Objective

The term ‘functional’ has a distinguished history, embodying a number of physiological concepts, but has increasingly come to mean ‘hysterical’. The DSM-V working group proposes to use ‘functional’ as the official diagnostic term for medically unexplained neurological symptoms (currently known as ‘conversion disorder’). This study aimed to explore the current neurological meanings of the term and to understand its resilience.

Design

Mixed methods were used, first interviewing the neurologists in a large UK region and then surveying all neurologists in the UK on their use of the term.

Results

The interviews revealed four dominant uses—‘not organic’, a physical disability, a brain disorder and a psychiatric problem—as well as considerable ambiguity. Although there was much dissatisfaction with the term, the ambiguity was also seen as useful when engaging with patients. The survey confirmed these findings, with a majority adhering to a strict interpretation of ‘functional’ to mean only ‘not organic’, but a minority employing it to mean different things in different contexts - and endorsing the view that ‘functional’ would one day be a neurological construct again.

Conclusions

‘Functional’ embodies real divisions in neurologists' conceptualisation of unexplained symptoms and, perhaps, between those of patients and neurologists: its diversity of meanings allows it to be a common term while meaning different things to different people, or at different times, and thus conceal some of the conflict in a particularly contentious area. This flexibility may help explain the term's longevity.

Background

Monetary incentives are an effective way of increasing response rates to surveys, though they are generally less effective in physicians, and are more effective when the incentive is paid up-front rather than when made conditional on completion.

Methods

In this study we examine the effectiveness of pre- and post-completion incentives on the response rates of all the neurologists in the UK to a survey about conversion disorder, using a cluster randomised controlled design. A postal survey was sent to all practicing consultant neurologists, in two rounds, including either a book token, the promise of a book token, or nothing at all.

Results

Three hundred and fifty-one of 591 eligible neurologists completed the survey, for a response rate of 59%. While the post-completion incentive exerted no discernible influence on response rates, a pre-completion incentive did, with an odds-ratio of 2.1 (95% confidence interval 1.5 - 3.0).

Conclusions

We conclude that neurologists, in the UK at least, may be influenced to respond to a postal survey by a pre-payment incentive but are unaffected by a promised reward.

Objective

the Functional Somatic Syndromes (FSS) show considerable co-morbidity, leading some to suggest they may be aspects of the same disorder. This study aims to review the evidence for overlap in the phenomenology of the FSS.

Methods

a selective review of peer-reviewed articles on the co-occurrence of FSS symptoms and diagnoses.

Results

considerable evidence of overlap was found at the level of symptoms, of diagnostic criteria, and of clinical diagnoses made.

Conclusions

phenomenological commonalities support a close relationship between the FSS, though differences remain in other domains. Whether the FSS may best be considered the same or different will depend on the pragmatics of diagnosis.