right parasellar space hypointense tohyperintense on T1- and T2-weighted images, whichpresented a slight rim of enhancement after contrast injection(Fig. 1). The posterior vertical segment and the posteriorbend of the intracavernous carotid artery were displacedantero-medially (Fig 1). Analysis of MR images suggestedthat the tumor was an interdural dermoid cyst of the lateralwall of the cavernous sinus.The patient underwent a right fronto-temporal cranioto-my for intradural resection of the tumor, which was ob-served bulging into and deforming the lateral wall of thecavernous sinus. The outer (or meningeal) layer of thelateral wall was incised over the most prominent part ofthe tumor, and its greasy content associated with hair tuftswas progressively removed. The capsule adherent to theinner (or membranous) layer of the lateral wall of the cav-ernous sinus was dissected and removed in a piecemealfashion.Histopatological examination confirmed that the tumorwas a dermoid cyst.The patient’s postoperative recovery was uneventful. Atthe 1-month follow-up examination, diplopia had resolvedand MR images obtained at this time revealed total tumorresection (Fig. 1).Interdural dermoid cysts of the lateral wall of the cavern-ous sinus have been rarely reported in the literature [1, 5].The lateral dural wall of the cavernous sinus is composed oftwo layers, the outer layer (meningeal layer or dura propria)and the inner membranous layer (or endosteal layer), whichis formed by the dural sleeves of CN III, IVand V1 [3, 7].According to this meningeal architecture, interduraldermoid cysts generally induce symptoms due to involve-ment of the ophthalmic division of the trigeminal nerve,oculomotor nerve and trochlear nerve [1, 5]. In the present

Background. The authors retrospectively reviewed the results of two different treatment modalities (surgery and endovascular approach) in patients with intracranial micro-arteriovenous malformations (micro-AVMs). The goal of this study is to evaluate the respective role of surgical treatment and superselective acrylic embolization in the management of micro-AVMs. Method. Fourteen patients with micro-AVMs who had been treated by surgical resection or endovascular acrylic embolization during a 6-year period were analyzed. The average age at presentation was 44.6 years (range, 24–65 yr) with no sex dominance. All patients presented with an intracranial haemorrhage, which was superficial in twelve patients and in eloquent brain areas in seven patients. Severe neurological deficits were observed in eleven patients. Findings. Digital subtraction angiography (DSA) demonstrated micro-AVMs in eleven patients (78.5%) while in three patients (21.5%) the micro-AVM was detected only by superselective angiography (SA). Eight patients underwent surgical intervention which led to definitive resection in seven with no peri-operative morbidity. SA was performed in nine patients and followed by successful acrylic embolization of the micro-AVM in seven with haemorrhagic complications in two patients. All fourteen lesions were completely obliterated as demonstrated angiographically. Outcomes were classified according to the Modified Rankin Scale. With a mean long term clinical follow-up of 33 months (range, 8–75 mo), seven patients were Grade 0, six patients were Grade I and one patient was Grade IV. Conclusions. SA is deemed necessary to visualize micro-AVMs in case of questionable or negative findings also at delayed DSA in young healthy patients with otherwise unexplained intracranial haemorrhage. Obliteration of micro-AVM can be accomplished either surgically or endovascularly; however, the endovascular approach is associated with a defined procedural risk for haemorrhagic complications and long term angiographic follow-up is necessary.

Dural plasmacytomas are very rare and often disregarded in the differential diagnosis of more common lesions of the convexity. We report two cases. Both patients exhibited headache as a main symptom. Computed tomography and magnetic resonance showed a homogeneously enhanced lesion without calcification and without bone involvement.

Tension pneumocephalus complicating ventriculoperitoneal shunt is extremely rare. We report an elderly male who developed delayed tension pneumocephalus 12 months after ventriculoperitoneal shunt for hydrocephalus complicating aneurysmal subarachnoid hemorrhage. Fine-cut reformatted computer tomography scan revealed a large pneumatocele on the petrous apex associated with tegmen tympani defect. The shunt valve pressure was temporarily raised from 120 mm H 2 O to 200 mm H 2 O, and the patient underwent successful subtemporal extradural repair of the bony defect in the temporal bone. Although extremely rare, otogenic tension pneumocephalus is a potentially life-threatening condition, and urgent surgical repair of the bony defect in the temporal bone reduces the risk of both the morbidity and mortality.

The improved knowledge of clinical and emodynamical aspects of extracranial arteriovenous malformations in the 18 th century provided a foundation for the understanding and treatment of cerebrovascular pathology. It was not until the late 19 th century that detailed clinicopathological reports of intracranial arteriovenous malformations were published. In this historical context, a seminal report written by the Italian surgeon Francesco Rizzoli is worthy of notice, the Giulia case. A 9-year-old girl presenting with seizures and an occipital pulsanting swelling was examined in 1873 by Rizzoli. He was able to use Giulia's signs and symptoms to predict the complex angioarchitecture of her ''arteriovenous aneurysm passing through the wall of skull''. The postmortem dissection completely confirmed the supposed diagnosis, disclosing a direct communication between the hypertrophic branches of the ocipital artery and the transverse sinus. The clinical course of that case is briefly reviewed in this article and the diagnosis of this unusual arteriovenous shunt is discussed in light of the current neurosurgical knowledge.

BACKGROUND AND PURPOSE: Few collected series of cerebral microarteriovenous malformations (micro-AVMs) have been reported. Our propose was to assess the unique diagnostic and therapeutic challenges posed by these lesions and their influence on outcomes. METHODS: The clinical presentation, diagnostic features, principles of endovascular or surgical treatment, and outcomes for a consecutive series of 10 patients (five male, five female; mean age, 48.8 years; age range, 31–65 years) with angiographically demonstrated cerebral micro-AVMs were retrospectively analyzed. RESULTS: All patients presented with a cerebral hematoma (supratentorial in eight, infratentorial in two, intraventricular in one, subarachnoid in one; mean volume, 11.6 cm(3)), which was superficially situated in nine patients. Neurologic deficits were observed in nine patients, and three patients had seizures. The mean delay between the onset of symptoms and diagnosis was 129.8 days (range, 6 days to 1 year). Superselective angiography was performed in seven patients and followed by successful acrylic embolization of the lesion in five. Five patients underwent surgical intervention, which led to definitive resection. Although long-term neurologic problems were present in eight patients, they were able to return to their previous activities and employment. CONCLUSION: The diagnosis of cerebral micro-AVMs requires a high index of suspicion, especially in young adults with atypical hemorrhaging. Single-shot embolization of micro-AVMs may be a safe alternative to the established surgical therapy in select cases. Outcomes depend mostly on the clinical conditions at admission.

We propose an easy-to-construct digital video editing system ideal to produce video documentation and still images. A digital video editing system applicable to many video sources in the operating room is described in detail. The proposed system has proved easy to use and permits one to obtain videography quickly and easily. Mixing different streams of video input from all the devices in use in the operating room, the application of filters and effects produces a final, professional end-product. Recording on a DVD provides an inexpensive, portable and easy-to-use medium to store or re-edit or tape at a later time. From stored videography it is easy to extract high-quality, still images useful for teaching, presentations and publications. In conclusion digital videography and still photography can easily be recorded by the proposed system, producing high-quality video recording. The use of firewire ports provides good compatibility with next-generation hardware and software. The high standard of quality makes the proposed system one of the lowest priced products available today.