Imaging Brain Mechanisms of Functional Somatic Syndromes: Potential as a Biomarker?, 2020, Kano et al

[Andy]

To paraphrase, "We've found changes in the brains of people with "FSS", this then proves that "FSS" is valid category! It certainly doesn't mean that there is an actual disease mechanism at work, oh no!"

When patients present with persistent bodily complaints that cannot be explained by a symptom-linked organic pathology (medically unexplained symptoms), they are diagnosed with ‘functional’ somatic syndromes (FSS). Despite their prevalence, the management of FSS is notoriously challenging in clinical practice. This may be because FSS are heterogeneous disorders in terms of etiopathogenesis. They include patients with primarily peripheral dysfunction, primarily centrally driven somatic symptoms, and a mix of both. Brain-imaging studies, particularly data-driven pattern recognition methods using machine learning algorithms, could provide brain-based biomarkers for these clinical conditions.

In this review, we provide an overview of our brain imaging data on brain-body interactions in one of the most well-known FSS, irritable bowel syndrome (IBS), and discuss the possible development of a brain-based biomarker for FSS. Anticipation of unpredictable pain, which commonly elicits fear in FSS patients, induced increased activity in brain areas associated with hypervigilance during rectal distention and non-distention conditions in IBS. This was coupled with dysfunctional inhibitory influence of the medial prefrontal cortex (mPFC) and pregenual anterior cingulate cortex (pACC) on stress regulation systems, resulting in the activated autonomic nervous system (ANS) and neuroendocrine system stimulated by corticotropin-releasing hormone (CRH). IBS subjects with higher alexithymia, a risk factor for FSS, showed stronger activity in the insula during rectal distention but reduced subjective sensitivity. Reduced top-down regulation of the ANS and CRH system by mPFC and pACC, discordance between the insula response to stimulation and subjective sensation of pain, and stronger threat responses in hypervigilance-related areas may be a candidate brain-based biomarker.

Open access, https://www.jstage.jst.go.jp/article/tjem/250/3/250_137/_html/-char/en

FSS are common in all areas of medicine, with patients assigned to different types of specialists depending on the symptoms. These include pain at various locations (abdomen, chest, head, back, muscles or joints), diarrhea or constipation, dizziness, palpitations, fatigue, exhaustion, movement disorders, pseudo-seizures, and more (..). The most prevalent FSS include irritable bowel syndrome (IBS), functional dyspepsia, fibromyalgia, chronic fatigue syndrome, and chronic low-back pain, and these share clinical features

The conclusion

Chronic somatic symptoms without clear organic cause proven by medical examination, called FSS, have not been always managed well in clinical practice despite the high prevalence. The reason is that its pathophysiology is conceptualized as a dysfunction in brain-body interaction which does not originate from a single organ. Moreover, symptoms-based criteria can be adapted to patients with a heterogeneous pathological background, which can be peripheral oriented, brain oriented, and most often mixed. Brain imaging studies over the past 20 years have facilitated our understanding of the contribution of the brain to FSS etiopathogenesis. Our brain imaging studies in patients with IBS provided information on the mechanism of FSS: the influence of an unpredictable situation on brain processing of noxious visceral perception, dysfunction of brain regulation of the stress response system including the ANS and CRH related system, and the stronger activity in the visceral perception cortex with discordant subjective sensations associated with alexithymia. Recent advances in analysis of brain imaging data, such as machine learning begun the challenge to make a brain-based biomarker to diagnose or to predict clinical outcome. From our brain imaging data, the mPFC/ACC and insula projection to hypothalamus, amygdala, and PAG associated with the ANS and CRH related system as top-down regulation, and cognitive and emotional modulation or discrepancy between subjective sensation and physiological perception can be a possible candidate brain-based biomarker. There is still a huge gap between what brain imaging studies have provided so far and a real tool for clinical practice. Therefore, it is desirable that a brain-based biomarker will be developed from a variety of large data, to be tested in individual patients and to be optimized so that it can predict a target of clinical therapy for each patient.

