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Kenneth M. Heilman - One of the best experts on this subject based on the ideXlab platform.
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unilateral apraxic agraphia without ideomotor Apraxia in a patient with callosal and frontal lobe lesions p3 198
Neurology, 2018Co-Authors: Tigran Kesayan, Kenneth M. HeilmanAbstract:Objective: NA Background: Injury to the areas that store the spatial-temporal movement representations required to write, or a disconnection of these engrams from the motor areas can cause apraxic agraphia. Apraxic agraphia along with ideomotor Apraxia (IMA) of the left hand has been described from callosal lesions. We report a woman with apraxic agraphia of her left hand who did not demonstrate IMA. Design/Methods: Case Report: A 37 year-old right-handed woman with a history of alcohol abuse developed an apraxic agraphia of her left hand, and a limb-kinetic Apraxia (LKA), a loss of precise, independent and coordinated finger movements of both hands, as determined by the coin rotation test. However, she was without an IMA. MRI imaging reveal lesions of the genu and splenium of the corpus callosum (CC) and leukoaraiosis in the frontal lobes. Results: NA Conclusions: Discussion: These CC changes may be a form of Marchifava-Bignami disease. Injury to the CC can cause left hand LKA, and LKA can impair writing. However, this woman had a LKA of both hands, but her apraxic agraphia was limited to left hand. Diffusion tensor imaging studies have shown that patients with alcohol abuse can develop changes in the frontal white matter, and our patient did reveal some leukoaraiosis of her frontal white matter. Therefore, it is possible that frontal white matter injury was responsible for this patient’s bilateral LKA, and these white matter or callosal injuries may have also disconnected the letter spatial-temporal movement engrams from the motor areas of the right hemisphere causing an apraxic agraphia of her left hand. However, additional studies assessing patients with alcohol abuse for LKA and apraxic agraphia are needed Study Supported by: NA Disclosure: Dr. Kesayan has nothing to disclose. Dr Heilman has nothing to disclose.
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unilateral apraxic agraphia without ideomotor Apraxia from a callosal lesion in a patient with marchiafava bignami disease
Neurocase, 2018Co-Authors: Tigran Kesayan, Kenneth M. HeilmanAbstract:ABSTRACTApraxic agraphia can be caused by left hemispheric cerebral lesions in the area that contains the spatial representations of the movements required to write, from a lesion in, or connections to, the frontal premotor cortex that converts these spatial representations to motor programs (Exner’s area). A right-handed woman with Marchiafava Bignami disease and lesions of the genu and splenium of her corpus callosum had apraxic agraphia without ideomotor Apraxia of her left. A disconnection of Exner’s area in the left hemisphere from the right hemisphere’s premotor and motor areas may have led to her inability to write with her left hand.
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unilateral apraxic agraphia without ideomotor Apraxia from a callosal lesion in a patient with marchiafava bignami disease
Neurocase, 2018Co-Authors: Tigran Kesayan, Kenneth M. HeilmanAbstract:Apraxic agraphia can be caused by left hemispheric cerebral lesions in the area that contains the spatial representations of the movements required to write, from a lesion in, or connections to, th...
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callosal ideomotor Apraxia in alzheimer s disease
Journal of Clinical and Experimental Neuropsychology, 2017Co-Authors: Ann Marie Ciminoknight, Leslie Gonzalez J Rothi, Ying He, Kenneth M. HeilmanAbstract:ABSTRACTBackground/objective: Impaired ability to perform skilled movements with the left upper limb in patients with corpus callosum injury has been well described (callosal Apraxia) with some displaying spatial–temporal errors primarily in response to verbal commands (verbal callosal disconnection Apraxia), with imitation, and when using actual tools (callosal ideomotor Apraxia). Additionally some patients with callosal injury also make content errors when selecting and using the incorrect tool with their left upper limb (callosal conceptual Apraxia). Interestingly, patients with Alzheimer’s disease (AD) reveal anatomic evidence of callosal degeneration but callosal Apraxia in AD has not been described. The purpose of this study was to learn whether patients with AD display forms of callosal Apraxia. Method: Participants were 22 right-handed patients with AD and 24 matched controls. Both upper limbs were tested by having subjects pantomime transitive movements to command and imitation. Participants also...
