Dysprosody - History

History

The first documented occurrence of dysprosody was described by Pierre Marie, a French neurologist, in 1907. Marie described the case of a Frenchman who started speaking in an Alsatian accent after suffering from a cerebrovascular accident which caused right hemiplegia.

The next documented report of dysprosody occurred in 1919 by Arnold Pick, a German neurologist. He noticed a 29-year-old Czechoslovakian had started speaking in a Polish accent following a stroke. Pick's patient also suffered from right hemiparesis, a lesser version of hemiplagia, and aphasia after the stroke. Pick noticed that not only was the accent altered, but the timing of the speech was slower, and the patient spoke with uncharacteristic grammatical mistakes. Pick later wanted to follow up on his research but was not able to, since the patient had died with no autopsy performed.

The most well documented account of dysprosody was in 1943 by G. H. Monrad-Krohn. A woman, Astrid L., in Norway was hit with a shell fragment during an air raid in 1941 through her left frontal bone, leaving her brain exposed. She was unconscious for four days and when she regained consciousness at the hospital, she was hemiplegic on her right side, was suffering from seizures, and was aphasic. Initially she could only speak in monosyllables, yes and no, but then started to form sentences. When first starting to speak again, she also spoke with uncharacteristic grammatical errors, but over time they became much less pronounced and eventually she gained back full fluency of speech. However, she sounded as though she was speaking her native Norwegian with a German accent. It was two years later that she was admitted to the Neurological University Clinic in Oslo, Norway and seen by Dr. Monrad-Krohn. Krohn examined the patient and noted that there was no noticeable difference in her fluency, motor functions, sensory functions, or coordination. Upon examination of her skull, he found a large scar on the left fronto-temporo-parietal region. This was not as helpful as Krohn would have liked. Since the scar was so extensive, it was impossible for Krohn to pinpoint the exact region of the brain which was causing this altered speech. Krohn then ran tests on Astrid to assess her language comprehension. He found that in addition to her altered speech patterns, she had trouble finding the Norwegian words for trivial objects, such as light switch and match box. She also had to repeat the examiner's questions aloud before answering, had to say words out loud to herself before writing them down, and had difficulty comprehending written instructions. Krohn could not understand how she had acquired a foreign accent; it could not be attributed to any known disorder or disease. For those who suffer from this type of dysprosody, it is interesting to note that sometimes the accents they speak are from countries to which the person has never been. This fact is very puzzling for neuroscientists, since dialects and accents are considered to be an acquired behavior of learning pitches, intonations and stress patterns.

There have been another 21 cases documented up until 1978. Thirteen of those cases were documented at the Mayo Clinic, while the others were documented at clinics and hospitals elsewhere.

There have been more recent occurrences of people who have developed accents after brain injuries, specifically strokes. In 1999, Judi Roberts suffered a stroke which paralyzed the right side of her body, leaving her unable to speak. Over time, her speech began to improve, eventually recovering full fluency, but she developed a British accent despite having lived in the US for her whole life. In 2006, another report was documented of Linda Walker, a native of England, who developed a foreign accent after suffering from a stroke.