12 fascinating advances in epilepsy: big data to pacemakers

I recently posted on the role of vagus nerve stimulation (VNS) in epilepsy. Exciting as it is, there are several cutting edge developments in epilepsy that are making VNS ‘old school’. Here is a round-up of 12 such developments

1. Big data to improve epilepsy care

"Scatter plot" by UCRL - Visualizations that have been created with VisIt. at wci.llnl.gov. Licensed under Public Domain via Commons - https://commons.wikimedia.org/wiki/File:Scatter_plot.jpg#/media/File:Scatter_plot.jpg
“Scatter plot” by UCRL – Visualizations that have been created with VisIt. at wci.llnl.gov. Licensed under Public Domain via Commons – https://commons.wikimedia.org/wiki/File:Scatter_plot.jpg#/media/File:Scatter_plot.jpg

Big Data is spreading its tentacles everywhere and epilepsy is no exception. Take this review in Lancet Neurology for example; titled ‘Epilepsy in 2015: the year of collaborations for big data’, it reviews the impact of big data in five key epilepsy areas such as surgery, effect of epilepsy on pregnancy, and risks if anti-epileptic drugs (AEDs). I was however more impressed by the paper in Neurology titled Predicting frequent ED use by people with epilepsy with health information exchange data‘ which shows how big data may be used to identify frequent emergency department attenders. The authors showed how big data achieves this; the whole aim is to pick out those patients may benefit most from targeted-interventions. The article itself doesn’t mention big data, but the accompanying editorial fortunately does.

2. Better epilepsy monitoring devices

"EEG Recording Cap" by Chris Hope - http://www.flickr.com/photos/tim_uk/8135755109/. Licensed under CC BY 2.0 via Commons - https://commons.wikimedia.org/wiki/File:EEG_Recording_Cap.jpg#/media/File:EEG_Recording_Cap.jpg
“EEG Recording Cap” by Chris Hope – http://www.flickr.com/photos/tim_uk/8135755109/. Licensed under CC BY 2.0 via Commons – https://commons.wikimedia.org/wiki/File:EEG_Recording_Cap.jpg#/media/File:EEG_Recording_Cap.jpg

 

The management of epilepsy is very dependent on the accurate assessment of each patient’s day-to-day event pattern. In the simplest form, this is by a seizure diary. Seizures, the abnormal electrical brain activity that result in epilepsy, do not always manifest as recognisable events. Furthermore, many abnormal movements and behaviours do not necessarily arise from seizures. The neurologist therefore often recommends some form of prolonged brain activity monitoring to sort out what is actually happening. This is often done with procedures such as ambulatory electroencephalogram (EEG) and video EEG telemetry. These are all inconvenient and may only be used for a limited period. It is therefore reassuring that there are better techniques on the way. This press release from the World Federation of Neurology titled New epilepsy monitoring devices offer alternatives to inpatient video EEG lists ‘an array’ of devices such as the Brain Sentinel® System and the EEG PatchTM. These go further than just identifying the seizure activity; they allow patients to monitor clinical and subclinical seizure activity in the everyday home environment and get advance warning before a seizure strikes‘. What could be better for people with epilepsy?

3. Precision medicines for epilepsy

 

Drug firms 'creating ills for every pill' by Publik15 on Flikr. https://www.flickr.com/photos/publik15/3415531899
Drug firms ‘creating ills for every pill’ by Publik15 on Flikr. https://www.flickr.com/photos/publik15/3415531899

Epilepsy is a disease with several types and subtypes, and many genetic forms. Treating epilepsy therefore requires a close fit (no pun intended) of the disease type to its treatment. This is however a difficult task because many epilepsies are poorly defined, and the activity of anti-epileptic drugs (AEDs) are poorly understood. Whilst there are general principles of action of AEDs, these may not apply to individual patients. Herein then lies the promise of precision medicines which, making use of the patient’s genetic makeup or genome, offer a better match of AEDs to individuals. It is still early days but the course is being charted; the EpiPM Consortium recently published ‘A roadmap to precision medicines in the epilepsies‘ in Lancet Neurology.

4. Better prediction of SUDEP

"Ventricular fibrillation" by Jer5150 - Own work. Licensed under CC BY-SA 3.0 via Commons - https://commons.wikimedia.org/wiki/File:Ventricular_fibrillation.png#/media/File:Ventricular_fibrillation.png
“Ventricular fibrillation” by Jer5150 – Own work. Licensed under CC BY-SA 3.0 via Commons – https://commons.wikimedia.org/wiki/File:Ventricular_fibrillation.png#/media/File:Ventricular_fibrillation.png

 

Sudden unexpected death in epilepsy (SUDEP) is a nightmare. It strikes out of the blues, shocking families and neurologists alike. How to predict and prevent this phenomenon is a holy grail in epilepsy care. It is therefore gratifying news in a recent article in the journal Brain that there is a potential SUDEP imaging biomarker. The authors of the paper, titled Structural imaging biomarkers of sudden unexpected death in epilepsyreport that the magnetic resonance imaging (MRI) scans of people at risk of SUDEP show characteristic signs. The main feature is a larger grey matter volume in the right hippocampus and amygdala. The rest of the story is more tricky to understand and involves impaired oxygen regulation leading to the abnormal heart rhythms that presumably cause SUDEP. OK, just take it that this is a potential biomarker to risk-stratify patients for SUDEP!

