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A review of early accounts of dysphasia (Benton and Joynt, 1960) credits Valerus Maximus in 30 A.D. with the earliest description of acquired dyslexia: a case of head injury producing an isolated acquired dyslexia. After an interval of almost two millenia, sporadic reports of acquired dyslexia became more common in the 1800’s but definitive steps toward understanding the acquired disorders of written language were not made until Dejerine (1891, 1892). His descriptions of the clinical findings and anatomical correlations of acquired dyslexia, with and without dysgraphia, remain essentially unaltered as the foundation of the study of disorders of written language.

It is traditional that a review of the anatomy of language disorders commences with a summary of the history of the disputes between the proponents of the two main streams of thought about brain-language relationships. The ebb and flow of popularity of various localizationist and globalist theories is colorful and instructive, but it is well reviewed elsewhere (Hecaen and Albert, 1978). This issue is no longer relevant in the sense considered by previous generations. Clearly brain functions are not equally represented in all regions. Interhemispheric differences exist in 1) the perception and manipulation of higher level sensory information, 2) the Organization of axial, limb and buccofacial movements and 3) the ability to generate speech and language. These interhemispheric differences are based in part on anatomical asymmetries which are evident in fetal life (Wada et al., 1975). There is intrahemispheric specialization in brain function as well, and within the left hemisphere, much of this specialization in function constitutes the anatomy of language. Even many ostensible critics of the localizationist theories resorted to a system of language Classification that carried implicit functional localization which strongly resembled the classical formulations of Wernicke (1874) and Dejerine (1914). For example, Marie (1917), Head (1926), and Goldstein (1948), despite their reputations as antilocalizationists, utilized systems of Classification based on functional anatomy.

Syndromes of dysphasia may vary from the forms described in the preceding sections, or certain aspects of dysphasic syndromes may appear more prominently than others, depending on associated clinical conditions, language background of the patient, history of left-handedness, lesion localization, or individual differences. In this section we consider clinical features of some of these special forms of dysphasia.

The Syndrome of Broca’s dysphasia often evolves over a period of months and sometimes years from an initial stage of global dysphasia, but may occasionally appear in its own right as an acute dysphasia. In the completely developed picture of Broca’s dysphasia, spontaneous speech is nonfluent and agrammatic, while auditory comprehension is preserved at levels adequate for understanding most conversation and even at nearly normal levels in some patients. Sentence repetition is seriously impaired, although repetition of one- or two-word segments may be possible. Writing is usually on a par with speech. Reading aloud parallels the limited Output of spontaneous speech but reading for meaning, though sometimes slow and painstaking, is usually preserved at the level of auditory comprehension. Naming on visual confrontation is often slightly superior to the ability to generate names in spontaneous speech or in response to word definitions. Right hemiparesis affecting the arm more than the leg, buccofacial apraxia, and ideomotor apraxia of the motorically spared left Upper extremity are common. In the acute stage, if the initial deficit of auditory comprehension is mild, disturbances of writing are minimal and hemiparesis is not marked, and rapid improvement from a State of severe nonfluency is to be expected over several days or weeks. In these latter patients, agrammatism, as measured in handwriting samples or in a story completion task in which the patient is required to supply the proper grammatical form of a word that completes a sentence, is not prominent.