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Apraxia the neuropsychology of action
2014Co-Authors: Leslie Gonzalez J Rothi, Kenneth M. HeilmanAbstract:The purpose of this book is to provide the reader with a perspective on Apraxia that considers a link between the pathology of Apraxia and normal motor skill. In addition, it is the intention of the authors to provide information that is theoretically interesting as well as clinically applicable. The book is a collection of papers by various authors working in the area of Apraxia, almost exclusively with limb aparaxia specifically. Beginning with Hugo Liepman's work of the late 19th century, a cognitive neuropsychological model of limb Apraxia is reviewed, the use of new technologies that are informative about the mechanisms of limb praxis are discussed, and issues related to research as well as clinical assessment/management of the disorder are provided. While acquired limb Apraxia is the focus of the book, there are also chapters on handedness, developmental Apraxia of speech, and disorders of handwriting.
Wolfram Ziegler - One of the best experts on this subject based on the ideXlab platform.
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complexity of articulation planning in Apraxia of speech the limits of phoneme based approaches
Cognitive Neuropsychology, 2017Co-Authors: Wolfram ZieglerAbstract:This report presents evidence suggesting that the phoneme-based approach taken by Romani, Galuzzi, Guariglia, and Goslin (Comparing phoneme frequency, age of acquisition, and loss in aphasia: Implications for phonological universals. Cognitive Neuropsychology, this issue) falls short of capturing the complexity of articulation planning in patients with Apraxia of speech. Empirical and modelling data are reported to demonstrate that the apraxic pathomechanism resides in the hierarchical architecture of phonological words rather than in the context-independent properties of phonemes. Because the factors determining complexity of articulation planning are interlaced between gestural, syllabic, and metrical levels, they cannot be captured by markedness rankings limited to any of these levels.
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the role of metrical information in Apraxia of speech perceptual and acoustic analyses of word stress
Neuropsychologia, 2016Co-Authors: Ingrid Aichert, Mona Spath, Wolfram ZieglerAbstract:Several factors are known to influence speech accuracy in patients with Apraxia of speech (AOS), e.g., syllable structure or word length. However, the impact of word stress has largely been neglected so far. More generally, the role of prosodic information at the phonetic encoding stage of speech production often remains unconsidered in models of speech production. This study aimed to investigate the influence of word stress on error production in AOS. Two-syllabic words with stress on the first (trochees) vs. the second syllable (iambs) were compared in 14 patients with AOS, three of them exhibiting pure AOS, and in a control group of six normal speakers. The patients produced significantly more errors on iambic than on trochaic words. A most prominent metrical effect was obtained for segmental errors. Acoustic analyses of word durations revealed a disproportionate advantage of the trochaic meter in the patients relative to the healthy controls. The results indicate that German apraxic speakers are sensitive to metrical information. It is assumed that metrical patterns function as prosodic frames for articulation planning, and that the regular metrical pattern in German, the trochaic form, has a facilitating effect on word production in patients with AOS.
