Ashok Pillai

Temporal fossa arachnoid cyst presenting with bilateral subdural hematoma following trauma: two case reports

IntroductionIntracranial arachnoid cysts are considered to be congenital malformations with a predilection for the temporal fossa. They are often asymptomatic but can sometimes be symptomatic due to enlargement or hemorrhage. There are multiple case reports of arachnoid cysts becoming symptomatic with hemorrhagic complications following head trauma. In such cases, the bleeding is often confined to the side ipsilateral to the arachnoid cyst. Occurrence of contralateral subdural hematomas in patients with temporal fossa arachnoid cysts has rarely been observed and is reported less frequently in the medical literature.Case presentationWe report two cases of people (a 23-year-old man and a 41-year-old man) with temporal fossa arachnoid cysts complicated by a subdural hematoma following head injury. Both patients developed a subdural hematoma contralateral to the side of a temporal fossa arachnoid cyst. It is likely that lack of adequate intracranial cushioning in the presence of an intracranial arachnoid cyst may result in injury not only to ipsilateral but also to contralateral bridging veins, following head trauma.ConclusionIt is important to identify and report such rare complications with intracranial arachnoid cysts, so that asymptomatic patients with an intracranial arachnoid cyst can be counseled about such possibilities following head trauma.

Surgical management of a pial arteriovenous fistula with giant varix in an infant

A seven-month-old infant presented with a generalized seizure. The radiological evaluation revealed a large arteriovenous fistula in the left sylvian region. The fistula connected the left middle cerebral artery and the vein of Trolard. A giant varix was present at the venous end. The child underwent craniotomy, complete disconnection of the fistula and excision of the varix. Except for recurrent seizures, which were eventually controlled on anticonvulsants, the childs neurological development has been good on long-term follow-up of three years. Pial arteriovenous fistulae are rare intracranial vascular malformations. Though significant operative risks exist, they can be successfully managed surgically with good long-term prognosis.

Massive spontaneous hemothorax, giant intrathoracic meningocele, and kyphoscoliosis in neurofibromatosis type 1.

Neurofibromatosis type 1 (NF-1) is a heterogeneous autosomal dominant disease with an incidence ranging from 1 in 2500 to 1 in 3000. Rare intrathoracic vascular disorders resulting in massive spontaneous hemothorax with fatal consequences may occur in these patients, so also are various types of skeletal dysplasia which may result in dramatic presentations, posing management challenges to the attending physicians. We report the case of a 43-year-old woman with NF-1 who developed spontaneous massive hemothorax and was discovered to have a concurrent giant intrathoracic meningocele and thoracic kyphoscoliosis with severe vertebral dysplastic changes. Surgical treatment via a right thoracotomy with primary repair of the meningocele and spinal fusion with fibula graft resulted in good outcome. This case represents an extreme manifestation of this otherwise indolent disease in clinical practice.

Intraventricular chordoid meningioma in a child: fever of unknown origin, clinical course, and response to treatment

The authors present the case of an 11-year-old boy with an intraventricular chordoid meningioma, which is a rare presentation of prolonged fever of unknown origin due to a rare tumor in a rare location. The fever resolved after excision of the lesion. Subsequent imaging revealed recurrence at 1 year. After a repeat excision and fractionated radiotherapy, the patient has remained disease free 5 years after the first surgery. Very few cases of intraventricular chordoid meningioma have been reported to date. The pathological features and clinical course are described. A review of the literature describing management options for this tumor type, recently found to have a higher recurrence rate, is described herein.

