Medicine is as much defined by diseases as by the people who named them. Neurology particularly has a proud history of eponymous disorders which I discussed in my other neurology blog, Neurochecklists Updates, with the title 45 neurological disorders with unusual EPONYMS in neurochecklists. In many cases, it is a no brainer that Benjamin Duchenne described Duchenne muscular dystrophy, Charle’s Bell is linked to Bell’s palsy, Guido Werdnig and Johann Hoffmann have Werdnig-Hoffmann disease named after them. Similarly, Sergei Korsakoff described Korsakoff’s psychosis, Adolf Wellenberg defined Wellenberg’s syndrome, and it is Augusta Dejerine Klumpke who discerned Klumpke’s paralysis. The same applies to neurological clinical signs, with Moritz Romberg and Romberg’s sign, Henreich Rinne and Rinne’s test, Jules Babinski and Babinski sign, and Joseph Brudzinski with Brudzinki’s sign.
Yes, it could become rather tiresome. But not when it comes to diseases which, for some reason, never had any names attached to them. Whilst we can celebrate Huntington, Alzheimer, Parkinson, and Friedreich, who defined narcolepsy and delirium tremens? This blog is therefore a chance to celebrate the lesser known history of neurology, and to inject some fairness into the name game. Here then are 25 non-eponymous neurological diseases and the people who discovered, fully described, or named them.
In all fairness, neurologists only very rarely come across patients with Wilson’s disease. This disorder of excessive copper deposition in tissues is however not vanishingly rare. And because it is one of the few curable neurological disorders, it is drummed into the brain of every neurologist to consider Wilson’s disease in any person, at any age, with any movement disorder. Dystonia is probably the most characteristic movement disorder in Wilson’s disease, and one of its classical signs is rhisus sardonicus, a fixed vacuous smile (which, by the way, may also be seen in tetanus). Other movement disorders of Wilson’s disease include parkinsonism, wing-beating tremor, ataxia, myoclonus, chorea, athetosis, stereotypies, tics, and restless legs syndrome. It is therefore not surprising that the disorder is named after one of neurology’s greats, Samuel Alexander Kinnier Wilson.
The other name for Wilson’s disease is hepatolenticular degeneration. ‘Lenticular’ in this context refers to the favoured brain targets of Wilson’s disease, the lentiform nuclei. These are the putamen and globus pallidus, which, along with the caudate nucleus, make up the basal ganglia. The basal ganglia are very important in the coordination of movement, and are also dysfunctional in disorders such as Huntington’s disease and Parkinson’s disease.
Wilson’s disease is however more than a brain disorder because it is, quintessentially, multi-systemic. The monicker hepatolenticular, for example, hints at the prominent and varied involvement of the liver in Wilson’s disease. Liver dysfunction here ranges from mild elevation of liver enzymes, to frank hepatic failure requiring liver transplantation. The eye is another important organ targeted by Wilson’s disease, and the neurologist is ever searching for the tell-tale but elusive Kayser-Fleischer ring. This is a brownish tinge seen around the iris caused by copper deposition, and named after the German ophthalmologists Bernhard Kayser and Bruno Fleischer. Another distinctive eye sign in Wilson’s disease is the sunflower cataract. The long reach of Wilson’s disease however extends to almost every organ system.
Wilson’s disease is all about the ‘C’ words. The first ‘C’, Copper, is of course the essential element recognised as Cu, with atomic number 29, and snugly occupying group 4 in the periodic table. An autosomal recessive genetic mutation in ATP7B, thecopper transporter gene, means some people are unable to move copper around the body. It therefore accumulates, and is eventually deposited, in almost every organ. Oh, and it also overflows in high amounts in urine.
The other ‘C’ word is Ceruloplasmin, the blood protein that binds up the dangerous free-floating copper in the blood. The blood level of ceruloplasmin is low in Wilson’s disease because it is overwhelmed by the massive amounts of copper. The classical laboratory features of Wilson’s disease are therefore raised blood copper, low blood ceruloplasmin, and elevated 24 hour urinary copper excretion. The diagnosis of Wilson’s disease may also involve a liver biopsy to confirm copper accumulation, but this is rarely required. Long-term treatment depends on one of several therapeutic options for chelating or binding copper. Surveillance requires a tight monitoring regime to monitor the metabolic profile of the disease, and the complications its treatment.