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how much is a word predicting ease of articulation planning from apraxic speech error patterns
Cortex, 2015Co-Authors: Wolfram Ziegler, Ingrid AichertAbstract:Abstract Background According to intuitive concepts, ‘ease of articulation’ is influenced by factors like word length or the presence of consonant clusters in an utterance. Imaging studies of speech motor control use these factors to systematically tax the speech motor system. Evidence from Apraxia of speech, a disorder supposed to result from speech motor planning impairment after lesions to speech motor centers in the left hemisphere, supports the relevance of these and other factors in disordered speech planning and the genesis of apraxic speech errors. Yet, there is no unified account of the structural properties rendering a word easy or difficult to pronounce. Aim To model the motor planning demands of word articulation by a nonlinear regression model trained to predict the likelihood of accurate word production in Apraxia of speech. Method We used a tree-structure model in which vocal tract gestures are embedded in hierarchically nested prosodic domains to derive a recursive set of terms for the computation of the likelihood of accurate word production. The model was trained with accuracy data from a set of 136 words averaged over 66 samples from apraxic speakers. In a second step, the model coefficients were used to predict a test dataset of accuracy values for 96 new words, averaged over 120 samples produced by a different group of apraxic speakers. Results Accurate modeling of the first dataset was achieved in the training study ( R 2 adj = .71). In the cross-validation, the test dataset was predicted with a high accuracy as well ( R 2 adj = .67). The model shape, as reflected by the coefficient estimates, was consistent with current phonetic theories and with clinical evidence. In accordance with phonetic and psycholinguistic work, a strong influence of word stress on articulation errors was found. Conclusions The proposed model provides a unified and transparent account of the motor planning requirements of word articulation.
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Apraxia of speech
Handbook of Clinical Neurology, 2008Co-Authors: Wolfram ZieglerAbstract:Publisher Summary Apraxia of speech is described as an impairment of the capacity to program the movements of the articulators for the purpose of speaking. Patients with Apraxia of speech may present with a broad variety of clinical signs, depending on the severity of their speech impairment and the pattern of accompanying aphasic symptoms. In its most severe form, Apraxia of speech may result in a total inability to voluntarily produce even a single word, syllable, or speech sound (apraxic mutism). The primary cause of apraxic speech impairment is left hemisphere stroke. The great majority of patients with Apraxia of speech have suffered from infarction or hemorrhage of the left middle cerebral artery (central cortical branch) and its perforating arteries, or of the left lateral lenticulostriate arteries. Other etiologies can also cause Apraxia of speech, e.g., traumatic brain injury, hematoma caused by arteriovenous malformation, or brain tumor. Broca's attempt at localizing the “faculty of articulate language” has often been considered as the birth of modern neuropsychology. The treatment of persisting Apraxia of speech is a notorious therapeutic challenge. In clinical practice, speech therapists dispense a variety of well established treatment techniques, but there is only little empirical support for their effectiveness.
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a nonlinear model of word length effects in Apraxia of speech
Cognitive Neuropsychology, 2005Co-Authors: Wolfram ZieglerAbstract:Previous studies of length effects in normal and disordered spoken language production were based on a linear view of words as strings of phonemes or syllables. This approach was limited by an inherent interaction of numbers of phonemes and syllables with syllable complexity. The present investigation was therefore based on a metrical tree model of word form representations, which was implemented by a nonlinear regression model predicting accurate word production in Apraxia of speech. One hundred data samples from 20 apraxic speakers were used to estimate the probabilties of accurate production for a data corpus of 72 carefully controlled words and nonwords of varying lengths. The nonlinear regression model explained almost 80% of the variance in these data. The shape of the model indicated a preserved cohesion of phonetic representations at the rime and the foot level in Apraxia of speech.
Kathleen Y Haaland - One of the best experts on this subject based on the ideXlab platform.
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motor adaptation deficits in ideomotor Apraxia
Journal of The International Neuropsychological Society, 2017Co-Authors: Pratik K Mutha, Lee H Stapp, Robert L Sainburg, Kathleen Y HaalandAbstract:OBJECTIVES: The cardinal motor deficits seen in ideomotor limb Apraxia are thought to arise from damage to internal representations for actions developed through learning and experience. However, whether apraxic patients learn to develop new representations with training is not well understood. We studied the capacity of apraxic patients for motor adaptation, a process associated with the development of a new internal representation of the relationship between movements and their sensory effects. METHODS: Thirteen healthy adults and 23 patients with left hemisphere stroke (12 apraxic, 11 nonapraxic) adapted to a 30-degree visuomotor rotation. RESULTS: While healthy and nonapraxic participants successfully adapted, apraxics did not. Rather, they showed a rapid decrease in error early but no further improvement thereafter, suggesting a deficit in the slow, but not the fast component of a dual-process model of adaptation. The magnitude of this late learning deficit was predicted by the degree of Apraxia, and was correlated with the volume of damage in parietal cortex. Apraxics also demonstrated an initial after-effect similar to the other groups likely reflecting the early learning, but this after-effect was not sustained and performance returned to baseline levels more rapidly, consistent with a disrupted slow learning process. CONCLUSIONS: These findings suggest that the early phase of learning may be intact in Apraxia, but this leads to the development of a fragile representation that is rapidly forgotten. The association between this deficit and left parietal damage points to a key role for this region in learning to form stable internal representations. (JINS, 2017, 23, 139-149).