An unusual parasagittal tumour with acute blindness and response to cerebrospinal fluid shunting

We report a seven-year-old girl who presented with a sudden tumor apoplexy due to a parasagittal hemangiopericytoma. Following tumor excision, the child was noted to have bilateral optic nerve dysfunction and progressive papilledema, despite rapid overall neurological improvement. Based on the clinical features, we feel that this case represents an unusual form of visual deterioration related to impaired CSF absorption somehow precipitated by the acute tumour apoplexy. This unusual case of blindness responded significantly to CSF shunting. Several reports exist describing raised intracranial pressure with papilledema caused by nonthrombotic sinus occlusion due to tumors in proximity to the posterior superior sagittal sinus, torcular herophili and the jugular outlet. Communicating hydrocephalus, pseudotumor syndrome or intracranial venous sinus obstruction should be considered when otherwise inexplicable visual loss coexists with optic nerve dysfunction and papilledema. We emphasize the importance of a thorough search for the cause of visual loss.

Trans-sylvian Approach to Microvascular Decompression for Trigeminal Neuralgia in Syndromic Cranial Base Settling

BACKGROUND AND IMPORTANCE The lateral suboccipital approach for microvascular decompression (MVD) of the trigeminal nerve has become a standard-of-care over the past several decades. Syndromic cranial base settling, a rare but known cause for trigeminal neuralgia (TN), poses significant dilemmas in clinical management. In such cases, distorted anatomy may render surgery via the suboccipital approach difficult or even impossible. CLINICAL PRESENTATION A 34-yr-old male with osteogenesis imperfecta and severe basilar invagination suffered from TN that was refractory to medication and stereotactic radiosurgery. MVD of the fifth nerve root was performed via a pterional trans-sylvian approach after 3-dimensional trajectory modeling suggested the feasibility of this approach. He experienced complete resolution of TN and remains free of both pain and medications after 18 mo of follow-up. CONCLUSION This microsurgical trajectory, previously undescribed for TN, provides good visualization of the trigeminal root entry zone, thereby offering an excellent surgical option for severe TN in the setting of abnormal posterior fossa anatomy.

Role of magnetoencephalography and stereo-electroencephalography in the presurgical evaluation in patients with drug-resistant epilepsy

In selected patients with drug-resistant focal epilepsies (DRFE), who otherwise are likely to be excluded from epilepsy surgery (ES) because of the absence of a magnetic resonance imaging (MRI)-demonstrable lesion or discordant anatomo-electro-clinical (AEC) data, magnetoencephalography (MEG) may help to generate an AEC hypothesis and stereo-electroencephalography (SEEG) may help to verify the hypothesis and proceed with ES. The sensitivity of MEG is much better in localizing the spiking zone in relation to lateral temporal and extratemporal cortical regions compared to the mesial temporal structures. MEG has a dominant role in the presurgical evaluation of patients with MRI-negative DRFEs, insular epilepsies, and recurrent seizures after failed epilepsy surgeries, and in guiding placement of invasive electrodes. Moreover, postoperative seizure freedom is better if MEG spike source localized cortical region is included in the resection. When compared to subdural grid electrode recording, SEEG is less invasive and safer. Those who are otherwise destined to suffer from uncontrolled seizures and their consequences, SEEG guided ES is a worthwhile and a cost-effective option. Depending on the substrate pathology, there is > 80-90% chance of undergoing ES and 60-80% chance of becoming seizure-free following SEEG. Recent noninvasive techniques aimed at better structural imaging, delineating brain connectivity and recording specific intracerebral EEG patterns such as high frequency oscillations might decrease the need for SEEG; but more importantly, make SEEG exploration more goal-directed and hypothesis-driven.

Exploring the role of defective fibronectin matrix assembly in the VHL-associated CNS hemangioblastoma.

