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Ebook Escourolle & poirier’s manual of basic neuropathology: Part 2

(BQ) Part 2 book "Escourolle & poirier’s manual of basic neuropathology" presentation of content: Acquired metabolic disorders, hereditary metabolic diseases, congenital malformations and perinatal diseases, pathology of skeletal muscle, pathology of peripheral nerve, diseases of the pituitary gland. | 9 Acquired Metabolic Disorders L E I L A C HI M E LLI AND F R A N Ç O I S E G R AY A WIDE range of systemic acquired metabolic diseases can also affect the central and/or peripheral nervous system (e.g. hypoxia, hypoglycemia, disorders of serum electrolytes, vitamin deficiencies, and exogenous intoxications). By and large, the morphologic manifestations of most of these diseases in the various organs of the body are nonspecific. In the central nervous system (CNS), on the other hand, lesions may find expression via selective involvement of some brain regions with simultaneous complete preservation of others, a phenomenon often referred to as selective vulnerability. The pathogenesis of the predisposition to injury of some anatomical areas and/or of some specific, largely neuronal, cell types varies considerably from one disease to another and is undoubtedly multifactorial in all. Differences in the vascular patterns of irrigation and resulting alterations in regional perfusion may explain, at least partly, the phenomenon of selective vulnerability in some disorders. Regional variations in the biochemical characteristics of neuronal populations or, most likely, in the distribution of receptors for various excitatory amino acids may also play a role in some others. 1. CEREBRAL HYPOXIA The brain normally receives about 15% of the cardiac output, consumes about 20% of the blood oxygen, and consumes about 10% to 20% of the blood glucose. Different states of deficient oxygen supply and utilization or deficient substrate may produce prominent cerebral hypoxic changes: • Anoxic or hypoxic hypoxia results from decreased pulmonary access to oxygen. This may be due to insufficient oxygen in the inspired air. It also may result from upper airway obstruction or may accompany pulmonary disorders that impede the uptake of oxygen. In rare instances (i.e., hyperthermia) it may be due to increased metabolic demand. • 205 • Anemic hypoxia results from decreased .