Bansal (eye) pupil reaction test

[Amw66]

Split from Eye movements may be key to chronic fatigue syndrome diagnosis


Bansal uses an eye reaction test I believe as part of his diagnosis process .

 

[JemPD]

Bansal uses an eye reaction test I believe as part of his diagnosis process .

really? i wonder what that is?

 

[Dolphin]

Bansal uses an eye reaction test I believe as part of his diagnosis process .

Investigating unexplained fatigue in general practice with a particular focus on CFS/ME
Amolak S Bansal
https://bmcprimcare.biomedcentral.com/track/pdf/10.1186/s12875-016-0493-0.pdf

Abnormalities of the pupils to light are seen in patients with cerebral ischaemic events, certain brain neoplasms, local disturbance in neural transmission and demyelination. Checking the pupil reflexes is often undertaken to detect alterations in the brainstem pathways mediating the perception of light, accommodation to distance and near vision and changes based on ambient illumination. In patients with CFS/ME I have observed two unusual responses that are evident on prolonged illumination of the pupils. The more frequent finding seen in three quarters of patients is a rhythmic contraction and dilatation of the pupils. The second pattern is a paradoxical dilation of the pupils after an initial contraction. The latter is seen in patients with autoimmune autonomic neuropathy that is caused by IgG antibodies to the ganglionic acetylcholine receptor [44]. However, these autoantibodies are absent in the patients with CFS with this type of pupil abnormality. Interestingly these CFS/ME patients are more frequently faint on standing, have poor tolerance of prolonged standing and other features of POTS. In my experience other symptoms of a more generalised autonomic neuropathy are absent. The cause of these changes in the pupil reflexes is unclear but a persistent state of adrenergic over activity may be involved. This may oppose the constricting action of direct pupil illumination and produce the fluctuating response in many and a more significant but delayed dilatation in others. Interestingly, a delay in pupil constriction to direct light was reported in depressed patients by Fountoulakis et al. [45] and attributed to reduced noradrenergic tone.

 

[Dolphin]

Investigating unexplained fatigue in general practice with a particular focus on CFS/ME
Amolak S Bansal
https://bmcprimcare.biomedcentral.com/track/pdf/10.1186/s12875-016-0493-0.pdf

https://ammes.org/2017/02/23/invest...al-practice-with-a-particular-focus-on-cfsme/

Some information on an unpublished study on pupil responses:

Dr Bansal mentions he has observed unusual responses by the pupils to light. I thought I would highlight a study that was done in the late 1990s looking at this. Unfortunately the researcher passed away before it could be published. Perhaps there are better sources than these lay articles but I thought they might be of some use in the hope that the finding might be followed up again.

Eye test hope for ME sufferers

Jenny Hope

A new eye test can ‘see’ changes in the brain triggered by the crippling disease ME. The advance comes from a number of research projects that could lead to better treatments for the illness once ridiculed as ‘yuppie flu’.

It gives fresh hope to an estimated 150,000 victims of chronic fatigue syndrome, which can leave those worst affected bedridden with pain, suffering short-term memory loss and unable to walk even short distances.

Scientists at the Royal Free Hospital and the City University in London have found a way to measure changes in the eyes of ME patients which may show they lack an important brain chemical.

A study by Dr Ian James and Professor John Barbur checked the pupils of 16 ME patients and 24 healthy individuals, using a computer to measure changes identified between the two groups.

They found patients with chronic fatigue had larger pupils and also had a stronger reaction to light and other stimuli. The changes could be linked to a deficiency of the brain chemical serotonin, which is known to occur in ME and is also linked to depression.

Professor John Hughes, chairman of the Chronic Fatigue Syndrome Research Foundation, said the research should make it possible to understand changes occurring in the brain of a sufferer.

This could help those studying the effect of different drugs and possibly help doctors diagnose CFS, he added.

At present there are no reliable tests, although a checklist of symptoms developed five years ago is being used by doctors worldwide.

