What are the advances in the management of cluster headache?

Cluster headaches are nasty, excruciatingly severe, headaches. They are not called suicide headaches without good reason. Cluster headaches are typically one-sided, localised around the orbit. The eye on the affected side classically turns red and waters. The nostril follows suit by either running or blocking up. The episodes last between 45 minutes to 3 hours during which the hapless victims pace up and down, feeling like smashing their heads against a concrete wall. Relief is short-lasting because the headache cycle repeats itself several times a day, for weeks and months on end. People with episodic cluster headaches may go several months without headaches, but those with the chronic form are not afforded this luxury.

Lego splitting headache. Matt Brown on Flikr. https://www.flickr.com/photos/londonmatt/15191073177
Lego splitting headache. Matt Brown on Flikr. https://www.flickr.com/photos/londonmatt/15191073177

Treatment of cluster headache is typically three-pronged: acute treatment with triptansintermediate prevention with oral steroids; and prevention with verapamil. OK, I over simplify. Each of these strategies has 2nd, 3rd, and 4th line options. Verapamil, the cornerstone of treatment, comes with significant risks to the heart. And in extreme cases, invasive measures are called upon to save the day.

By Hansjorn - το :Αρχείο:Poseidon sculpture Copenhagen 2005.jpg, CC BY-SA 3.0, Link
By Hansjorn – το :Αρχείο:Poseidon sculpture Copenhagen 2005.jpg, CC BY-SA 3.0, Link

Unfortunately all these treatments fail miserably more often than we like to admit. Even invasive treatments are not always successful in cluster headaches. Neurologists and patients alike are therefore always on the lookout for developments which will improve the understanding and management of cluster headaches. And, thankfully, there are a few.

A. Abnormal tyrosine metabolism and cluster headache

By No machine-readable author provided. Benjah-bmm27 assumed (based on copyright claims). - No machine-readable source provided. Own work assumed (based on copyright claims)., Public Domain, Link
By No machine-readable author provided. Benjah-bmm27 assumed (based on copyright claims). – No machine-readable source provided. Own work assumed (based on copyright claims)., Public Domain, Link

The sad fact about cluster headache is, nobody knows what causes it. We know it is due to some malfunction of the autonomic nervous system, and to the trigeminal, or fifth, cranial nerve. This is why it is called a trigeminal autonomic cephalalgia. We know that it favours men who smoke. Beyond this we are rather clueless. It is therefore with high hopes that I read about abnormal tyrosine metabolism in chronic cluster headache, in the journal Cephalalgia. The authors report that people with cluster headaches have high levels of the products of tyrosine metabolism in their blood, such as dopamine, noradrenaline, and tyramine. If this turns out to be confirmed, it may open the way to the development of newer and more effective treatments for this painful condition.

B. Heart monitoring on verapamil

https://pixabay.com/en/pulse-trace-healthcare-medicine-163708/
https://pixabay.com/en/pulse-trace-healthcare-medicine-163708/

The heart is at risk whenever people are put on verapamil. This is because it may induce abnormal and dangerous heart rhythms. It is therefore important to check the electrocardiogram (ECG) of people on verapamil. Guidelines suggest checking the ECG before starting, 10 days after starting, and before each dose increment. It was therefore disconcerting that a recent study, published in the journal Neurology, found that 40% of people on verapamil never had any form of heart monitoring. The paper, titled electrocardiographic abnormalities in patients with cluster headache on verapamil therapy, is an audit of >200 people with cluster headaches on high dose verapamil. In those who had cardiac monitoring, the authors found ECG abnormalities in more than 50%, some very significant and life threatening. A similar finding was reported in an older study published in the Journal of Headache and Pain, titled cardiac safety in cluster headache patients using the very high dose of verapamil (≥720 mg/day). Worrying! Time to take ECG monitoring more seriously in people on verapamil. 