Is it however not all and dusted for Wilson’s disease. Not at all. There are advances being made to simplify the diagnosis and monitoring of this devastating disease, and below are 5 exciting developments in the management of Wilson’s disease.
I learnt of this from a paper published in the European Journal of Neurology titled Exchangeable copper: a reflection of the neurological severity in Wilson’s disease. The authors, Aurelia Poujois and colleagues, investigated this new technique of measuring exchangeable copper (CuEXC) as an aid to the diagnosis of Wilson’s disease, and as an indicator of the severity of extra-hepatic damage. They studied 48 newly diagnosed subjects and found that CuEXC is a reliable test for making the diagnosis, and a cut-off value of >2.08 μmol/l is a marker of severe organ damage. Other papers have confirmed the value of exchangeable copper, even if they call it relative exchangeable copper.
Slávka Kaščáková and colleagues, in their paper published in the journal Pathology, touted X-ray fluorescence as a rapid way to quantify copper in tissues, thereby facilitating the diagnosis of Wilson’s disease. The rather technical paper, titled Rapid and reliable diagnosis of Wilson disease using X-ray fluorescence, describes the technique as ‘high‐resolution mapping of tissue sections’ which enables the measurement of ‘the intensity and the distribution of copper, iron and zinc while preserving the morphology’. This technique can, we have to accept, reliably distinguish Wilson’s disease from other diseases such as haemochromatosis and alcoholiccirrhosis. Not a bad deal, but the squeamish neurologist must realise it requires a liver biopsy!
Quantitative transcranial ultrasound
The typical method of ‘seeing’ the brain abnormalities of Wilson’s disease is by magnetic resonance imaging (MRI). Ultrasound is however much cheaper and easier, and would be a preferable option if it can be shown to be sensitive and specific. And this is what Gotthard Tribl and colleagues demonstrated in their paper published in the Journal of Neurological Sciences titled Quantitative transcranial sonography in Wilson’s disease and healthy controls: cut-off values and functional correlates. They reported that in Wilson’s disease, the lenticular nuclei (we are familiar with this now) and substantia nigra (literally a black substance in the midbrain) are hyperechogenic compared to normal control subjects. They also came up with reliable cut-off for normality. To make things better, the thalami and midbrain are also hyperechogenic. And to add the cherry on top, the third ventricle is enlarged. More than expected from a rather simple technology.
Optical coherence tomography (OCT)
Hardly a day goes by that one doesn’t read a report on the applicability of optical coherence tomography (OCT) in one neurological disorder or the other. And Wilson’s disease is clearly not going to be the exception. OCT simply assesses the thickness or density of the retinal nerve fiber layer (RNFL), and this is reduced in many neurodegenerative diseases. In their paper titled Optical coherence tomography as a marker of neurodegeneration in patients with Wilson’s disease, Ewa Langwińska-Wośko and colleagues studied 58 subjects with Wilson’s disease. They reported that OCT can reliably measure the severity of Wilson’s disease, and it may reliably monitor disease progression. Another simple and non-invasive tool with big potential.
The treatment of Wilson’s disease centres on chelation or binding of copper. And the three major players here are Penicillamine, Trientine, and Zinc, each with its own unique advantages and serious complications. They are however all rather cumbersome and inconvenient to administer and monitor. Into this unsatisfactory situation enters a study which promises to ease the burden for neurologist and patient. The trial is titled Bis-choline tetrathiomolybdate in patients with Wilson’s disease: an open-label, multicentre, phase 2 study, and it is published in the journal Lancet Gastroenterology and Hepatology. The authors, Karl Heinz Weiss and colleagues, investigated bis-choline tetrathiomolybdate (nicknamed WTX101), which they described as ‘an oral first-in-class copper-protein-binding molecule’. It binds up copper that is either stuck in the liver or swimming freely in blood. 70% of the 28 subjects they treated met the criteria for treatment success, and they were not unduly bothered by any nasty side effects. To add to this favourable profile, WTX101 has the convenience of a once dailydosing regime.
