Regular visitors to this blog know that we love catchy article titles. It is always heartwarming to see how some authors create imaginative and inventive headlines. This skill involves the ability to play with words, and the capacity to be double-edged. This is why this blog keeps a lookout for fascinating neurology titles. And in line with this tradition, and in no particular order of inventiveness, here are 15more catchy neurology titles!
This paper, for some unfathomable reason, set out to ask if the public knows the difference between what psychiatrists and psychologists actually do. And the authors discovered that “there is a lack of clarity in the public mind about our roles”. More worryingly, or reassuringly (depending on your perspective), they also found out that “psychologists were perceived as friendlier and having a better rapport“. Not earth-shattering discoveries, but what a great title!
Optical coherence tomography (OCT) is a cool tool which measures the thickness of the retinal fiber layer (RFL). And it has the habit of popping its head up in many neurological specialties. In this case, the specialty is multiple sclerosis, and the subject is how OCT influences its diagnosis and surveillance. Surely a window into the brain is easier to achieve than one into the soul.
The homonculus is the grotesque representation of the body on the surface or cortex of the brain. This paper reviews how formidable neurosurgeons such as Wilder Penfield worked out the disproportionate dimensions of this diminutive but influential man. He (always a man for some reason) has giant hands, a super-sized mouth, very small legs, and a miniature trunk. The clever brain doesn’t readily allocate its resources to large body parts that perform no complex functions! But be warned, this article is no light-weight reading!
This title is a play on words around MR-guided focussed ultrasound surgery (MRgFUS), an emerging technique for treating disorders such as essential tremor and Parkinson’s disease (PD). This review looks at the controversial fuss that this technique has evoked.
This paper explores the interesting subject of delusional misidentification syndromes (DMSs). The authors argue that few concepts in psychiatry can be as confusing as DMSs. And they did an excellent job of clearing our befuddlement around delusions such as Capgras and Fregoli. Very apt title, very interesting read.
This title belongs to a review of trypanosomiasis, aka sleeping sickness. It is a superb play on words, one that evokes several levels of meaning. It is simple and yet complex at the same time. Great imagination.
This paper discusses two parts of nervous system that are affected by toxoplasmosis. Playing on the symbolic contradiction between intellect and strength, the authors show how toxoplasmosis is an ecumenical abuser: it metes out the same fate to both brain and brawn.
Nitrous oxide, or laughing gas, is now “the seventh most commonly used recreational drug”. But those who pop it do so oblivious of the risk of subacute combined degeneration. This damage to the upper spinal cord results from nitrous oxide-induced depletion of Vitamin B1 (thiamine). Not a laughing matter at all!
Dopamine transport (DaT)scan is a useful brain imaging tests that helps to support the diagnosis of Parkinson’s disease and other disorders which disrupt the dopamine pathways in the brain. It is particularly helpful in ruling out mimics of Parkinson’s disease such as essential tremor. When to request a DaT scan is however a tricky question in practice. This paper, with its Shakespearean twist, looks at the reliability of DaT scans.
It should be no surprise if Shakespeare rears his head more than once in this blog post. Not when the wordsmith is such a veritable source of inspiration for those struggling to invent catchy titles. This paper looks at taupathy, a neurodegeneration as tragic as Hamlet. It particularly comments on an unusual taupathy, one induced by traumatic brain injury. Curious.
What better way to call attention to a serious complication than a catchy title like this one. This paper highlights the neurological complications of coarctation of the aorta, a serious congenital cardiovascular disease. And the key concerns here are the risks of stroke and cerebral aneurysms. Cardiologists, mind the brain!
This paper reviews the unexpected biochemical links between diabetes and Parkinson’s disease. And this relationship is assuming a rather large dimension. Why, for example, are there so many insulin receptors in the power house of Parkinson’s disease, the substantia nigra? A sweet curiosity.
The foraman ovale is a physiological hole-in-the-heart which should close up once a baby is born. A patent foramen ovale (PFO) results when this hole refuses to shut up. PFOs enable leg clots to traverse the heart and cause strokes in the brain. This paper reviews the evidence that surgically closing PFOs prevents stroke. Common sense says it should, but science demands proof. And the authors assert that they have it all nicely tied up. Hmmm.
