Supraorbital Craniotomy for Large Anterior Skull Base Meningiomas: A Technical Note.

BACKGROUND: Supraorbital craniotomy (SOC) has brought a paradigm shift in approaching anterior skull base lesions. With better understanding of relevant anatomy, the indications are being stretched from highly selected, small-to-moderate-sized tumors to large and complex anterior skull base lesions. OBJECTIVE: We share our experience and discuss the nuances of surgery for large anterior skull base meningiomas using the SOC. METHODS: This is a single institute study using prospectively collected retrospective data from seven cases of large anterior skull base meningiomas (>3 cm) using the SOC. We reviewed the indications, safety, and procedural complications in these cases. RESULTS: Simpson's Grade 2 excision was achieved in all these seven cases, with faster postoperative recovery. Follow-up clinical outcome and cosmesis were satisfactory. CONCLUSION: SOC is a safe alternative for the standard skull base approaches in treating large anterior skull base meningiomas. The SOC can be effectively used to treat selected large anterior skull base meningiomas.

Software-based simulation for preprocedural assessment of braided stent sizing: a validation study.

OBJECTIVEThe authors sought to validate the use of a software-based simulation for preassessment of braided self-expanding stents in the treatment of wide-necked intracranial aneurysms.METHODSThis was a retrospective, observational, single-center study of 13 unruptured and ruptured intracranial aneurysms treated with braided self-expanding stents. Pre- and postprocedural angiographic studies were analyzed. ANKYRAS software was used to compare the following 3 variables: the manufacturer-given nominal length (NL), software-calculated simulated length (SL), and the actual measured length (ML) of the stent. Appropriate statistical methods were used to draw correlations among the 3 lengths.RESULTSIn this study, data obtained in 13 patients treated with braided self-expanding stents were analyzed. Data for the 3 lengths were collected for all patients. Error discrepancy was calculated by mean squared error (NL to ML -22.2; SL to ML -6.14, p < 0.05), mean absolute error (NL to ML 3.88; SL to ML -1.84, p < 0.05), and mean error (NL to ML -3.81; SL to ML -1.22, p < 0.05).CONCLUSIONSThe ML was usually less than the NL given by the manufacturer, indicating significant change in length in most cases. Computational software-based simulation for preassessment of the braided self-expanding stents is a safe and effective way for accurately calculating the change in length to aid in choosing the right-sized stent for optimal placement in complex intracranial vasculature.

Extrapontine Myelinolysis and Reversible Parkinsonism After Hyponatremia Correction in a Case of Pituitary Adenoma: Hypopituitarism as a Predisposition for Osmotic Demyelination.

BACKGROUND: Osmotic demyelination syndrome commonly follows rapid correction of hyponatremia. Although pons is a common location, extrapontine locations, such as striatum and thalamus, have been reported. CASE DESCRIPTION: A 48-year-old woman presented with masked facies, shuffling gait, and pill-rolling tremors suggestive of acute-onset parkinsonism. Hyponatremia was diagnosed following a bout of diarrhea, which was corrected with hypertonic saline. Magnetic resonance imaging of the brain showed a giant pituitary adenoma. Hyperintensities on T2-weighted imaging were also seen at the level of pons and bilateral striatum. Central pontine myelinolysis and extrapontine myelinolysis were diagnosed. Hormonal assay showed hypocortisolism, secondary hypothyroidism, and hypogonadism. The patient was started on levodopa-carbidopa, steroids, and thyroxine. She underwent transnasal pituitary adenoma excision. At 6 months postoperatively, she had recovered completely with normal gait. Repeat imaging showed complete resolution of myelinolysis. At 36 months, she continued to have hypocortisolism and hypothyroidism requiring replacement. CONCLUSIONS: Extrapontine myelinolysis with parkinsonism and asymptomatic central pontine myelinolysis is rare with few cases described in the literature. Our patient had a pituitary adenoma with hyponatremia requiring sodium correction, and we believe that hypopituitarism might have predisposed her to osmotic demyelination. We reviewed relevant literature on extrapontine myelinolysis in suprasellar tumors and the pathophysiology. Hypopituitarism is an underrecognized cause of hyponatremia. When treating a patient with hyponatremia, knowing the pituitary function status is a prerequisite for the physician to prevent osmotic demyelination syndrome.

