Alexia

Abstract

Alexia is a neurological term of Greek origin [A + Gk lex(is)]. It designates a partial or complete inability to read aloud and to comprehend the meaning of printed material, and is also applied to difficulty in learning how to read. The term is generally synonymous with dyslexia, especially in the British literature where dyslexia is the preferred word. In practice, alexia is often used to mean a complete inability to read and dyslexia denotes a milder or partial form of the defect. When it is used unqualified, alexia stands for the acquired form of reading disability which occurs in a previously literate person as a result of focal brain damage. Acquired alexia impairs the reading of sentences and words; in many cases, it may preclude even the reading of single letters. The most common cause of acquired alexia is stroke, i.e., focal brain damage in the form of infarction or hemorrhage, caused by cerebrovascular disease; however cerebral tumors, inflammatory processes, and head injury, among others, can also cause alexia. There are two major types of acquired alexia: in one the reading disorder is accompanied by agraphia, known as alexia-with-agraphia; in another patients retain the ability to write, known as alexia-without-agraphia, or pure alexia.