Frontiers in Psychology (Apr 2015)
Transcortical Motor Aphasia in Recovery: A Case Report
Abstract
Introduction The symptomatology of transcortical motor aphasia (TMA) or dynamic aphasia (Luria & Tsvetkova, 1970) allows the clinician to investigate “the particularly interesting stage in transition from initial thought to final verbal expression” and “to study in pure form the lack of speech initiative” (Rubens, 1976,p. 302). The symptoms described in the literature include: difficulty initiating speech, limited spontaneous speech, intact repetition, good auditory comprehension. In contrast, agrammatic sentence production is associated with Broca’s aphasia. Language data from a participant presenting with TMA and also agrammatic symptoms who showed a good recovery are analyzed. The aim of this presentation is to tease apart the observed language features to arrive at a better understanding of the nature of specific symptoms and their impact on language processing. Methods Participant GS: a 17-year-old carpenter’s apprentice, suffered a massive stroke. A complete occlusion of the left anterior-cerebral-artery was diagnosed. Procedure From 4 weeks to 10 months post onset GS was administered standardized language tests and tasks covering all linguistic levels. A matched control person (MH) was also tested. Results Selected results and examples are given in Table 1. GS’s initiation of spontaneously produced speech is captured by his slow rate of production and verbal output for texts in comparison to control MH. As shown in Table 1, specific syntactic features showed impairment. At six months his aphasia had evolved into a mild impairment. Discussion The utterances produced by a classical TMA patient are usually grammatical. In part, this applies to G.S. However, he also reveals the following difficulties: simplification of syntactic structure, substitutions and omissions of articles, frequent omission of prepositions, verb agreement and selection errors, and reversal of subject and object noun phrases various sentence and discourse level tasks. GS’s difficulties initiating spontaneous speech in comparison to the relative sparing of speech evoked through external stimulation – especially repetition of spoken language, visual confrontation naming and good auditory comprehension skills can be distinguished from the agrammatic symptomatology by classifying GS as presenting with the third type of transcortical motor aphasia put forward by Freedman, Alexander, & Naeser (1984): “TMA during recovery from Broca’s aphasia”. Kleist (1934) provides support for this third type of TMA; he stressed that patients with ‘adynamic language’ revealed difficulty producing sentences to the point of agrammatism. Based on analyses of GS’s initial symptoms and the evolution of his language skills, those features associated with TMA can be distinguished from the Broca’s agrammatic symptoms. The agrammatic deficits are considered in part to stem from an Impairment of automatic processing. Due to the long latencies in initiating his utterances those categories particularly affected in GS, namely the omission of articles and prepositions, are exactly those features put forward by Whitaker (1976) to be automatically processed. On the other hand, the reversal errors are associated with an impairment of the linear scheme of the phrase observed in dynamic aphasia. In summary, despite an initial massive lesion, GS showed a remarkable recovery as shown by his language profile at six months post onset.
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