In vivo MRI signatures of hippocampal subfield pathology in intractable epilepsy.

OBJECTIVES: Our aim is to assess the subfield-specific histopathological correlates of hippocampal volume and intensity changes (T1, T2) as well as diff!usion MRI markers in TLE, and investigate the efficacy of quantitative MRI measures in predicting histopathology in vivo. EXPERIMENTAL DESIGN: We correlated in vivo volumetry, T2 signal, quantitative T1 mapping, as well as diffusion MRI parameters with histological features of hippocampal sclerosis in a subfield-specific manner. We made use of on an advanced co-registration pipeline that provided a seamless integration of preoperative 3 T MRI with postoperative histopathological data, on which metrics of cell loss and gliosis were quantitatively assessed in CA1, CA2/3, and CA4/DG. PRINCIPAL OBSERVATIONS: MRI volumes across all subfields were positively correlated with neuronal density and size. Higher T2 intensity related to increased GFAP fraction in CA1, while quantitative T1 and diffusion MRI parameters showed negative correlations with neuronal density in CA4 and DG. Multiple linear regression analysis revealed that in vivo multiparametric MRI can predict neuronal loss in all the analyzed subfields with up to 90% accuracy. CONCLUSION: Our results, based on an accurate co-registration pipeline and a subfield-specific analysis of MRI and histology, demonstrate the potential of MRI volumetry, diffusion, and quantitative T1 as accurate in vivo biomarkers of hippocampal pathology

Carotid endarterectomy: The procedure of choice for carotid stenosis

Ischemic stroke is the commonest cause of neurological morbidity and mortality. Carotid endarterectomy has been shown to be beneficial in preventing ischemic strokes in patients with significant stenosis of the carotid artery, both in symptomatic and asymptomatic patients. Carotid artery stenting has been proposed as an alternative to CEA for this population. This paper reviews the available literature on carotid endarterectomy comparing it to the best medical therapy and carotid artery stenting in the prevention of ischemic strokes in patients with carotid stenosis. The use of newer imaging techniques and tools to redefine the existing idea of “asymptomatic” stenosis and post procedural strokes has also been reviewed. We present a concise review of existing data that shows unequivocally that endarterectomy still remains superior to stenting and best medical therapy as of now

Giant cavernous carotid aneurysm with spontaneous ipsilateral ICA occlusion: Report of 2 cases and review of literature

Giant aneurysms of the cavernous carotid artery are rare entities which present predominantly with features of compression of the adjacent neural structures, most commonly the III, IV, VI and V cranial nerves. Historically, treatment options included occlusion of the feeding vessel, direct surgery on the aneurysm, bypass procedures and in recent times, the use of endovascular devices. While intramural thrombus formation is commonly seen in giant aneurysms, we present 2 cases of giant cavernous aneurysms which on evaluation were found to have spontaneous occlusion of the feeding internal carotid artery secondary to thrombus formation, and review the available literature regarding the same

Concomitant occurrence of vestibular schwannoma and epidermoid tumor

The occurrence of two tumors adjacent to each other at the same site is very rare. We present here, a patient with a vestibular schwannoma found adjacent to an epidermoid tumor in the cerebellopontine angle

Clinical, histopathological and immunohistochemical profile of central neurocytomas: An institutional series and literature review

Aim: Central neurocytomas are rare intra ventricular tumors, which are largely benign in both histology and clinical picture, though a subset of patients with tumor demonstrating clinically aggressive nature exists. This study analyzes the clinicopathological profile of neurocytoma, and aims to identify potential histopathological, and immunohistochemical factors that may govern the behavior and recurrence of these tumors. Materials and Methods: A retrospective analysis of 22 patients of central neurocytoma managed surgically at our institution from 1997 to 2006 was performed. Histopathology was reviewed; Immunohistochemistry to assess synaptophysin, glial fibrillary acidic protein (GFAP) expression and Ki-67 labeling (LI) index was performed. Results: The mean age at presentation was 27.9 years with an equal number of male and female patients. Fourteen patients underwent surgery by transcallosal approach and eight by transcortical approach. Gross total or near total tumor decompression was performed in 13 out of 22 patients (59%). Adjuvant therapy was not advised following primary surgery. Tumor recurrence was documented in three patients. The time to recurrence ranged from 21 to 61 months. Histopathological variations such as intra-tumoral hypercellularity, necrosis, ganglionic cell differentiation, and tumor cell GFAP expression were noted; which however, did not show any significance with respect to predicting recurrence. The initial mean Ki-67 LI index of recurrent tumors was 4±3.5 versus 2.3±2.1 in the ones that did not recur, but this difference was not statistically significant. Conclusions: Central neurocytomas are rare tumors, which are largely benign, with a good prognosis. Management needs to be individualized and recurrences can occur even after total resection. Immunohistochemical findings assist in establishing the diagnosis. The behavior of the tumor is not always predictable and recurrent tumors are often more aggressive than the primary