C. New preventative drug options

By Stomac - Own work, CC BY-SA 2.0 fr, Link
By StomacOwn work, CC BY-SA 2.0 fr, Link

Besides verapamil, there are many other options for cluster headache prevention. The list is quite long, and this is the case whenever we are uncertain of what else really works. That is why I was relieved to see a recent guideline on treatment of cluster headaches touting new evidence to guide neurologists. Published in the journal Headache, it is titled Treatment of Cluster Headache: The American Headache Society Evidence-Based Guidelines. This guideline establishes that lithium is effective in preventing cluster headache, but valproate is probably ineffective. More importantly, the guidelines introduce new effective preventative agents such as civamide nasal spray, melatonin, and warfarin. For transitional prevention, occipital nerve injection comes through with glowing tributes. Progress, surely!

D. Neurostimulation for cluster headache

By C. Clark - NOAA Photo Library (direct), NOAA Central Library; OAR/ERL/National Severe Storms Laboratory (NSSL), Image ID: nssl0010, Public Domain, Link
By C. Clark – NOAA Photo Library (direct), NOAA Central Library; OAR/ERL/National Severe Storms Laboratory (NSSL), Image ID: nssl0010, Public Domain, Link

It is no longer surprising to find neurostimulation cropping up in the treatment of any neurological disorder. And cluster headache is no exception. The most effective agent, according to the latest guidelines, is sphenopalatine ganglion stimulation. It now ranks very high in the acute treatment of cluster headache, even if less effective than the good old, conventional acute treatments which are subcutaneous sumatriptan, intransal zolmitriptan, and 100% oxygen. Neurostimulation is also likely to play a future preventative role in cluster headaches, and the candidates here are invasive and non-invasive vagus nerve stimulation. We are waiting with bated breaths!

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For more on vagus nerve stimulation, you may check out my previous post titled Vagus nerve stimulation: from neurology and beyond!

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neurochecklists-image

 

 

What are the most iconic neurological disorders?

Neurology is a broad specialty covering a staggering variety of diseases. Some neurological disorders are vanishingly rare, but many are household names, or at least vaguely familiar to most people. These are the diseases which define neurology. Here, in alphabetical order, is my list of the top 60 iconic neurological diseases, with links to previous blog posts where available.

 

1. Alzheimer’s disease

By uncredited - Images from the History of Medicine (NLM) [1], Public Domain, https://commons.wikimedia.org/w/index.php?curid=11648572
By uncredited – Images from the History of Medicine (NLM) [1], Public Domain, https://commons.wikimedia.org/w/index.php?curid=11648572

2. Behcet’s disease

By Republic2011 - Own work, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=17715921
By Republic2011Own work, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=17715921

3. Bell’s palsy

By http://wellcomeimages.org/indexplus/obf_images/69/f2/8d6c4130f4264b4b906960cf1f7e.jpgGallery: http://wellcomeimages.org/indexplus/image/M0011440.html, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=36350600
By http://wellcomeimages.org/indexplus/obf_images/69/f2/8d6c4130f4264b4b906960cf1f7e.jpgGallery: http://wellcomeimages.org/indexplus/image/M0011440.html, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=36350600

4. Brachial neuritis

5. Brain tumours

6. Carpal tunnel syndrome

7. Cerebral palsy (CP)

8. Cervical dystonia

9. Charcot Marie Tooth disease (CMT)

By http://wellcomeimages.org/indexplus/obf_images/66/09/4dfa424fe11bb8dc56b2058f04ba.jpgGallery: http://wellcomeimages.org/indexplus/image/V0026141.html, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=36578490
By http://wellcomeimages.org/indexplus/obf_images/66/09/4dfa424fe11bb8dc56b2058f04ba.jpgGallery: http://wellcomeimages.org/indexplus/image/V0026141.html, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=36578490

10. Chronic inflammatory demyelinating polyneuropathy (CIDP)

11. Cluster headache

12. Creutzfeldt-Jakob disease (CJD)

By Unknown - http://www.sammlungen.hu-berlin.de/dokumente/11727/, Public Domain, https://commons.wikimedia.org/w/index.php?curid=4008658
By Unknownhttp://www.sammlungen.hu-berlin.de/dokumente/11727/, Public Domain, https://commons.wikimedia.org/w/index.php?curid=4008658

