Ioannis Mavroudis
Foreign accent syndrome (FAS) is a rare speech disorder characterized by the emergence of a new, seemingly foreign accent in a person’s native language. The search results provide insights into FAS occurring in functional neurological disorders and after mild traumatic brain injuries (mTBIs).
FAS in Functional Neurological Disorders
Several search results [1][4][7] indicate that FAS can manifest as a functional speech disorder (FSD) or functional neurological disorder (FND), where there is no clear structural brain lesion or neurological cause identified. In these cases, FAS is considered to have a psychogenic or functional etiology, potentially triggered by psychological factors or stress.
The study in [1] describes a case of FAS characterized as an FSD, where the patient developed an “Eastern European accent” along with nonnative word use and word order changes after a functional movement disorder. Behavioral intervention helped correct the sound-level changes and resolve the language dialect-like changes.
Result [7] notes that positive features of functional FAS, such as inconsistency, intermittency, and incongruence with structural lesions, can be present even in cases with structural brain damage. The study found that functional features were present in all cases, regardless of the probable etiology (functional, structural, or mixed).
FAS after Mild Traumatic Brain Injury
Several search results [2][5][13] report cases of FAS developing after mild traumatic brain injuries (mTBIs) or closed head injuries, even in the absence of significant structural brain lesions on imaging.
In [13], the patient experienced FAS without other neurological deficits after a minor head injury. Single-photon emission computed tomography (SPECT) suggested abnormal function in the left dorsolateral inferior frontal gyrus and caudate nucleus as the underlying basis, despite normal magnetic resonance imaging (MRI) findings.
Result [5] describes a case of FAS developing after an mTBI, suggesting that even mild brain injuries can potentially lead to the emergence of this speech disorder.
Overall, the search results indicate that FAS can occur in functional neurological disorders without a clear structural cause, as well as after mTBIs, potentially due to subtle functional or metabolic changes in the brain not detected by conventional imaging techniques [1][4][7][2][5][13].
Citations:
[1] https://www.semanticscholar.org/paper/b0cec3ba1553b8a48b0a85480a1a7e10bdcfd9a0
[2] https://www.semanticscholar.org/paper/680e2fc552518a0b9b890aed4eeab5971399025b
[3] https://pubmed.ncbi.nlm.nih.gov/38015188/
[4] https://pubmed.ncbi.nlm.nih.gov/30627878/
[5] https://www.semanticscholar.org/paper/c3ae13e0c51896120885187c0d6e271fca5c6c63
[6] https://www.semanticscholar.org/paper/4a24a862908a57598d694499062e5d4e220b42c6
[7] https://pubmed.ncbi.nlm.nih.gov/30826739/
[8] https://www.semanticscholar.org/paper/748e64b1aca86709b53ce1aa3aae9452362caef9
[9] https://pubmed.ncbi.nlm.nih.gov/33678617/
[10] https://pubmed.ncbi.nlm.nih.gov/30592118/
[11] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10817245/
[12] https://www.semanticscholar.org/paper/f0dcc68a96674e21cfa620fcde3e438607646742
[13] https://www.semanticscholar.org/paper/911897dd5deb36d094e62086a5fd5a50f1bec356
[14] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10137654/
[15] https://www.semanticscholar.org/paper/5573638a1ac9de73a37fb07b0fb30296aafa2083
[16] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8921281/
[17] https://pubmed.ncbi.nlm.nih.gov/36995471/
[18] https://pubmed.ncbi.nlm.nih.gov/37688998/
[19] https://pubmed.ncbi.nlm.nih.gov/36717160/
[20] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8968958/
