Progressive supranuclear palsy presenting with dynamic aphasia

Verbal adynamia in parkinsonian syndromes: behavioral correlates and neuroanatomical substrate

“…Taken together, our findings are in line with previous evidence for impaired organization of language output in parkinsonism (Petrova et al, 2016) but suggest a more specific limitation of verbal generation. Besides corroborating previous work showing reduced verbal fluency in parkinsonism (Herrera, Cuetos, & Ribacoba, 2012), the profiles of verbal adynamia exhibited by both our patient groups were broadly in keeping with the findings documented in previous detailed case studies of patients with PSP and dynamic aphasia (Esmonde et al, 1996; Robinson et al, 2006; Robinson et al, 2015). However, our study did not differentiate parkinsonian syndromes.…”

“…The present evidence implicates core inferior frontal and posterior superior temporal components of the dominant hemisphere language network: similar cortical regions have been linked to propositional speech output in the healthy brain (Wagner et al, 2001) and have been previously shown to be damaged in PDD, CBS, and PSP (Boxer et al, 2006). More specifically, this dominant hemisphere fronto-striatal network (and within this network, left inferior frontal cortex) has been linked to the pathogenesis of dynamic aphasia in detailed case studies of patients with neurodegenerative and focal brain pathologies (Costello & Warrington., 1989; Esmonde et al, 1996; Robinson, 2013; Robinson et al, 2006, 2015; Rohrer et al, 2010). Our study was not equipped to resolve the several candidate mechanisms that have been proposed to underpin dynamic aphasia; however, inferior frontal cortex is likely to be involved in discourse and fluent thought sequencing, as well as verbal response selection, all of which are potentially vulnerable in parkinsonian disorders (Boxer et al, 2006).…”

“…Here, we refer to speech as exemplified by everyday conversation, in which we are generally required to create a verbal message, however banal. Deficits of propositional speech output we subsume under the general term “verbal adynamia;” in its most well-defined and selective form, impaired generation of novel verbal messages leads to a characteristic, specific language disorder, “dynamic aphasia.” Dynamic aphasia is characterized by disproportionate impoverishment of propositional speech despite relatively preserved ability to produce speech in specific contexts such as naming, repetition, or reading; the core cognitive deficit has been variously held to reflect impaired construction of a sentence scheme, generation of novel verbal ideas, fluent sequencing of verbal thought, or selection among prepotent verbal alternatives (Costello & Warrington, 1989; Blank, Scott, Murphy, Warburton, & Wise, 2002; Esmonde, Giles, Xuereb, & Hodges, 1996; Robinson, Shallice, & Cipolotti, 2006; Wagner, Pare-Blagoev, Clark, & Poldrack, 2001; Warren, Warren, Fox, & Warrington, 2003). These formulations are not mutually incompatible and more than one cognitive mechanism may operate, particularly in the setting of strategic or diffuse brain damage (Esmonde et al, 1996; Robinson et al, 2006; Robinson, Spooner, & Harrison, 2015).…”

“…Dynamic aphasia has been documented in association with various focal brain lesions involving the dominant frontal lobe and its connections (Blank et al, 2002; Braun, Guillemin, Hosey, & Varga, 2001; Robinson, 2013; Wagner et al, 2001) as well as neurodegenerative syndromes implicating this circuitry, notably PSP (Bak, Hodges, & Thomas, 2008; ; Esmonde et al, 1996; Litvan et al, 1996; Robinson, 2013; Robinson et al, 2015; Warren et al, 2003). Propositional speech production is mediated by a distributed neural network including left superior and inferior frontal gyri, frontal operculum, and posterior superior temporal cortex (Blank et al, 2002; Braun et al, 2001; Wagner et al, 2001).…”

L'aphasie (primaire) progressive: un diagnostic simple ou complexe

“…Quand la répétition est normale, on parle aussi d'aphasie transcorticale motrice. Cette variante aé té rapportée principalement dans la PSP [20][21][22]. Bien que difficiles àdifférencier de l'atteinte exécutive globale, des difficultés langagières similaires sont connues dans la DFT [23] (voir aussi tableau 2).…”