Structural abnormalities in the brains of POTS patients-left insula

[Seven7]

Big news! Researchers have identified structural abnormalities in the brains of POTS patients. One of the areas identified, the left insula, is part of the insular cortex, an area of the brain involved with the body's regulation of the autonomic nervous system and perceptions of pain. The full article is not available yet, but as soon as it's published, we will provide a patient-friendly explanation of the findings. This study could open the door for a whole new area of POTS research!

https://www.facebook.com/DysautonomiaInternational

http://journal.frontiersin.org/Journal/119937/abstract
tructural brain abnormalities in postural tachycardia syndrome: A VBM-DARTEL study
Satoshi Umeda1*, Neil A. Harrison2, Marcus Gray3, Christopher Mathias4 and Hugo Critchley2

• 1Psychology, Keio University, Japan
• 2Brighton and Sussex Medical School, University of Sussex, United Kingdom
• 3The University of Queensland, Australia
• 4National Hospital for Neurology and Neurosurgery, University College London, United Kingdom

Postural tachycardia syndrome (PoTS), a form of dysautonomia, is characterized by orthostatic intolerance, and is frequently accompanied by a range of symptoms including palpitations, lightheadedness, clouding of thought, blurred vision, fatigue, anxiety and depression. Although the estimated prevalence of PoTS is approximately 5-10 times as
common as the better-known condition orthostatic hypotension, the neural substrates of the syndrome are poorly characterized. In the present study, we used magnetic resonance imaging (MRI) with voxel-based morphometry (VBM) applying the diffeomorphic anatomical registration through exponentiated lie algebra (DARTEL) procedure to examine variation in regional brain structure associated with PoTS. We recruited eleven patients with established PoTS and twenty-three age-matched normal controls. Group comparison of grey matter volume revealed diminished grey matter volume within the left anterior insula, right middle frontal gyrus and right cingulate gyrus in the PoTS group. We also observed lower white matter volume beneath the precentral gyrus and paracentral lobule, right pre- and post-central gyrus, paracentral lobule and superior frontal gyrus in PoTS patients. Subsequent ROI analyses revealed significant negative correlations between left insula volume and trait anxiety and depression scores. Together, these findings of structural differences, particularly within insular and cingulate components of the salience network, suggest a link between dysregulated physiological reactions arising from compromised central autonomic control (and interoceptive representation) and increased vulnerability to psychiatric symptoms in PoTS patients.

Keywords: Autonomic Disorders, postural tachycardia syndrome, MRI, VBM, DARTEL, insula, interoception, salience network, Anxiety, Depression

Citation: Umeda S, Harrison NA, Gray M, Mathias C and Critchley H

Received: 30 Sep 2014; Paper pending published: 01 Dec 2014.

 

[Seven7]

Interesting so many of have POTs and POTs like issues, and the abnormalities is in the left brain side too. So whatever abnormalities found in cfs is close to the POTs location??? This is Extremely Interesting!!!!

 

[Marco]

Very interesting if repeatable although I'm not sure everyone will appreciate the implications as I read them.


"Subsequent ROI analyses revealed significant negative correlations between left insula volume and trait anxiety and depression scores."

This supports my expectation that mood/psychiatric symptoms in POTS and ME/CFS are indicative of the underlying problem and not a reaction to chronic illness.

"Together, these findings of structural differences, particularly within insular and cingulate components of the salience network,"

This is along similar lines to ME/CFS findings that suggest disrupted gating/attentional processes with the possibility that normal sensations may be interpreted as more 'salient' (important/serious) than they merit.

... "suggest a link between dysregulated physiological reactions arising from compromised central autonomic control (and interoceptive representation) and increased vulnerability to psychiatric symptoms in PoTS patients."

Interoceptive representation again presumably referring to how patients interpret and experience internal sensations.

Although i could be barking up the wrong tree. The full paper may offer a different explanation.

 

[adreno]

Well. Structural abnormalities of the insula is also associated with psychosis, bipolar, depression and anxiety disorders:

http://www.biomedcentral.com/1471-244X/12/45

 

[Valentijn]

This supports my expectation that mood/psychiatric symptoms in POTS and ME/CFS are indicative of the underlying problem and not a reaction to chronic illness.

Not really - it's a POTS study, not an ME/CFS study. And only a minority of ME patients have POTS, while the majority have NMH.

There's also no indication yet of what instrument was used to assess psychiatric symptoms. It's quite possible that the brain abnormalities are causing physical symptoms which are interpreted as signs of anxiety or depression. This happens quite often with research into chronic illnesses, and the primary author is a psychologist.

They also list anxiety and depression as symptoms of POTS, so may have created a self-fulfilling prophecy if those were part of the recruitment criteria. The psych definition of anxiety has about a 99% overlap with the physical symptoms of orthostatic intolerance (except that people don't actually "feel" anxious), and many questionnaires consider any reduction in physical or cognitive activities (both likely to occur with OI) to be a result of depression.

 

[Valentijn]

In addition to the primary author being a psychologist, the others are a neuropsychiatrist, a psychologist with psychiatric training, a guy with a PhD in imaging, and a hypermobility guy who works at a clinic which only seems to offer physiotherapy and CBT.

Overall, I'd expect to see an undue emphasis on psychological, psychiatric, and behavioral factors from this bunch, at least in the intro and discussion sections. I also wouldn't be surprised if they did indeed use inappropriate questionnaires to diagnose anxiety and depression.

 

[Marco]

Not really - it's a POTS study, not an ME/CFS study. And only a minority of ME patients have POTS, while the majority have NMH.