A rare case of solid calcified intramedullary neurenteric cyst: Case report and technical note.

Neurenteric cysts are rare lesions of the spinal cord, constituting less than 1.3% of all spinal cord tumors. Approximately 90% of neurenteric cysts are located in the intradural extramedullary compartment, while the remaining 10% are divided between an intradural intramedullary or extradural location. They are usually extramedullary and found in the lower cervical and thoracic spine. We report a case of 8 year old child with totally solid calcified intramedullary cyst which has hitherto not been reported in literature. We discuss the challenges faced in the diagnosis and surgical management of such lesions and a brief review of pertinent literature.

Giant posterior fossa dural cavernoma in a child.

PURPOSE: Extra-axial (dural) cavernomas are rare and constitutes 5% of all cavernomas. They are thought to arise from the venous plexus of the dura. They can reach large sizes before diagnosis and can have an aggressive presentation. METHODS: The authors report a rare case of giant cavernoma based on the posterior fossa dura adjacent to the sigmoid sinus (sino-dural angle) in an 8-year-old boy which was excised with good outcome. The authors describe its clinico-radiological profile and outcome characteristics along with a comprehensive review of relevant literature. RESULTS: This child underwent retromastiod craniectomy and complete excision of the dural cavernoma. The dural attachment was coagulated. Histopathological examination confirmed the diagnosis. CONCLUSION: We report cavernoma needs to be considered in the differential diagnosis of a dural-based posterior fossa lesion in paediatric population as complete excision is possible.

Angioglioma of the Spinal Cord.

BACKGROUND: Angiogliomas are rare low-grade glial tumors with significant vascular components. These tumors are usually seen in the brain, and spinal cord angiogliomas have not been reported in the literature until now. CASE DESCRIPTION: We report the case of a 15-year-old boy with an angioglioma of the medulla and cervicodorsal spine, which was completely excised through a combined suboccipital craniotomy and cervicodorsal laminotomy. The patient experienced excellent clinical recovery after the surgery, and follow-up contrast magnetic resonance imaging showed complete excision of the tumor. CONCLUSION: The fact that increased vascularity in a glioma does not always indicate a higher grade is confirmed by the unique histology of angiogliomas. These tumors can present with intratumoral bleeding. Awareness of these entities is extremely important. Complete excision can be attempted, and the postoperative prognosis is very good.

Stent-Assisted Coiling of Aneurysm in a Persistent Primitive Lateral Vertebrobasilar System.

Fenestrations of cerebral arteries are relatively common. Knowledge of their structure has recently gained clinical significance with increasing awareness of fenestration aneurysms. Persistent primitive lateral vertebrobasilar (PPLVB) anastomoses are an extreme end of the embryologic mishaps causing these fenestrations, and their occurrence has only been reported twice. We report the first case of an aneurysm within the PPLVB in a patient with unilateral subclavian stenosis. The unique anatomy of these aneurysms and relation with important perforators and brainstem make surgery extremely difficult and require advanced endovascular techniques like balloon remodeling and stent assistance. Three-dimensional rotational angiography can help in providing clarity to the aneurysmal anatomy and planning treatment. The purpose of this case report is to bring to notice the possibility of such aneurysms and use the unique anatomy to understand various tools available in the endovascular surgeon's armamentarium.

Paediatric calcified intramedullary schwannoma at conus: A common tumor in a vicarious location.

Spinal schwannomas are commonly intradural extramedullary in location. As Schwann cells are not common in the central nervous system, intramedullary schwannomas are a rare entity. In adults, an estimated sixty cases have been reported in English literature. They are rarer in children (less than ten cases), and preoperative diagnosis becomes a prerogative in achieving total excision. Cervical cord is a common location and less commonly they occur in the conus. We report a rare case of calcified conus intramedullary schwannoma in a child without neurofibromatosis, who presented with conus-cauda syndrome of 1-year duration. Literature has been reviewed regarding its origin, pathophysiology, radiological features, and surgical management. This child underwent laminotomy and subtotal resection of the lesion. Histopathologically, tumor had typical features of schwannoma and was positive for S-100 immunoperoxidase. We believe that schwannoma needs to be considered in the preoperative differential diagnosis of a conus tumor in children as complete excision is possible in these benign tumors, thus affecting a cure.

