Foreign accent syndrome (FAS) is an extremely rare neurological condition characterized by the acquired foreign accent (that is though not connected with the birthplace or the place where the person spent their lifetime) and is caused by the left hemisphere brain damage.
FAS is a speech disorder caused by the damage to the brain usually due to a stroke. The affected people develop a new accent to their native language, sometimes the country of origin of the accent could have even never been visited by the person.
There are three types of FAS: neurogenic, psychogenic and mixed.
The damage to the left brain hemisphere (where the center of speech is located) leads to different disorders of the speech and FAS as well. Most of the cases were caused by the stroke, although brain trauma also affects the brain function. Typically the lesion’s site is very small, not bigger than 3 cm. All of the cases have involved either prerolandic motor cortex (Brodmann’s area 4), frontal motor association cortex (Brodmann’s areas 6 or 44), or striatum. Several cases of FAS among psychiatric patients were reported, although no visual damage to the brain could’ve been found (schizophrenia, bipolar disorder, psychosis, mania).
Arterial hypertension increases the risk of the stroke and at the same time the risk of acquiring a neurologic deficit. Occasions associated with the risk of brain injury are also creating risk of FAS.
Symptoms of foreign accent syndrome
FAS is characterized by a motor speech disorder when an affected person develops a speech accent that is very different from their premorbid speech. Usually FAS remains for some time and then vanishes spontaneously.
The changes appear 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. Some common speech changes associated with FAS include:
- Unusual prosody – equal and excess stress (especially in multi-syllabic words)
- Consonant substitution, deletion, or distortion
- Voicing errors
- Trouble with consonant clusters
- Vowel distortions, prolongations, substitutions (i.e. “yeah” pronounced as “yah”)
- “uh” inserted into words
Diagnostic assessment includes blood and urine testing, EEG, CT, MRI, fMRI, SPECT or PET and psychological examination.
The speech-language therapy, behavioral speech therapy was proposed. Nootropics are supposed to improve cognitive function, vitamins may be used to increase functioning of central nervous system.