It is reassuring that so much as happening at the cutting edge of Wilson’s disease, and neurologists can’t wait to see when these will form part of their armamentarium.
Adult attention deficit hyperactivity disorder (ADHD) is a key psychiatric disorder. It is characterised by some core clinical featureswhich are hyperactivity, inattention, impulsivity, disorganisation, and low stress tolerance. People with ADHD have several life impediments that characterise their day-to-day lives; these include difficulty starting tasks, struggling to prioritise, and failing to pay attention to details. Enduring chaotic lifestyles, they struggle to keep up with their academic, employment, and relationship commitments.
For the public and for most physicians, ADHD is recognised only as a childhood disorder. But 10-60% of childhood onset ADHD persist into adulthood. Furthermore, about 4.5% of adults have ADHD. The failure to recognise ADHD as an adult problem therefore means it is easily missed in adult psychiatry and neurology clinics. Referring to this in a review published in the journal Psychiatry (Edgmont), David Feifel labelled adult ADHD as the invisible rhinoceros (you must read the article to understand why it is not the elephant in the room). Concerned that many adults with ADHD are misdiagnosed as suffering with anxiety or depression, he urged psychiatrists to routinely screen for adult ADHD in every adult presenting with these disorders.
The scale of the failure to diagnose adult ADHD was emphasised by Laurence Jerome in a letter to the Canadian Journal of Psychiatry. Titled Adult attention-deficit hyperactivity disorder is hard to diagnose and is undertreated, his letter highlighted the finding of the US ADHD National Comorbidity Survey which concluded that most adults with ADHD have ‘never been assessed or treated’. He argued that this oversight places heavy lifetime burdens on adults with ADHD such as impaired activities of daily living, academic underachievement, poor work record, marital breakdown, and dysfunctional parenting. A great burden indeed, but a preventable and treatable one!
How is all this psychiatry relevant to the general neurologist? Well, many manifestations of ADHD are the stuff of the neurology clinic. Cognitive dysfunction for example is prevalent in adult ADHD, and it may present to the neurologist as impaired short term memory, executive dysfunction, impaired verbal learning, and, of course, impaired attention. Sleep related disordersare also frequent in adult ADHD, and these include excessive daytime sleepiness (EDS), restless legs syndrome (RLS), periodic leg movements of sleep (PLMS), and cataplexy. There are also several other neurological co-morbidities of adult ADHD such as epilepsy and learning disability.
It is therefore high time for neurologists and psychiatrists to reveal the invisible rhinoceros!
This comes from an editorial in Lancet Neurology urging a joint approach to preventing stroke and dementia, a strategy the author calls ‘the lowest hanging fruit in the fight against these two greatest threats to the brain’. He argues that ‘at the moment, the fruit might be hanging too low for our gaze, and we are wrongly fixated on the distant future of Alzheimer’s disease treatment. We might have to stoop to conquer‘.
This opinion piece in Practical Neurologytakes a stab at the age-old neurological test of sensory impairment. Subject are asked to stand up and try to maintain their balance with their eyes shut. The author asserts that this, the Romberg’s test, ‘lacks essential specificity’, ‘risks physical injury’, and is ‘redundant’. He argues that there are much better, and safer, ways of testing for sensory ataxia. There goes an interesting test!
This is from a case report of a 69-year old man in the journal Neurology. He presented with unusual crying spells which turned out to be dacrystic (crying) seizures. This case is eventually revealed to be a case of….sorry, no spoilers. Click on the link to find out.
I am no fan of Game of Thrones, but it is an in-your-face television series which provides the setting for this catchy title. The mechanistic target of rapamycin (mTOR) pathway is underlies the pathology of tuberous sclerosis. It is therefore the target of many therapeutic strategies in the form of mTOR inhibitors. And the 4 kingdoms? You have to read the piece from the New England Journal of Medicine…perhaps after you have watched the TV series!