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 are always cautious when making a diagnosis of Parkinson’s disease (PD). This shouldn’t be the case because PD is not difficult to recognise-at least not most of the time. For one, PD has classical clinical signs- the trio of resting tremor, slow movements (bradykinesia), and stiffness (rigidity). For another, it is asymmetrical, starting and remaining worse on one side of the body.
All these features are however vague in the early stages of PD. To make matters worse, there are many other diseases that mimic PD. These include multiple system atrophy (MSA), progressive supranuclear palsy (PSP), Lewy body disease (LBD), corticobasal degeneration (CBD), and even SWEDDS (if it exists at all!). And always lurking in the shadows, waiting to catch the neurologist out, are dystonic tremor and essential tremor.
These PD mimics challenge and intrigue neurologists in equal measure. They contribute to the delayed and missed diagnosis of PD in 20% of cases. Are there shortcuts out there to improve our diagnostic accuracy? A simple test perhaps? Maybe some biomarker? Here are 6 budding contestants.
1. Dopamine transporter (DAT) scans
DAT scans are now in general, even if not universal, use. They help to distinguish PD from conditions such as essential tremor or drug-induced Parkinsonism. DAT scans are however expensive, and they do not distinguish PD from many of its other mimics such as MSA, PSP, (you know the roll call). There are indications that DAT scans may be normal in cases of PD. We therefore clearly need better, cheaper (and newer!) PD biomarkers than DAT scans.
2. Cerebrospinal fluid (CSF) biomarkers
Perhaps the answer is in a spinal tap or lumbar puncture (LP). A lumbar puncture is a simple but dreaded test. It is however useful for giving us access to the cerebrospinal fluid (CSF) that bathes the brain and spinal cord. Analysis of the CSF often gives the game away in many neurological disorders. It is not surprising therefore that researchers looked at a panel of nine CSF biomarkersthat may identify PD. The paper, published in the JNNP, suggests that there may be biomarker roles for neurofilament light chain (NFL), soluble amyloid precursor protein (sAPP), and α-synuclein (of course). CSF α-synuclein is the focus of another paper in BioMedCentral whichreports that one form, oligomeric α-synuclein, is theone to watch out for.
Another set of CSF biomarkers is related to blood vessel formation (angiogenesis). I came across this in a paper in Neurology titled Increased CSF biomarkers of angiogenesis in Parkinson disease. The authors are referring to vascular endothelial growth factor (VEGF) and its receptors VEGFR-1 and VEGFR-2. Others are placental growth factor (PlGF), angiopoietin 2 (Ang2), and interleukin-8. Enough to keep researchers busy for a while.
3. Peripheral blood biomarkers
Even the most compliant patient would prefer to have a blood test rather than a spinal tap. Thankfully there are some blood-based biomarkers in the offing. One set are called α-synuclein blood transcripts (SNCA transcripts). The authors of an article published in the journal Brain report that SNCA transcripts are consistently reduced in the blood of people with early PD. The accompanying editorial however cautions on the utility of these SNCA transcripts because low levels are also seen in some people who do not have PD. The true value of SNCA transcripts may lie in their ability to predict cognitive decline, but how many people really want to know that?
Other potential blood based biomarkers mentioned are uric acid and epidermal growth factor (EGF).
4. Retinal optical coherence tomography (OCT)
Even better than blood and spinal fluid biomarkers would be something totally painless. And to the rescue comes retinal optical coherence tomography (OCT). OCT uses light waves to take pictures of the retina. This allows measurement of the size of different parts of the retina; the area of interest in PD is called the foveal pit. A paper in Movement Disorders reports that OCT is a sensitive marker of PD. The authors show that the foveal pit in PD has a unique form; it is shallow in the superior-inferior and the nasal-temporal slopes. Perhaps neurologists will soon be running to ophthalmologists, cap-in-hand, to save their blushes.
