Review Comorbidity rates of autism spectrum disorder and functional neurological disorders: A systematic review, meta-analysis... 2024 Vickers et al

Full title: Comorbidity rates of autism spectrum disorder and functional neurological disorders: A systematic review, meta-analysis of proportions and qualitative synthesis

Abstract

This study evaluated the comorbidity rates of autism spectrum disorder (ASD) with functional neurological disorders (FNDs). A systematic review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A subset of data was suitable for meta-analysis of proportions. Studies which assessed either the prevalence of ASD in patients with FNDs, or the prevalence of FNDs in patients with ASD were considered. Critical appraisal was conducted using Joanna Briggs Institute Critical Appraisal Tools. Fourteen studies met the inclusion criteria. Three cross-sectional studies which reported the comorbidity of ASD among children presenting with functional seizures met inclusion for meta-analysis.

The pooled comorbidity rate of ASD in this group was 10.26% [3.92, 18.95], with an I2 value of 81%, indicating significant heterogeneity between studies. Most included studies (n = 5) reported on the rates of Somatic Symptom Disorders in adults with ASD. Comorbidity rates were also reported for ASD with Functional Motor Disorders and for mixed FND cohorts. Critical appraisal indicated that studies were underpowered, did not match cases with controls and failed to account for confounding factors. Identifying ASD and FND comorbidity may guide treatment options and reduce the risks of unnecessary medical investigations.

Lay abstract

Autism spectrum disorder (ASD) and functional neurological disorders (FND) are relatively common conditions, and there has been recent interest in the overlap between them. Both conditions share core features of alexithymia, impaired interoception and deficits in attentional focus. To date, relatively little is known about the comorbidity rates between ASD and FND. This is the first meta-analysis and qualitative synthesis on the subject.

We found that around 10% of children presenting with functional seizures have a comorbid ASD diagnosis. People with ASD are more likely than the neurotypical population to have functional somatic disorders, and there is also evidence that ASD rates are higher for other FNDs such as functional motor disorders. Since FND comes with risks of unnecessary medical procedures and investigations, it is important to recognize the potential for people with ASD to have an FND comorbidity.

Paywall, https://journals.sagepub.com/doi/10.1177/13623613241272958

 

Does any one else find this chilling?

Given we are looking at a neurodivergent population can we know that what is being labelled ’FND’ here corresponds to what is labelled ’FND’ in other populations, but more worrying, if like ME/CFS, people on the Autistic Spectrum are at higher risk of other potentially treatable medical conditions, including such as cardiovascular issues or cancer, this desire to ‘reduce the risk of unnecessary medical investigations’ could result in failure to identify conditions that left untreated could become severely disabling or even life threatening.

Thinking back to when I was still working in the 1980s and 1990s, colleagues working with Learning Disabilities and perhaps to a lesser extent with ADS were constantly fighting for equal access to general medical care. Does this paper risk a return to the ‘bad old days’?

What comes to mind is the theme coming out of Maeve’s recent inquest hearings of a reluctance to ‘medicalise’ what was a serious medical issue because of clinical staff’s false beliefs about ME/CFS. Obviously medical care needs to respond to any issues specific to concurrent diagnoses such as hypersensitivities, but an FND diagnosis misused to block access to appropriate medical care has horrific overtones.

 

If we want to avoid unnecessary medical investigations, then we should get rid of the FND paradigm. Easier and more honest to say we don't know.

 

I thought of it a bit differently. If you believe autistic people are more likely to have FND, then doctors will just say "You're not sick, just crazy, it's the autism" much like how they dismiss women. Autistic people may describe their symptoms in language others have trouble understanding, which can be an additional barrier to getting conditions diagnosed.

When I first got PEM, I described it as confusion, not fatigue, and even now, I don't feel that tired when I have PEM, I just feel like my executive function is completely shot.

 

Given the atrocious state of research on both issues, how this is basically bunching up bad evidence and concluding whatever they want, this is a good example of yes, yes, two wrongs don't make a right but what about, like, dozens of wrongs?

Nope. Still doesn't make it right.

Might as well be about the overlap of either with witchcraft. You know the ones. Long hair. No children. You just yell WITCH! at them and bam! Diagnosis performed.