There's also no indication yet of what instrument was used to assess psychiatric symptoms. It's quite possible that the brain abnormalities are causing physical symptoms which are interpreted as signs of anxiety or depression. This happens quite often with research into chronic illnesses, and the primary author is a psychologist.

They also list anxiety and depression as symptoms of POTS, so may have created a self-fulfilling prophecy if those were part of the recruitment criteria. The psych definition of anxiety has about a 99% overlap with the physical symptoms of orthostatic intolerance (except that people don't actually "feel" anxious), and many questionnaires consider any reduction in physical or cognitive activities (both likely to occur with OI) to be a result of depression.

I'm aware of the arguments. I'm just not convinced by them.

 

[adreno]

Overall, I'd expect to see an undue emphasis on psychological, psychiatric, and behavioral factors from this bunch, at least in the intro and discussion sections. I also wouldn't be surprised if they did indeed use inappropriate questionnaires to diagnose anxiety and depression.

I'm not sure I see the problem here. POTS is not diagnosed on questionnaires. And anxiety disorder does not include OI. Anxiety is a symptom of OI, but that doesn't mean it's misinterpreted. It's perfectly plausible that some of these POTS patients suffer feelings of anxiety and depression, however much these are grounded in physical factors.

 

[Valentijn]

Anxiety is a symptom of OI, but that doesn't mean it's misinterpreted.

And pretty much every symptom of OI is also considered to be a symptom of Generalized Anxiety Disorder, according to the DSM-V and ICD-10. Of course, those technically require you to feel worried, but that's an expected result of not being able to stand up and think at the same time. And the bit about exceptions for physiological causes tends to get over-looked, assuming any assessment for OI is even made.

 

[adreno]

And pretty much every symptom of OI is also considered to be a symptom of Generalized Anxiety Disorder, according to the DSM-V and ICD-10. Of course, those technically require you to feel worried, but that's an expected result of not being able to stand up and think at the same time. And the bit about exceptions for physiological causes tends to get over-looked, assuming any assessment for OI is even made.

As I read the abstract, patients are already diagnosed with POTS. Therefore, it is not confused with GAD. That might be the case elsewhere, but I don't see the problem here.

 

[Valentijn]

As I read the abstract, patients are already diagnosed with POTS. Therefore, it is not confused with GAD. That might be the case elsewhere, but I don't see the problem here.

The symptoms which qualify them as having POTS can also qualify them as having GAD, if inappropriate diagnostic methods are used. And inappropriate diagnostic methods are very frequently used by some groups, as we've often seen in CFS research.

 

[Marco]

It's perfectly plausible that some of these POTS patients suffer feelings of anxiety and depression, however much these are grounded in physical factors.

We really have to stop thinking of these always as discrete disorders and accept that they are often symptoms that can result from inflammation whether sickness behaviour due to infection; from diabetes; vascular disease; arthritis or whatever.

 

[adreno]

We really have to stop thinking of these always as discrete disorders and accept that they are often symptoms that can result from inflammation whether sickness behaviour due to infection; from diabetes; vascular disease; arthritis or whatever.

Did I say they were discrete disorders? I said they were symptoms of POTS.

 

[xchocoholic]

And pretty much every symptom of OI is also considered to be a symptom of Generalized Anxiety Disorder, according to the DSM-V and ICD-10. Of course, those technically require you to feel worried, but that's an expected result of not being able to stand up and think at the same time. And the bit about exceptions for physiological causes tends to get over-looked, assuming any assessment for OI is even made.

Great point. How often do doctors look for OI ? How often are mild allergic reactions overlooked even ?

 

[Gijs]

Many people with ME, CFS or POTS have encephalitis. With CPET scans you can prove this (microglia). There are differences in the affected areas of the brain in patients. This explains different experience of symptoms. I have POTS and also anxiety and panic attacks not as a result of a psychological factor. The feeling comes and goes without just psychological reason. It has a physical cause within the brain.

 

[adreno]

The symptoms which qualify them as having POTS can also qualify them as having GAD, if inappropriate diagnostic methods are used. And inappropriate diagnostic methods are very frequently used by some groups, as we've often seen in CFS research.

POTS is objectively diagnosable, unlike general anxiety. Do you find it likely that participants were diagnosed with POTS without having it? I have never seen any research on POTS that did not include objective markers.

 

[Marco]

Did I say they were discrete disorders? I said they were symptoms of POTS.

No you didn't. I was agreeing with you. Sorry for the confusion.

 

[Valentijn]

POTS is objectively diagnosable, unlike general anxiety. Do you find it likely that participants were diagnosed with POTS without having it? I have never seen any research on POTS that did not include objective markers.

Even when diagnosed properly, researchers with a psychological bent will often still allow acknowledged physiological POTS symptoms to be used in diagnosing anxiety.

 

[adreno]

Even when diagnosed properly, researchers with a psychological bent will often still allow acknowledged physiological POTS symptoms to be used in diagnosing anxiety.

There is no difference between anxiety from POTS, and anxiety from other causes. Anxiety is still anxiety, although the causes vary. What you are saying makes no sense. If patients with POTS state they feel anxiety, they feel anxiety. The feeling of anxiety cannot be separated from it's physical underpinning (the POTS).

 

[adreno]

Subsequent ROI analyses revealed significant negative correlations between left insula volume and trait anxiety and depression scores.

@Valentijn

However, we might agree that the researchers seems focused on the anxiety and depression symptoms, rather than the more physical symptoms of OI. Why wasn't this analysis matched with OI severity for example? That would have been more interesting. Perhaps such an analysis was done, but no correlation found. It that case, the brain abnormalities are unlikely to be specific for POTS/OI.