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A 57‐year‐old man presented with dynamic aphasia with evolving agrammatism and anomia. Additionally, he exhibited emerging atypical parkinsonism and features of behavioral variant frontotemporal dementia. Insights pertinent to this complex clinical presentation are discussed. [ABSTRACT FROM AUTHOR]

The diagnostic criteria for progressive supranuclear palsy (PSP) incorporate two speech-language disturbances (SLDs), non-fluent/agrammatic primary progressive aphasia and progressive apraxia of speech, but overlook the inclusion of other SLDs, including dynamic aphasia (DA). Thus, there is a need to reappraise the broad spectrum of SLDs in PSP to include other presenting phenotypes. Here we report findings from the study of two elderly patients with PSP presenting with DA and irrepressible echolalia. Both patients had markedly impoverished verbal production, but their performance in other tasks (repetition and naming) and auditory comprehension were preserved or only mildly impaired. Experimental tests of DA revealed impaired word and sentence generation in response to verbal and non-verbal stimuli. Additional language and cognitive testing revealed different types of echolalia (mitigated, automatic, and echoing approval) as well as impaired inhibitory control and social cognition (mentalizing). Both patients had negative neuropsychiatric alterations (i.e., apathy, aspontaneity, and indifference/emotional flatness). Brain magnetic resonance imaging in both patients showed atrophy of the midbrain tegmentum and superior medial frontal cortex suggestive of PSP, yet further evaluation of the neural correlates using multimodal neuroimaging and neuropathological data was not performed. However, based on the already known neural basis of DA and echolalia in PSP and stroke, we suggest that, in the present cases, neurodegeneration in the midbrain tegmentum, superior medial frontal lobe, and caudate nucleus was responsible for DA and that decreased activity in these regions may play a permissive role for eliciting verbal echoing via disinhibition of the perisylvian speech-language network.

The diagnostic criteria for progressive supranuclear palsy (PSP) incorporate two speech-language disturbances (SLDs), non-fluent/agrammatic primary progressive aphasia and progressive apraxia of speech, but overlook the inclusion of other SLDs, including dynamic aphasia (DA). Thus, there is a need to reappraise the broad spectrum of SLDs in PSP to include other presenting phenotypes. Here we report findings from the study of two elderly patients with PSP presenting with DA and irrepressible echolalia. Both patients had markedly impoverished verbal production, but their performance in other tasks (repetition and naming) and auditory comprehension were preserved or only mildly impaired. Experimental tests of DA revealed impaired word and sentence generation in response to verbal and non-verbal stimuli. Additional language and cognitive testing revealed different types of echolalia (mitigated, automatic, and echoing approval) as well as impaired inhibitory control and social cognition (mentalizing). Both patients had negative neuropsychiatric alterations (i.e., apathy, aspontaneity, and indifference/emotional flatness). Brain magnetic resonance imaging in both patients showed atrophy of the midbrain tegmentum and superior medial frontal cortex suggestive of PSP, yet further evaluation of the neural correlates using multimodal neuroimaging and neuropathological data was not performed. However, based on the already known neural basis of DA and echolalia in PSP and stroke, we suggest that, in the present cases, neurodegeneration in the midbrain tegmentum, superior medial frontal lobe, and caudate nucleus was responsible for DA and that decreased activity in these regions may play a permissive role for eliciting verbal echoing via disinhibition of the perisylvian speech-language network. [ABSTRACT FROM AUTHOR]

The acquisition and evolution of speech production, discourse and communication can be negatively impacted by brain malformations. We describe, for the first time, a case of developmental dynamic dysphasia (DDD) in a right-handed adolescent boy (subject D) with cortical malformations involving language-eloquent regions (inferior frontal gyrus) in both the left and the right hemispheres. Language evaluation revealed a markedly reduced verbal output affecting phonemic and semantic fluency, phrase and sentence generation and verbal communication in everyday life. Auditory comprehension, repetition, naming, reading and spelling were relatively preserved, but executive function was impaired. Multimodal neuroimaging showed a malformed cerebral cortex with atypical configuration and placement of white matter tracts bilaterally and abnormal callosal fibers. Dichotic listening showed right hemisphere dominance for language, and functional magnetic resonance imaging (fMRI) additionally revealed dissociated hemispheric language representation with right frontal activation for phonology and bilateral dominance for semantic processing. Moreover, subject D also had congenital mirror movements (CMM), defined as involuntary movements of one side of the body that mirror intentional movements of the other side. Transcranial magnetic stimulation and fMRI during voluntary unimanual (left and right) hand movements showed bilateral motor cortex recruitment and tractography revealed a lack of decussation of bilateral corticospinal tracts. Genetic testing aimed to detect mutations that disrupt the development of commissural tracts correlating with CMM (e.g., Germline DCC mutations) was negative. Overall, our findings suggest that DDD in subject D resulted from the underdevelopment of the left inferior frontal gyrus with limited capacity for plastic reorganization by its homologous counterpart in the right hemisphere. Corpus callosum anomalies probably contributed to hinder interhemispheric connectivity necessary to compensate language and communication deficits after left frontal involvement.

