Medical Sciences

  Liver failure: Liver failure itself is not a disease but a consequences of many liver diseases which fails the liver. Liver failure occurs in three clinical scenarios 1.       Acute liver failure 2.       Chronic liver failure 3.       Acute on chronic liver failure ACUTE LIVER FAILURE: DEFINITION: Define as liver disease that produce hepatic encephalopathy within six months of diagnosis. FULMINANT LIVER FAILURE: When encephalopathy develops within 2 weeks of jaundice. SUB-FULMINANT LIVER FAILURE: When encephalopathy develops within 3 months of jaundice.                                                        ...

 Brain herniation: DEFINITION: Displacement of brain tissue from one compartment to another in response to increase intracranial pressure . Intracranial compartment is divided by rigid dural folds ,if pressure in increased portion of brain are displaced across thses rigid structures,herniation leads to compromise blood supply to compressed tissue producing infarction ,additional swelling and further herniation. TYPES OF HERNIATION: 1. SUFBFALCIAN [CINGULATE] HERNIATION. 2. TRANSTENTORIAL[UNCINATE] HERNIATION. 3. TONSILLAR HERNIATION. SUBFALCIAN HERNIATION: DEFINITION: Unilateral or asymmetrical expansion of cerebral hemisphere that causes cingulate gyrus to displace under edge of falx cerebri. This herniation compress the anterior cerebral artery. TONSILLAR HERNIATION: DEFINITION: Displacement of cerebral tonsils through foremen magnum. This displacement cause compression of brain stem which comprises the vital respiratory and cardialC centers in medulla. TRANSTENTORIAL HERNI...

 CEREBRAL EDEMA: DEFINITION: Accumulation of fluid within the brain parenchyma following a generalized injury to brain. TYPES: There are two types of cerebral edema  1.Vasogenic Edema. 2.Cytotoxic Edema. VASOGENIC EDEMA: • It is defined as accumulation of extracellular fluid which occurs when blood brain barrier is disrupted. • Fluid moves from vascular compartment to extracellular spaces of brain . It is further divided into types namely 1.localized [for example after inflammation] 2.Gneralized .[for example after profuse injury] CYTOTOXIC EDEMA: • This type of edema is because of generalized hypoxia ,ischemia and exposure to certain toxin. • All these events leads to neuronal and glial cell injury which ultimately results in accumulation of fluid in extracellular spaces. CONSEQUENCES OF EDEMA: 1. Brain become edematous and soft. 2. Overfill the cranial vault. 3. Gyri become flattened. 4. Sulci become narrowed. 5. Ventricular cavities become compressed.