I probably won't read further than this. But, these papers are truly amazing. Turns out personality traits and adverse childhood experiences can't explain FND, despite heroic efforts on the part of decades of investigators to make it so.
So, what is correlated?
- medical and surgical co-morbidities. And, what do the authors take from that finding? That these FND patients like undergoing surgical procedures, especially sterilisation. So, nothing to do with those co-morbidities, or, heaven forbid, some damage associated with the surgery
and
- being a health worker in something like an ED. And, what do the authors take from that finding? That it's the stress of the environment - nothing to do with the constant exposure to disease, and the physical effects of shift work and long hours.
I'm currently looking up the range of papers that got listed after the sterilisation suggestion (it alarmed me so much - and made me think of it being like when lots of people with ME got diagnosed with depression first it got claimed by some that indicated that was a common comorbidity rather than indicative of culture and misdiagnosis ie were people sterilising people as 'a fix'
back in the day).
I'm quite surprised that of this list quite a few are papers of things like people with Parkinsons and Lewy body dementia.
But I'm already shocked and I've only got to the first paper in this list of
7 9 papers here: "Medical and surgical comorbidities present a clearer pattern in FND. Higher rates of surgical procedures and a history of neurological and other disease diagnoses have been recognized as important risk factors. The high rate of sterilization, particularly compared to gender-matched controls, might suggest a greater willingness to undergo surgical procedures in FND patients [
34,
50,
51,
52,
53,
54,
55,
56,
57]. "
This first one is from 1997 (!) and is from a London Neuro dept:
Slater revisited: 6 year follow up study of patients with medically unexplained motor symptoms | The BMJ
The authors include Anthony David, although he isn't the lead author (Crimlisk et al)
The abstract 'conclusion' was as follows: "Unlike Slater's study of 1965, a low incidence of physical or psychiatric diagnoses which explained these patients' symptoms or disability was found. However, a high level of psychiatric comorbidity existed."
and the key messages in the abstract:
Key messages
- Motor symptoms that remain unexplained medically despite thorough investigation are a common clinical problem, but the emergence of a subsequent organic explanation for these symptoms is rare
- The prevalence of coexistent affective and anxiety disorders is high and many patients also have a personality disorder
- Patients with a shorter duration of symptoms and coexistent anxiety or depression are likely to do better at follow up
- Reinvestigation of these patients is both expensive and potentially dangerous and should be avoided where no clear clinical indication exists
But in the full article, In the results section it is noted that 31 of their sample had a history of organic neurological disorder: 15 with organic brain disease (inc migraine, epilepsy, parkinsons) and 16 with 'neurological diorder no brain disease' (inc 9 having previous disc surgery, 3 Peripheral nerve palsy, and then things like chiari malformation, myasthenia graivs, diabetic neuropathy). "The current unexplained symptoms were similar to those related to the previous neurological disorder in only 11 subjects (15%)."
It seems 3 of the 64 over the follow-up period were found to have alternative neuro diagnoses: myotonic dystrophy 4 years later, spinocerebellar degeneration 3 years after his admission (English not being his first language was the 'communication issue'), and paroxysmal hemidystonia. Two of these ended up with breathing and swallowing issues etc so pretty severe stuff and I don't know if those conditions these days would be any less likely to be misdiagnosed into FND or such deterioration could be prevented in the eventually diagnosed condition by earlier treatment?
This is from the discussion
The incidence of subsequent neurological disorder in our study—indicative of initial misdiagnosis—was low. There was also little evidence that symptoms reflected new presentations of an undiagnosed psychiatric disorder. Mitigating factors explain misdiagnosis. In one subject, the diagnosis may have been missed because paroxysmal dystonias have only recently been recognised as a neurological entity.
14 In two others, communication problems may have played a part. It is impossible to assert that the symptoms of the other subjects will never be explained by neurological diagnoses, but after 6 years of follow up this is increasingly unlikely. The high diagnostic accuracy probably reflects improved diagnostic skills as well as better non-invasive investigative techniques.
Hmm mitigating factors for where they didn't pick up another
neurological diagnosis - if communication problems may have played a part in two of these, wouldn't it be relevant to flag 'the issue of communication problems' rather than just list it as a mitigating factor, it seems a bit insightful of attitude?
The equal sex ratio in our cohort, different from the female preponderance of previous studies, remains unexplained. However, the high incidence of affective, anxiety, somatisation, and personality disorders is similar to that previously reported.
15–
17 Although five subjects had died by the time of follow up, their deaths did not reflect missed neurological diagnoses. It is important to remember that conversion disorder does not protect patients from developing serious physical illness. The presence of somatisation in other systems may have lead to delay in the diagnosis of severe non-neurological illnesses in two subjects. In a further two subjects who died at a young age, death may have been related to the sequelae of underlying psychiatric disorder.
5 subjects died by the time of follow-up but they didn't reflect missed
neuro diagnoses. Is that good enough? and more importantly did their FND diagnosis or management play a part in anything missed or whether their death had been avoidable?
This, in 1997, explicitly notes that even if the diagnosis was correct it doesn't 'protect' people from developing serious physical illness. SO how have we got to the point now where it can mean people aren't being investigated?
Few studies have looked at indicators of prognosis. Our results support previous work which found that a short duration of symptoms was associated with a good outcome.
7 8 19 Pending litigation—as is often suggested anecdotally—also emerged as an indicator of poor prognosis.
Changed marital status (in either direction) seemed to predict a good outcome, presumably reflecting a favourable change in personal circumstances.
The association between comorbid psychiatric disorder and good outcome underlines the importance of screening for affective and anxiety disorders in these patients. These disorders may make some people vulnerable to developing conversion symptoms, which if managed inappropriately may lead to enduring disability. The findings suggest that treatments may need to be targeted specifically. Treating depression and anxiety aggressively and exploring relevant personal circumstances may reduce disability in some patients, while for those with several physical symptoms and personality disorder, prevention of iatrogenic damage and cost effective management strategies aimed at damage limitation may be more appropriate.
The changed marital status and then concluding it must be 'reflecting a favourable change in personal circumstances' seems gobsmacking of the level of scientific thinking - cart before horse much? It is pretty tricky to complete a divorce (and all the other complications) if you are getting more and more ill, and I imagine that unless you are already in a very long-term relationship then going from dating to marriage becomes harder the iller you are?
they've associated comorbid psychiatric disorder with good outcome so hence suggested where that is present to treat those aggressively. Whereas almost leading on as a non-sequitur they've then said 'while for those with several physical symptoms
and personality disorder' (I'm hoping they didn't mean it to read as it does) 'prevention of iatrogenic damage - what are they hinting at with that? - and 'cost effective management strategies aimed at damage limitation' doesn't sound particularly great? I'd like to know more about what they mean by 'damage limitation' and these strategies are?
This is the bit that is interesting:
Referral bias may explain the high social class, older age, and chronicity of our cohort compared with other studies.
6 19 Similarly, the extent to which organic disorders were excluded by special investigation may not be typical of that in other centres.