BREAKTHROUGH FOR ME by Geraint Jones

For years, ME has been treated with suspicion by doctors. Many believe that for every genuine sufferer there is another who simply believes himself to be ill. Experts cannot agree on whether the condition is a physical illness or a psychological disorder which exists only in the victim’s mind. One reason for this scepticism is that, as yet, no one has been able to provide an accurate diagnosis for ME, or myalgic encephalomyelitis, which is known to affect 150,000 people in Britain. There is no known cure and treatment is often based on antidepressant drugs like Prozae, with limited success.

All this may be about to change. Dr Ian James, consultant and reader in clinical pharmacology at London’s Royal Free Hospital School of Medicine, believes that he has found a way of diagnosing the chronic fatigue syndrome and hopes to use it to develop a treatment programme. The breakthrough came after months of research spearheaded by Dr James and Professor John Barbur of London’s City University. It centres round the discovery that the eyes of ME sufferers respond to light and motion stimuli in an unusual way.

“Several doctors treating ME patients noticed that they showed an abnormal pupil response”, says Dr James. “When the pupil is subjected to changes in light, or is required to alter focus from a close object to one further away, it does so by constricting and dilating. ME patients’ eyes do this as well but there is an initial period of instability when the pupil fluctuates in size”.

Using a computerised “pupilometer”, which precisely measures eye responses, Dr James embarked on a detailed study of this phenomenon on ME patients, using non-sufferers as a control. A variety of shapes were flashed on to a screen and moved across it, while a computer precisely measured pupil reflex to each of the 40 tests. Results confirmed that the pupil fluctuation was peculiar to those participants who suffered from ME.

Dr James concluded that the abnormal pupil response is a result of some kind of interference in the transfer of impulses from the brain to the eye. He believes that ME is the result of a deficiency of a neuro-transmitter called 5HT, whose job it is to pass impulses through nerves to cells. The eyes of ME sufferers treated with 5HT behave normally. “I do not yet know how the ME virus causes abnormalities in 5HT transmission but it does inhibit its function”, says Dr James.

 

[Woolie]

Smells a bit off to me, this.

Pupillometry is used a lot in cognitive psychology because pupils are markers of all sorts of things. People's pupils will repond to changes in the nature of some repeating stimulus, even if its auditory (e.g, beep, beep, beep, boop, beep), they'll respond to pretty much any attention-grabbing stimulus. They are also pretty sensitive markers of changes in affect, and to painful sensations anywhere in the body.

So there are dozens of reasons why PwME might show unusual pupil responses, which have nothing to do with abnormalities in the brain stem.

These responses might be tracking some of the cognitive limitations associated ME that change the way people orient to new stimuli, or they could be tracking some other feature, such as automonic abnormaities. You really can't say, its just an outcome measure, and the trick is in teasing apart what factors are causing he abnormalties.

 

[Sean]

Sounds like brain scans. Sure it is objective data, but what does it mean?

 

[Forbin]

I think it would only be a "key" to chronic fatigue syndrome if it were very specific to ME/CFS patients as well as a common finding in ME/CFS patients.

I've certainly experienced visual problems that I connect to ME - mainly related to difficulties with convergrance and "fusion" of the stereo image - but also with visual "flicker," which might be caused by rapid changes in pupil diameter, but I think there's also likely a strong link between the vestibular system and "aiming" difficulties with the eyes.

The wide number of possible combinations of various visual and balance problems makes me sceptical that a single "signature" will cover a high percentage of patients, but I'm glad someone is actually studying this. It might at least lead to patients with these problems being further evaluated for possible ME/CFS

 

[Hutan]

Abnormal quantitative pupillary light responses following COVID-19, 2022, Bitirgen et al
new study out, finding issues with pupil contraction, although, at first glance, different to what Bansal reported.

 

[CRG]

Bansal doesn't use the term "Parasympathetic Nervous System Dysfunction" but it seems to cover some of the general pathology he (unreferenced) refers to - this paper:
Parasympathetic Nervous System Dysfunction, as Identified by Pupil Light Reflex, and Its Possible Connection to Hearing Impairment includes a review of PNSD studies in addition to making the interesting connection with hearing impairment.