What is foreign accent syndrome

Foreign accent syndrome is a speech disorder that is defined by the emergence of a peculiar manner of articulation and intonation which is perceived as foreign ¹⁾. Foreign accent syndrome is a an extremely rare condition where speech is characterized by a new accent to the patient’s native language ²⁾. This new accent is foreign to both the speaker and the listener ³⁾. It is important to note that the affected patient may never have lived in the country of origin of the new accent ⁴⁾. There are three main variants of foreign accent syndrome reported in the literature: neurogenic, psychogenic, and mixed ⁵⁾. For all the types of foreign accent syndrome, the listener’s perception is important and ruling out pareidolia is imperative ⁶⁾. The characteristics of foreign accent syndrome may involve changes in the pronunciation of words, syntax, and vocabulary as well as changes in the length of the vowels and tenseness, which in phonology is a particular vowel and/or consonant quality that is phonemically contrastive in many languages including English ⁷⁾. Other changes include inappropriate stresses of sentences and words. Accents from different parts of the world have been reported and examples include French, English, German, Swedish, Welsh, Spanish, Chinese, Korean, and Irish accents ⁸⁾. While there have been many cases of neurogenic foreign accent syndrome, few cases of psychogenic foreign accent syndrome have been reported ⁹⁾.

Foreign accent syndrome is an extremely rare syndrome with only 100 cases reported in the literature since it was first described in 1907 by French neurologist Pierre Marie ¹⁰⁾. Foreign accent syndrome is a poorly understood phenomenon; it is most likely not a true accent change, rather the perception to the listener as a foreign accent. Foreign accent syndrome results from damage to the processes involving articulation. A single cortical area is not responsible for total speech pronunciation, rather it is a complex motor speech network, involving multiple areas. In most cases of acquired foreign accent syndrome the new accent is secondary to small focal lesions involving components of the bilaterally distributed neural network for speech production ¹¹⁾. In the past few years foreign accent syndrome has also been described in different psychiatric conditions (conversion disorder, bipolar disorder, and schizophrenia) as well as in developmental disorders (specific language impairment, apraxia of speech) ¹²⁾.

In the vast majority of individuals with foreign accent syndrome the condition is acquired after brain damage or it emerges during the course of psychiatric illnesses (e.g., schizophrenia) ¹³⁾. Even less frequently, foreign accent syndrome occurs during speech-language development ¹⁴⁾. In these cases, toddlers develop the language (lexicon and grammar), but not the pronunciation (accent) that is peculiar to the community to which they belong ¹⁵⁾.

Foreign accent syndrome is characterized as a pseudoaccent, where listeners categorize speech alterations as resembling a foreign accent ¹⁶⁾, but actually it is an impairment of the finer linguistic abilities such as pauses and vocal stress ¹⁷⁾. Foreign accent syndrome is postulated to be due to changes in accentuation of syllables. Foreign accent syndrome is not the result from previous experience from another language and patients with foreign accent syndrome have usually never visited the country their accent resembles ¹⁸⁾.

Foreign accent syndrome causes

Foreign accent syndrome has been associated with various causes as surveyed in the literature. The most common cause involves a vascular lesion affecting the motor speech areas in the language dominant hemisphere ¹⁹⁾. But it has been linked to other causes such as metastatic breast cancer ²⁰⁾, traumatic brain injury ²¹⁾ and even as an initial symptom of multiple sclerosis ²²⁾. Additionally, migraines have been implicated as well.

Furthermore, the areas affected in foreign accent syndrome are scattered. The majority of cases involve the motor speech areas, but the dominant precentral gyrus, inferior central gyrus, corpus callosum and insula also have been implicated in foreign accent syndrome ²³⁾. Other case reports have shown involvement in the non-dominant rolandic and temporal areas ²⁴⁾. In a review of 16 cases of foreign accent syndrome, both cortical and subcortical processes were found to be involved ²⁵⁾. Therefore, there is no clear lesion which can explain foreign accent syndrome consistently. Due to the intricate nature of speech production, possibly a subtle disruption of the motor speech network may lead to foreign accent syndrome, while major disruptions can lead to aphasias. Furthermore, it has been theorized that foreign accent syndrome may be due to a mild deficit in motor planning ²⁶⁾, where this intricate network is disrupted. In most case reports of foreign accent syndrome, lesion size has been minimal where it is usually less than three centimeters in diameter and typically involves only a single gyrus ²⁷⁾. Another theory involves the possibility of increased activity of certain areas rather than deficiencies. One report describes an ischemic event of the left putamen in which functional MRI was performed. The authors noted statistically increased activity of the ventral angular gyrus and the central sulcus ²⁸⁾. They concluded these areas are implicated in foreign accent syndrome.