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coordination deficits in ideomotor Apraxia during visually targeted reaching reflect impaired visuomotor transformations
Neuropsychologia, 2010Co-Authors: Pratik K Mutha, Robert L Sainburg, Kathleen Y HaalandAbstract:Ideomotor limb Apraxia, commonly defined as a disorder of skilled, purposeful movement, is characterized by spatiotemporal deficits during a variety of actions. These deficits have been attributed to damage to, or impaired retrieval of, stored representations of learned actions, especially object-related movements. However, such deficits might also arise from impaired visuomotor transformation mechanisms that operate in parallel to or downstream from mechanisms for storage of action representations. These transformation processes convert extrinsic visual information into intrinsic neural commands appropriate for the desired motion. These processes are a key part of the movement planning process and performance errors due to inadequate transformations have been shown to increase with the dynamic complexity of the movement. This hypothesis predicts that apraxic patients should show planning deficits when reaching to visual targets, especially when the coordination and/or dynamic requirements of the task increase. Three groups (18 healthy controls, 9 non-apraxic and 9 apraxic left hemisphere damaged patients) performed reaching movements to visual targets that varied in the degree of interjoint coordination required. Relative to the other two groups, apraxic patients made larger initial direction errors and showed higher variability during their movements, especially when reaching to the target with the highest intersegmental coordination requirement. These problems were associated with poor coordination of shoulder and elbow torques early in the movement, consistent with poor movement planning. These findings suggest that the requirement to transform extrinsic visual information into intrinsic motor commands impedes the ability to accurately plan a visually targeted movement in ideomotor limb Apraxia.
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ideomotor limb Apraxia in huntington s disease implications for corticostriate involvement
Neuropsychologia, 2003Co-Authors: Joanne M Hamilton, Kathleen Y Haaland, John C Adair, Jason BrandtAbstract:Abstract Ideomotor limb Apraxia, a disorder of goal-directed movement, has been attributed to lesions in the frontal and parietal lobes, but the role of subcortical structures is less certain. In order to determine its prevalence in a disorder affecting the basal ganglia and corticostriatal connections, we examined imitation of hand gestures in Huntington’s disease (HD) patients. We also assessed the relationship between Apraxia and cognitive and motor dysfunction in an effort to better understand the neural underpinnings of Apraxia in HD. If damage restricted to the basal ganglia produces ideomotor limb Apraxia, then we would expect to find evidence of Apraxia in patients who were early in the disease course when selective striatal damage is most common. Such a pattern, however, was not found in our sample. Instead, patients with greater neurological impairment and with a longer duration of disease were more likely than less affected patients to demonstrate Apraxia. Apraxia was not related to severity of chorea, but was associated with greater impairment in eye movements, voluntary movements, and verbal fluency. These findings suggest that Apraxia in HD results from damage to the corticostriate pathways and the basal ganglia rather than from damage restricted to the basal ganglia.