5. Out-of-hospital status epilepsy injections

 

By AngelHM (Own work) [CC BY-SA 4.0 (http://creativecommons.org/licenses/by-sa/4.0)], via Wikimedia Commons
By AngelHM (Own work) [CC BY-SA 4.0 (http://creativecommons.org/licenses/by-sa/4.0)%5D, via Wikimedia Commons

A generalised tonic-clonic (or grand mal) seizure often self-terminates within 5 minutes. It may however be prolonged, or occur repeatedly, and this is called status epilepsy or status epilepticus. Out-of-hospital care to terminate status epilepticus often involves the use of buccal Midazolam or, thankfully fading into history, rectal Diazepam. The most effective short-term treatment is however intravenous Lorazepam, but this may only be administered in hospital. Is there something as effective as intravenous Lorazepam which could be administered by paramedics in the community? You guessed it, there probably is. A recent trial published in the New England Journal of Medicine (NEJM) shows that pre-hospital intramuscular Midazolam delivered by paramedics is effective. There are safety issues to sort out but this development promises to avert brain damage that may result from prolonged convulsions. Neuroscience News offers a simplified version of this study.

6. Optogenetics to improve arousal during a seizure

Optogenetics is the use of light to control cell activity in living tissues. I previously listed this in my previous post as one of 10 remarkable breakthroughs that will change neurology. A recent paper in the journal Epilepsia showed how optogenetics may improve epilepsy. Published under the rather unwieldy title Optogenetic stimulation of cholinergic brainstem neurons during focal limbic seizures…., the authors report the application of optogenetics to stimulate subcortical brainstem cells during a focal epileptic seizure. The story is rather complicated but this technique somehow causes inhibition of the cortical cells that generate seizures. A lot of the physiology remains to be sorted, but hey, its shining a light on a difficult problem!

7. 3D electroencephalography (3D-EEG)

 

"Spike-waves". Licensed under CC BY-SA 2.0 via Commons - https://commons.wikimedia.org/wiki/File:Spike-waves.png#/media/File:Spike-waves.png
“Spike-waves”. Licensed under CC BY-SA 2.0 via Commons – https://commons.wikimedia.org/wiki/File:Spike-waves.png#/media/File:Spike-waves.png

The electroencephalogram (EEG) is an indispensable tool in the diagnosis of epilepsy. It helps, amongst other things, to localise the site of a seizure discharge, and to classify the epilepsy type. It is however a rather insensitive tool for planning epilepsy surgery compared to imaging techniques such as positron emission tomography (PET) and single photon emission computed tomography (SPECT) scans which are far better. 3D EEG is however set to make its mark in this area if a recent paper in Epilepsia fulfils its promise. Titled ‘The diagnostic utility of 3D electroencephalography source imaging in pediatric epilepsy surgery‘, the authors show that 3-D EEG is comparable to PET and SPECT in planning epilepsy surgery; and it is also cheaper and less risky.

8. Neurotransmitter imaging of epilepsy

By courtesy of Massachusetts General Hospital and Draper Labs [Public domain], via Wikimedia Commons
By courtesy of Massachusetts General Hospital and Draper Labs [Public domain], via Wikimedia Commons

Epilepsy surgery relies on accurate mapping of the seizure focus. Current techniques are however still suboptimal and scientists are exploring better ways of doing this. One promising field is neurotransmitter-based imaging, and the main neurotransmitter here is glutamate. This MRI technique called glutamate chemical exchange saturation transfer (GluCEST) promises to identify seizure foci that are otherwise difficult to detect. You may read the technical aspects in the original paper in Science Translational Medicine, or go for the layman’s version in Neuroscience News.

An extension of glutamate imaging uses PET scans and relies on imaging NMDA, one type of glutamate receptor. This technique is reported in the Journal of Neurology, Neurosurgery and Psychiatry (JNNP) in an article titled NMDA receptor binding in focal epilepsies. The principle behind NMDA imaging is the knowledge that NMDA receptor ion channels are overactive in epilepsy. Isn’t it nice when science follows first principles!