13. Duchenne muscular dystrophy (DMD)

By G._Duchenne.jpg: unknown/anonymousderivative work: PawełMM (talk) - G._Duchenne.jpg, Public Domain, https://commons.wikimedia.org/w/index.php?curid=9701531
By G._Duchenne.jpg: unknown/anonymousderivative work: PawełMM (talk) – G._Duchenne.jpg, Public Domain, https://commons.wikimedia.org/w/index.php?curid=9701531

14. Encephalitis

15. Epilepsy

16. Essential tremor

17. Friedreich’s ataxia

By Unknown - http://www.uic.edu/depts/mcne/founders/page0035.html, Public Domain, https://commons.wikimedia.org/w/index.php?curid=3960759
By Unknownhttp://www.uic.edu/depts/mcne/founders/page0035.html, Public Domain, https://commons.wikimedia.org/w/index.php?curid=3960759

18. Frontotemporal dementia (FTD)

19. Guillain-Barre syndrome (GBS)

By Anonymous - Ouvrage : L'informateur des aliénistes et des neurologistes, Paris : Delarue, 1923, Public Domain, https://commons.wikimedia.org/w/index.php?curid=28242077
By Anonymous – Ouvrage : L’informateur des aliénistes et des neurologistes, Paris : Delarue, 1923, Public Domain, https://commons.wikimedia.org/w/index.php?curid=28242077

20. Hashimoto encephalopathy

21. Hemifacial spasm

22. Horner’s syndrome

By Unknown - http://ihm.nlm.nih.gov/images/B15207, Public Domain, https://commons.wikimedia.org/w/index.php?curid=19265414
By Unknownhttp://ihm.nlm.nih.gov/images/B15207, Public Domain, https://commons.wikimedia.org/w/index.php?curid=19265414

23. Huntington’s disease (HD)

https://en.wikipedia.org/wiki/George_Huntington#/media/File:George_Huntington.jpg
https://en.wikipedia.org/wiki/George_Huntington#/media/File:George_Huntington.jpg

24. Idiopathic intracranial hypertension (IIH)

25. Inclusion body myositis (IBM)

26. Kennedy disease

27. Korsakoff’s psychosis

28. Lambert-Eaton myasthenic syndrome (LEMS)

29. Leber’s optic neuropathy (LHON)

30. McArdles disease

31. Meningitis

32. Migraine

33. Miller-Fisher syndrome (MFS)

By J3D3 - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=34315507
By J3D3Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=34315507

34. Motor neurone disease (MND)

35. Multiple sclerosis (MS)

36. Multiple system atrophy (MSA)

37. Myasthenia gravis (MG)

38. Myotonic dystrophy

39. Narcolepsy

40. Neurofibromatosis (NF)

41. Neuromyelitis optica (NMO)

42. Neurosarcoidosis

43. Neurosyphilis

44. Parkinson’s disease (PD)

45. Peripheral neuropathy (PN)

46. Peroneal neuropathy

47. Progressive supranuclear palsy (PSP)

48. Rabies

49. Restless legs syndrome (RLS)

50. Spinal muscular atrophy (SMA)

51. Stiff person syndrome (SPS)

52. Stroke

53. Subarachnoid haemorrhage (SAH)

54. Tension-type headache (TTH)

55. Tetanus

56. Transient global amnesia (TGA)

57. Trigeminal neuralgia

58. Tuberous sclerosis

59. Wernicke’s encephalopathy

By J.F. Lehmann, Muenchen - IHM, Public Domain, https://commons.wikimedia.org/w/index.php?curid=9679254
By J.F. Lehmann, Muenchen – IHM, Public Domain, https://commons.wikimedia.org/w/index.php?curid=9679254

60. Wilson’s disease

By Carl Vandyk (1851–1931) - [No authors listed] (July 1937). "S. A. Kinnier Wilson". Br J Ophthalmol 21 (7): 396–97. PMC: 1142821., Public Domain, https://commons.wikimedia.org/w/index.php?curid=11384670
By Carl Vandyk (1851–1931) – [No authors listed] (July 1937). “S. A. Kinnier Wilson“. Br J Ophthalmol 21 (7): 396–97. PMC: 1142821., Public Domain, https://commons.wikimedia.org/w/index.php?curid=11384670

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The Neurology Lounge has a way to go to address all these diseases, but they are all fully covered in neurochecklists. In a future post, I will look at the rare end of the neurological spectrum and list the 75 strangest and most exotic neurological disorders.

