Ibrahim Imam STRANGE BUT TRUE

On the seizure-detecting instincts of pets

Like something from a futuristic medical thriller, you have mice diagnosing bladder tumours, and dogs detecting prostate cancer, just by sniffing the urine of patients. And like a plot from a Sci-Fi film, dogs are also trained to smell-out malaria. But we are not forward to the future – we are still in the here and now. And it is not just cats, dogs, and mice; pouched rats and nematodes have staked their claim as well. And the number of diseases that pets can presumably detect grows longer by the day (OK perhaps by the year), and these range from diabetic hypoglycaemia, colorectal cancer and migraine, to infections such as Clostridium difficile and tuberculosis. And whilst there are many animals in on the act, they are just bit players on this set – dogs are by far the superstars of the show.

Baxter gives me the sniff test. VirtKitty on Flickr. https://www.flickr.com/photos/lalouque/3881459268/

As weird as it may sound, many of the reports being anecdotal, there are actually grains of truth and crumbs of evidence supporting the claim that pets are not just for Christmas. For example, there is a trail of research studies confirming the effectiveness of seizure detecting dogs; one paper specifically reports that they enabled 90% of subjects to reduce their seizure frequency by 34-50%. Although the time from seizure-detection to the actually seizure varies wildly, from 10 seconds to 5 hours before the epileptic attack, there seems to be enough time in most cases for the subject to take preventative measures.

Roger Hiorns’ Seizure. Hilary Perkins on Flickr. https://www.flickr.com/photos/cowbite/3781509099

But not all dogs are as skilled in the act as others, and your best bet is on alerting dogs which have a stronger bond with their owners. And if you want to pick a dog for its seizure-detecting skills, go for one that scores high in motivation…and low in neuroticism. This is important because the ability of dogs to detect seizures is not always benign; they are known to respond by attacking the subject or their helpers as part of an untrained fight or flight reaction. It is important therefore that seizure-alerting dogs are trained not to be stressed, and to respond appropriately.

Beware of the angry dog. Julija Rauluševičiūtė on Flickr. https://www.flickr.com/photos/cowbite/3781509099

But what are dogs actually detecting when they detect seizures? The conventional theory is that they are responding to subtle changes in behaviour; this may therefore explain why dogs can also warn of impending non-epileptic attacks, an observation that has been duplicated in another paper. The other possibility however is that the dogs are detecting disease-specific odours. This concept should not be surprising because, for example with infections, it has been shown that endotoxins induce a detectable aversive body odour. Similarly with liver disease, exhaled breath is already being considered in sorting out differential diagnoses. One premise behind the disease-odour hypothesis is the existence of disease-specific volatile organic compounds (VOCs). It feels all so exciting-no wonder there is now a well-developed scientific field of exhaled air analytics.

Breath. Andrea Castelletti on Flickr. https://www.flickr.com/photos/daltraparte/3050309593

But as with all things in life, and particularly in science, here are always the naysayers, the gatecrashers to the party. And so it is that, with the case of seizures, there are those who are not convinced that pets possess the guile to pick up seizures. For example, in a small study of 3 subjects in an epilepsy monitoring unit, Rafael Ortiz and Joyce Liporace, reporting in the journal Epilepsy and Behaviour, found that seizure alert dogs were not effective in predicting seizures. In another paper  published in the journal Epilepsy Research, titled Can seizure-alert dogs predict seizures?, Stephen Brown and Laura Goldstein observed that there is “no rigorous data” to support the assertion that seizure alert dogs accurately predict seizures. Another detailed review in Plos One in 2018, by Amélie Catala and colleagues, concluded that appropriate empirical evidence that dogs can alert or respond to epileptic seizures is still missing. 

By https://wellcomeimages.org/indexplus/obf_images/3c/f4/5188f74ad62c7b5634b55047ac5d.jpgGallery: https://wellcomeimages.org/indexplus/image/V0016630.htmlWellcome Collection gallery (2018-03-23): https://wellcomecollection.org/works/kbcqbc43 CC-BY-4.0, CC BY 4.0, Link

 

But as the overused cliché goes, absence of evidence is not the evidence of absence. So how can we prove that dogs are indeed detecting seizure-specific odours? This is the task Amélie Catala and her colleagues also set out to accomplish when they made 5 dogs to sniff the odours obtained from 5 people with epilepsy. They tasked the dogs to tell apart the odours obtained around the time of the subjects’ seizures, from the odours obtained at other times when there were no proximate seizures. Reporting their findings in Science Report in 2019, under the title Dogs demonstrate the existence of an epileptic seizure odour in humans, they found that all the 5 dogs easily distinguished the seizure-related odours from the non-seizure related odours. But the small scale of the trial (were there just not enough dogs to go round?) justifies the authors’ call for larger trials to confirm their findings.

 

Big Nose Strikes Again. Bazusa on Flikr. https://www.flickr.com/photos/bazusa/260401471

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This is clearly still a grey area in epilepsy management, but one with a high potential if explored further. Are there any pet-loving neurologists willing to get in on the act? Do come along with your pets!

Ibrahim Imam GENERAL

25 non-eponymous neurological disorders… and the names behind them

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, Joseph 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.

