Crossed apraxia of speech: A case report

Testing hypotheses about the underlying deficit of apraxia of speech through computational neural modelling with the DIVA model

Purpose: A recent behavioural experiment featuring a noise masking paradigm suggests that Apraxia of Speech (AOS) reflects a disruption of feedforward control, whereas feedback control is spared and plays a more prominent role in achieving and maintaining segmental contrasts. The present study set out to validate the interpretation of AOS as a possible feedforward impairment using computational neural modelling with the DIVA (Directions Into Velocities of Articulators) model.Method: In a series of computational simulations with the DIVA model featuring a noise-masking paradigm mimicking the behavioural experiment, we investigated the effect of a feedforward, feedback, feedforward + feedback, and an upper motor neuron dysarthria impairment on average vowel spacing and dispersion in the production of six/bVt/speech targets.Result: The simulation results indicate that the output of the model with the simulated feedforward deficit resembled the group findings for the human speakers with AOS best.Conclusion: These results provide support to the interpretation of the human observations, corroborating the notion that AOS can be conceptualised as a deficit in feedforward control.

A case of crossed aphasia with apraxia of speech

Apraxia of speech (AOS) is a rare, but well-defined motor speech disorder. It is characterized by irregular articulatory errors, attempts of self-correction and persistent prosodic abnormalities. Similar to aphasia, AOS is also localized to the dominant cerebral hemisphere. We report a case of Crossed Aphasia with AOS in a 48-year-old right-handed man due to an ischemic infarct in right cerebral hemisphere.

The relationship between working memory and apraxia of speech

The present study aimed to verify the relationship between working memory (WM) and apraxia of speech and explored which WM components were involved in the motor planning of speech. A total of 22 patients and 22 healthy adults were studied. These patients were selected according to the following inclusion criteria: a single brain lesion in the left hemisphere, presence of apraxia of speech and sufficient oral comprehension. This study involved assessment of apraxia of speech and evaluation of working memory capacity. The performance of apraxic patients was significantly poorer than that of controls, where this reached statistical significance. The study concluded that participants with apraxia of speech presented a working memory deficit and that this was probably related to the articulatory process of the phonoarticulatory loop. Furthermore, all apraxic patients presented a compromise in working memory.

Phonological error analysis of acquired speech apraxia

BACKGROUND

the phonological characterization of the errors present in the speech of individuals with speech apraxia can elucidate several aspects of this disorder and consequently lead to the development of effective therapeutic interventions. Generally, studies that have characterized the errors present in speech apraxia were developed in other languages other than the Brazilian Portuguese (BP). The existing national literature about this theme is based on these studies.

AIM

to present the phonological analysis of the errors present in the speech of individuals with speech apraxia, speakers of the BP language.

METHOD

20 adults with speech apraxia were evaluated. The analysis of phonological errors, such as substitution and omission was made.

RESULTS

a few of the most affected phonemes in the speech of apraxic individuals (/b/, /lambda / e /3 /), speakers of the BP language, were different from those usually described in international studies.

CONCLUSION

results suggest that the errors present in the speech of apraxic individuals can suffer the influence of language once the most frequent errors found in the present study were different from those described in the international literature.