How is migraine research soothing the pain of neurology?

Migraine is a very common medical disorder. 15% of the world’s population have migraine, and 2% have chronic migraine. Most migranuers never need to see a neurologist because they have learnt how to manage their headaches. Neurologists are called in only when the usual treatments fail, often a euphemism for ‘inadequate doses and duration of treatment’.

Migraine. Quinn Dumbrowski on Flikr. https://www.flickr.com/photos/quinnanya/3820597553/in/photostream/
Migraine. Quinn Dumbrowski on Flikr. https://www.flickr.com/photos/quinnanya/3820597553/in/photostream/

Many people with difficult to control migraine however really have just that…difficult to control migraine. And it is the most avid neurologist who doesn’t silently sigh and grunt at referrals which say the patient has tried every migraine treatment, to no avail. And with good reason: the journey for people with chronic migraine is hardly ever smooth-sailing.

By User:S. JähnichenBrain_bulbar_region.svg: Image:Brain human sagittal section.svg by Patrick J. Lynch; Image:Brain bulbar region.PNG by DO11.10; present image by Fvasconcellos. - Brain_bulbar_region.svg, CC BY 2.5, https://commons.wikimedia.org/w/index.php?curid=6049291
By User:S. JähnichenBrain_bulbar_region.svg: Image:Brain human sagittal section.svg by Patrick J. Lynch; Image:Brain bulbar region.PNG by DO11.10; present image by Fvasconcellos. – Brain_bulbar_region.svg, CC BY 2.5, https://commons.wikimedia.org/w/index.php?curid=6049291

Why does migraine remain such a pain, and what hope is there to relieve the headache for patients and their neurologists? Here are 8 prospective candidates jostling to soothe the pain.

 

1. The hypoxia hypothesis for migraine triggers

There are probably as many migraine triggers as there are migraine hypotheses. Some of the triggers are curious, as discussed in my previous blog Migraine and its strange and surprising associations. Some researchers think the common link to migraine triggers is low oxygen or hypoxia. Writing in the prestigious journal Brain, they report on Migraine induced by hypoxia: an MRI spectroscopy and angiography study. Sorry, the full paper is locked to non-subscribers, but the abstract is unequivocal: hypoxia induces migraine-like attacks. And the accompanying editorial is agog with the prospects this study opens up with its headline, Hypoxia, a turning point in migraine pathogenesis? Who doesn’t love turning points, especially as the previous turning points can then be conveniently forgotten?

2. Migraine with cranial autonomic symptoms-clarified

Alison Smith on Flikr. https://www.flickr.com/photos/polygrams/232755351/in/photostream/
Alison Smith on Flikr. https://www.flickr.com/photos/polygrams/232755351/in/photostream/

Migraine with unilateral cranial autonomic symptoms is a new construct for most jobbing neurologists (OK I may just be speaking for myself here). Unilateral cranial autonomic symptoms (UAS) refer to one-sided symptoms such as reddening of the eye, blockage or running of the nose, a droopy eyelid, and a small pupil. These features are however classically seen in conditions called trigeminal autonomic cephalalgias (TACS), the main one being cluster headache.

Neurologists often see people with classical migraine but who, in addition, have UAS. The cognitive dissonance this causes the neurologist is relieved by making a diagnosis of cluster migraine. It is therefore important to know that unilateral cranial autonomic symptoms are common in migraine. The authors studied >750 migraine sufferers who also had UAS, and report that it is a severe, one-sided headache. Worse still, it goes on for more than the 72 hours which headache experts have ‘specified’ as the maximum duration for migraine. Naughty, naughty. Hopefully this study will put the final nail in the coffin of cluster migraine-it is Migraine with UAS from now on.