Background: Language and communication are fundamental to the human experience, and, traditionally, spoken language is studied as an isolated skill. However, before propositional language (i.e., spontaneous, voluntary, novel speech) can be produced, propositional content or 'ideas' must be formulated. Objective: This review highlights the role of broader cognitive processes, particularly 'executive attention', in the formulation of propositional content (i.e., 'ideas') for propositional language production. Conclusions: Several key lines of evidence converge to suggest that the formulation of ideas for propositional language production draws on executive attentional processes. Larger-scale clinical research has demonstrated a link between attentional processes and language, while detailed case studies of neurological patients have elucidated specific idea formulation mechanisms relating to the generation, selection and sequencing of ideas for expression. Furthermore, executive attentional processes have been implicated in the generation of ideas for propositional language production. Finally, neuroimaging studies suggest that a widely distributed network of brain regions, including parts of the prefrontal and parietal cortices, supports propositional language production. Implications: Theoretically driven experimental research studies investigating mechanisms involved in the formulation of ideas are lacking. We suggest that novel experimental approaches are needed to define the contribution of executive attentional processes to idea formulation, from which comprehensive models of spoken language production can be developed. Clinically, propositional language impairments should be considered in the context of broader executive attentional deficits. [ABSTRACT FROM AUTHOR]

Abstract Energization is the process of initiating and sustaining a response over time. It has been described as one of three key "supervisory" attentional control processes associated with the frontal lobes. Attentional mechanisms, such as energization, are critical for a range of cognitive functions, such as spontaneous speech and other higher-order tasks. We aimed to investigate the process of energization in a case series of patients with progressive supranuclear palsy (PSP). Patients with a diagnosis of PSP (N = 5), patient controls with a neurodegenerative condition (Alzheimer's disease N = 3, frontotemporal dementia N = 2) and healthy older adult controls (N = 30) were assessed on a standard neuropsychological battery, including executive tasks and standard attention and language tests. Energization was investigated using word fluency tasks, samples of spontaneous speech and an experimental button-pressing concentration task. Response rates for the word fluency, spontaneous speech and concentration tasks were separated into time periods, in order to compare response rates at different points across the tasks (e.g., first 15 s vs. last 45 s in a 60 s task). Four PSP patients showed a clear response pattern indicative of a decrease in energization. Healthy and patient controls remained consistent in their responding over time. Understanding how these underlying processes are impaired in PSP can ultimately inform intervention and management strategies, and has theoretical implications for models of spoken language production. Highlights • Patients with progressive supranuclear palsy are unable to maintain consistent responding. • This pattern is characteristic of an energization impairment. • Deficient energization observed on an experimental task, word fluency and in spontaneous speech. • Energization plays a key role in the generation of ideas for spontaneous speech. [ABSTRACT FROM AUTHOR]

Verbal adynamia (impaired language generation, as during conversation) has not been assessed systematically in parkinsonian disorders. We addressed this in patients with Parkinson's dementia, progressive supranuclear palsy and corticobasal degeneration. All disease groups showed impaired verbal fluency and sentence generation versus healthy age-matched controls, after adjusting for general linguistic and executive factors. Dopaminergic stimulation in the Parkinson's group selectively improved verbal generation versus other cognitive functions. Voxel-based morphometry identified left inferior frontal and posterior superior temporal cortical correlates of verbal generation performance. Verbal adynamia warrants further evaluation as an index of language network dysfunction and dopaminergic state in parkinsonian disorders. [ABSTRACT FROM AUTHOR]

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.

