A Case Study of Agrammatic Dissociations in Speaking and Reading

Background and Aim : This paper reports agrammatic dissociations in speaking and reading in a Persian-speaking patient (A.G.) who became aphasic as a result of ischemic CVA. His clinical linguistic profile was assessed 15 months post-onset to determine the severity of impairments in different spoken and written skills. His MRI scans during acute and subacute stages indicated evidence of extensive cerebral edema predominantly in the left temporoparietal language areas and in the Anterior Cingulate Cortex (ACC) of the left cerebral hemisphere.Methods : We initially evaluated A.G.’s clinical linguistic profile by administering the bedside version of Persian Western Aphasia Battery (P-WAB-1) which indicated an Aphasia Quotient (AQ) index of 86. His written skills were examined using the reading subtests of Persian Diagnostic Aphasia Battery (P-DAB-3) which indicated a Language Quotient (LQ) index of 60. We also employed subtests of the Bilingual Aphasia Test (BAT, Persian version) to evaluate his word reading, sentence reading, and sentence repetition.Results : His overall clinical linguistic picture based on the initial assessment results during the chronic stage indicated mild aphasia severity with good auditory comprehension, good repetition, good confrontation naming, but nonfluent speech which conform to syndrome of transcortical motor aphasia. Notably, the present case exhibited three striking characteristics in the performance of different language modalities. First, the data showed a modality-specific dissociation between speaking and reading modalities with relatively spared auditory comprehension but severely impaired reading comprehension. Second, we observed a set of task-specific agrammatic symptoms mainly in out-loud sentence reading but well-preserved sentence repetition. Third, we noted certain universal and language-specific agrammatic impairments mainly in his reading performance that were in accord with the structural properties of Persian.Conclusion : Overall, the present clinical linguistic data as they relate to the lesion sites argue against the classical narrow localization models of brain and language. The dissociation between impairments of different language skills and levels is an indication that disorders in linguistic levels are not monolithic. Instead, the data lend support to non-unitary models of aphasia as a symptom complex phenomenon.

کلیدواژه ها:

agrammatic dissociations ، language-specific impairment ، modality-specific deficits ، Persian