3. Persistent migraine aura or visual snow?

By Googleaseerch at the English language Wikipedia, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=3359664
By Googleaseerch at the English language Wikipedia, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=3359664

I admit I didn’t know persistent migraine aura (PMA) even existed before now. It is migraine aura lasting more than a week, and it has two subtypes-persistent primary visual disturbance (PPVD) and typical aura (TA). Digging deeper, I found that PMA could easily be confused with something called visual snow. Another new one for me. An article in Brain titled ‘Visual snow’ – a disorder distinct from persistent migraine aura makes the differences clear. With its co-author no less than the headache authority Peter Goadsby, go on and read all about it-its open access after all. For a simplified read, try this piece in About Health titled Why Visual Snow Syndrome is Not a Migraine Variant. Another small step to making the right diagnosis.

4. Monoclonal antibodies for migraine

monoclonal-antibody-services.jpg. 元永利 on Flikr. https://www.flickr.com/photos/linsc/4628425031/in/dateposted/
monoclonal-antibody-services.jpg. 元永利 on Flikr. https://www.flickr.com/photos/linsc/4628425031/in/dateposted/

Neurologists have a long list of interventions for migraine. The treatments range from Triptans to Topiramate, from Propranolol to Pizotifen. But the long list of interventions is no comfort for the equally long list of dissatisfied chronic migraine sufferers. Perhaps what we need are newer and better drugs. And monoclonal antibodies are in the frontline here. Take TEV-48125 and AMG 334  both reported in Lancet Neurology. These are monoclonal antibodies against the calcitonin gene receptor peptide (CGRP) receptor. The articles are classical illustrations of bench-to-bedside neurology, treatment following where the hypothesis leads. The hypothesis in this case stipulates that the CGRP system is central to the pathology in migraine, and CGRP may be a migraine biomarker. TEV-48125 and AMG 334 are entering phase 3 trial stages. And we can’t wait, what with both treatments having a unique 4-weekly subcutaneous injection regime! AMG 334, also known as erenumab, has passed phase 3 trials with good results.

5. Statins and Vitamin D: new tricks for old dogs

Statins are very old dogs in medicine, and their classical trick is to lower cholesterol levels. They are however very adaptive, these statins. They have edged into secondary stroke prevention, and they are now trying to muscle into migraine prevention. But for migraine they are planning a double act with Vitamin D. The cat was let out of the bag by Annals of Neurology in an article titled Simvastatin and vitamin D for migraine prevention: A randomized, controlled trial. There were only 57 study subjects but the results are encouraging; >25% of the study subjects reported a >50% reduction in migraine days; only 3% of those not on the magic combination showed this type of improvement. Note here that neurologists never promise you 100% reduction in your migraine days. Clever, clever.

6. Memantine-another old dog

Another old dog looking for new tricks is Memantine. This is a drug which usually gets its accolades in the fields of dementia and eye movement disorders. It is however not getting the appreciation it thinks it rightly deserves, and it is seeking a wider audience. And is there a wider audience than in the migraine arena? Memantine made its grand migraine debut through the journal Headache in an article titled  Memantine for Prophylactic Treatment of Migraine Without Aura. It may turn out to be a damp squid because the researchers only compared it to placebo. But guess its unique selling point… its potential safety in pregnancy. We have to wait and see what the migraine arena masters think of this.

7. Transcranial magnetic stimulation (TMS):old tricks for a new dog 

Away with old dogs, and welcome back more new dogs. One is transcranial electrical stimulation (TMS) which now has the blessing of the UK National Institute of Clinical and Health Excellence (NICE) for migraine treatment and prevention. See my previous blog, Are magnets transforming neurological practice, for more on TMS.

8. Peripheral nerve stimulation

Another new dog is reported in Neurology with the self-explanatory title: Migraine prevention with a supraorbital transcutaneous stimulator. Nerve stimulation is of course an old trick in migraine, but the supraorbital nerve is a new target. This article from Pain Physician gives a detailed review of peripheral nerve stimulation and migraine.

