The myths and legends of diagnosis – PD Cutting Edge Science

This session is part of a series of write-ups on Parkinson's Cutting Edge Science for Clinicians 4; the conference summary for which is here. The conference was chaired by Dr Emily Henderson and Prof Annette Hand.

Dr Lara Teare, Clinical Lead for Neurology at University Hospital Coventry and Warwickshire, gave the first presentation of the conference. She discussed the myths and legends of diagnosis, pulling apart each with clarity and ease.

Myth: It's easy

Lara spoke about happiness at feeling a certainty in diagnosis, and remarked on how confidence first increases whilst at medical school, then begins to reduce again when, as a consultant, patient cases become more and more complex (fig 1).

Lara highlighted the many elements that can shake confidence in a certain diagnosis, from patients returning with unexpected symptoms or a poor or lacking response to medications, new areas of learning that develop such as the 18 different forms of progressive supranuclear palsy (PSP) including the one which looks like multiple system atrophy (MSA)!

Legend: It's important to be right - isn't it?

Despite the desire to accurately diagnose, Lara shared that there are diagnostic errors made in up to 15% of patients.

Diagnostic errors might be system errors such as a mislaid history letter from the GP or cognitive errors such as a failure to synthesise the information in front of us. An unclear picture of symptoms due to people assuming that health changes are 'natural aging' can also impact, as well as a reliance on clinical clues and an ignoring of opposing clues. Premature closure - a narrowing of expectation or an assumption of a previously made diagnosis as correct, can also impact.

Lara presented a variety of papers and guidance examining this 'legend' and highlighting the nuances within it.

Myth: Levodopa responsiveness

Levodopa responsiveness has been seen as 'a hallmark for the diagnosis of IPD', however, it is not always an indication, as demonstrated in a recent paper (Martin 2021).

Legend: The patient will tell all

Lara talked about the importance of taking in the unconscious information that a person is giving. She advocated always going to collect the patient from the waiting room, and watching and noticing them outside of the clinical appointment, noticing how they are acting with other people around them, assessing their walking to the appointment, their skin or expression, and so on.

To support this, Lara shared several videos of different people with Parkinson's, walking, finger tapping and so on.

Lara took questions following her session, including around making a good diagnosis remotely. Lara was clear that taking a good history can be done 'blind-folded' but losing the opportunity to observe people around that discussion can significantly impact the full story of that person. Whilst phone and video calls are better than no appointment at all, face to face for diagnostic clinics will always be better.

Another question asked was around the appropriate lead physician for older people with Parkinson's: 'In light of multimorbidity, should neurologists accept elderly care patients of 65 plus or should these patients go de facto to Care of the Elderly?'

Lara responded that the ideal solution is joined up service between neurologists and geriatricians, something which both the new GIRFT for Neurology report and the integrated care agenda are in support of. Some of the New Care Models vanguards may provide ideas around joined up working, e.g. the Neuro Network vanguard running from the Walton Centre and covering a population of 3 million (New care models: Vanguards - developing a blueprint for the future of NHS and care services, p56).