9. Better mapping of seizure focus

"MRI Location Hippocampus up." by Amber Rieder, Jenna Traynor - Own work. Licensed under CC0 via Commons - https://commons.wikimedia.org/wiki/File:MRI_Location_Hippocampus_up..png#/media/File:MRI_Location_Hippocampus_up..png
“MRI Location Hippocampus up.” by Amber Rieder, Jenna Traynor – Own work. Licensed under CC0 via Commons – https://commons.wikimedia.org/wiki/File:MRI_Location_Hippocampus_up..png#/media/File:MRI_Location_Hippocampus_up..png

Surgery is a very useful tool in treatment of drug-resistant epilepsy. Epilepsy surgery is however not universally successful because localisation of the seizure focus is often imprecise. One promising way to improve the localisation of the seizure focus is to map the changes in oxygen levels that occur in the brain during an epileptic seizure. A paper in the JNNP reports that this is feasible with the use of simultaneous EEG (electroencephalography) and fMRI (functional magnetic resonance imaging). It’s all rather complicated stuff and I recommend this version from the Epilepsy Society which offers an excellently simplified summary. 

10. Personalised epilepsy surgery

"White Matter Connections Obtained with MRI Tractography" by Xavier Gigandet et. al. - Gigandet X, Hagmann P, Kurant M, Cammoun L, Meuli R, et al. (2008) Estimating the Confidence Level of White Matter Connections Obtained with MRI Tractography. PLoS ONE 3(12): e4006. doi:10.1371/journal.pone.0004006. Licensed under CC BY 2.5 via Commons.
White Matter Connections Obtained with MRI Tractography” by Xavier Gigandet et. al. – Gigandet X, Hagmann P, Kurant M, Cammoun L, Meuli R, et al. (2008) Estimating the Confidence Level of White Matter Connections Obtained with MRI Tractography. PLoS ONE 3(12): e4006. doi:10.1371/journal.pone.0004006. Licensed under CC BY 2.5 via Commons.

 

A holy grail of epilepsy (OK, there are many holy grails) is to individualise all types of epilepsy treatment, including surgery. Personalised epilepsy surgery is guided by a simulated model of a patient’s brain neural connections or connectome. This technique is reported in PLOS Computational Biology  under the title Predicting surgery targets in temporal lobe epilepsy through structural connectome based simulations. Why scientists love long windy titles baffles me. Anyway, the authors first acquired a map of their subject’s brain connectivity using an MRI technique called diffusion tensor imaging (DTI). They then applied a computerised model of how a seizure propagates to the connectivity map. In this way they are able to establish a more accurate surgical target. The area that is resected at surgery using this technique produced better outcomes than resection using a standard procedure. Makes sense to me.

11. Endoscopic epilepsy surgery

"Flexibles Endoskop" by de:Benutzer:Kalumet - Own work. Licensed under CC BY-SA 3.0 via Commons - https://commons.wikimedia.org/wiki/File:Flexibles_Endoskop.jpg#/media/File:Flexibles_Endoskop.jpg
“Flexibles Endoskop” by de:Benutzer:Kalumet – Own work. Licensed under CC BY-SA 3.0 via Commons – https://commons.wikimedia.org/wiki/File:Flexibles_Endoskop.jpg#/media/File:Flexibles_Endoskop.jpg

 

Although surgery is a good technique for epilepsy, it is an invasive procedure with attendant risks. Endoscopy, using minimal access to perform great feats, reduces this risk significantly. It is widely practiced in medicine and indeed neurosurgeons use it to relieve raised intracranial pressure in some cases. It is therefore a relief to learn that major epilepsy operations may be performed endoscopically. A recent article in the Journal of Neuroscience titled ‘Endoscopic corpus callosotomy and hemispherectomy reports the effectiveness of endoscopy in epilepsy operations such as corpus callosotomy; a procedure that interrupts the large bundle of nerve fibers that connect the two brain hemispheres. You may read the easy version in Mental Floss.

12. Deep brain stimulation for epilepsy

 

By Shamir R, Noecker A and McIntyre C [CC BY 3.0 (http://creativecommons.org/licenses/by/3.0)], via Wikimedia Commons
By Shamir R, Noecker A and McIntyre C [CC BY 3.0 (http://creativecommons.org/licenses/by/3.0)%5D, via Wikimedia Commons

Deep brain stimulation (DBS) is now routine in many neurological diseases such as Parkinson’s disease (PD). Epilepsy has been slow to catch on but this is changing. A recent piece on the Mayo Clinic website peered into the future treatment options for epilepsy and referred to pacemaker-like devices to control the seizure focus. There are many studies showing the feasibility and effectiveness of implantable devices which directly stimulate an epileptic focus to abort a seizure. One such system is Responsive Brain Neurostimulator (RNS® System)It may be counterintuitive but stimulation rather than suppression is the key. A review of Responsive neurostimulation in epilepsy says ‘the strategy is to interfere as early as possible with the accumulation of seizure activity to prematurely abort or even prevent an upcoming seizure’.

"Hippocampus small" 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.. Licensed under CC BY-SA 2.1 jp via Commons - https://commons.wikimedia.org/wiki/File:Hippocampus_small.gif#/media/File:Hippocampus_small.gif
“Hippocampus small” 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.. Licensed under CC BY-SA 2.1 jp via Commons – https://commons.wikimedia.org/wiki/File:Hippocampus_small.gif#/media/File:Hippocampus_small.gif

The future is bright for epilepsy care-and it can’t come soon enough for the millions of people whose lives are restricted and compromised by this disease.