The vanishing shunt valve.

PURPOSE: Ventriculoperitoneal (VP) shunt is one of the most commonly performed procedures by a neurosurgeon. It is occasionally fraught with the most bizarre complications. Understanding the pathophysiology of these complications can help us make the procedure safe and more effective. METHODS: The authors report a case of 8-year-old boy, previously operated for lumbar myelomeningocele and hydrocephalus with an intra diploic migration of shunt tube and shunt dysfunction, and discuss the pathophysiology, diagnosis, and surgical strategy. RESULTS: After diagnosis of shunt malfunction, shunt revision was done with placement of new system and removal of the old apparatus. Patient had a remarkable recovery after the surgery. CONCLUSION: Intradiploic migration is an extremely rare cause of shunt malfunction and has never been reported in literature before. Possible mechanism is that prolonged pressure on the valve due to recumbent head position in a paraplegic child might have led to new bone formation and subsequent intradiploic migration of the valve. Careful planning the position of shunt valve in relation to head position, especially in children who are recumbent due to paraplegia might avoid this untoward complication.

Intracerebellar malignant nerve sheath tumor in a child: case report and review of literature.

PURPOSE: Intracerebellar malignant nerve sheath tumor (ICMNST) is an extremely rare entity, only two cases have been reported previously, and this is the first case to be reported in a child. The histogenesis, diagnosis, and management of this entity are very ambiguous, and natural history in a child is unknown. METHODS: The authors report a 7-year-old girl who presented with ataxia and signs of raised intracranial pressure and discuss the challenges in diagnosis, surgical strategy, and treatment. RESULTS: Following gross total resection and radiation to tumor bed, the patient had unremarkable recovery and is recurrence free at 1-year follow-up. CONCLUSION: ICMNSTs are extremely rare tumors of the cerebellum. Preoperative radiological diagnosis is not possible due to its close radiological resemblance to other common posterior fossa tumors. Immunohistochemistry plays a pivotal role in clinching the diagnosis. Though the reported adult counterparts have shown dismal prognosis, the pediatric counterparts may fare better with good surgical resection followed by radiotherapy.

Intrafistula pressure measurement in traumatic carotid cavernous fistulas--key to increasing safety and effectiveness of endovascular coiling.

BACKGROUND: Very few diseases demostrate the tremendous variation and capricious results common with the clinical ensemble of carotid cavernous fistulas (CCFs). The treatment modality for CCFs has changed from surgical to endovascular therapy. Many options exist in endovascular therapy ranging from balloons to coils and liquid embolization agents like Onyx. This study was undertaken to assess the role of recording intra-fistula pressure (IFP) during endovascular coiling of CCFs in order to help us better understand the angiodynamics of the fistula and to make coiling safer and effective. METHODS: IFP measurement was done in 15 cases of traumatic CCF undergoing endovascular coiling. Patients were prospectively analyzed by pre- and post- procedural clinical profile, degree of recovery and time until fistula occlusion. Univariate analysis was used to find the correlation between the reduction in IFP, the degree of fistula obliteration and time until occlusion. RESULTS: Of the 15 patients who underwent endovascular coiling 13 had total occlusion of the fistula, 1 patient had subtotal occlusion and 1 patient had no occlusion of the fistula. There was 100 % internal carotid artery (ICA) patency. Univariate analysis showed a strong correlation between the degree of reduction in IFP and time required for fistula occlusion (p < 0.001). Patients with a significant drop in IFP were also preceived as having a higher chance of fistula occlusion after waiting 30 min. CONCLUSION: To our knowledge this is the largest series in published literature focused on using only detachable coils as the first line embolizing agent in treatment of traumatic CCFs. We conclude that IFP monitoring will play an important role in making treatment of CCFs safer and more effective. The aim of coiling the fistula is not to tightly pack the fistula as during treatment of aneurysms; rather it is to reduce flow across the fistula leading to thrombosis thus reducing the requirement of coils.