Abstract Background: Central nervous system (CNS) hemangioblastoma (HB) is the most common tumor in the von Hippel Lindau (VHL) disorder, the hereditary tumor syndrome caused by the biallelic mutations of the VHL gene. The disrupted VHL and Elongin protein interaction on hypoxia-inducible factor-1α (HIF-1α) induces a set of hypoxia-inducible genes, resulting in an unchecked endothelial cell proliferation that then leads to hemangioblastoma formation. However, recent studies have shown that disruptive germline mutations of VHL need not result in hemangioblastoma, though it can cause other manifestations of the VHL syndrome. Similarly, sporadic hemangioblastoma can occur rarely without a somatic biallelic VHL mutation. The VHL protein was earlier found to be associated with the deposition of matrix fibronectin (FN) protein in the renal extracellular matrix. Methods: The present study was designed to investigate the deposition of the matrix FN protein in VHL-associated hemangioblastoma. Results: Seven HB tumor samples from the VHL syndrome had lower expressions of tissue FN compared to the control cerebellum samples or the control blood vessel sample. On comparing the VHL and FN protein expressions in a timed endothelial tube assay, the VHL protein expression was absent during the initial phase of tube formation but started expressing after 6 h. The levels of matrix form of FN gradually increased along with the VHL expression during the maturation of tube formation. Tube formation was found to be enhanced with extraneously added soluble FN and inhibited by matrix FN. Similarly, tube formation was inhibited by a modified tripeptide (RGD) inhibitor of integrin (-αVβ3), namely, Cyclo-Ala-Arg-Gly-Asp-3-aminomethylbenzoyl. Conclusions: Our study implicates that the extracellular deposition and matrix formation of FN is important for vascular endothelial proliferation, and that its absence has roles in the development of hemangioblastoma in the VHL syndrome.

Cerebrospinal Fluid Hyaluronan and Neurofibromatosis Type 2

Neurofibromatosis type 2 (NF-2) is associated with mainly three types of recurrent benign tumors restricted to the central nervous system: schwannoma, meningioma and ependymoma. The absence of the protein NF2/Merlin causes an uninterrupted cell proliferation cascade originating from an abnormal interaction between an extracellular mucopolysaccharide, hyaluronan (HA), and schwann cell surface CD44 receptor, which has been identified as one of the central causative factors for schwannoma. Most tumors in NF-2 have a predilection to originate from either arachnoid cap cells or schwann cells of the cisternal portion of nerve rootlets that share a continuous exposure to cerebrospinal fluid (CSF). We hypothesize that the CSF HA may play a role in tumorigenesis in NF-2. In a prospective analysis over a period of one year, the levels of medium to low molecular weight HA (LMW HA) was estimated in the CSF of three subjects with central schwannomas and compared against that of age-sex matched controls, using Cetyltrimethylammonium bromide coupled turbidimetric assay and found to be seventeen-fold higher in the schwannoma subjects compared to the controls. HA was observed to be actively secreted by cultured schwannoma cells isolated from tumor tissues commensurate with their proliferation rate. On cell viability index analysis to compare the cell proliferation of astrocytoma cells with LMW HA vs. oligomeric HA (OHA), we found a decrease in cell proliferation of up to 30% with OHA. The study provides initial evidence that CSF HA may have a central role in the tumorigenesis of schwannoma in NF-2.

Ventriculo-ureteral shunt insertion using percutaneous nephrostomy: a novel minimally invasive option in a patient with chronic hydrocephalus complicated by multiple distal ventriculoperitoneal shunt failures.

The management of ventriculoperitoneal (VP) shunt failure is a common problem in neurosurgical practice. On occasion, extraperitoneal sites for CSF diversion are required when shunting to the peritoneal cavity has failed after multiple attempts. The authors report a novel minimally invasive procedure allowing cannulation of the ureter for the purpose of ventriculo-ureteral (VU) shunting. Sixteen years prior to presentation, this 46-year-old woman had contracted tuberculous meningitis and had chronic hydrocephalus, with multiple distal shunt failures in recent months. A percutaneous nephrostomy was used to pass the distal catheter based on intraoperative retrograde pyelography. Following successful placement of the VU shunt, the patients hydrocephalus stabilized and she returned to her regular functional status. The only long-term complication noted within 36 months of follow-up was a transient episode of electrolyte disturbance and dehydration associated with a diarrheal illness that responded to adequate hydration and salt supplementation. By its minimally invasive nature, this approach offers a reasonable extraperitoneal alternative after multiple distal shunt catheter failures have occurred.