How do cognitive biases compromise neurological practice?

Cognitive biases are pervasive human instincts. They are essentially shortcuts or heuristics we use all the time to make quick judgments. They crop up whenever we make decisions especially when time is limited and facts are scarce. The heuristics and biases field has burgeoned and flourished and its main exponent is the psychologist Daniel Kahneman. His book Thinking, Fast and Slow is a bestseller, and it was the subject of a recent Practical Neurology Book Club.

The general perception is that biases impair logical reasoning. There is however a lot of debate about whether heuristics and biases are evils to avoid, or virtues to apply carefully and selectively. Several authors have projected the positive aspects of biases, and the most prominent book is perhaps Gary Klein’s Sources of Power: How People Make Decisions.

How do biases and heuristics impact on neurological practice? My first clue to this was in an article in the Annals of Neurology titled How Neurologists Think: A Cognitive Psychology Perspective on Missed Diagnoses. This masterpiece explored the major biases which may lead neurologists astray when they make diagnoses. Using appropriate clinical vignettes the authors exhaustively discussed five classical biases:

Hubert Robert [Public domain], via Wikimedia Commons
Hubert Robert [Public domain], via Wikimedia Commons

A more recent article  in the journal Neurology also dwelt on the importance of shortcuts in neurological clinical reasoning. The article, aptly titled Recognising and Reducing Cognitive Bias in Clinical and Forensic Neurology, addresses some other significant biases:

 

Anchor by Plbmak on Flikr. https://www.flickr.com/photos/8829172@N02/2763895688
Anchor by Plbmak on Flikr. https://www.flickr.com/photos/8829172@N02/2763895688

 

The consensus seems to be that biases are very effective when experts use them in their specific fields. However we need to be aware when we are misapplying them. Neurologists, like all physicians, need to monitor their thinking process carefully to avoid making quick but inaccurate clinical judgments. Fortunately both articles discuss the de-biasing strategies which help to prevent the pitfalls of cognitive biases.

 

Black and White Hindsight by Tim J Keegan on Flikr. https://www.flickr.com/photos/suburbanbloke/2722713030
Black and White Hindsight by Tim J Keegan on Flikr. https://www.flickr.com/photos/suburbanbloke/2722713030

 

There are many other cognitive biases out there, aiding and laying traps in equal measure. Rolf Dobelli for instance lists 99 biases that may impair our thinking in his excellent The Art of Thinking Clearly. I have reviewed this and other decision-making and patient safety books on www.thedoctorsbookshelf.com.  OK I admit it- I am making a shameful pitch for my other blog, but why not?

10 bizarre things neurologists do to their patients

This is a follow-up to my previous blog post, So what is remarkable about neurology anyway? That post reviewed the challenging tasks neurologists face everyday. How do they go about it? How do they evaluate their patients with suspected neurological disorders?

Neurology by MV Maverick on Flikr. https://www.flickr.com/photos/themvmaverick/11396461045
Neurology by MV Maverick on Flikr. https://www.flickr.com/photos/themvmaverick/11396461045

 

For the uninitiated, the process of the neurological assessment must seem like an outlandish ritual. Unlike cardiologists who approach patients with the familiar stethoscope, neurologists come armed to the hilt with an arsenal of threatening equipment. Patients are often bewildered, and occasionally irritated, with the neurological exam. Admitted, they sometimes, they sometimes emerge from the assessment feeling battered and bruised-all for a good cause of course!

So what are these bizarre deeds that marks the neurological consultation?

1. Neurologists welcome you with an overly firm handshake 

By liftarn (http://openclipart.org/media/files/liftarn/2604) [Public domain], via Wikimedia Commons
By liftarn (http://openclipart.org/media/files/liftarn/2604) [Public domain], via Wikimedia Commons

The handshake is a valuable neurological tool. It tells the neurologist right from the beginning if there is any weakness or if there is a form of muscle stiffness called myotonia. Therefore avoid the neurologist’s handshake if you suffer with arthritis or other painful hand conditions.

2. Neurologists make you do the catwalk 

The way you walk, the gait, may show the neurologist a variety of clues or signs. There are a variety of abnormal gaits that often point to a diagnosis even before the consultation actually begins. Examples include the shuffling gait in Parkinson’s disease, the hemiparetic gait in Stroke, and the waddling gait in diseases that give rise to hip girdle weakness. More embarrassing for some patients is that the neurologist may actually ask them to do a catwalk, all for the sake of making a diagnosis you must understand!