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Amyotrophic lateral sclerosis (ALS)

Jean-Martin Charcot

Készítette: Unidentified photographer – http://resource.nlm.nih.gov/101425121, Közkincs, Hivatkozás

Aphantasia

Francis Galton (and Adam Zeman)

By Eveleen Myers (née Tennant) – http://www.npg.org.uk/collections/search/portrait/mw127193, Public Domain, Link

Chronic inflammatory demyelinating polyneuropathy (CIDP)

Peter J Dyck

By Dr. Jana – http://docjana.com/#/saltatory ; https://www.patreon.com/posts/4374048, CC BY 4.0, Link

Corticobasal degeneration (CBD)

WRG Gibb, PJ Luthert, C David Marsden

https://upload.wikimedia.org/wikipedia/commons/c/cd/ProteineTau.jpg

Epilepsy

Hippocrates

Hippocrates. Eden, Janine and Jim on Flickr. https://www.flickr.com/photos/edenpictures/8278213840

Essential tremor

Pietro Burresi

By Undescribed – Own work, CC BY-SA 4.0, Link

Frontotemporal dementia (FTD)

Arnold Pick

By Unknown author – http://www.uic.edu/depts/mcne/founders/page0073.html, Public Domain, Link

Inclusion body myositis (IBM)

E J Yunis and F J Samaha

CC BY-SA 3.0, Link

Meningitis

Vladimir Kernig and Jozef Brudzinski

By A. F. Dressler – Festschrift zum 70. Geburtstag Dr. Woldemar Kernig’s: Von Verehrern und Schülern herausgegeben als Festnummer der St. Petersburger medicinischen Wochenschrift St. Petersburger medizinische Wochenschrift, Bd. 35, Nr. 45. (1910), Public Domain, Link

Migraine

Aretaeus of Cappadocia

By Cesaree01 – Own work, CC BY-SA 4.0, Link

Multiple sclerosis (MS)

Jean-Martin Charcot

“Journal.pone.0057573.g005” http://www.plosone.org/article/info:doi/10.1371/journal.pone.0057573#pone-0057573-g005. Licensed under CC BY 2.5 via Wikimedia Commons.

Multiple system atrophy (MSA)

Milton Shy and Glen Drager

By Kenneth J. Nichols,Brandon Chen, Maria B. Tomas, and Christopher J. Palestro – Kenneth J. Nichols et al. 2018. Interpreting 123I–ioflupane dopamine transporter scans using hybrid scores., CC BY 4.0, Link

Myasthenia gravis (MG)

Samuel Wilks

By Unknown author – http://ihm.nlm.nih.gov/images/B25782, Public Domain, Link 

Myotonic dystrophy

Hans Gustav Wilhelm Steinert

By Unknown author – reprinted in [1], Public Domain, Link 

Neurofibromatosis

Friedreich Daniel von Recklighausen

By Unknown author – IHM, Public Domain, Link 

Narcolepsy

Jean-Baptiste-Edouard Gélineau

https://upload.wikimedia.org/wikipedia/commons/7/74/Jean_Baptiste_Edouard_G%C3%A9lineau.jpg

Poliomyelitis

Michael Underwood

By Manuel Almagro Rivas – Own work, CC BY-SA 4.0, Link

Progressive supranuclear palsy (PSP)

John Steele, John Richardson, and Jerzy Olszewski

By Dr Laughlin Dawes – radpod.org, CC BY 3.0, Link

Restless legs syndrome (RLS)

Karl Axel Ekbom

By Peter McDermott, CC BY-SA 2.0, Link

Stiff person syndrome (SPS)

Frederick Moersch and Henry Woltmann

By Pecatum – Own work, CC BY-SA 4.0, Link

Synesthesia

Georg Sachs and Gustav Feschner

Synaesthesia. aka Tman on Flickr. https://www.flickr.com/photos/rundwolf/7001467111/

Stroke

Hippocrates

By editShazia Mirza and Sankalp GokhaleSee also source article for additional image creators. – editShazia Mirza and Sankalp Gokhale (2016-07-25). Neuroimaging in Acute Stroke.Attribution 4.0 International (CC BY 4.0), CC BY 4.0, Link

Tabes dorsalis

Moritz Romberg

By https://wellcomeimages.org/indexplus/obf_images/39/1d/edecf5a530781f5c10603a50fa35.jpghttps://wellcomecollection.org/works/gctr3stg CC-BY-4.0, CC BY 4.0, Link

Trigeminal neuralgia

John Fothergill

By Gilbert Stuart – http://www.pafa.org/Museum/The-Collection-Greenfield-American-Art-Resource/Tour-the-Collection/Category/Collection-Detail/985/mkey–1923/, Public Domain, Link

Tuberous sclerosis

Désiré-Magloire Bourneville

By Unknown author – Bibliothèque Interuniversitaire de Médecine – http://www.bium.univ-paris5.fr/images/banque/zoom/CIPB0452.jpg, Public Domain, Link

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Reunion of neurologists at the Salpêtrière hospital. Photograph, 1926 https://commons.wikimedia.org/w/index.php?curid=36322408

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Let us then celebrate the pioneers…

Eponymous and anonymous alike

Ibrahim Imam CATCHY ARTICLE TITLES

10 more catchy titles from the recent neurology literature

Ibrahim Imam GENERAL, NEUROLOGY PATIENTS

7 remarkable patients who determined the course of neuroscience

It is no exaggeration to say that most progress in medicine has been achieved one unfortunate patient after another. Either by accident, or by misguided design, our understanding of human physiology and pathology have frequently come at the expense of the misfortune of countless patients, and it continues to do so. Whilst large trials teach us a lot about the characteristics of diseases, it is however the single case study that often reveals the most defining insights. For example, it was the accidental gunshot injury sustained by Alexis St Martin that led to our understanding that the gastric phase of digestion depends on the acid produced by the stomach. The gory injury resulted in a permanent fistula between St Martin’s stomach and his skin, a veritable window through which the army doctor, William Beaumont, peered to see nature at work.

