Alexia and agraphia: contrasting perspectives of J.-M. Charcot and J. Hughlings Jackson.

OBJECTIVE

To evaluate 19th-century concepts of cerebral localization for complex mental activities, focusing on alexia and agraphia in published writings of Jean-Martin Charcot (1825-1893) and John Hughlings Jackson (1835-1911).

BACKGROUND

In the early 1860 s, Broca's reports on a special role for the left frontal lobe in articulate language ignited frenetic interest in cerebral localization. Disorders of written language (alexia and agraphia) were enmeshed in ensuing discussions of how the brain was organized for language and other complex behaviors.

DESIGN/

METHODS

Focused review and analysis of Charcot's and Hughlings Jackson's publications on aphasia, alexia, and agraphia.

RESULTS

In the wake of Broca's observations, the extent to which language functions in general--or such specialized functions as reading and writing--might involve focal cerebral representation was controversial. Based on his clinical-pathologic approach to "regional diagnosis," Charcot came to value insights provided by "partial isolated aphasias." He described patients with isolated alexia and agraphia, and he proposed a functional-anatomic framework to accommodate these disorders. Adopting a hierarchical model of nervous system organization, Hughlings Jackson argued that reading and writing could not be dissociated from other aspects of "intellectual language." Charcot's reductionism was typical of his era, but Hughlings Jackson's more holistic approach was to gain ascendancy in early decades of the 20th century.

CONCLUSIONS

Charcot's and Hughlings Jackson's positions on alexia and agraphia reflected contrasting philosophical approaches to the study of brain disorders. Their views informed the opinions of their contemporaries and neurologic heirs in important debates on cerebral organization.