Other bizarre associated tests are walking an imaginary tightrope, standing on one leg, standing on tip toes and then on the heels, and marching in one spot with eyes shut

3. Neurologists stare intently at you 

"Thisisbossi Symmetry" by Andrew Bossi - Own work. Licensed under CC BY-SA 3.0 via Wikimedia Commons - https://commons.wikimedia.org/wiki/File:Thisisbossi_Symmetry.JPG#/media/File:Thisisbossi_Symmetry.JPG
“Thisisbossi Symmetry” by Andrew Bossi – Own work. Licensed under CC BY-SA 3.0 via Wikimedia Commons – https://commons.wikimedia.org/wiki/File:Thisisbossi_Symmetry.JPG#/media/File:Thisisbossi_Symmetry.JPG

 

The face often give the neurologist the clue to many diagnoses. Conditions such as Bell’s palsy and Stroke are evident from the face as are Parkinson’s disease, myotonic dystrophy and facio-scapulo-humeral muscular dystrophy (FSHD). There’s no need to blush therefore when the intent gaze seems to go on endlessly.

4. Neurologists come up very close- to peer into your soul

If the eyes are the windows to the soul, then neurologists are second only to ophthalmologists in recognising this nebulous entity. The back of the eye, or retina, holds a variety of valuable clues for many neurological diseases. The neurologist typically looks for signs of increased pressure in the head and this may occur with brain tumours, meningitis, encephalitis, This may also occur without any obvious cause in a condition called idiopathic intracranial hypertension (IIH). Other eye signs such as cataracts and pigmented retina seen with disorders for example mitochondrial diseases. 

To peer into the soul, the neurologist may come very uncomfortably close, (hoping the aftershave isn’t too strong and that the morning deodorant has lasted till then). Don’t hold your breath however, as this gazing into the soul may take longer than you anticipate.

5. Neurologists ask you to roll your eyes-in all sorts of directions

Muscles of the eye, circa 1900 by Double-M on Flikr. https://www.flickr.com/photos/double-m2/5551619158
Muscles of the eye, circa 1900 by Double-M on Flikr. https://www.flickr.com/photos/double-m2/5551619158

 

Abnormal eye movements are key pointers to many neurological disorders. There are six muscles that move each eyeball, and these are under the control of three pairs of cranial nerves-the oculomotor, the trochlear, and the abducens nerves. These nerves in turn are coordinated by complex nerve cell bodies or nuclei in the brain stem.The eyelids and pupils are also muscles under control of nerves.

These cranial nuclei coordinate a symphony of unparalleled and unimaginable complexity. This allows us to focus on moving objects without any hinderance. Things may go wrong with this symphony, and this typically results in double vision (diplopia) and droopy eyelids (ptosis). Diseases that cause these symptoms include brain aneurysms, myasthenia gravis (MG), and brainstem stroke. Some diseases may cause the eyeballs to move in uncontrollable and chaotic ways called nystagmus, oscillopsia, and opsoclonus (neurologists love these names!) 

Don’t be shocked therefore when your neurologist asks you to look up, look down, look to the right and left; to follow this or the other hand; to look at this fist then at these fingers…. It’s all a helpful game-honest!

6. Neurologists ask you to pretend to brush your teeth 

 

"Marcel Marceau - 1974" by press photo - ebay. Licensed under Public Domain via Commons.
Marcel Marceau – 1974” by press photo – ebay. Licensed under Public Domain via Commons.

 

Your neurologist may request you to brush your teeth or hair with an imaginary brush, or ask you to do victory sign or the thumbs-up sign (never thumbs-down mind you). Almost verging on the comedic, this is a serious test because these simple tasks are impaired in many diseases. The difficulty in performing tasks one has previously been proficient at is called dyspraxia, or apraxia if the ability is completely lost. Without any weakness or numbness, people with dyspraxia are unable to use common tools and equipment, reporting that they have no idea how to manipulate them. This could be seen in some forms of stroke and some dementias. Do decline however if she asks you to mimic the great mime Marcel Marceau.

7. Neurologists ask you to wiggle your tongue and poke it out 

New Zealand Maori culture 009 by Steve Evans on Flikr. https://www.flickr.com/photos/babasteve/5418324230
New Zealand Maori culture 009 by Steve Evans on Flikr. https://www.flickr.com/photos/babasteve/5418324230

 

The tongue is a very important muscle and holds countless clues for the neurologist. It is innervated by the last of the 12 cranial nerves, the hypoglossal nerve. which may be paralysed by a very localised stroke and this is often in the context of a condition called cervical artery dissection. This is a tear in one of the big arteries in the neck which take blood to the brain. The tear may arise from trivial neck movements and manipulations such as look up for a long time or staying too long on the hairdressers couch. A clot then forms at the site of the tear, and this then migrates to block a smaller blood vessel supplying the brainstem where the hypoglossal nerve sets off from…phew! Anyway, when this kind of stroke occurs, the tongue deviates to the the weaker side when it is poked out.

The more general weakness of the tongue is seen in conditions such as motor neurone disease (MND), in which the tongue also quivers at rest-something neurologists call fasciculations. The cheeky neurologist (pun intended) will ask you to push against her finger through your cheek to test its full strength.

Another problem that may affect the tongue is myotonia, a condition in which he tongue and other muscles are stiff and relax very slowly after they are activated. To test this, your neurologist may actually tap on your tongue, and then watches in fascination as it stiffens and then relaxes very slowly. Strong but slow moving tongues may be seen in Parkinson’s disease (PD). So, when next your neurologist says ‘open up’, he really means business.