By Jesse Shire Myer – A book, Life and Letters of Dr. William Beaumont …, Public Domain, Link

But enough of other organs; our interest is of course the nervous system. Who then were the tragic heroes of neuroscience, the valiant who submitted their bodies in life, and their brains in death, for the advancement of science? Who are the famous, and the infamous, in the annals of the brain? Here is our run down of 7 remarkable patients who defined the history of neuroscience.

Brain with Hands. Michael Coglan on Flickr. https://www.flickr.com/photos/mikecogh/21837053882

 

7. Patient SM

Patient SM is one of the lesser known figures in neuroscience, but her contribution to the science of emotions is immense. As someone who simply did not know what it was to experience fear, she provided the clues to the anatomical foundations of our passions. It turned out that the source of her fearlessness were lesions in her amygdala. It is little wonder that her life was characterised by risky ventures and perilous experiences, as she was incapable of detecting and avoiding danger. The amygdala is now established as the command and control centre for the emotions. One could argue, albeit unoriginally, that to lose one amygdala may be an accident, but to lose both will have to be termed a disaster. And in the case of Patient SM, her catastrophe is a result of Urbach–Wiethe disease, a disorder which destroys both amygdalas…but mercifully spares the hippocampus.

By Images are generated by Life Science Databases(LSDB). – from Anatomography, website maintained by Life Science Databases(LSDB).You can get this image through URL below. 次のアドレスからこのファイルで使用している画像を取得できますURL., CC BY-SA 2.1 jp, Link

6. Anna ‘O’

By Original uploader was Kaesar at it.wikipedia – Link

Bertha Pappenheim, better known by her nickname ‘Anna O‘, was the seminal hysterical patient reported by Josef Breuer and Sigmund Freud. It is probably to her singular credit that the concept of hysteria became a neuroscience curiosity, even if this was on the fringes. Her constellation of symptoms will however be familiar to every neurologist: limb paralysis, speech difficulties, visual impairment, hallucinations, and episodes of loss of consciousness. It is clear that this disorder lives on, and after several iterations, now comes under the remit of functional neurological disorders (FND). It is interesting that Freud had the largely correct insight that behind many cases of hysteria lies some form of trauma.

5. Blanche Wittman

By André Brouillet – Photo prise dans un couloir de l’université Paris V, Public Domain, https://commons.wikimedia.org/w/index.php?curid=3820726

The great French neurologist Jean-Martin Charcot is not a person to be outdone by other neuroscientists, and this applies to his one-time protege, Sigmund Freud. It is therefore not surprising that in studying hysteria, he outdid Freud by finding a more remarkable subject called Blanche Wittman. She became his star attraction in the demonstrations he held at the Pitié-Salpêtrière Hospital where she performed for the great and the good of French neurology. It is in this way that she achieved abiding fame in the iconic painting of Pierre Aristide André Brouillet. Her dramatic hysterical attacks earned her the sobriquet ‘The Queen of Hysterics‘, but her contribution to the actual science of the brain is rather underwhelming. There is however no denying that she is a lasting landmark in the history neuroscience.

4. Auguste Deter

By Unknown author – Unknown source, Public Domain, Link

Whilst the name Alois Alzheimer has gone down in history for describing the fearsome dementia that bears his name, the name of the patient who made it all possible is not a household one at all. Auguste Deter was the first person to be diagnosed with the horrendous disease which still ravages mankind, and without any cure in sight. After studying her illness in life, Alzheimer had the fortune of examining her brain after her death. It is his detailed examination that revealed what we now know as the hallmarks of the disease, senile plaques and neurofibrillary tangles. It is remarkable that a recent analysis of Alzheimer’s preserved histopathological slides revealed that Auguste Deter carried the classical presenilin 1 (PSEN1) gene mutation that is associated with the disease. Can neuroscience ever be any more satisfying than that!

3. Louis Victor Leborgne

By Polygon data were generated by Database Center for Life Science(DBCLS)[2]. – Polygon data are from BodyParts3D[1], CC BY-SA 2.1 jp, Link
Yet another watershed neuroscience patient whose name doesn’t often ring any bells, or flow easily off the tongue. Leborgne’s misfortune was to develop a curious inability to speak, now recognised as expressive aphasia. He was only able to communicate with a single word, tan, and this explains his nickname, Patient Tan. Paul Broca’s fortune, on the other hand, was to study Leborgne in life, and to examine his brain after death. This singular patient made Broca a household name because this type of speech difficulty is also known as Broca’s aphasia. Broca also localised the lesion responsible for Leborgne’s aphasia, and it was in a part of the dominant hemisphere now known as Broca’s area. Two eponyms for the price of one you may say. Leborgne is also probably the turning point for the contentious concept of cerebral localisation, resurrecting it from the ashes of phrenology.

2. Phineas Gage

By Author of underlying work unknown. – File:PhineasPGage.jpg, Public Domain, Link

Phineas Gage is remarkable for achieving what few other neuroscience patient have, entry into popular folklore. The victim of a work-related accident, Gage sustained a unique form of brain injury when he was impaled by a tamping rod whilst trying to set explosions as part of his work as a rail construction worker. The explosion was accidentally set off prematurely, and the rod was propelled through Gage’s left cheek bone, through his left eye socket, and it then penetrated both frontal lobes. It was remarkable that Gage was not physically inconvenienced immediately following the accident, but surviving the whole affair was just the beginning of his real misfortune; his personality, previously calm and dedicated, became volatile and disinhibited. In relating the story of Gage, there is no getting away from a famous quotation; those who knew him before his accident pithily remarked that Gage ‘was no longer Gage‘. It is to his misfortune that we owe our understanding of the important role the frontal lobes play in regulating personality and behaviour.