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spatial deficits in ideomotor limb Apraxia a kinematic analysis of aiming movements
Brain, 1999Co-Authors: Kathleen Y Haaland, Deborah L Harrington, Robert T KnightAbstract:Ideomotor limb Apraxia is a classic neurological disorder manifesting as a breakdown in co-ordinated limb control with spatiotemporal deficits. We employed kinematic analyses of simple aiming movements in left hemisphere-damaged patients with and without limb Apraxia and a normal control group to examine preprogramming and response implementation deficits in Apraxia. Damage to the frontal and parietal lobes was more common in apraxics, but neither frontal nor parietal damage was associated with different arm movement deficits. Limb Apraxia was associated with intact preprogramming but impaired response implementation. The response implementation deficits were characterized by spatial but not temporal deficits, consistent with decoupling of spatial and temporal features of movement in limb Apraxia. While the apraxics' accuracy was normal when visual feedback was available, it was impaired when visual feedback of either target location or hand position was unavailable. This finding suggests that ideomotor limb Apraxia is associated with disruption of the neural representations for the extrapersonal (spatial location) and intrapersonal (hand position) features of movement. The non-apraxic group's normal kinematic performance demonstrates that the deficits demonstrated in the apraxic group are not simply a reflection of left hemisphere damage per se .
Tigran Kesayan - One of the best experts on this subject based on the ideXlab platform.
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unilateral apraxic agraphia without ideomotor Apraxia in a patient with callosal and frontal lobe lesions p3 198
Neurology, 2018Co-Authors: Tigran Kesayan, Kenneth M. HeilmanAbstract:Objective: NA Background: Injury to the areas that store the spatial-temporal movement representations required to write, or a disconnection of these engrams from the motor areas can cause apraxic agraphia. Apraxic agraphia along with ideomotor Apraxia (IMA) of the left hand has been described from callosal lesions. We report a woman with apraxic agraphia of her left hand who did not demonstrate IMA. Design/Methods: Case Report: A 37 year-old right-handed woman with a history of alcohol abuse developed an apraxic agraphia of her left hand, and a limb-kinetic Apraxia (LKA), a loss of precise, independent and coordinated finger movements of both hands, as determined by the coin rotation test. However, she was without an IMA. MRI imaging reveal lesions of the genu and splenium of the corpus callosum (CC) and leukoaraiosis in the frontal lobes. Results: NA Conclusions: Discussion: These CC changes may be a form of Marchifava-Bignami disease. Injury to the CC can cause left hand LKA, and LKA can impair writing. However, this woman had a LKA of both hands, but her apraxic agraphia was limited to left hand. Diffusion tensor imaging studies have shown that patients with alcohol abuse can develop changes in the frontal white matter, and our patient did reveal some leukoaraiosis of her frontal white matter. Therefore, it is possible that frontal white matter injury was responsible for this patient’s bilateral LKA, and these white matter or callosal injuries may have also disconnected the letter spatial-temporal movement engrams from the motor areas of the right hemisphere causing an apraxic agraphia of her left hand. However, additional studies assessing patients with alcohol abuse for LKA and apraxic agraphia are needed Study Supported by: NA Disclosure: Dr. Kesayan has nothing to disclose. Dr Heilman has nothing to disclose.
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unilateral apraxic agraphia without ideomotor Apraxia from a callosal lesion in a patient with marchiafava bignami disease
Neurocase, 2018Co-Authors: Tigran Kesayan, Kenneth M. HeilmanAbstract:ABSTRACTApraxic agraphia can be caused by left hemispheric cerebral lesions in the area that contains the spatial representations of the movements required to write, from a lesion in, or connections to, the frontal premotor cortex that converts these spatial representations to motor programs (Exner’s area). A right-handed woman with Marchiafava Bignami disease and lesions of the genu and splenium of her corpus callosum had apraxic agraphia without ideomotor Apraxia of her left. A disconnection of Exner’s area in the left hemisphere from the right hemisphere’s premotor and motor areas may have led to her inability to write with her left hand.
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unilateral apraxic agraphia without ideomotor Apraxia from a callosal lesion in a patient with marchiafava bignami disease
Neurocase, 2018Co-Authors: Tigran Kesayan, Kenneth M. HeilmanAbstract:Apraxic agraphia can be caused by left hemispheric cerebral lesions in the area that contains the spatial representations of the movements required to write, from a lesion in, or connections to, th...