8. Neurologists flex their muscles against yours

 

"FreestyleWrestling2" by Staff Sergeant Jason M. Carter, USMC - Defenseimagery.mil, VIRIN 040307-M-RS496-226. Licensed under Public Domain via Commons - https://commons.wikimedia.org/wiki/File:FreestyleWrestling2.jpg#/media/File:FreestyleWrestling2.jpg
“FreestyleWrestling2” by Staff Sergeant Jason M. Carter, USMC – Defenseimagery.mil, VIRIN 040307-M-RS496-226. Licensed under Public Domain via Commons – https://commons.wikimedia.org/wiki/File:FreestyleWrestling2.jpg#/media/File:FreestyleWrestling2.jpg

 

OK, she will not literally wrestle you to the ground but it may appear so at times. Pushing against your head, pressing down against your elbows, leaning hard against your leg-she will do everything to show she is stronger than you. Only if she fails will she score your power as grade 5/5-the best you can get. If you do not score full marks however you place the neurologist in a bit of a quagmire; a score between 0-5 is not always easy to allocate, and the obsessive neurologist may get in a bind and may give you marks such as 3+ or 4-. Just for fun let her win, and see her consternation!

9. Neurologists hit you with a hammer-in all sorts of places

Lego man and reflex hammer by Dr. Mark Kubert on Flikr. https://www.flickr.com/photos/clearpathchiropractic/7590265518
Lego man and reflex hammer by Dr. Mark Kubert on Flikr. https://www.flickr.com/photos/clearpathchiropractic/7590265518

 

The reflex hammer is perhaps the most well-recognised tool of the neurologist. These hammers come in all shapes and sizes, and some are really quite scary. People expect to have their knees tapped and look forward to what they have seen many times on TV-the leg kicking out. Most patients find this amusing. They are however often surprised  when the neurologist proceeds to use the hammer on their jaw, elbow, wrist and ankles. The then often bristle at having the soles of their feet stroked by the end of the hammer’s handle, a sharp uncomfortable end it is. All the hammer does is to stretch the tendons of muscles, and this elicits a reflex that causes the muscle to contract or tighten up. This response may be exaggerated (hypereflexia) if there is any problem in the central nervous system. Conversely the reflex response may be diminished (hyporeflexia) with problems of the peripheral nervous system.  Stroking the foot is called the Babinski response and gives a similar form of information to the neurologist. But beware the neurologist who then proceeds to stroke the side of your foot or squeeze your shins, all in an effort to get the same information-it is really an unnecessary and uncomfortable duplication of tests.

10. Neurologists prick and prod you with a sharp pin

Now this must take the cake, and quite rightly often comes at the end of the neurological examination. As threatening as this tests appears, this is probably the neurologist at his most acute. Using a sterile pin, the neurologist asks you to respond ‘yes’ if the sensation you perceive is sharp, and ‘no’ if it is dull. He then carefully proceeds to map out areas of reduced sensation or feeling, frowning as he struggles to keep track of your responses in his mind. He tries to establish if you have a glove and stocking pattern of sensory loss seen in peripheral neuropathy (nerve end damage). It may also be a dermatomal pattern seen with radiculopathy (trapped nerve in the spine). Unfortunately for the neurologist however many patients do not understand the rules of the game and give all sorts of unimaginable responses; not surprising when one is under the threat of a sharp pointy object!

"User-FastFission-brain". Licensed under CC BY-SA 3.0 via Wikimedia Commons - https://commons.wikimedia.org/wiki/File:User-FastFission-brain.gif#/media/File:User-FastFission-brain.gif
“User-FastFission-brain”. Licensed under CC BY-SA 3.0 via Wikimedia Commons – https://commons.wikimedia.org/wiki/File:User-FastFission-brain.gif#/media/File:User-FastFission-brain.gif

 

These are but a few of the bizarre doings of neurologists.  Seeing a neurologist soon? Be prepared-you have been warned!

PS. Images used in this blog post are for illustration purposes only and do not necessary depict the actual equipment used by neurologists. The examination steps described are however a good reflection of actual neurological practice.

Vagus nerve stimulation: from neurology and beyond!

The vagus nerve is one of 12 pairs of nerves that come off the lower part of the brain called the brainstem. It is the tenth in line and therefore also called the tenth cranial (or X) nerve.

 

By Brain_human_normal_inferior_view_with_labels_en.svg: *Brain_human_normal_inferior_view.svg: Patrick J. Lynch, medical illustrator derivative work: Beao derivative work: Dwstultz [CC BY 2.5 (http://creativecommons.org/licenses/by/2.5)], via Wikimedia Commons
By Brain_human_normal_inferior_view_with_labels_en.svg: *Brain_human_normal_inferior_view.svg: Patrick J. Lynch, medical illustrator derivative work: Beao derivative work: Dwstultz [CC BY 2.5 (http://creativecommons.org/licenses/by/2.5)%5D, via Wikimedia Commons

It is an interesting nerve for various reasons. Unlike other cranial nerves, it travels way beyond the head and neck. It has a very long course through the neck to the chest and abdomen. Furthermore it regulates a wide variety of organ functions such as heart, respiratory and gut activities. An important branch of the vagus nerve is the recurrent laryngeal nerve which innervates the larynx (voice box). 