 

1. Henry Molaison

By Images are generated by Life Science Databases(LSDB). – from Anatomography, website maintained by Life Science Databases(LSDB).You can get this image through URL below. 次のアドレスからこのファイルで使用している画像を取得できますURL., CC BY-SA 2.1 jp, Link

Known only as Patient HM throughout his life, Henry Gustav Molaison is perhaps the most important patient to ever cross the path of neuroscience. He earned this distinction on account of the profound amnesia he developed after he underwent brain surgery to control his severe epilepsy. Very bravely, his neurosurgeon, William Beecher Scoville, removed large chunks of his temporal lobes on both sides, a previously unheard of procedure. His epilepsy became largely controlled, but the aftermath was a disaster; he lost the ability to form new memories. As it has become a familiar refrain by now, Henry’s misfortune became a boon for neuroscience. He became probably the most extensively studied patient in the history of brain science; he spent the rest of his life undergoing one neuropsychological test or the other until neuroscientists obtained a thorough understanding of the anatomical and functional foundations of memory formation. Whilst the key lesson from his case is the important role of the hippocampus in memory formation, there is so much more he contributed to brain science in life. And even after death, his brain is an object of fascination for neuroscientists; they opened up his skull as soon as he died, took out his brain, and cut it up into tiny slices for further study. Henry is therefore the ultimate neuroscience patient who keeps giving even after departing this mortal coil.

Over the next few weeks I will be reviewing three excellent books on Henry Molaison in my book review blog, The Doctors Bookshelf. Why not follow me there to find out more about the remarkable man.

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Do you want to explore more interesting neuroscience patients?

Here are 9 to satisfy your urge!

 

Elliot

Giovanni A

Jane Avril

Lelong

Little Hans

Marquis de Dampierre

Patient JP

Patient NA

Carol Jennings

Ibrahim Imam CUTTING EDGE, GENERAL

The case for testing serum neurofilament light protein in MS

I am yet to request serum neurofilament light protein (NfL) in my practice. I am not sure yet why I should, but until now I confess I really haven’t looked for a reason to do so. I however know that some MSologists now tick it, along with other blood tests, when they investigate people they suspect may have multiple sclerosis (MS). NfL are proteins that are released by damaged neurones. Should I be requesting NfL in my clinical practice? I sniffed around to find the case for testing serum NfL, and below is what I found.

By GerryShaw – Standard tissue culture and immunofluorescencePreviously published: Unpublished, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=26518273

Many studies have looked at the value of NfL in MS. One such very well-planned study that addresses many of my questions is that by Guili Disanto and colleagues, published in the journal Annals of Neurology in 2017. In the paper, titled Serum Neurofilament light: a biomarker of neuronal damage in multiple sclerosis, the authors studied >380 people with MS and >150 healthy controls, and report four important findings.

By GerryShaw – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=17500647
  1. The levels of NfL in serum strongly correlate with the levels in cerebrospinal fluid (CSF) of people with MS.
  2. People with more active and more severe MS had higher levels of NfL.
  3. People with MS on disease modifying treatment (DMT) had lower NfL levels than those who were not on treatment.
  4. In people with MS who had their serum NfL tested serially over time, the level of NfL predicted those who will develop frequent relapses or progressive MS.

The authors concluded, with enough justification I think, that serum NfL is a “sensitive and clinically meaningful blood biomarker to monitor tissue damage and the effects of therapies in MS“.

Culture rat hippocampal neuron. ZEISS Microscopy on Flickr. https://www.flickr.com/photos/zeissmicro/24327909026

The strong correlation between cerebrospinal fluid (CSF) and serum NfL was also confirmed by a study published in the journal Neurology, by Lenka Novakova and colleagues titled Monitoring disease activity in multiple sclerosis using serum neurofilament light protein. As the title indicates, they discovered that serum NfL is as good as CSF NfL in monitoring the progression of MS.

Neuron. NICHD on Flickr. https://www.flickr.com/photos/nichd/21086076575

The observation that NfL predicts the course of MS is supported by many other studies, such as the one by Kristin Varhaug and colleagues in the journal Neurology Neuroimmunology and  Neuroinflammation whose title is also self-explanatory: Neurofilament light chain predicts disease activity in relapsing-remitting MS. A more recent paper, also published in Neurology, further reinforces the benefit of serum NfL in disease course prediction. It is titled Blood neurofilament light chain as a biomarker of MS disease activity and treatment response. In this paper, Jehns Kuhle and colleagues practically confirm all the above stated benefits of NfL, concluding that “our results support the utility of blood NfL as an easily accessible biomarker of disease evolution and treatment response”.

“Neuron” by Roxy Paine. Christopher Neugebauer on Flickr. https://www.flickr.com/photos/chrisjrn/4745660322

As for long term outcome, the 10 year follow up study by Alok Bahn and colleagues, published in the Multiple Sclerosis Journal in 2018, is most informative. In their paper titled Neurofilaments and 10-year follow-up in multiple sclerosis, the authors noted that “CSF levels of NfL at the time of diagnosis seems to be an early predictive biomarker of long-term clinical outcome and conversion from RRMS to SPMS”. Further support for the long term prognostic value of serum NfL comes from a paper published in 2018 in the journal Brain titled Serum neurofilament as a predictor of disease worsening and brain and spinal cord atrophy in multiple sclerosis. The authors, Christian Barro and colleagues, studied more than 250 people with MS and concluded that “the higher the serum neurofilament light chain percentile level, the more pronounced was future brain and cervical spinal volume loss“.

