Acquired neurogenic foreign accent syndrome after right-hemisphere lesion with left cerebellar diaschisis: A longitudinal study

Revisiting the boundaries of different altered accents profiles

A speaker's accent is regarded as an essential aspect of their identity to the extent that its abnormal modulation may have several negative consequences. Although the so-called foreign accent syndrome (FAS) is the best-known impairment, other altered accent profiles (AAPs) are likely to be more common and often go undiagnosed. Despite significant progress during the last two decades, several consequences of AAPs have yet to be systematically evaluated. Moreover, a common finding in several previous reports is the incompleteness of diagnostic work-up and the rarity of studies reporting longitudinal evolution and treatment approaches. In disorders with presumed low prevalence like AAPs, it is imperative to carry out a comprehensive analysis, documenting not only the altered accent profiles but also the neural correlates and associated disorders affecting cognition, behaviour, quality of life, and outcomes after treatment. This article highlights how to move forward in the multimodal evaluation of altered accents by integrating information from different sources.

Progressive verbal apraxia of reading

We identified a syndrome characterized by a relatively isolated progressive impairment of reading words that the patient was able to understand and repeat but without other components of speech apraxia. This cluster of symptoms fits a new syndrome designated Progressive Verbal Apraxia of Reading. A right-handed man (AB) came with a 2.5-year history of increasing difficulties in reading aloud. He was evaluated twice, 2 years apart, using multimodal neuroimaging techniques and quantitative neurolinguistic assessment. In the laboratory, reading difficulties arose in the context of intact visual and auditory word recognition as well as intact ability to understand and repeat words he was unable to read aloud. The unique feature was the absence of dysarthria or speech apraxia in tasks other than reading. Initial imaging did not reveal statistically significant atrophy. Structural magnetic resonance and FDG-PET imaging at the second assessment revealed atrophy and hypometabolism in the right posterior cerebellum, in areas shown to be part of his language network by task-based functional neuroimaging at initial assessment. This syndromic cluster can be designated Progressive Verbal Apraxia of Reading, an entity that has not been reported previously to the best of our knowledge. We hypothesize a selective disconnection of the visual word recognition system from the otherwise intact articulatory apparatus, a disconnection that appears to reflect the disruption of multisynaptic cerebello-cortical circuits.

Impacts of language perception and attitudes in Foreign Accent Syndrome

Sociolinguistic factors such as status and prestige can significantly impact the persistence of an accent in a patient with Foreign Accent Syndrome (FAS). FAS is a rare acquired syndrome that affects a speaker's accent typically caused by a stroke or trauma. In this presented FAS case study, we explore two distinct perspectives on a shift from a Sicilian to a North-East variety of Italian accent, caused by an accident trauma. Data have been collected with an ethnographic approach to explore the patient's narrative towards his 'foreign accent'. Firstly, the study analyzes the perception of native listeners through a speech sample perception test of different varieties of Italian. The listeners' responses revealed a diversified classification of the accent, highlighting the listener's crucial role in assigning the status of 'foreignness' to a particular variety. Additionally, an analysis with Praat software showed that the FAS speaker used a variety with some Sicilian and North-East traits. Secondly, the study investigated the patient's perception of their new accent through an ethnographic approach and participant observer technique. The results revealed a typology of FAS speakers that correlated with sociolinguistic factors not previously identified by research. In conclusion, this study sheds light on the complex interplay between sociolinguistic factors and FAS, demonstrating the importance of exploring FAS under various perspectives of research.

A multimodal imaging approach to foreign accent syndrome. A case report

This article describes a case of Foreign accent syndrome (FAS) in an Italian woman who developed a Canadian-like foreign accent without brain damage (functional FAS). The patient underwent an in-depth neuroimaging and (neuro)psychological evaluation. Language networks in the frontotemporal-parietal areas were typically activated bilaterally through fMRI and MEG assessments based on task-based data. Resting-state fMRI showed preserved connectivity between language areas. An obsessive-compulsive personality profile and mild anxiety were found, suggesting psychological and psychiatric factors may be relevant. Accordingly with our findings, multimodal imaging is beneficial to understand FAS neurological and functional etiologies.

Spinal or cortical direct current stimulation: Which is the best? Evidence from apraxia of speech in post-stroke aphasia

To date, new advances in technology have already shown the effectiveness of non-invasive brain stimulation and, in particular, of transcranial direct current stimulation (tDCS), in enhancing language recovery in post-stroke aphasia. More recently, it has been suggested that the stimulation over the spinal cord improves the production of words associated to sensorimotor schemata, such as action verbs. Here, for the first time, we present evidence that transpinal direct current stimulation (tsDCS) combined with a language training is efficacious for the recovery from speech apraxia, a motor speech disorder which might co-occur with aphasia. In a randomized-double blind experiment, ten aphasics underwent five days of tsDCS with concomitant treatment for their articulatory deficits in two different conditions: anodal and sham. In all patients, language measures were collected before (T0), at the end (T5) and one week after the end of treatment (F/U). Results showed that only after anodal tsDCS patients exhibited a better accuracy in repeating the treated items. Moreover, these effects persisted at F/U and generalized to other oral language tasks (i.e. picture description, noun and verb naming, word repetition and reading). A further analysis, which compared the tsDCS results with those collected in a matched group of patients who underwent the same language treatment but combined with tDCS, revealed no differences between the two groups. Given the persistency and severity of articulatory deficits in aphasia and the ease of use of tsDCS, we believe that spinal stimulation might result a new innovative approach for language rehabilitation.

Contribution of the Cerebellum and the Basal Ganglia to Language Production: Speech, Word Fluency, and Sentence Construction-Evidence from Pathology

Evidence reported in recent decades increasingly confirms that both the cerebellum and the basal ganglia, which are primarily involved in movement control, also have a significant role in a vast range of cognitive and affective functions. Evidence from pathology indicates that the disorders of some aspects of language production which follow damage of the cerebellum or respectively basal ganglia, i.e., disorders of speech, word fluency, and sentence construction, have identifiable neuropsychological profiles and that most manifestations can be specifically attributed to the dysfunctions of mechanisms supported by one or the other of these structures. The cerebellum and the basal ganglia are reciprocally interconnected. Thus, it is plausible that some disorders observed when damage involves one of these structures could be remote effects of abnormal activity in the other. However, in a purely clinical-neuropsychological perspective, primary and remote effects in the network are difficult to disentangle. Functional neuroimaging and non-invasive brain stimulation techniques likely represent the indispensable support for achieving this goal.