Due to a quirk of the embryonic development of the aorta, this nerve gets pulled down into the chest before it makes a U-turn back to the neck. It is therefore easily damaged in operations of the neck or chest, and therefore the bane of surgeons.

 

By Truth-seeker2004 (Own work) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons
By Truth-seeker2004 (Own work) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)%5D, via Wikimedia Commons

Scientists have recognised this characteristic feature of the vagus nerve and have tried to manipulate it for therapeutic reasons. The most well-recognised is the stimulation of the vagus nerve to control epileptic seizures. This vagus nerve stimulation (VNS) requires implanting a stimulator under the skin on the chest, and this is connected to the vagus nerve with wires. Somehow or the other, this stimulation modulates seizures. The Epilepsy Society has detailed information on the technical aspects of VNS, and below is a video showing how VNS works.

The American Academy of Neurology guidelines on VNS, published in the journal Neurology, help Neurologists decide when to use VNS. Below are the main indications for VNS in epilepsy:

  • Refractory partial onset seizures in adults >12 years not suitable for surgery
  • Partial or generalised seizures in children
  • Lennox-Gastaut syndrome (LGS)
  • Mood improvement in adult epilepsy

VNS has other neurological indications  which are coming online and top of these is Cluster headache. And now, just off the press, is a possible role for VNS in migraine.

Headache by openDemocracy on Flikr. https://www.flickr.com/photos/opendemocracy/1482020719
Headache by openDemocracy on Flikr. https://www.flickr.com/photos/opendemocracy/1482020719

 

There are however several non-neurological diseases that may benefit from VNS including arthritis, diabetes, hiccups and heart failure. Science News explores these indications further in an article interestingly titled Viva Vagus: Wandering Nerve Could Lead to Range of TherapiesLike opening a can of worms, VNS may extend it’s tentacles far and wide; imagine for example that there is a study looking at the benefit of VNS in bulimia.

"Bulimiav bvjkfhdnijf" by Merlymeleanrossana - Treball propi. Licensed under CC BY-SA 3.0 via Wikimedia Commons - https://commons.wikimedia.org/wiki/File:Bulimiav_bvjkfhdnijf.jpg#/media/File:Bulimiav_bvjkfhdnijf.jpg
“Bulimiav bvjkfhdnijf” by Merlymeleanrossana – Treball propi. Licensed under CC BY-SA 3.0 via Wikimedia Commons – https://commons.wikimedia.org/wiki/File:Bulimiav_bvjkfhdnijf.jpg#/media/File:Bulimiav_bvjkfhdnijf.jpg

 

Whatever next?

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

neurochecklists-image

 

 

Is this the most stunning video clip about brain facts?

I must admit video clips are not my thing but I came across this very well made video I felt compelled to share. It came to my attention from unusual sites for medical information- Business Insider UK and Tech Insider. Nothing better to broaden one’s horizon! It is a very-well made video and presents some very awesome facts. See for yourself!

 

 

Whilst at it there is also a slightly less stylish clip but full of interesting brain facts, very well-presented. I think its also worth a view.

 

 

If you do not like video clips then perhaps you will be interested in these 10 things that change your brain sourced from OpenMind. Open mind indeed!

_________________________________________________________________________

neurochecklists-image

 

 

 

Metronidazole-two case lessons for neurologists

I came across two articles recently which highlighted neurological complications of metronidazole I was previously unaware of.

321-Metronidazole by Chris on Flikr. https://www.flickr.com/photos/chrisinplymouth/3947569729
321-Metronidazole by Chris on Flikr. https://www.flickr.com/photos/chrisinplymouth/3947569729

 

The first is a case report of metronidazole-induced encephalopathy in the journal Neurocritical Care. I admit I only read the abstract and the key word there is involvement of the dentate nuclei.

 

Metronidazole by Chris on Flikr. https://www.flickr.com/photos/chrisinplymouth/3949517597/
Metronidazole by Chris on Flikr. https://www.flickr.com/photos/chrisinplymouth/3949517597/

 

The second case report is of metronidazole-induced ataxia in the journal Movement Disorders.

 

These are rather uncommon side-effects and should not deter from prescribing metronidazole. But it is just worth looking more carefully at that medication list if your next patient  has unexplained encephalopathy or ataxia.

 

 

Are magnets transforming neurological practice?

The armoury of the neurologist is traditionally a cocktail of tablets and injections. The neurosurgeons and neuroradiologists seem to have all the fancy gadgets. This may however be changing with techniques that are gradually creeping into neurological practice. One such technique is transcranial magnetic stimulation (TMS). This is a non-invasive method of stimulating specific parts of the brain using a magnetic field generator or coil.