Nervous Tissue: Spinal Cord Motor Neuron. Berkshire Community College on Flickr. https://www.flickr.com/photos/146824358@N03/41850849912/in/album-72157666241437517/

It is pertinent to note that the MS sphere is not the only one in which NfL is making waves. It has been found to be elevated in many other disorders such as motor neurone disease (MND), multiple system atrophy (MSA), hereditary spastic paraplegia (HSP), stroke, active small vessel disease, and peripheral neuropathy (PN). With these disclaimers in place, it may just be time to start ticking that NfL box.

 

By GerryShaw – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=17502311

 

Ibrahim Imam GENERAL

The cutting-edge applications of ultrasound in neurology

Imaging is central to neurological practice. It doesn’t take much to tempt a neurologist to ‘order’ or ‘request’ an MRI or a CT. In appropriate circumstances the imaging is a DAT scan, and with a bit more savvy, exciting imaging modalities such as amyloid scans and tau PET scans. In the playpen of the neurologist, the more ‘high tech’ the imaging technology, the more cutting-edge it feels-even if it doesn’t make much of a difference to the patient. Ultrasound on the other hand is the mongrel of imaging technologies. Too simple, too cheap, too available, too unsophisticated-not better than good old X-rays. It is safe to assume that the pen of the neurologist hardly ever ticks the ultrasound box. What for?
prd brain scan. Patrick Denker on Flickr. https://www.flickr.com/photos/pdenker/74684051
And yet, ultrasound has an established, even if poorly appreciated, place in neurological imaging. It is perhaps best known for its usefulness in assessing carpal tunnel syndrome at the wrist. But, for the neurologist, CTS is sorted out by wrist splints, steroid injections, and decompression surgery-forgetting that there may just be a ganglion, a cyst, or a lipoma lurking in there. Ultrasound also has a place in the assessment of muscle disorders, picking up anomalies and detecting distinctive muscle disease patterns. The only problem is that, even when radiologists and neurologists put their heads together, they struggle to understand what the patterns actually mean. And since the first pass of this blog post, I was reminded of the place of ultrasound-guided lumbar puncture in improving the safety and accuracy of this otherwise blind procedure. And there are even guidelines to help takers. My guess is that most neurologists prefer the thrill of hit-and-miss that goes with conventional LP. For many reasons therefore, the ultrasound box remains un-ticked.
By RSatUSZ – PACS UniversitätsSpitalZürich, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=11272585
Despite these limitations, the place of ultrasound remains entrenched in neurological practice. Indeed, ultrasound has been spreading its wings to exotic places, broadening its range, and asserting its presence. Perhaps it is time to reconsider the humble ultrasound, and to catch up with what it has been up to. Here then are 3 emerging roles of ultrasound in neurology

Therapeutic ultrasound

The role of ultrasound in treatment is reviewed in the excellent paper in Nature Neurology titled Ultrasound treatment of neurological diseases-current and emerging applications. And the emphasis is on trans-cranial MR-guided focused ultrasound (tcMRgFUS). tcMRgFUS is making waves in the treatment of essential tremor (ET), Parkinson’s disease (PD), and central pain. The benefit for PD is already filtering out into the popular press such as this article in STAT titled New treatment offers some hope for an unshakable tremor. Ultrasound is also rapidly emerging as an option in the ablation of brain tumours, and in the treatment of stroke (sonothrombolysis). 

By Images are generated by Life Science Databases(LSDB). – from Anatomography, website maintained by Life Science Databases(LSDB).You can get this image through URL below. https://commons.wikimedia.org/w/index.php?curid=7845026

Drug delivery into the brain

The blood brain barrier is a rigidly selective barricade against most things that venture to approach the brain-even if their intentions are noble. This is a huge impediment to getting drugs to reach the brain where they are badly needed. It is therefore humbling that it is the simple ultrasound that is promising to smuggle benevolent drugs across the blockade to aid afflicted brains. This was reported in the journal Science Translational Medicine, and the article is titled Clinical trial of blood-brain barrier disruption by pulsed ultrasound. The trial subjects were people with the notorious brain tumour, glioblastoma. They were injected with their conventional chemotherapy drugs, delivered along with microbubbles. The blood brain barrier was then repeatedly ‘pelted’ with pulsed ultrasound waves; this seem to leapfrog the drugs into the brain in greater than usual concentrations, enough to do a much better job. This surely makes films such as Fantastic Voyage and Inner Space not far-off pipe-dreams.

Bubbles. Jeff Kubina on Flickr. https://www.flickr.com/photos/kubina/153871892

Treatment of coma

Some of the emerging neurological applications of ultrasound are even more Sci-Fi than pulsed ultrasound. And a sign of this Sci-Neuro world is this report titled UCLA scientists use ultrasound to jump-start a man’s brain after coma. One is tempted to dismiss this as ‘fake news’ but it is a proper case report, in a proper scientific journal, Brain Stimulation, and with a proper scientific title, Non-Invasive Ultrasonic Thalamic Stimulation in Disorders of Consciousness after Severe Brain Injury: A First-in-Man Report. By targeting ultrasounds to the subject’s thalamus, the authors assert, the subject just woke up (and presumably asked for a hot cup of tea!). A word of caution is however needed; the authors rightly point out that it may have all been…coincidental!