Ingrid Aichert - One of the best experts on this subject based on the ideXlab platform.
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the role of metrical information in Apraxia of speech perceptual and acoustic analyses of word stress
Neuropsychologia, 2016Co-Authors: Ingrid Aichert, Mona Spath, Wolfram ZieglerAbstract:Several factors are known to influence speech accuracy in patients with Apraxia of speech (AOS), e.g., syllable structure or word length. However, the impact of word stress has largely been neglected so far. More generally, the role of prosodic information at the phonetic encoding stage of speech production often remains unconsidered in models of speech production. This study aimed to investigate the influence of word stress on error production in AOS. Two-syllabic words with stress on the first (trochees) vs. the second syllable (iambs) were compared in 14 patients with AOS, three of them exhibiting pure AOS, and in a control group of six normal speakers. The patients produced significantly more errors on iambic than on trochaic words. A most prominent metrical effect was obtained for segmental errors. Acoustic analyses of word durations revealed a disproportionate advantage of the trochaic meter in the patients relative to the healthy controls. The results indicate that German apraxic speakers are sensitive to metrical information. It is assumed that metrical patterns function as prosodic frames for articulation planning, and that the regular metrical pattern in German, the trochaic form, has a facilitating effect on word production in patients with AOS.
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how much is a word predicting ease of articulation planning from apraxic speech error patterns
Cortex, 2015Co-Authors: Wolfram Ziegler, Ingrid AichertAbstract:Abstract Background According to intuitive concepts, ‘ease of articulation’ is influenced by factors like word length or the presence of consonant clusters in an utterance. Imaging studies of speech motor control use these factors to systematically tax the speech motor system. Evidence from Apraxia of speech, a disorder supposed to result from speech motor planning impairment after lesions to speech motor centers in the left hemisphere, supports the relevance of these and other factors in disordered speech planning and the genesis of apraxic speech errors. Yet, there is no unified account of the structural properties rendering a word easy or difficult to pronounce. Aim To model the motor planning demands of word articulation by a nonlinear regression model trained to predict the likelihood of accurate word production in Apraxia of speech. Method We used a tree-structure model in which vocal tract gestures are embedded in hierarchically nested prosodic domains to derive a recursive set of terms for the computation of the likelihood of accurate word production. The model was trained with accuracy data from a set of 136 words averaged over 66 samples from apraxic speakers. In a second step, the model coefficients were used to predict a test dataset of accuracy values for 96 new words, averaged over 120 samples produced by a different group of apraxic speakers. Results Accurate modeling of the first dataset was achieved in the training study ( R 2 adj = .71). In the cross-validation, the test dataset was predicted with a high accuracy as well ( R 2 adj = .67). The model shape, as reflected by the coefficient estimates, was consistent with current phonetic theories and with clinical evidence. In accordance with phonetic and psycholinguistic work, a strong influence of word stress on articulation errors was found. Conclusions The proposed model provides a unified and transparent account of the motor planning requirements of word articulation.
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syllable frequency and syllable structure in Apraxia of speech
Brain and Language, 2004Co-Authors: Ingrid Aichert, Wolfram ZieglerAbstract:Recent accounts of the pathomechanism underlying Apraxia of speech (AOS) were based on the speech production model of Levelt, Roelofs, and Meyer, and Meyer (1999)1999. The apraxic impairment was localized to the phonetic encoding level where the model postulates a mental store of motor programs for high-frequency syllables. Varley and Whiteside (2001a) assumed that in patients with AOS syllabic motor programs are no longer accessible and that these patients are required to use a subsyllabic encoding route. In this study, we tested this hypothesis by exploring the influence of syllable frequency and syllable structure on word repetition in 10 patients with AOS. A significant effect of syllable frequency on error rates was found. Moreover, apraxic errors on consonant clusters were influenced by their position relative to syllable boundaries. These results demonstrate that apraxic patients have access to the syllabary, but that they fail to retrieve the syllabic motor patterns correctly. Our findings are incompatible with a subsyllabic route model of Apraxia of speech.
