Thursday, October 18, 2007

Two breakthrough brain studies!

There is a new article out based on brain imaging work from two top neuroscientists Kate Watkins and Smith at Oxford on the brain of young people: see here and the abstract below:
Using functional and diffusion imaging, we examined brain structure and function in the motor and language areas in a group of young people who stutter. During speech production, irrespective of fluency or auditory feedback, the people who stuttered showed overactivity relative to controls in the anterior insula, cerebellum and midbrain bilaterally and underactivity in the ventral premotor, Rolandic opercular and sensorimotor cortex bilaterally and Heschl's gyrus on the left. These results are consistent with a recent meta-analysis of functional imaging studies in developmental stuttering. Two additional findings emerged from our study. First, we found overactivity in the midbrain, which was at the level of the substantia nigra and extended to the pedunculopontine nucleus, red nucleus and subthalamic nucleus. This overactivity is consistent with suggestions in previous studies of abnormal function of the basal ganglia or excessive dopamine in people who stutter. Second, we found underactivity of the cortical motor and premotor areas associated with articulation and speech production. Analysis of the diffusion data revealed that the integrity of the white matter underlying the underactive areas in ventral premotor cortex was reduced in people who stutter. The white matter tracts in this area via connections with posterior superior temporal and inferior parietal cortex provide a substrate for the integration of articulatory planning and sensory feedback, and via connections with primary motor cortex, a substrate for execution of articulatory movements. Our data support the conclusion that stuttering is a disorder related primarily to disruption in the cortical and subcortical neural systems supporting the selection, initiation and execution of motor sequences necessary for fluent speech production.
Another similar study will come out very soon. Studying and finding similar things. I'll talk about it as soon as it is published.

These two studies are especially significant as they studied young people's brains which should be less affected by years of stuttering. There is now very convincing evidence that brains of people who stutter are structurally different. WE HAVE DIFFERENT BRAINS!

17 comments:

Matt said...

Wow, very interesting. I look forward to future updates surrounding this...

Jerome said...

>WE HAVE DIFFERENT BRAINS!

Is that supposed to be really be a revelation? ;) I thought so all the time.

Great news though that research is addressing the problem of stuttering more and more.

Anonymous said...

The most interesting finding in this study is the reduced white matter anisotropy underlying an underactivated functional area. I am also pleased to see that this study somewhat replicated the results of the earlier Sommer (2002) DTI investigation - compromised white matter underlying the Rolandic operculum. Even if this study has methodological problems (warping teenage brins to 28 year - old brains for statistical comparison) it is an important and small step forward. I agree with Jerome, it is not surprising that the brains of people who stutter are structurally differnt - the evidence has been mounting for years. Consider the CT study by Strub in 1987, the work of Foundas in the early 2000s and the two voxel-based morphemtry studies by Jancke (2002) and Beal (2007) that demonstrated differences in grey and white matter make up of speech and auditory areas in people who stutter.

Tom Weidig said...

Yes, but these studies are on young people and not adults. Also, Watkins and Smith seems very rigorous in their approach.

I am not surprised myself, but this comes as a shock to many in the "community". There is clearly something wrong / non-standard in the stuttering brain.

I havent seen Beal 2007. I'll search for it.

Tom Weidig said...

Re Sommer replication, the second study that will soon be published, also finds similar results.

Anonymous said...

"Second, we found underactivity of the cortical motor and premotor areas associated with articulation and speech production."

Hmm... Very interesting. It seems to me like this finding would open up new ways for pharmacological treatment. We already knew that dopamine antagonists are somewhat effective in the treatment of stuttering because they curb the over-activity in the midbrain, but this new finding suggests that another (or additional) way to treat the condition would be to use some neurotransmitter agonist or re-uptake inhibitor to increase the activity in the under-active cortical motor and premotor areas.

I wonder if the under-activity in the cortical motor and premotor areas is my primary problem and this is why Ritalin, which is a dopamine and serotonin agonist, actually increases my fluency.

-Silent P.

Anonymous said...

I'm so glad to be reading about this under-activity in motor function.

I've always felt that I LACKED something in the brain that other speakers have... no matter how much I slow down and create a rhythm in my speech, it's so forced and deliberate, the timing is all off.

Can't wait for the 2nd research paper...

Simona

Anonymous said...

Is anybody studying a BRAIN-GUT connection?

I'm not a scientist or doctor, but I've been researching other brain conditions like Autism, a developmental disorder of the brain where many studies have shown neurotransmitter abnormalities that also affect motor function.