The awakening (arm). Jeff Kubina on Flickr. https://www.flickr.com/photos/kubina/153871892

Ultrasound is clearly humble no more.

Big ambition trumps humble beginnings.

Ibrahim Imam CUTTING EDGE, GENERAL, GENERAL NEUROLOGY, UNDER-EXPLORED NEUROLOGY

What are the emerging treatments for neurofibromatosis?

Neurofibromatosis (NF) is one of the major neurocutaneous disorders neurologists see. These are disorders which primarily affect the nervous system and have prominent skin manifestations. Also known as phakomatoses, they are typified by abnormal growths and a variety of cancers. They include well-defined conditions such as tuberous sclerosis complex (TSC), Sturge-Weber syndrome (SWS), von Hipple Lindau disease (VHL), schwannomatosis, and the various PTEN hamartoma tumour syndromes. There are two types of neurofibromatosis, NF1 and NF2. NF2 is characterised by vestibular schwannomas, tumours arising from the sheath that encases the nerve that control balance, and by meningiomas, tumours of the covering of the brain.

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NF1, also known as von Recklinghausen disease is, by far, the commoner form of neurofibromatosis. It is readily recognised on the skin by the frequently multiple and disfiguring nerve tumours called neurofibromas. Other benign skin lesions include the coffee-coloured skin lesions aptly called cafe-au-lait spots, armpit lesions called axillary freckles, and small lesions on the iris of the eyes called Lisch nodules. More sinister skin lesions called malignant peripheral nerve sheath tumours (MPNST) are, as the name implies, capable of spreading to other organs such as the lungs. Other sinister tumours in NF1 include gliomas of the brain and optic nerve, gastrointestinal stromal tumours (GIST) of the gut, and rhabdomyosarcomas of bone.

By Seiradcruz at English Wikipedia, CC BY-SA 3.0, Link

What can neurologists do for people with neurofibromatosis? Traditionally, nothing much apart from watchful waiting. We would monitor for the development of tumours by regular surveillance MRI scans of the brain and spine, and refer people with painful, compressive, or malignant lesions to the plastic surgeons or neurosurgeons to do what they do best, taking things out. Surgery may work fine for simple neurofibromas, but it is less practical for the complex or plexiform type. Thankfully, many neuroscientists are working hard, looking at different approaches to managing neurofibromas. To illustrate, below are 5 emerging treatments for neurofibromatosis. 

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Selumetinib

In a 2016 paper in the New England Journal of Medicine, Eva Dombi and colleagues investigated the effect of selumetinib, an oral inhibitor of an enzyme called MAPK kinase (MEK) in 24 children with NF1. The paper, titled Activity of selumetinib in neurofibromatosis type 1-related plexiform neurofibromas, showed that selumetinib reduced the size of neurofibromas, and there was evidence that it improved pain and reduced disfigurement.

By Dimitrios Malamos – Own work, CC BY 4.0, Link

Imatinib

In a 2012 paper published in Lancet Oncology, Kent Robertson and colleagues, investigated the potential benefit of Imitanib, an inhibitor of the enzyme tyrosine kinase, in 36 people with NF1. The paper, titled Imitatinib mesylate for plexiform neurofibromas in patients with neurofibromatosis type 1: a phase 2 trial, showed at least a 20% reduction in one or more plexiform neurofibromas.

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Sirolimus

Brian Weiss and colleagues investigated the effect of sirolimus, an inhibitor of mTOR complex 1, in 46 people with NF1 and published their findings in the journal Neuro-Onclology. The paper, titled Sirolimus for progressive neurofibromatosis type 1-associated plexiform neurofibromas, demonstrated that sirolimus prolonged the time to progression (TTP) of plexiform neurofibromas by about 4 months. A modest effect they admit, but nevertheless, a hope-raising effect.

By ajc3527 – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=59202851

Everolimus

Everolimus is already making waves in the treatment of various lesions in tuberous sclerosis complex, and it is not surprising that it has turned up here. In their paper titled Treatment of disfiguring cutaneous lesions in neurofibromatosis-1 with everolimus, published in the journal Drugs in R&D, John Slopis and colleagues reported that everolimus significantly reduced the surface volume of NF1 lesions, including plexiform neurofibromas. The authors were however cautious, calling for future studies to confirm these results. Unfortunately, one such study in the Journal of Investigational Dermatology poured cold water on the reported benefit of everolimus. The paper was titled Absence of Efficacy of Everolimus in Neurofibromatosis 1-Related Plexiform Neurofibromas: Results from a Phase 2a Trial. Hopefully future studies will be more favourable!

By MarinaVladivostok – Own work, CC0, Link

Pegylated interferon alfa-2b

Regina Jakacki and colleagues looked at the effect of pegylated interferon alfa-2b on plexiform neurofibromas and found a greater than doubling of their time to progression (TTP). Their paper is published in Neuro-Oncology, and it is titled Phase II trial of pegylated interferon alfa-2b in young patients with neurofibromatosis type 1 and unresectable plexiform neurofibromas. As the authors studied a reasonable number of subjects, 84, and as the trial was placebo-controlled trial, this result is unlikely to be overturned by future trials…but only time will tell.

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Therefore is clearly enough justification for hope in the search for a cure for neurofibromatosis.

Ibrahim Imam CUTTING EDGE

What is the state of gene therapy for Parkinson’s disease?