 

Migraine Aura Kaleidoscope. Joana Roja on Flikr. https://www.flickr.com/photos/cats_mom/2988669345/in/photostream/
Migraine Aura Kaleidoscope. Joana Roja on Flikr. https://www.flickr.com/photos/cats_mom/2988669345/in/photostream/

 

Migraine remains challenging to neurologists and distressing for their patients. Perhaps we can now dispense hope along with prescriptions.

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What are the most controversial questions in neurology?

Uncertainty and doubt abound in Neurology. There are many evidence-free areas where experts rub each other the wrong way. These controversies are big and occur in all neurology subspecialties. Controversy-busters have tried for about a decade to iron out these wrinkles on neurology’s face, but the unanswered questions remain. This is why there is a 10th World Congress of Controversies in Neurology (CONy) holding in Lisbon this year.

I want to assure you I have no conflict of interest to declare in this blog. My interest is to explore  which questions have plagued this conference over the last 10 years to pick out the most controversial topics in neurology. To do this I reviewed all previous conference programs and focused on the items that were slated for debate. I looked for practical topics that have remained unresolved, or are just emerging. Here are my top controversial neurological questions:

Raccoon argument II. Tambako The Jaguar on Flikr. https://www.flickr.com/photos/tambako/7460999402
Raccoon argument II. Tambako The Jaguar on Flikr. https://www.flickr.com/photos/tambako/7460999402

 

1st CONy 2007 (Berlin, Germany)

  • Clinically isolated syndromes (CIS): To treat or not to treat
  • Is stem cell therapy an imminent treatment in advanced multiple sclerosis (MS)?
  • Vascular cognitive impairment is a misleading concept?
  • Is mild cognitive impairment a misleading concept?

 

2nd CONy 2008 (Athens, Greece)

  • Can physical trauma precipitate multiple sclerosis?
  • Should patients with Parkinson’s disease (PD) be treated in the pre-motor phase?
  • What is the first line therapy for chronic inflammatory demyelinating polyneuropathy (CIDP)?
  • Is intravenous immunoglobulin (IVIg) effective in chronic myasthenia gravis (MG)?
  • Tau or ß-amyloid immunotherapy in Alzheimer’s disease (AD)?
  • Chronic fatigue syndrome is an organic disease and should be treated by neurologists?

 

3rd CONy 2009 (Prague, Czech Republic)

  • Should cerebrospinal fluid (CSF) be tested in every clinically isolated syndrome?
  • Can we prevent multiple sclerosis (MS) by early vitamin D supplementation and EBV vaccination?
  • Does Parkinson’s disease (PD) have a prion-like pathogenesis?
  • Patients with medication overuse headache should be treated only after analgesic withdrawal?

 

 

4th CONy 2010 (Barcelona, Spain)

  • Camptocormia in parkinson’s disease (PD): Is this dystonia or myopathy?
  • Does chronic venous insufficiency play a role in the pathogenesis of multiple sclerosis (MS)?
  • IVIg or immunosuppression for long-term treatment of CIDP?

 

5th CONy 2011 (Beijing, China)

  • Is sporadic Parkinson’s disease etiology predominantly environmental or genetic?
  • Is multiple sclerosis (MS) an inflammatory or a primarily neurodegenerative disease?
  • Are the new multiple sclerosis oral medications superior to conventional therapies?
  • Is bilateral transverse venous sinus stenosis a critical finding in idiopathic intracranial hypertension (IIH)?

 

6th CONy 2012 (Vienna, Austria)

  • Will there ever be a valid biomarker for Alzheimer’s disease (AD)?
  • Is amyloid imaging clinically useful in Alzheimer’s disease (AD)?
  • Do functional syndromes have a neurological substrate?
  • Should blood pressure be lowered immediately after stroke?
  • Migraine is primarily a vascular disorder?