I know this is *controversial*, but many doctors (and families) believe Autism is initially triggered by a depleted immune system & vaccine overdose between the ages 0-3. The gastro-intestinal tracts of many autistic kids are coated with yeast and severe candida overgrowth--from being striped down w/ antibiotics--which some doctors say cause the OCD behavior. Sometimes by changing the diet, behavior and speech can be altered in kids with Autism. Many mothers are cutting out allergens that the immune system can't handle (wheat/yeast/dairy/food additives) and supplementing their diets w/ vitamin B12 shots at regular intervals makes huge gains in their brain function, normal behavior, and speech.

A lot of conditions that affect the brain and motor function (parkinson's, epilepsy, autism, stuttering) seem to have more similarities than differences...

I'm (casually) thinking about doing a month of the special diet restrictions recommended to children with Autism to see if it does anything to my brain...

Has anyone seen any stuttering research on immune, dietary, vitamin deficiencies? Any thoughts?

Simona

Anonymous said...

Are stutterers born with a different brain or does the stress of stuttering somehow rewire the brain over time? I remember as a 6 or 7 year old having some problems with my speech but I don't think I considered myself a stutterer because I didn't have the stress or anxiety usually associated with stuttering. It was only after a string of bad blocks while talking to two kids of the same age and hearing one of them say, “He's a stutterer”, as I walked away, that the realization came over me that I was a stutterer. Then the standard avoidance behavior kicked in and I had this dread belief that I was a stutterer.

Anonymous said...

Re: being born with different brains:-
Our son started stuttering as soon as he began putting two words together. His stuttering was very significant, so that by the age of 4 he had a very hard time getting thoughts out, speaking with peers, in preschool or the neighborhood. But he rarely seemed aware that he was stuttering. He just kept going--working on getting out what he was trying to say. Speech therapy at age 4 was a huge help--but added a negative thought to the mix--that he felt he had to be perfect. Private small schools until 5th grade--no teasing and still very little awareness of when he was stuttering. Only later, like was mentioned, did he become aware- self conscious of his stuttering and avoid situations where he felt he might stutter. So-- I believe that the neurological differences are definitely there before awareness of the stuttering. He also had less significant secondary behaviors/ movements-- I am not sure how they are related. I am sure that these behaviors could not possibly be self reinforcing, so my guess is that however stress impacts the neurochemistry of stuttering, this is what impacts the tic like movements.
Like Silent P. -- Adderall has made an impact on reducing the stuttering, but Lexapro has had a much more significant impact.
There was an interesting article on Wikipedia/ stuttering on how diet can affect stuttering (I think it was low meat/ protein or something), but the effects were minimal for the "cost" in a significant diet change.
Lynne

Anonymous said...

Hi Tom

I'm the anonymous from "the most interesting finding" post above. I agree it is encouraging that these studies are on "young people" but there are serious methodological considerations with regards to this paper. Although of average size for neuroimaing papers on stuttering, the cohort studied is too small to have used such a wide range of participants (female & male, one left hander, at least one 14 year old). Many, many developmental changes - both functional and structural - occur between the ages of 14 and 21. There are just too many differences between a 14 year old brain and a 28 year old brain to include them in the same group. Studies of brain development over the period of late adolesence use very large popoulations with about as many people in each year (12, 13, 14, 15, 16 etc year olds) as this paper as in each group. Check out the work of Scott Holland from Cincinati (sp?) Children's Hospital - they have paediadric templates in development for statistical analysis of neuroimaging results in children that require a breakdown of sex and age in order to ensure accurate results.

I also think it is very interesting that no behavioural differences were found between the different auditory feedback conditions in the stuttering group. It is likely because the altered feedback was not tailored to the individual to improve fluency (at least temporarily).

My impression - a good paper but not a breakthrough. A baby-step towards our understanding of the brain, speech production and breakdowns in speech production.

Tom Weidig said...

Hi to all anonymous,

pls use some pseudo-name, so we can distinguish who is who.

To the last one,

I am aware of the difficulties, but I trust the people who do this because I have seen how good and professional they are.

The breakthrough is not on the papers alone, but within the context. For me personally, it is the last nail in the coffin towards an experimentally established fact. Two independent groups. Professional neuroscientist. The Watkins group having no connection to stuttering. And they both used young people.

It is very very difficult for a reasonable person to argue that most stuttering is not related to significant structural abnormalities.

To the other anonymous,

"Are stutterers born with a different brain or does the stress of stuttering somehow rewire the brain over time? I remember as a 6 or 7 year old having some problems with my speech but I don't think I considered myself a stutterer because I didn't have the stress or anxiety usually associated with stuttering. It was only after a string of bad blocks while talking to two kids of the same age and hearing one of them say, “He's a stutterer”, as I walked away, that the realization came over me that I was a stutterer. Then the standard avoidance behavior kicked in and I had this dread belief that I was a stutterer."

