Childhood Speech Disorder Apraxia: Underlying Brain Pathway Identified

MedicalResearch.com Interview with:

Prof. Angela Morgan PhDNHMRC Practitioner Fellow and Leads the Speech and Language GroupMurdoch Children's Research Institute

Prof. Morgan

Prof. Angela Morgan PhD
NHMRC Practitioner Fellow and
Leads the Speech and Language Group
Murdoch Children’s Research Institute

MedicalResearch.com: What is the background for this study? What are the main findings? 

Response: Approximately 5% of school-aged children have a communication impairment that affects speech, language, or both. There are many subtypes of speech sound disorders, but the most severe is  (CAS), which impacts sequencing of speech movements. Childhood apraxia of speech  occurs in around 1 in 1000 children. In persistent cases of CAS, speech cannot easily be understood throughout life. Although CAS is rare, unravelling its neurobiological causes is likely to identify brain networks crucial to more common and less severe forms of speech disorders.

Here we provide comprehensive speech and neuroimaging data on a large novel family where one parent and 11 children presented with features of childhood apraxia of speech. Brain MRI scanning revealed changes in core parts of the brain responsible for speech production. Even though CAS manifests as a problem with talking, we found disruptions in an underlying pathway of the brain normally associated with language (the meaning and grammar of what we say), rather than speech production. Our findings identify disruption of the dorsal language stream as a novel finding in developmental speech disorders. Overall, our data confirm the early role of this stream in auditory-to-articulation transformations.  Continue reading

How Do We Retrieve Speech From Our 50,000 Word Mental Dictionary?

MedicalResearch.com Interview with:

Stephanie Ries, PhD Assistant Professor School of Speech, Language, and Hearing Sciences Center for Clinical and Cognitive Neuroscience San Diego State University Director of the Laboratory for the Brain Dynamics of Language San Diego, CA

Dr. Reis

Stephanie Ries, PhD
Assistant Professor
School of Speech, Language, and Hearing Sciences
Center for Clinical and Cognitive Neuroscience
San Diego State University
Director of the Laboratory for the Brain Dynamics of Language
San Diego, CA

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: Our study is about how we retrieve words when we speak. We routinely do this rather effortlessly. Healthy adults can produce about 2 to 3 words per second selected among over 50,000 words in our mental dictionary. However, the neural mechanisms allowing us to do so are not well known. This process relies on two complementary mechanisms: the activation of words, and the selection of words. Our study shows that these mechanisms co-occur in time: meaning one does not end when the other starts, and in space: some brain regions, such as the posterior inferior temporal gyrus, support both mechanisms sequentially.

We were able to get an unprecedented look into the neural underpinnings of this process by studying brain activity recorded directly at the cortical surface in patients undergoing intracranial EEG monitoring for intractable epilepsy. While these patients were monitored, we asked them if they would agree to participate in our study, which consisted in naming pictures for about 10 minutes. Most of the time, they agreed. We were then able to analyze the intracranial electrical signal in relation to the pictures that were named. Such occasions are extremely rare.

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Intensive Therapy Facilitates Language Recovery in Chronic Aphasia After Stroke

MedicalResearch.com Interview with:
Caterina Breitenstein, PhD
Department of General Neurology, University of Muenster, Germany
Annette Baumgärtner, PhD
Faculty of Health and Social Sciences, Fresenius University of Applied Sciences, Hamburg, Germany

MedicalResearch.com : What is the background for this study? What are the main findings?

Response: For a long time, it has been assumed that language recovery is limited to the first months after the initial stroke. During the past two decades, however, several clinical studies and systematic reviews have challenged this dogma by demonstrating functional gains in stroke survivors during the chronic post-stroke stage (at least 6 months post the initial stroke) whenever speech and language therapy (SLT) intensity was sufficiently high (i.e., at least 5 h/week for several weeks). These studies, however, lacked the methodological quality required for evidence-based interventions (for criteria, please refer to http://www.cebm.net/ocebm-levels-of-evidence). Until now, this lack in evidence severely hampers stroke survivors’ access to language rehabilitation services .

The present multicenter randomized controlled healthcare trial FCET2EC (acronym stands for “From Controlled Experimental Trial to=2 Everyday Communication) is the first study worldwide to compare three weeks of intensive SLT provided under routine clinical conditions to an equally long period of no (or low intensity) SLT. After 3 weeks of intensive individualized therapy, the 156 stroke survivors with chronic aphasia verbally expressed themselves more effectively in daily-life communicative situations, like changing a doctor’s appointment by a telephone call. Additionally, patients and their significant other rated their communication-related quality of life as significantly improved.

Last but not least, therapy effects remained stable over a follow-up period of six months after the intensive intervention.

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