Restless legs syndrome (RLS) does what it says on the can. Victims need to only sit or lie down for a few seconds before creepy-crawly sensations literally drive them up the wall. The discomfort is as insatiable as the urge to move is uncontrollable. It is, literally again, a nightmare; a frantic evening quickly followed by a frenetic night.
Neurologists rarely struggle to make the diagnosis of RLS. And with the efforts of support groups such as the RLS foundation, patients are now well-informed about the diagnosis. To the chagrin of the neurologists, patients often come with a list of medications they have tried, and failed.
The list of RLS risk factors is quite long. Some of these are modifiable, and the ‘must-exclude’ condition here, iron deficiency, requires checking the level of ferritin in blood. Other modifiable risk factors are quite diverse such as obesity, migraine, and even, surprisingly, myasthenia gravis (MG). Most RLS risk factors, such as peripheral neuropathy and Parkinson’s disease (PD), are unfortunately irreversible; in these cases some form of treatment is required.
Neurology is a broad specialty covering a staggering variety of diseases. Some neurological disorders are vanishingly rare, but many are household names, or at least vaguely familiar to most people. These are the diseases which define neurology. Here, in alphabetical order, is my list of the top 60 iconic neurological diseases, with links to previous blog posts where available.
The Neurology Lounge has a way to go to address all these diseases, but they are all fully covered in neurochecklists. In a future post, I will look at the rare end of the neurological spectrum and list the 75 strangest and most exotic neurological disorders.
Neurologists breathe guidelines. And they churn them out at a breathtaking pace. It is extremely difficult keeping up with what’s in, what’s out, and what’s back in again! Often the new guidelines add nothing new, or the important points are buried in sheafs of text justifying the guidelines.
But we can’t get away from them. How then do neurologists keep up, short of becoming paranoid? By becoming obsessive! In developing neurochecklists I had no idea keeping up with the guidelines would be a challenging task because they are released in quick succession. I have looked back to see which are the latest practical guidelines, released in the last 12 months or so. Here they are by disease… but be quick before the guideline-masters revise them…again!
The American Academy of Neurology (AAN) and the American Epilepsy Society published their 1st seizure management guidelines in Neurology. Among the key recommendations are to inform patients of a 2-year recurrence risk of 21-45%, and that a nocturnal seizure is among the usual culprits that increase the risk. The vexing question of whether to treat a 1st unprovoked seizure remains that-vexing.
Not to be outdone, the International League Against Epilepsy (ILAE) released it’s evidence-based guidelines and recommendations for the management of infantile seizures. Published in Epilepsia in late 2015, it shows that Levetiracetam is tops for both focal and generalised seizures. It also confirmed the hard-earned place of Stiripentol alongside Valproate and Clobazam for Dravet syndrome. It is open access so well-worth a detailed look.
Duchenne muscular dystrophy (DMD)
Steroids are now standard treatment in Duchenne’s muscular dystrophy (DMD). A recent practice guideline update on corticosteroids in Duchenne’s highlights this, and it also indicates the strength of evidence for the different benefits. There is Level B evidence that steroids improve strength and lung function, and Level C for delaying scoliosis and cardiomyopathy. Enough to encourage any doubters out there.
Facio-scapulo-humeral muscular dystrophy (FSHD)
Not one I thought had guidelines, but this FSHD diagnosis and management guidelines turned out to be quite useful. The guidelines address four key areas-diagnosis, predictors of severity, surveillance for complications, and treatment. And if you like flow charts, there is an excellent one here. A lot of helpful tips here for example, subjects with large D4Z4 gene deletions are more prone to earlier and more severe disability, and these patients should be reviewed by a retinal specialist.
Multiple sclerosis (MS)
Multiple sclerosis (MS) is one of the most shifty conditions when it comes to guidelines, both diagnostic and management. Take the latest NICE MS guidelines, 39 pages long. All sensible stuff mind you, with time-restricted targets such as 6 weeks for a post-diagnosis follow-up, and 2 weeks to treat a relapse. Mind you, just to keep neurologists on their toes!