5. Salivary gland α-synuclein
Back to painful biomarkers I’m afraid, all in aid of clinching an early diagnosis you must understand. This time it’s salivary gland biopsy. Some eager researchers took biopsy samples of the submandibular salivary glands of people with early PD. They then looked for, and found, α-synuclein in about 75% of them. Their paper is published in Movement Disorders titled Peripheral Synucleinopathy in Early Parkinson’s Disease: Submandibular Gland Needle Biopsy Findings. Unfortunately 20% of control subjects without PD also had α-synuclein in their salivary glands. Could these people have pre-manifest PD? We must await larger and longer studies before we start needling away at the salivary glands of the worried-well.
Neurologists do not break into a sweat when they make the diagnosis of essential tremor (ET). Theoretically, at least, they shouldn’t. Essential tremor presents with an obvious shaking of the hands when performing tasks; this is unlike the tremor of Parkinson’s disease which is typically at rest. Neurologists also have handy evidence-based treatment guidelines which recommend medications such as Propranolol and Primidone.
Essential tremor is however anything but straightforward. Tremor is a feature of many other medical and neurological diseases. Neurologists also know that essential tremor may mimic Parkinson’s disease and dystonic tremor. To muddy the waters further, essential tremor also has non-motor symptoms such as cognitivedifficulties. And to add to the frustration, the touted evidence-based treatments, when tolerated, rarely work well enough. These twists and turns that accompany essential tremor are the reasons a review article in Practical Neurology labelled it ‘deceptively simple‘. This deception extends to the core puzzle in essential tremor-what causes it? Here are two tantalising suggestions which attempt to answer this question.
Is essential tremor a neurodegenerative disease?
Neurodegeneration is the usual suspect when neurologists are looking for ‘a cause’. With essential tremor the focus has been on the cerebellum, the part of the brain that co-ordinates movements. This is logical because tremor is a classical symptom of diseases of the cerebellum. This link, circumstantial as it is, has led researchers to interrogate the cerebellum in essential tremor. In doing this they also wondered if the problem is neurodegenerative. The logic behind this line of thinking is explained in a paper published in JAMA Neurology in 2009 titled, Essential tremors: a family of neurodegenerative disorders?
Pursuing this lead, some researchers have tried to hone down on which of the different types of cerebellar cells is involved in essential tremor. Writing in the journal Movement Disorders, the authors are convinced that the seat of neurodegeneration in essential tremor is the Purkinje cell. Purkinje cells are unique cerebellar cells which are vulnerable to all sorts of insults. The researchers in this case demonstrated significantly fewer Purkinje cells in the brains of people with essential tremor than in control subjects without the disease. And they attributed this pathology to neurodegeneration (what else?). The answer to a long-standing riddle, or a hasty conclusion?
Is essential tremor a channelopathy?
Neurologists have known for a long time that essential tremor has a strong genetic element. The diagnosis always feels more certain when there is another family member with tremor. The exact nature of this genetic link is however uncertain. Into this void comes a research paper suggesting that people with essential tremor may have abnormal cellular channels. Channels are proteins in the cell wall that let electrolytes like sodium and potassium in and out, and channelopathies are diseases that affect these channels. The authors of this paper studied a large essential tremor family who also suffer with epilepsy, a typical channel disorder. And the genetic tests they carried out revealed an abnormality in the SCN4A sodium channel. Correlation or causation? The mystery only deepens, I think.
As researchers dig deeper, they will have to decide if it’s neurodegeneration or channelopathy. Or perhaps both. This may then open the doors to better treatments for the disease, confining Propranolol and Primidone to the history books.
If you missed my blog on Klotho, you should check it out first before continuing. Below are the other four new things I learnt on the first full day of the American Neurological Association meeting, Chicago 2015:
BIN1 is the second commonest monogenic genetic cause of Alzheimer’s disease (AD). And I never even heard of BIN1 before today. Work by Erik Roberson
LINGO 1 is probably the only gene established to be associated with Essential Tremor (ET). Presentation by Ludy Shih
FLAIR* MRI imaging of Multiple Sclerosis (MS) shows either a centripetal or centrifugal pattern of inflammatory lesions with serious implications to prognosis. Work by Daniel Reich of NINDS
Diabetic peripheral neuropathy is a result of the metabolic syndrome; research by Lucy Hinder in mice suggests this is potentially reversible