 

[Sean]

Of course, it could not be remotely possible that the brain is being swamped by somatic stimuli arising from an as yet unrecognised biophysical pathology.

No sirree. Definitely not that. It's all in the psycho-mind.

Where's my knighthood?

 

[Mithriel]

Here maybe all this banging my head against walls is causing my neurological problems and I do need some behavioural therapy!!!

 

[Mithriel]

IBS subjects with higher alexithymia, a risk factor for FSS,

They assume a direction of causality, but it is just as possible that people diagnosed with FSS are unhappy with life because they have an idiot for a doctor.

 

[Hutan]

Anticipation of unpredictable pain, which commonly elicits fear in FSS patients, induced increased activity in brain areas associated with hypervigilance during rectal distention and non-distention conditions in IBS.

If they were doing what I think they were doing, I think most people might be feeling a bit hypervigilant.

 

[Hutan]

In addition, FSS have common psychological characteristics that make brain dysfunction a likely contributing cause: female predominance,

Oh FFS. I can't read anymore of this tonight.

 

[Sly Saint]

Our brain imaging studies in patients with IBS provided information on the mechanism of FSS: the influence of an unpredictable situation on brain processing of noxious visceral perception, dysfunction of brain regulation of the stress response system including the ANS and CRH related system, and the stronger activity in the visceral perception cortex with discordant subjective sensations associated with alexithymia.

"Alexithymia (literally 'no words for feelings') refers to a person's inability to identify or verbally describe his or her feelings. The psychiatric syndrome is prevalent in patients with psychosomatic problems, substance abuse, and anxiety disorders, but alexithymic symptoms occur along a continuum."
oh please.

 

[Invisible Woman]

no words for feelings

I have a feeling. I have a feeling this is a heap of sh*te.

Edit - to be clear the research not Sly Saint's post!

 

[Snowdrop]

It certainly doesn't hurt the hypothesis when your paper is full of self citations either.

Admittedly that's just a cheap jab because I'm feeling uncharitable about a paper that makes sweeping assumptions then calls it science.

 

[Invisible Woman]

"Alexithymia (literally 'no words for feelings') refers to a person's inability to identify or verbally describe his or her feelings. The psychiatric syndrome is prevalent in patients with psychosomatic problems, substance abuse, and anxiety disorders, but alexithymic symptoms occur along a continuum."
oh please.

A further thought -

I wonder has it ever occurred to any of these navel gazers that there might be a good reason for the patient's inability to describe how they feel. It might be the sensations they are feeling are completely beyond their normal experience and so they don't have words for it.

For example - if I say PEM y'all know exactly what I mean. 10 years ago the term didn't exist. Now I know that's a not a word, but you get what I mean.

Currently we have the word fatigue which utterly fails to describe how many of us feel. Perhaps that's still the case because the vocabulary of our illness has been forced on us by those who don't have a clue what our experience feels like.

Also the term alexythmia is normally used when referring to emotional feelings and not sensations. Seems like they are playing a little loose with the term alexythmia or perhaps they just couldn't find the right word.

 

[Amw66]

I wish I had gone for creative writing. If this is anything to go by I could have excelled

 

[NelliePledge]

How does Alexithymia fit with excessive focussing on symptoms and catastrophising. Or is it a case of you’re psychologised if you don’t talk openly about your symptoms and psychologised if you do talk openly about them. Demonstration of the heads I win tails you lose mentality of this group.

 

[alktipping]

the ability of so called educated people to astound me with their stupidity is just overwhelming . do they not have their ridiculous papers proof read by at least some one who understands that littering a paper with supposedly clever words does not actually mean the paper is worthy of printing unless its for toilet paper . it reminds me of children who having heard a new word try to put it into as many sentences as possible in order to feel more intelligent than their friends in children this behaviour is cute a part of learning language in adults however it screams incompetence or a lack of understanding certainly not what I would expect from someone with a degree level of education in any none bullshit profession .