Frontal dynamic aphasia is characterised by a profound reduction in spontaneous speech despite well-preserved naming, repetition and comprehension. Since Luria (1966, 1970) designated this term, two main forms of dynamic aphasia have been identified: one, a language-specific selection deficit at the level of word/sentence generation, associated with left inferior frontal lesions; and two, a domain-general impairment in generating multiple responses or connected speech, associated with more extensive bilateral frontal and/or frontostriatal damage. Both forms of dynamic aphasia have been interpreted as arising due to disturbances in early prelinguistic conceptual preparation mechanisms that are critical for language production. We investigate language-specific and domain-general accounts of dynamic aphasia and address two issues: one, whether deficits in multiple conceptual preparation mechanisms can co-occur; and two, the contribution of broader cognitive processes such as energization, the ability to initiate and sustain response generation over time, to language generation failure. Thus, we report patient WAL who presented with frontal dynamic aphasia in the context of progressive supranuclear palsy (PSP). WAL was given a series of experimental tests that showed that his dynamic aphasia was not underpinned by a language-specific deficit in selection or in microplanning. By contrast, WAL presented with a domain-general deficit in fluent sequencing of novel thoughts. The latter replicated the pattern documented in a previous PSP patient ( Robinson, et al., 2006 ); however, unique to WAL, generating novel thoughts was impaired but there was no evidence of a sequencing deficit because perseveration was absent. Thus, WAL is the first unequivocal case to show a distinction between novel thought generation and subsequent fluent sequencing . Moreover, WAL's generation deficit encompassed verbal and non-verbal responses, showing a similar (but more profoundly reduced) pattern of performance to frontal patients with an energization deficit. In addition to impaired generation of novel thoughts, WAL presented with a concurrent strategy generation deficit, both falling within the second form of dynamic aphasia comprised of domain-general conceptual preparation mechanisms. Thus, within this second form of dynamic aphasia, concurrent deficits can co-occur. Overall, WAL presented with the second form of dynamic aphasia and was impaired in the generation of novel thoughts and internally-generated strategies, in the context of PSP and bilateral frontostriatal damage. [ABSTRACT FROM AUTHOR]

Background and Objective: Primary progressive aphasia (PPA) is a neurodegenerative disorder characterized by progressive language impairment. The three variants of PPA include the nonfluent/agrammatic, semantic, and logopenic types. The goal of this report is to describe two patients with a loss of speech initiation that was associated with bilateral medial frontal atrophy.Methods and Results: Two patients with progressive speech deficits were evaluated and their examinations revealed a paucity of spontaneous speech; however their naming, repetition, reading, and writing were all normal. The patients had no evidence of agrammatism or apraxia of speech but did have impaired speech fluency. In addition to impaired production of propositional spontaneous speech, these patients had impaired production of automatic speech (e.g., reciting the Lord's Prayer) and singing. Structural brain imaging revealed bilateral medial frontal atrophy in both patients.Conclusion: These patients' language deficits are consistent with a PPA, but they are in the pattern of a dynamic aphasia. Whereas the signs-symptoms of dynamic aphasia have been previously described, to our knowledge these are the first cases associated with predominantly bilateral medial frontal atrophy that impaired both propositional and automatic speech. Thus, this profile may represent a new variant of PPA. [ABSTRACT FROM AUTHOR]

Background: Idiopathic basal ganglia calcification (IBGC), also known as Fahr's disease, is a rare disorder characterized by widespread cerebral calcifications, an autosomal dominant pattern of inheritance and clinical and genetic heterogeneity. The recently identified IBGC gene, SLC20A2, encodes for type III sodium-dependent phosphate transporter 2 and its loss-of-function mutations may lead to the regional accumulation of inorganic phosphate in the brain, causing calcium phosphate deposition. Objective: To describe the clinical, neuroimaging and genetic findings in an Italian family with IBGC. Methods: The family members underwent clinical and radiological examination in order to diagnose IBGC according to standard criteria and screening for SLC20A2 gene mutations. The affected subjects also underwent neuropsychological longitudinal assessments and functional neuroimaging investigations. Results: The 2 affected family members harbored a novel missense mutation, G1618A, in the SLC20A2 gene, leading to gly540-to-arg (G540R) substitution in a highly conserved residue. This is the first SLC20A2 gene mutation associated with familial IBGC reported in the Italian population and is damaging according to all prediction programs. In the index case we observed a fair correlation between cortical areas with no calcifications but with significant hypometabolism at [18F]FDG-PET (inferior frontal premotor cortex) and the neuropsychological picture dominated by dynamic aphasia and buccofacial apraxia. Conclusion: These findings expand the catalog of SLC20A2 mutations identified to date and add dynamic aphasia to the spectrum of neuropsychological deficits reported in IBGC, supporting the use of functional neuroimaging studies for better investigation of genotype-phenotype correlations. © 2014 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

We describe a patient (KO) with reduced spontaneous speech, resembling dynamic aphasia, after awake glioma surgery in the proximity of the supplementary motor area. Naming, repetition, and comprehension were intact. He was tested with an extensive neuropsychological test-battery and a protocol for dynamic aphasia at 1 year. He presented with postoperative reduced spontaneous speech and selective executive function deficits. Most language recovery took place at 3 months postoperatively, whereas the executive functions improved between 3 months and 1 year. Results suggest that resection near the supplementary motor area could increase the risk of cognitive disturbances at long term, especially language. [ABSTRACT FROM PUBLISHER]

