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…
Neural Tube Defects Definition Failure in the proper closure of part or all of the neural tube; called induction disorder (neural tube induced by the notochord and paraxial mesoderm during the third to fourth week of gestation) Clinical Features Epidemiology…
Definition Displacement of brain tissue from one intracranial compartment to another; these compartments are separated by rigid structures such as dura or bone Clinical Features You’re Reading a Preview Become a Clinical Tree membership for Full access and enjoy Unlimited…
Definition Buildup of cerebrospinal fluid (CSF) within the ventricles leading to brain swelling, increased intracranial pressure, and damage to brain tissue; most often caused by obstruction of CSF flow at common sites of obstruction: foramina of Monro, Luschka, and Magendie;…
Definition Excess fluid accumulation within the brain parenchyma Brain, blood, and cerebrospinal fluid (CSF) exist in rigid compartments of skull and dura, leaving limited room for parenchymal expansion Cerebral edema results in increased intracranial pressure (ICP) Two principal types of…
Skeletal muscle, which represents 40 % of the weight of a reasonably fit human, has one major function: converting food into force. The unit of contraction in skeletal muscle is the sarcomere, a 2.5 × 1 × 1 µm lattice of interdigitating thick (predominantly myosin) and…
Non-glial tumors constitute the bulk of neoplasms encountered in the central nervous system (CNS). They include a wide variety of tumor types and a spectrum of behaviors ranging from benign to highly malignant. This chapter discusses some of the more…