White matter-Maximien Parchappe and the integration of articulate language

History of aphasia: A broad overview

This chapter gives a broad overview of the description and theorizing of a wide range of language disorders resulting from brain damage, commonly classified under the umbrella term "aphasia." It covers works written in Antiquity up to the 20th century. Moreover, it looks at disturbances in various language modalities such as speech, language comprehension, reading, writing, and sign language. In addition, also forms of the more recently discovered primary progressive aphasia are discussed. Finally, important developments in the history of assessment and rehabilitation of language disorders are described. To properly characterize disorders of language, these developments are discussed from the perspectives of neurology, psychology, and linguistics.

The memory for words: Armand Trousseau on aphasia

Of all the nineteenth-century physicians whose names still resonate today, Armand Trousseau is perhaps the one most familiar, for his description of carpal spasm as a sign of hypocalcemia (Trousseau's sign) and his description of the hypercoagulable state associated with cancer (Trousseau's syndrome). In the last three years of his life, Trousseau turned his attention to aphasia, which he included in his 1864 and 1865 lectures given at Hôtel-Dieu Hospital in Paris and which he discussed in an address to the Imperial Academy of Medicine in 1865. Trousseau preceded Wernicke in describing aphasia as a symptom complex, in which he included Broca's aphemia, receptive aphasia, the inability to read with and without the inability to write (alexia with and without agraphia), the inability to name common objects (amnesic aphasia or anomia) and to recognize numbers (acalculia), and the inability to draw. Trousseau concluded that such a varied symptomatology could not arise from a single area, and he proposed that lesions of the posterior inferior frontal convolution identified by Broca, of the insula and corpus striatum and of the temporal and parietal lobes, could give rise to aphasia. The role of the posterior temporal lobe in receptive aphasia was confirmed by Wernicke in 1874, and the role of the inferior parietal lobule in agraphia and alexia was confirmed by Dejerine in 1891. Trousseau thought that aphasia resulted from the loss of the memory for words and for the synergistic actions of the movements of articulations learned in early childhood. Trousseau added inattention, lack of comprehension, and cognitive decline to amnesia as contributing factors to the verbal and nonverbal expression of thought. Trousseau constructed a comprehensive theory of aphasia that unified its semiology, localization, and pathophysiology. This construct had the virtue of being predictive and falsifiable by the clinico-pathological method. Through insight born of observation, Trousseau identified the issues that dominated aphasiology into the twenty-first century.

The perversion of language: Jules Baillarger on aphasia, the lateralization of speech, and the Baillarger-Jackson principle

Jules Baillarger was one of the foremost figures of nineteenth-century neurobiology. He is remembered today for his discovery that the human cerebral cortex is composed of six intercalated layers. Even today, two horizontal fiber bundles within cortical layers IV and V are referred to as the outer and inner bands of Baillarger. It is a measure of the importance of Baillarger's discovery that his findings were elaborated upon with advances in microscopy and the development of methods for staining neurons and myelin by, notably, Theodor Meynert and Santiago Ramon y Cajal. Furthermore, Baillarger's observation that there are variations in the thickness of one or another of the six cortical layers in different cortical regions, and the discovery of giant pyramidal motor neurons in layer V of the precentral gyrus, ultimately led to the cytoarchitectonic and myeloarchitectonic maps of Oscar Vogt and Cécile Vogt-Mugnier, and of their student Korbinian Brodmann (1908). Less well known are Baillarger's contributions to the semiology of aphasia and the pivotal role he played in the recognition of the localization and lateralization of speech to the left hemisphere. Paul Broca's localization of articulate language to the posterior aspect of the frontal lobes and Marc Dax's discovery that speech is a function of the left hemisphere were vigorously challenged within French academic medicine until 1865, when Baillarger gave two addresses to the Royal Academy of Medicine. In the first address, he described a form of aphasia he called the perversion of language, which we now call fluent aphasia, and reported that aphasic patients can express words or parts of sentences when they are angry or excited, a phenomenon now known as the Baillarger-Jackson principle. In his second address, Baillarger supported the lateralization of speech to the left hemisphere of the brain and referred to this association as Dax's "singular law," and supported the localization of speech to the posterior aspect of the left inferior frontal gyrus. Baillarger's description of the perversion of language and of the influence of emotions on speech presaged the discipline of aphasiology, and his support for the lateralization of speech to the left hemisphere marks the first instance of the unequivocal recognition of asymmetrical hemispheric functions by academic medicine. This article reviews these aspects of Baillargher's career. Critical sections of his papers on cortical structure, aphasia, and functional hemispheric asymmetry are translated by the author.