MS diagnosis and follow up is often the game of countinglesions on MRI scans. The question of what to count, and when to do so, is addressed in the recent MAGNIMS MS consensus guidelines. More recommendations than guidelines, these did not challenge the sacrosanct MacDonald criteria for dissemination in time, but tinker with dissemination in place. They suggest, for example, that optic nerve lesions be counted. The MAGNIMS consensus guidelines on the use of MRI goes on to stipulate when and how to count lesions throughout the course of MS. Not an easy bedtime read.
Finally, Neurology published guidelines on rehabilitation in MS. Unfortunately there are quite a few qualifying ‘possibles‘ and ‘probables‘ which water down the strength of most of the recommendations. But what else do we have to go by?
The Journal of Neurology, Neurosurgery and Psychiatry (JNNP) published a review of CIDP in February 2015. It covers everything ”from bench to bedside”, but heavily skewed towards the former. It confirms that CIDP is a “spectrum of related conditions”, great news for splitters, and disappointing for lumpers. I personally struggle with the concepts of sensory and focal CIDP, have never diagnosed CANOMAD, but never tire of listening to Michael Lunn on VEGF, or be fascinated by the links between CIDP and POEMSsyndrome. The review, an editors choice, is open access, and is backed by the authority of Richard Hughes; you really have no choice but to read it!
Unruptured intracranial aneurysms
The America Stroke Association (ASA) published new guidelines on management of unruptured aneurysms in a June 2015 issue of Stroke. It gives a comprehensive review of cerebral aneurysms, addressing the “presentation, natural history, epidemiology, risk factors, screening, diagnosis, imaging and outcomes from surgical and endovascular treatment“. It also suffices for a review article. Some recommendations are easily overlooked such as counsel against smoking and monitor for hypertension (evidence level B). Some important recommendations however have weak evidence, for example surveillance imaging after endovascular treatment (evidence level C).
The guidelines still advocate screening if there are 2 or more affected first degree family members. (I confess my threshold is lower than this). The extensive list of at-risk conditions for aneurysms include the usual suspects such as adult polycystic kidney disease and fibromuscular dysplasia. New culprits (at least to me) are microcephalic osteodysplastic primordial dwarfism, Noonan syndrome, and α-glucosidase deficiency.
The American Stroke Association (ASA), along with the American Heart Association (AHA), released their guidelines for the management of spontaneous intracerebral haemorrhage in 2015. There are several additional recommendations to the previous guidelines; these include the recommendation to control hypertension immediately from onset to prevent recurrent haemorrhage.
The ASA/AHA also published their updated guidelines on endovascular stroke therapy in 2015. To to show how important this treatment has become, the debate now is whether to use thrombectomy alone, or after thrombolysis. And the winner is…to use thrombectomy after thrombolysis. The eligibility checklist for endovascular therapy with a stent retriever is thankfully quite short.
OK, I confess these guideline are from 2014, a bit dated. But how often does one think ‘guidelines’ in the context of Friedreich’s ataxia. Furthermore, this Consensus clinical management guidelines for Friedreich ataxia is open access! Published in Orphanet Journal of Rare Diseases, they are the product of 39 experts, and consist of 146 recommendations! They cover everything from sleep, spasticity, and scoliosis to diabetes, dysphagia, and dysarthria. I bet you don’t enquire about restless legssyndrome (RLS) in your patients with FA!
Motor neurone disease (MND)
And hot off the press are the NICE guidelines on motor neurone disease (MND). One thing to mention is its sheer volume- 319 pages long, and containing 123 recommendations! The guidelines targets every aspect of MND care, and it’s futile trying to master it all. Each specialist can really only pick and choose which aspect is relevant to them. There is a lot of balancing of clinical and economic benefits, and this is reflected by questions such as “what are the most clinically- and cost-effective methods of maintaining nutrition…?” The guidelines address several long-standing issues such as the clinically appropriate timing for placing PEG tubes. Whether they add anything really new is however debatable.
Do you have a recent guideline or update to share? Please leave a comment.