Oligodendroglioma Definition A diffuse infiltrating glioma of adults consisting of cells resembling oligodendroglia, often with chromosomal deletions of 1p and 19q; typically located in the cerebral hemispheres World Health Organization (WHO) Grade II Clinical Features Epidemiology Constitute 3% of primary…
Diffuse Astrocytoma Definition Infiltrating glial neoplasm with astrocytic features, typically with some degree of pleomorphism, increased cellularity and slow growth; also known as low-grade diffuse astrocytoma World Health Organization (WHO) Grade II Clinical Features Epidemiology Peak incidence in fourth decade,…
Epidural Hematoma Definition Collection of blood within a potential space between skull and dura mater. Clinical Features Epidemiology Occurs in 1% to 4% of imaged head trauma patients Seen in 5% to 15% of patients with fatal head injuries Age…
Contusion/Laceration (Including Coup and Contrecoup Lesions) Definition Direct injury to surface of brain parenchyma, usually involving the cortical gray matter Contusion: a “bruise” of the brain with intact pia mater Laceration: tearing of brain tissue with breached pia mater Clinical…
Cerebral Amyloid Angiopathy Definition Vasculopathy arising from deposition of Aβ-amyloid peptide within walls of meningeal and superficial cortical blood vessels, which can lead to acute focal, multifocal, or lobar hemorrhages; a small subset of patients develop an intense inflammatory response…
Giant Cell Arteritis Definition Panarteritis affecting medium-sized and large extracranial branches of the aorta; most common primary vasculitis to affect the nervous system Clinical Features Epidemiology Incidence: 15 to 25 cases per 100,000 Peak incidence in individuals 75 to 85…
Arteriovenous Malformations (AVM) Definition Abnormal collection of thick-walled blood vessels with intervening gliotic brain tissue; arterial blood flows directly into draining veins without interposed capillary beds in this “high-flow” vascular malformation Clinical Features Epidemiology AVMs are congenital lesions Prevalence is…
Saccular (“Berry”) Aneurysms Definition A localized dilatation or ballooning of a cerebral artery that lacks an internal elastic lamina and has disrupted muscular layers; subarachnoid hemorrhage (SAH) commonly occurs with aneurysm rupture; intraventricular hemorrhage may also occur; synonyms: saccular aneurysm,…
Ischemic Cerebrovascular Disease Definition Atherothrombosis of large vessels or embolic occlusion of distal vessels, resulting in absence of blood flow Majority of infarcts result from the disruption and embolization of platelet thrombi or atherosclerotic plaque material, leading to obstruction of…
Germinal Matrix Hemorrhage Definition Bleeding into the subependymal germinal matrix zone with or without subsequent dissection into the lateral ventricle (intraventricular hemorrhage) Germinal matrix zone (GMZ): Fetal periventricular structure that forms between the developing deep cerebral nuclei and ependymal lining…