In the differential diagnosis of foreign accent syndrome, apraxia of speech is necessary to be ruled out; it is surmised that foreign accent syndrome is not an AOS variant. Unlike AOS, foreign accent syndrome patients do not have difficulties with speech initiation ²⁹⁾. In diagnosing apraxia of speech, the Academy of Neurologic Communication Disorders and Sciences urged that certain clinical characteristics be employed: slow rate of speech, sound distortions resulting in slurred speech, distorted sound substitutions and prosodic abnormalities ³⁰⁾. These abnormalities were not seen in the patient In diagnosing foreign accent syndrome, certain clinical characteristics have been theorised. These characteristics include the speculation that vowels are more affected than consonants, vowel pronunciation is longer or laxer and lexical stress patterns are affected ³¹⁾. Another report states that the main characteristic of foreign accent syndrome was a change in emphasis of syllables ³²⁾.

Foreign accent syndrome symptoms

Foreign accent syndrome is an extremely rare speech disorder where speech is characterized by a new accent to the patient’s native language ³³⁾. This new accent is foreign to both the speaker and the listener ³⁴⁾. It is important to note that the affected patient may never have lived in the country of origin of the new accent ³⁵⁾.

There are three main variants of foreign accent syndrome reported in the literature ³⁶⁾:

1. neurogenic,
2. psychogenic, and
3. mixed.

In neurogenic foreign accent syndrome, although the exact mechanism is unclear, there is damage observed using neuroimaging techniques to the central nervous system from a stroke or traumatic brain injury ³⁷⁾. Vascular lesions usually involve the middle cerebral artery and motor speech areas such as precentral and middle frontal gyrus, anterior insular, inferior parietal, and adjacent subcortical regions as well as the cerebellum ³⁸⁾. The internal capsule and basal ganglia may also be affected. It has been shown that prosodic function is controlled bilaterally, with the linguistic aspect being controlled by the cortical area of the left hemisphere ³⁹⁾.

Until recently it has been assumed that foreign accent syndrome was not psychogenic. In the psychogenic variant of foreign accent syndrome, there may be an underlying psychological or psychiatric disorder such as psychosis, conversion disorder, bipolar disorder, or schizophrenia with ongoing episodes but without identifiable organic brain lesion deficits in the areas connected with language production and speech articulation, suggesting that various other factors and lesions are implicated ⁴⁰⁾. In the cases of psychosis, the new accent persists throughout the entire episode and may disappear after the psychotic episode subsides. The more severe the psychosis is, the more likely the syndrome remains. Many hypotheses have been postulated for foreign accent syndrome in conjunction with psychoses, which include the activation of positive psychotic symptoms, which may also be the provocateur of the accent, and neural circuitry suppression, which may show intermittent prominence ⁴¹⁾.

Finally, in the mixed variant, there may be features of both neurogenic and psychogenic characteristics ⁴²⁾. In these cases, the cause may primarily be neurogenic and then develop to be psychogenic. Researchers have described a loss of identity and the effort of the patient to improve the veracity of the accent as the patient evolves into a new identity ⁴³⁾. The distinction between neurogenic and psychogenic in phonetic or linguistic terms is important, because it may be the case that these foreign accent syndrome patients have different pronunciation characteristics. The former could result from dysarthria or apraxia, while the latter is somehow “put on” or taken on ⁴⁴⁾.

Foreign accent syndrome treatment

Foreign Accent Syndrome is still a rare and poorly understood condition, especially the psychogenic variety. Treatment always involve treating the underlying cause of the Foreign Accent Syndrome.