Abstract: MC is the first reported case of dynamic aphasia in the context of non-fluent progressive aphasia and Parkinson's disease. MC's language profile was characterised by the hallmark propositional language impairment despite well-preserved naming, reading, repetition and comprehension skills. The severity of MC's propositional language deficit was comparable to other dynamic aphasic patients. Word and sentence generation performance was severely impaired only when many competing responses were activated by a stimulus. Thus, when a dominant response was available verbal generation was satisfactory. MC also presented with a deficit in idea generation and fluent sequencing of novel thoughts as discourse generation was extremely reduced and perseverative. In addition, non-verbal generation was impaired although dissociations emerged. MC was able to generate novel designs and gestures but his performance was highly perseverative, and his motor movement selection was abnormal, resembling a non-random pattern. MC is the first dynamic aphasic case with concurrent deficits in three mechanisms thought crucial for conceptual preparation processes; namely impaired selection, impaired generation of ideas and impaired fluent sequencing of novel thoughts. The findings are discussed in relation to conceptual preparation processes and their organisation, accounts of dynamic aphasia and the roles of the left inferior frontal and basal ganglia regions in conceptual preparation processes for verbal and non-verbal generation. [Copyright &y& Elsevier]

Abstract: Much debate surrounds the role of the left inferior frontal gyrus (LIFG). Evidence from lesion and neuroimaging studies suggests the LIFG supports a selection mechanism used in single word generation. Single case studies of dynamic aphasic patients with LIFG damage concur with this and extend the finding to selection of sentences at the conceptual preparation stage of language generation. A neuropsychological group with unselected focal frontal and non-frontal lesions is assessed on a sentence generation task that varied the number of possible conceptual propositions available for selection. Frontal patients with LIFG damage when compared to Frontal patients without LIFG damage and Posterior patients were selectively impaired on sentence generation tests only when stimuli activated multiple conceptual propositions that compete with each other for selection. We found that this selective impairment is critical for reduced speech rate, the core deficit of dynamic aphasia, and we would argue it is causative for one form of dynamic aphasia associated with LIFG lesions. These results provide evidence that the LIFG is crucial for selecting among multiple competing conceptual propositions for language generation. [Copyright &y& Elsevier]

Patients with 'dynamic aphasia' exhibit reduced spontaneous speech despite well preserved basic language functions. This disorder may allow insights into the conceptual preparation of messages. Various cognitive approaches have located the patients' impairment at the level of preverbal message generation, including verbal planning, loss of inhibition of lexical concepts, and, most recently, generation of sequences of novel thoughts. We report the case of HK who presented with dynamic aphasia. The study had two goals: first, as HK was assessed over a longer period of time, changes in his performances could be documented which were relevant for the interpretation of the underlying disorder. The present study is the first to document changes across time and improvements of some of the skills involved in language production. Second, further investigations were carried out to clarify HK's underlying deficits. He was unimpaired on a number of 'verbal planning' tasks which argues for the preservation of those specific processes of verbal planning which Levelt (1989) termed 'microplanning'. It is suggested that HK's performance may be best described as an impairment at the level of 'macroplanning'. The deficit may lie in the generation of novel thoughts though minor modifications of this recent approach are being suggested. [ABSTRACT FROM AUTHOR]

We report the case of OTM who presented with dynamic aphasia following a stroke that occurred in the left basal ganglia. He showed drastically reduced spontaneous speech in the context of well preserved naming, repetition and comprehension skills. OTM was particularly impaired in generating words, sentences and phrases when cued by a stimulus allowing many response options. By contrast, when a single response was strongly suggested by a stimulus, he could generate verbal responses adequately. OTM's non-verbal response generation abilities varied across tasks. He performed in the normal range in a motor movement generation test and he produced as many figures as controls when tested on a figural fluency task. He showed, however, many perseverations on this test. Moreover in a random number generation task he produced more responses that were part of ascending and descending series of numbers. The patient's impairments are interpreted as a consequence of two deficits. The first of these consists of an inability to generate verbal responses particularly in situations of high competition and involves the function of left frontal regions. The second deficit is one of impaired novel thought generation as evidenced by perseverations. This second deficit has been proposed to be a function of basal ganglia damage. [ABSTRACT FROM AUTHOR]

We describe a 76-year-old man (ADY) with dynamic aphasia in the setting of a degenerative frontal lobe dementia: primary progressive dynamic aphasia. He displayed a striking paucity of propositional speech despite intact speech production, and preserved singing and prosody. Vocal expression in the verbal and musical domains was investigated in a series of neuropsychological experiments based on novel language and musical tasks that were designed to establish the nature and specificity of the verbal output deficit. The features of the language disorder indicated that the speech output pathway was disrupted at the early stage of generation of a new pre-verbal message. In contrast, tests of musical output demonstrated that the generation of new musical ideas was unimpaired. The domain-specificity of dynamic aphasia may result from the disruption of specific cognitive processes necessary for the creation of verbal messages, as well as selective damage of brain regions involved in language production. [ABSTRACT FROM AUTHOR]