 

 

7th CONy 2013 (Istanbul, Turkey)

  • Is intravenous thrombolysis the definitive treatment for acute large artery stroke?
  • Atrial fibrillation related stroke should be treated only with the new anticoagulants?
  • Is the best treatment for chronic migraine botulinum toxin?
  • IS CGRP the key molecule in migraine?
  • Is chronic cluster headache best treated with sphenopalatine ganglion (SPG) stimulation?
  • When should deep brain stimulation (DBS) be initiated for Parkinson’s disease?
  • Do interferons prevent secondary progressive multiple sclerosis (SPMS)?
  • Is deep brain stimulation (DBS) better than botulinum toxin in primary dystonia?
  • Are present outcome measures relevant for assessing efficacy of disease modifying therapies in multiple sclerosis (MS)?
  • Should radiologically isolated syndromes (RIS) be treated?
  • Does genetic testing have a role in epilepsy management?
  • Should cortical strokes be treated prophylactically against seizures?
  • Should enzyme-inducing antiepileptic drugs (AEDs) be avoided?
  • EEG is usually necessary when diagnosing epilepsy

 

8th CONy 2014 (Berlin, Germany)

  • Is late-onset depression prodromal neurodegeneration?
  • Does Parkinson’s disease begin in the peripheral nervous system?
  • What is the best treatment in advanced Parkinson’s disease?
  • Are most cryptogenic epilepsies immune mediated?
  • Should epilepsy be diagnosed after the first unprovoked seizure?
  • Do anti-epileptic drugs (AEDs) contribute to suicide risk?
  • Should the ketogenic diet be prescribed in adults with epilepsy?
  • Do patients with idiopathic generalized epilepsies require lifelong treatment?
  • Cryptogenic stroke: Immediate anticoagulation or long-term ECG recording?
Southern Chivalry: Argument Vs Clubs. elycefeliz on Flikr. https://www.flickr.com/photos/elycefeliz/6271932825
Southern Chivalry: Argument Vs Clubs. elycefeliz on Flikr. https://www.flickr.com/photos/elycefeliz/6271932825

 

9th CONy 2015 (Budapest, Hungary)

  • Is discontinuation of disease-modifying therapies safe in  long-term stable multiple sclerosis?
  • Is behavioral therapy necessary for the treatment of migraine?
  • Which is the first-line therapy in cases of IIH with bilateral papilledema?
  • Should patients with unruptured arterio-venous malformations (AVM) be referred for intervention?
  • Should survivors of hemorrhagic strokes be restarted on oral anticoagulants?
  • Will stem cell therapy become important in stroke rehabilitation?
  • Do statins cause cognitive impairment?

 

10th CONy 2016 (Lisbon, Portugal)

  • Which should be the first-line therapy for CIDP? Steroids vs. IVIg
  • Should disease-modifying treatment be changed if only imaging findings worsen in multiple sclerosis?
  • Should disease-modifying therapies be stopped when secondary progressive MS develops?
  • Should non-convulsive status epilepsy be treated aggressively?
  • Does traumatic chronic encephalopathy (CTE) exist?
  • Does corticobasal degeneration (CBD) exist as a clinico-pathological entity?
  • Is ß-amyloid still a relevant target in AD therapy?
  • Will electrical stimulation replace medications for the treatment of cluster headache?
  • Carotid dissection: Should anticoagulants be used?
  • Is the ABCD2 grading useful for clinical management of TIA patients?
  • Do COMT inhibitors have a future in treatment of Parkinson’s disease?

 

Debate Energetico. Jumanji Solar on Flikr. https://www.flickr.com/photos/jumanjisolar/5371921203
Debate Energetico. Jumanji Solar on Flikr. https://www.flickr.com/photos/jumanjisolar/5371921203

 

Going through this list, I feel reassured that the experts differ in their answers to these questions? The acknowledgement of uncertainty allows us novices to avoid searching for non-existent black and white answers. It is however also unsettling that I thought some of these questions had been settled long ago. It goes to show that apparently established assumptions are not unshakable?

Do you have the definitive answers to resolve these controversies? Are there important controversies that are missing here? Please leave a comment

 

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

 

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