First, some basic science to lay the groundwork for this blog post. Parkinson’s disease (PD) is all about dopamine, the chemical neurotransmitter that makes our movements smooth. It is produced by cells in the substantia nigra, a structure in the midbrain. The substantia nigra nerves project to the putamen, one of the structures that make up the basal ganglia, somewhere deep in the brain. The substantia nigra nerves are also called the nigrostriatal nerves because the putamen, along with the caudate nucleus and the nucleus accumbens, form a body called the corpus striatum. The work of these so-called nigrostriatal nerves is to produce and deliver dopamine to the putamen. In summary, the putamen is the playpen of dopamine; it is here that it does its work of smoothening our movements.

By BruceBlaus – Own work, CC BY-SA 4.0, Link

In Parkinson’s disease, the nogrostriatal system slowly degenerates, therefore becoming unable to supply enough dopamine to the putamen. The obvious solution is to find an alternative supply of dopamine for the putamen. The obvious way again would be to deliver dopamine orally as a tablet, but dopamine unfortunately does not cross the blood brain barrier. However, the similar but more pliant levodopa is able to do so. Once in the brain, levodopa is then converted to the active dopamine by an enzyme called aromatic L‐amino acid decarboxylase (AADC). Because this strategy is reasonably efficient, levodopa has become the foundation of PD treatment. But this strategy is totally dependent on the presence of enough AADC to convert levodopa to dopamine. And this is a vulnerability that PD explores to the full.

By Jynto (talk) – Own workThis image was created with Discovery Studio Visualizer., CC0, Link

Levodopa treatment is usually effective in the early stages of PD. But as the disease progresses, the degenerating nigrostriatal nerves increasingly struggle to produce enough AADC. Remember, AADC is essential for converting levodopa to the active dopamine. Without AADC, in other words, levodopa is useless. The declining ability to produce AADC is therefore the Achille’s heel of levodopa treatment. It is the reason people with advanced PD require increasingly higher doses of levodopa. It is the reason they get unpredictable treatment fluctuations. It is the reason they get abnormal movements called dyskinesias. To remedy this big flaw in the levodopa treatment strategy, and increase AADC levels in the putamen, neuroscientists have investigated the potential role of gene therapy. To unravel this topic, not a ride in the park by any means, I have relied on this excellent 2019 paper titled Magnetic resonance imaging–guided phase 1 trial of putaminal AADC gene therapy for Parkinson’s disease.

By Jynto (talk) – Own workThis image was created with Discovery Studio Visualizer., CC0, Link

If one group of cells becomes unable, or unwilling, to do its job, why not get another group of cells to take over the task? Indeed this simple concept lies at the heart of gene therapy for PD. And neuroscientists have identified the right type of cells to take over the job of producing AADC. These are the medium spiny neurones of the putamen which do not degenerate in PD. The brilliant strategy is to embed the gene for producing AADC into the DNA of the medium spiny neurones. A viral vector is required to carry the gene into the nerves, and the vector of choice here is adenovirus-associated virus (AAV). The vector ‘invades’ the medium spiny neurones and embeds the AADC gene into their DNA. The cells then start producing dopamine from levodopa. It is as simple as that in theory. It is easier said than done in reality.

By Thomas Splettstoesser (www.scistyle.com) – Own work, CC BY-SA 4.0, Link

The intricate steps involved in this strategy are outlined by Chadwick Christine and colleagues who carried out the phase 1 trial of AADC gene therapy. They infused the AAV viral vector directly into the putamen during neurosurgery, and they used magnetic resonance imaging to confirm that the injected material is delivered to the correct target. The detailed protocol refers to technical terms such as bilateral frontal burr holes, intraoperative delivery, neuro‐navigational systems, and the like. The whole affair however appears to be well-tolerated and reasonably successful; the authors reported a dose-dependent increase in AADC enzyme production, and their 15 subjects had more ‘on-time’, less troublesome treatment fluctuations, and required less levodopa. It is interesting that a similar benefit was demonstrated by Karin Kojima and colleagues when they used the same procedure in a genetic disorder called aromatic l-amino acid decarboxylase deficiency. In their paper titled Gene therapy improves motor and mental function of aromatic l-amino acid decarboxylase deficiency, the authors reported ‘remarkable’ motor improvement in all the six subjects they treated.

Public Domain, Link

An alternative approach to PD gene therapy is to use the AAV viral vector to deliver, not the gene for producing AADC this time, but the gene for producing glial cell line‐derived neurotrophic factor (GDNF). The idea behind this is, not to replace, but to flog the dying horse. The theory is that GDNF, a growth factor, should rejuvenate the flagging nigrostriatal nerves, thereby increasing their ability to produce dopamine. This approach was described by John Heiss and colleagues in their paper titled Trial of magnetic resonance–guided putaminal gene therapy for advanced Parkinson’s disease. The authors indeed demonstrated that GDNF-carrying adenovirus vectors can be safely infused into the putamen, and that the process is well-tolerated. They also demonstrated increased dopamine levels in the putamen in 12 of their 13 subjects.

Public Domain, Link

It is clearly early days, but there have been small successes along the way so far. Future trials, already underway, will tell us whether the hope is sustained or dashed. We must wait and see. In the meantime, you can read more about PD gene therapy in this update.

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Ibrahim Imam GENERAL, GENERAL NEUROLOGY, LISTENING POST

5 exciting developments in the management of Wilson’s disease

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.

By Carl Vandyk – Carl Vandyk, Public Domain, https://commons.wikimedia.org/w/index.php?curid=11384670

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.

