Neurological Aspects of Foreign Accent Syndrome in Stroke Patients

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.

Cerebral arteriovenous malformation and foreign accent syndrome: a case report

OBJECTIVE

This case study aims to present the Foreign Accent Syndrome (FAS) in a patient with Cerebral Arteriovenous Malformation (cAVM), considering neuropsychological, radiological and microsurgical aspects.

METHODS

The patient underwent preoperative neuropsychological assessment and MRI and Tractography were performed to identify fibers close to the lesion site. In the surgical procedure, a craniotomy was performed for excision of the cAVM. After surgery and 6 months after the surgical procedure, the patient underwent further and neuropsychological evaluations.

RESULTS

The presence of AVM located in the posterior part of the medial surface of the left superior frontal gyrus was identified and the neuropsychological evaluation found cognitive deficits and symptoms characteristic of FAS, which disappeared after resection.

CONCLUSION

This report presented a case of cAVM in which symptoms were found even without rupture, which was no longer observed after the surgical procedure, demonstrating the relationship of cAVM with the symptoms and neuroanatomical bases of FAS.

Foreign Accent Syndrome After COVID 19 Infection: A Case Report

ABSTRACT

Foreign accent syndrome (FAS) is an extremely rare disorder characterized by the appearance of speech changes that are perceived by the speaker and listeners as an acquired foreign accent. It still remains a poorly understood condition. Three main types of FAS have been reported in the medical literature as neurogenic, psychogenic, and mixed type. Psychogenic FAS includes all cases of FAS in which an organic cause has not been identified and a clear psychological factor has been identified after careful clinical, neurological, and neuroradiological examination. Although the COVID-19 epidemic, which has been ongoing since February 2020, primarily manifests itself with upper respiratory tract infection findings, it is seen that it also causes a wide range of neurological and psychiatric signs and symptoms. In this study, a 42-year-old female patient who started to have speech disorder after COVID-19 infection is presented in the light of clinical history, diagnosis, and differential diagnosis literature findings.

Affective Prosody and Its Impact on the Neurology of Language, Depression, Memory and Emotions

Based on the seminal publications of Paul Broca and Carl Wernicke who established that aphasic syndromes (disorders of the verbal-linguistic aspects of communication) were predominantly the result of focal left-hemisphere lesions, "language" is traditionally viewed as a lateralized function of the left hemisphere. This, in turn, has diminished and delayed the acceptance that the right hemisphere also has a vital role in language, specifically in modulating affective prosody, which is essential for communication competency and psychosocial well-being. Focal lesions of the right hemisphere may result in disorders of affective prosody (aprosodic syndromes) that are functionally and anatomically analogous to the aphasic syndromes that occur following focal left-hemisphere lesions. This paper will review the deductive research published over the last four decades that has elucidated the neurology of affective prosody which, in turn, has led to a more complete and nuanced understanding of the neurology of language, depression, emotions and memory. In addition, the paper will also present the serendipitous clinical observations (inductive research) and fortuitous inter-disciplinary collaborations that were crucial in guiding and developing the deductive research processes that culminated in the concept that primary emotions and related display behaviors are a lateralized function of the right hemisphere and social emotions, and related display behaviors are a lateralized function of the left hemisphere.

Donepezil alone and combined with intensive language-action therapy on depression and apathy in chronic post-stroke aphasia: A feasibility study

This study explored the feasibility and effectiveness of a short-term (10-week) intervention trial using Donepezil administered alone and combined with intensive language action therapy (ILAT) for the treatment of apathy and depression in ten people with chronic post-stroke aphasia. Outcome measures were the Western Aphasia Battery and the Stroke Aphasia Depression Questionnaire-21. Structural magnetic resonance imaging and ¹⁸fluorodeoxyglucose positron emission tomography were acquired at baseline and after two endpoints (Donepezil alone and Donepezil-ILAT). The intervention was found to be feasible to implement. Large treatment effects were found. Donepezil alone and combined with ILAT reduced aphasia severity, while apathy and depression only improved with Donepezil-ILAT. Structural and functional neuroimaging data did not show conclusive results but provide hints for future research. Given these overall positive findings on feasibility, language and behavioral benefits, further studies in larger sample sizes and including a placebo-control group are indicated.

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.

Foreign accent syndrome and other neuropsychological sequelae of a parieto-occipital lesion following COVID-19 associated posterior reversible encephalopathy syndrome

OBJECTIVE

We describe a previously fit and well 54-year-old female who acquired a range of severe and persisting neuropsychological impairments following a posterior reversible encephalopathy syndrome (PRES) complication of COVID-19. The initial presentation included aphasia, a neurogenic foreign accent syndrome (FAS) and a persisting complete cortical blindness from the underpinning parieto-occipital brain injury.

METHOD

Neuropsychological single clinical case report.

RESULTS

The patient retained insight and made good early progress with their adjustment to the numerous losses caused by the COVID-19 associated acquired brain injury. Comprehensive neuropsychological investigation characterised an acalculia, along with deficits in focused, sustained and divided attention impacting on verbal memory, working memory and executive functioning, amongst numerous relative strengths.

CONCLUSION

Similar to PRES from other aetiologies, COVID-19 associated PRES can in some cases cause irreversible acquired brain injury. The diverse neuropsychological effects need to be comprehensively investigated and managed. This case adds to the neuropsychological literature on PRES, FAS and acquired brain injury as a rare complication of SARS-CoV-2.

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.

Speech in the foreign accent syndrome: differential diagnosis between organic and functional cases

Foreign accent syndrome (FAS) is an extremely rare disorder, with 112 cases described until 2019. We compare two cases of the foreign accent syndrome in native speakers of Brazilian Portuguese in its classic form (FAS) and psychiatric variant (FALS). Two cases were analyzed: (1) a right-handed, 69-year-old man, with a prior history of stroke, and (2) a right-handed, 43-year-old woman, diagnosed with schizophrenia. They were evaluate for language and speech, including the speech intelligibility. Both patients had speech impairments complaints, similar to a new accent, without previous exposure to a foreign language. However, the onset of the speech disorder was sudden in case 1 and insidious and with transient events in case 2, with speech intelligibility scores of 95.5 and 55.3% respectively. Besides neurologic impairment, the clinical presentation of FALS was extremely severe and differed to that expected in FAS cases, in which speech intelligibility is preserved.

"Accent issue": foreign accent syndrome following ischemic stroke

BACKGROUND

Foreign accent syndrome (FAS) is arare syndrome associated with altered speech rhythm and prosody, which listeners perceive as foreign; cerebrovascular accidents, tumors and multiple sclerosis are reported as possible causes of FAS. The pathophysiology of FAS is not yet understood.

CASE PRESENTATION

A 68-year-old Italian man was admitted to the EmergencyDepartment for non-fluent aphasia and dysarthria. Computed tomography (CT) scan did not show abnormalities; the patient was treated with systemic thrombolysis. A repeated brain CT and magnetic resonance imaging (MRI) confirmed an infarct in the left primary motor cortex and mild extension to cortico-subcortical frontal regions. In the following days he gradually improved, speaking Italian fluently with a typical German accent. In conclusion, FAS is a rare motor speech disorder, often related to cerebrovascular accidents involving critical regions in the dominant hemisphere. In addition, the present case adds further evidence to the role of the left primary motor cortex in modulation of prosody. In rare cases FAS can be the only sign of stroke or can appear after recovery from post-stroke aphasia.