"Transcranial magnetic stimulation" by Eric Wassermann, M.D. - Wassermann, Eric. Transcranial Brain Stimulation. Behavioral Neurology Unit. National Institute of Neurological Disorders and Stroke, National Institutes of Health, United States Department of Health and Human Services. Archived from the original on 2013-10-29. Retrieved on 2013-10-29.. Licensed under Public Domain via Commons - https://commons.wikimedia.org/wiki/File:Transcranial_magnetic_stimulation.jpg#/media/File:Transcranial_magnetic_stimulation.jpg
“Transcranial magnetic stimulation” by Eric Wassermann, M.D. – Wassermann, Eric. Transcranial Brain Stimulation. Behavioral Neurology Unit. National Institute of Neurological Disorders and Stroke, National Institutes of Health, United States Department of Health and Human Services. Archived from the original on 2013-10-29. Retrieved on 2013-10-29.. Licensed under Public Domain via Commons – https://commons.wikimedia.org/wiki/File:Transcranial_magnetic_stimulation.jpg#/media/File:Transcranial_magnetic_stimulation.jpg

 

The classical neurological application of TMS is in the treatment and prevention of migraine. The role of TMS in migraine has been fairly well-studied although the impact on symptoms is modest. There is however enough evidence to convince the National Institute of Health and Care Excellence to issue NICE guidelines on TMS. These, as expected, prescribed hope and caution in equal measure.

A potential application of TMS is in Parkinson’s disease. A recent systematic review and meta-analysis in JAMA Neurology is fairly convincing that TMS improves the motor symptoms of Parkinson’s disease

"Basal ganglia in treatment of Parkinson's" by Mikael Häggström, based on image by Andrew Gillies/User:Anaru - Derivative of File:Basal ganglia circuits.png. Licensed under CC BY-SA 3.0 via Commons - https://commons.wikimedia.org/wiki/File:Basal_ganglia_in_treatment_of_Parkinson%27s.png#/media/File:Basal_ganglia_in_treatment_of_Parkinson%27s.png
“Basal ganglia in treatment of Parkinson’s” by Mikael Häggström, based on image by Andrew Gillies/User:Anaru – Derivative of File:Basal ganglia circuits.png. Licensed under CC BY-SA 3.0 via Commons – https://commons.wikimedia.org/wiki/File:Basal_ganglia_in_treatment_of_Parkinson%27s.png#/media/File:Basal_ganglia_in_treatment_of_Parkinson%27s.png

What of TMS as a cognitive enhancer? I came across the report that TMS may boost memory in Gizmag. OK it’s not a neurology journal but it made a more exciting headline than the original study published in Science  under the elusive title targeted enhancement of cortical-hippocampal brain networks and associative memory. In simple language, TMS may enhance the neural networks in the hippocampus, the brains memory hub. Whilst the study was carried out in people with normal memory, there are implications for cognitive disorders such as Alzheimer’s disease if the potential and promise of TMS are realised.

"Magnet0873" by Newton Henry Black - Newton Henry Black, Harvey N. Davis (1913) Practical Physics, The MacMillan Co., USA, p. 242, fig. 200. Licensed under Public Domain via Commons - https://commons.wikimedia.org/wiki/File:Magnet0873.png#/media/File:Magnet0873.png
“Magnet0873” by Newton Henry Black – Newton Henry Black, Harvey N. Davis (1913) Practical Physics, The MacMillan Co., USA, p. 242, fig. 200. Licensed under Public Domain via Commons – https://commons.wikimedia.org/wiki/File:Magnet0873.png#/media/File:Magnet0873.png

 

A further surprising application of TMS, potential of course, is in dyslexia. This is an emerging field, still under investigation, but imagine the potential this will unleash! There is a helpful review article in Neuroimmunology and Neuroinflammation which discusses the role of rapid rate TMS in the treatment of dyslexia.

"Dislexia nens" by cuidado infantil - cuidadoinfantil.net. Licensed under CC BY-SA 3.0 via Wikimedia Commons - https://commons.wikimedia.org/wiki/File:Dislexia_nens.jpg#/media/File:Dislexia_nens.jpg
“Dislexia nens” by cuidado infantil – cuidadoinfantil.net. Licensed under CC BY-SA 3.0 via Wikimedia Commons – https://commons.wikimedia.org/wiki/File:Dislexia_nens.jpg#/media/File:Dislexia_nens.jpg

 

We’re not quite there yet but there is hope for the neurological arsenal; who knows, we may soon dispense with all these difficult to swallow pills and cumbersome to deliver injections!

 

Medicine 01 by Taki Steve on Flikr. https://www.flickr.com/photos/13519089@N03/4746653392
Medicine 01 by Taki Steve on Flikr. https://www.flickr.com/photos/13519089@N03/4746653392

Interested in delving deeper into TMS?

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

neurochecklists-image