By Niubrad at the English Wikipedia, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=19495297

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.

By Herbert L. Fred, MD, Hendrik A. van Dijk – http://cnx.org/content/m15007/latest/, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=2746925

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, the copper 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.

Copper crystals. James St John on Flickr. https://www.flickr.com/photos/jsjgeology/17127538489

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.

By own work – adapted from http://www.pdb.org/pdb/files/1kcw.pdb using PyMOL, Public Domain, https://commons.wikimedia.org/w/index.php?curid=4982229

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.

Exchangeable copper

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.

By Alchemist-hp (pse-mendelejew.de) – Own work, CC BY-SA 3.0 de, https://commons.wikimedia.org/w/index.php?curid=6958463

X-ray fluorescence

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 alcoholic cirrhosis. Not a bad deal, but the squeamish neurologist must realise it requires a liver biopsy!

X-ray Fluorescence Analyzer. IAEA Imagebank on Flickr. https://www.flickr.com/photos/iaea_imagebank/30483472557

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.

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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. 

Optical coherence tomography of my retina. Brewbooks on Flickr. https://www.flickr.com/photos/brewbooks/8463332137

Bis-choline tetrathiomolybdate

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 daily dosing regime.

By I, Jonathan Zander, CC BY-SA 3.0, Link

 

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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.

Ibrahim Imam CUTTING EDGE, GENERAL NEUROLOGY

3 exciting emerging interventional treatments for Parkinson’s disease

Parkinson’s disease (PD) is one of the bedrock disorders of neurology. It is common, universal, well-defined, usually easily diagnosed, and eminently treatable, even if not curable. PD is so important that I have visited it so many times on this blog. My previous blog posts on this topic include:

What are the drugs promising neuroprotection in PD?

What is the state of Parkinson’s disease biomarkers? 

The emerging research boosting Parkinson’s disease treatment.

PD is debilitating even when treated. This is because of the staggering number of motor and non-motor symptoms it provokes. And there is the long list of side effects the treatments induce, such as abnormal movements called dyskinesias. There is therefore a never-ending need for more effective and less agonising treatments for PD. And this blog has kept a keen eye on any advances that will make this disorder more bearable for the sufferers and their families, and less nerve-racking for the treating neurologist. It is therefore gratifying to know that there are many developments in the management of PD, and here I focus on 3 emerging interventional treatments.

By Marvin 101 – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=7533521

 

Magnetic resonance-guided focused ultrasound (MRgFUS)

MRgFUS is a technique that uses thermal heat to create lesions in the brain. This is a much less invasive approach than the current interventional treatments for PD which are surgery and deep brain stimulation (DBS). Surgical interventions for PD work by making therapeutic lesions in the globus pallidus (pallidotomy). In a first of its kind, Young Cheol Na and colleagues used MRgFUS to create similar pallidal lesions. They published their finding in 2015 in the journal Neurology under the title Unilateral magnetic resonance-guided focused ultrasound pallidotomy for Parkinson disease. They reported improvement in the motor symptoms of PD, and in drug-induced dyskinesias. But before MRgFUS pallidotomy will take off, it has to be as good as surgical pallidotomy which reduces dyskinesias for as long as 12 years!

Blue sonar. Gisela Giardino on Flickr. https://www.flickr.com/photos/gi/192984384

Repetitive transcranial magnetic stimulation (rTMS) 

In a reasonably large randomized trial published in 2016 in the journal Neurology, Miroslaw Brys and colleagues reported that rTMS improves motor symptoms in PD. Titled Multifocal repetitive TMS for motor and mood symptoms of Parkinson disease, the study reports that the benefit was significant. Indeed a systematic review and meta-analysis by Ying-hui Chou and colleagues in the journal JAMA Neurology, published just the year before, had established the benefit of rTMS in PD. The review, titled Effects of repetitive transcranial magnetic stimulation on motor symptoms in Parkinson disease, concluded with the hope that their findings “may guide treatment decisions and inform future research“. Hopefully it has, because a 2018 paper, published in the Journal of Clinical Neuroscience, has gone on to establish that the best results for rTMS are obtained with stimulation of the primary and supplementary motor cortex. That’s scientific progress.

Magnetic Fields-15. Windell Oskay on Flickr. https://www.flickr.com/photos/oskay/4581194252

Spinal cord stimulation 

It appears counterintuitive to think of the spinal cord in the context of PD, which is after all a disease of the brain. That is until you remember that walking impairment is a major problem in PD, and the spinal cord is the gateway for gait. Inspired by this insight, Carolina Pinto de Souza and colleagues stimulated the spinal cords of people with PD who have already undergone deep brain stimulation surgery. They published their findings in the journal Movement Disorders with the title Spinal cord stimulation improves gait in patients with Parkinson’s disease previously treated with deep brain stimulation. A clear title like this leaves little room for commentary. The authors however studied only four subjects, a number clearly missing from the paper’s title, but the benefit is an encouraging 50-65% improvement in gait. The omission is forgiven.

Spinal cord 8. GreenFlames09 on Flickr. https://www.flickr.com/photos/greenflames09/116396804

Taking things a step further, Reon Kobayashi and colleagues, writing in the journal Parkinsonism and Related Disorders, reported that a new mode of spinal cord stimulation called BurstDR, does a much better job than conventional stimulation. Again, the title of the paper is self-explanatory: New mode of burst spinal cord stimulation improved mental status as well as motor function in a patient with Parkinson’s disease.

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Surely the future must be bright with all these developments in the field of PD.