‘The people of this country have had enough of experts…’

This extraordinary quotation is from a British politician who most definitely is not a neurologist, and certainly not a reader of Practical Neurology. Readers of this journal love experts, and particularly those who think critically about what they do, and can distil their knowledge so that we, the jobbing neurologists, can make this expertise available to our patients. Experts are sometimes characterised (unfairly) as knowing a lot about a little, about those rare diseases that we rarely see in the clinic.

Dementia is very common and all too often the diagnosis is relatively straightforward, particularly for more established disease. But having made the diagnosis what should we do next? Tony Bayer shares his expertise in the management of patients with dementia and highlights a range of simple and low-tech interventions that can help both the patient with dementia and their family (page 296).

Stroke is another common and important neurological disorder where treatment is evolving through therapeutic innovation and clinical trials. In many countries, stroke is a central part of neurological practice while elsewhere in the world neurologists are involved in stroke services to a variable degree. During the recent COVID-19 crisis, many neurologists have found themselves in the frontline of stroke management. Keith Muir and colleagues provide a practical update to help us manage stroke like an expert (page 306).

Neurologists are also becoming increasingly involved in other aspects of acute neurology, which require different skills and expertise. Emergency presentations of movement disorders are uncommon, though challenging. Vicky Marshall and colleagues provide a case-based review of this topic (page 270) to help our acute management.

Not uncommonly, we find that someone with cognitive or gait disturbance has white matter changes on their brain MRI. Sometimes, the underlying diagnosis is straightforward, corroborating a clinical suspicion. However, when it is not, how can we make a diagnosis from such a diverse range of possible options? David Lynch and colleagues have used their practical expertise to identify several rounds of diagnostic tests to lead us through this diagnostic jungle (page 280).

Primary lateral sclerosis is a diagnosis that requires patience, given that slowness of its evolution is a key diagnostic feature. This rarer motor neurone disease remains a challenge to diagnose and manage, but Martin Turner and Kevin Talbot provide us the benefit of their expertise (page 262).

Mitochondrial disorders are certainly rare but they are great mimics, and most likely we see more of them than we realise. Given their protean presentations, when should we think mitochondrial? Sir Douglass Turnbull draws upon his extensive clinical experience to highlight when we should think about mitochondrial disease (page 260).

Lumbar puncture is essential for the diagnosis of many conditions. Definitive results, such as bacterial culture or viral PCR, can take some time to become available and so we often must make inferences from other findings, notably from CSF protein and glucose concentrations. An additional cheap and readily available measure is the CSF lactate, which can help distinguish between viral and bacterial infections—as well as pointing to other rarer diagnoses, including mitochondrial disease. Aravindhan Baheerathan and colleagues provide a primer on CSF lactate, when we might test it and what it means (page 322).

New immunological treatments for malignancies, particularly haematological malignancies, appear to have remarkable outcomes. However, chimeric antigen receptor T cell therapy can be associated with significant neurological complications. At present, these treatments are available at a small number of centres; Claire Roddie and colleagues describe their experience (page 287) and tell us what a neurologist needs to know about this emerging treatment that seems destined for wider use.

Miriam Welgampola and colleagues bring out their neuro-vestibular expertise in describing a patient with a treatable form of vertigo (page 340) and Jeremy Isaacs and colleagues introduce us to the Parkinson’s variant known as DCTN1-related Parkinson-plus disorder (Perry syndrome) (page 319). The clinicopathological conference presents a great opportunity for the discussant to share their reasoning and to reveal their expertise. Ed Newman undertook this with great flair at a recent Association of British Neurologists meeting; he shares his discussion on page 326 and, as you will read, his expertise paid off.

Since early 2020, we have all rapidly learnt about SARS-CoV-2, acquiring knowledge and varying degrees of expertise, but none more so than those who have developed the illness. Sofia Mermelstein describes her personal experience of the virus, including her acute anosmia (page 345).

The sceptic’s medical dictionary defined an expert as ‘someone who comes from another place and brings slides’.¹ Ours do a bit more than that; we cannot get enough of experts.