It is not very unlikely that all of the structural difference is due to the effects of stuttering.

In your case, I would say that you always had some structural defficiency. You might not have been aware of your stuttering. Or may be it was lighter but became more severe later. Of course, your being aware of your stuttering can make it much worse especially in terms of avoidance. How a child deals with it does play a big role in how strong its handicap is. The structural defficiency is just the seed.

Anonymous said...

Silent P. here:

I was also stuttering ever since I began to talk, which was very early, by the way. I always had blocks; the only difference was always the ways in which I (my body) coped with them. It started with vowel prolongations and first syllable repetitions and eventually progressed to word avoidances/substitutions and facial contortions/secondaries.

I was born with the umbilical cord wrapped around my neck, a bluish skin-tone and trembling hands. Also, as soon as I was born, they took me away and did not let my parents hold me for about two weeks. I always wondered whether my stuttering was the result of brain damage or deep pre/post-natal psychological trauma. Being slowly strangled by your own umbilical cord inside your mamma’s womb must feel pretty bad.

-Silent P.

Anonymous said...

Hi Tom
Who is the second group and what is the second study using young people?

"Two independent groups. Professional neuroscientist. The Watkins group having no connection to stuttering. And they both used young people."

Mom: boy who stutters said...

This is all very interesting and I appreciate the info. from all of you.

Lidcombe has helped, but we missed the important window of opportunity (Preschool ages). We will continue with Lidcombe with school age adjustments, choral reading, and relaxation techniques. For those with young children that stutter, please have a look at the Lidcombe Program right away.

We are also trying a gluten free diet. There is a gut brain connection that includes neurotransmitters. Receptors are made of protein, I think lysine has been show to be a possible amino acid important to Dopamine receptor structure? Anyone know more?

Keeping a food diary and correlating it with disfluency ratings (2x/day) convinced me to make dietary changes. Two weeks is a good length of time to begin looking at this, imho.

Our son's cord was also wrapped during birth. He did not show signs of oxygen depvrivation at birth or by monitoring during labor, however.

There was a fairly recent study done by a faculty member at the U. of Maryland speech/language department that intrigued me. It showed some common personality traits among the stutterers participating in the research study. In my dealings with people who stutter, I have noticed some commonalities, also. Enough that I am starting to think there is so much more to this. Behavior is influenced by brain chemistry.

Hopefully, neuroscience will lead to a huge breakthrough in time for all those here to benefit. Personally, I'd like to see more collaboration from experts in all fields of study that we now know are involved in communication disorders. Wouldn't it be great to have a team of imaging folks, neuroscientists, speech/language professionals, dieticians, and physicians work this problem together?

mom: boy of stutterer, again said...

Here's the "thing" regarding dopamine:

There is a range of people with varying disorders that affect speech/communication. At the top of the range, there are people with schizophrenia that have too much dopamine uptake. Down the scale, we see people with Tourette's Syndrome who also have increased dopamine uptake. Consider their speech challenges. Stuttering is a side effect of medications that increase dopamine uptake. People with Asperger's Syndrome have decreased dopamine uptake and communication challenges. People who are Autistic have even less dopamine uptake. Many have trouble speaking.

Parents who have have put their children with autism on gluten free diets have reported that their children show increases of words spoken by up to a hundred words or more after one month of the diet.

Receptors that neurotransmitters(dopamine and serotonin are two)bind to are made of protein. Proteins are made of chains of amino acids in particulr sequences that are coded for by DNA. Alterations in shape affect the ability of the transmitter to bind with it's receptor. Diet and metabolism affect the availablity of these amino acids. Yeast affects absorption in the colon.

If our brains are not able to fucntion as designed due to unavailability of neurotransmitters, they will adapt.

Isn't it possible that the adaptations seen in the functional imaging studies summarized here are due to long term increases in dopamine uptake?

More than likely, stuttering is multifactorial and involves a genetic predisposition and environmental triggers.

These studies are significant progress and the dietary connection may be significant, also. One thing is certain, it is very important to treat stuttering using evidence based therapies at a young age to prevent long term brain or behavioral adaptations from occuring.

*Phew*
Who got me started? ;)

Pandoras Box said...

Hmm this is all quite interesting. I take different pharms for my stutter, lexapro, wellbutrin, klonopin, ritalin, sometimes even low dose ephedrine. I can tell you that when I use these and I can get out of anxiety and depression I can speak fluently. I'm not 100%. but this post has inspired me to research hows these pharms are influencing my brain. Because I still can't wrap my brain around it (no pun intended).It seems like its beyond my capacity but I intuitively feel like I'm so close to fluency. I'm like my own lab rat. but I agree that something is not right with my brain. These pharms have showed me that.