Can Aromatase Inhibitors and/or Surgery Relieve Endometriosis in Women?

Feature Image of artistic depiction of female pelvic area in pain due to endometriosis sourced from:

https://theheartysoul.com/endometriosis-heart-disease-risk/

Dear Pain Matters readers,

JESSICA HIRST, ENDOMETRIOSIS SUFFERER FOR 17 YEARS, WIFE AND MOTHER

Hearing about women like Jessica Hirst inspired me to write this blog post today:

Jessica Hirst (28), a mother of a baby boy, has endured severe pelvic pain due to aggressive endometriosis since she was 11 when her periods started.

Jessica and her family

Source: https://www.mamamia.com.au/endometriosis-stories/

Quoting Jessica:

‘It feels like someone is stabbing me repeatedly in the abdomen.  I get a constant burning pain.  There’s an aching that starts in my lower back and comes right down through my legs … it feels like there’s a bowling ball in my uterus.’

Unable to work due to pain, Jessica relies on her husband as her full-time carer.  Despite her excruciating pelvic pain, Jessica finds joy and happiness in their 18-month old baby boy.  Jess is urgently in need of treatment.

Source:  ‘It’s like someone’s stabbing me in the abdomen.’ – Jessica has been in pain since she was 11 (by Gemma Bath, 18 April 2019).

https://www.mamamia.com.au/endometriosis-stories/

OVERVIEW

Endometriosis is a painful disorder that affects up to 10% of all women of child-bearing age.  This includes approximately 1.5 million women in the UK and 176 million women worldwide.

Furthermore, 71% to 87% of all women with chronic pelvic pain plus 38% of all infertile women have endometriosis.

Endometriosis occurs when the tissue similar to the lining inside the uterus (i.e. endometrium) grows outside of the uterus.  This tissue may be found on the ovaries, fallopian tubes, tissue lining the pelvis (i.e. pelvic peritoneum), ureter, bladder, bowel and recto-vaginal septum.  It has even been found in the lungs and diaphragm in rare instances.

Endometriosis can cause severe pelvic pain during periods, ovulation and/or sex.  Heavy and/or irregular menstrual cycles, infertility, low energy levels, poor sleep and fatigue result.  Symptoms vary depending on where the rogue endometrium grows.  This can affect the women’s overall health and well-being (Amsterdam et al, 2005).

DIAGNOSIS AND TREATMENT OPTIONS

Diagnosis

Women often suffer years of pain before they are finally diagnosed with endometriosis.  It takes 7.5 years on average before endometriosis is diagnosed.  This is because the pain and other symptoms are all-too-often dismissed as ‘normal’ and ‘not serious’.

Endometriosis is diagnosed via biopsy obtained during diagnostic laparoscopy.  This involves keyhole surgery under general anaesthetic.

Treatment Options

Endometriosis is said to be incurable (Howarth, 2019) …

… but is this always true??  Read on…

Several treatments exist that may offer relief from pelvic pain due to endometriosis:

• Oral contraceptives;*
• Aromatase inhibitors (e.g. letrozole, anastrazole); and
• Surgery (excision) to remove endometrial tissue that grows outside of the uterus.

Whilst excision of endometriosis may offer pain relief in some women, multiple surgeries may be required.  Furthermore, there is a risk of recurrence.  Finally, surgery is more invasive than treatment involving aromatase inhibitors.

Studies suggest that aromatase inhibitors (e.g. letrozole; anastrazole) may reduce masses hence leading to relief from pelvic pain due to endometriosis.

Aromatase inhibitors have been used to treat postmenopausal breast cancer patients for over 10 years.

SUCCESSFUL STUDIES AND CASES INVOLVING AROMATASE INHIBITORS FOR PELVIC PAIN AND ENDOMETRIOSIS

(1) An American Study (N=10) Involving Aromatase Inhibitors (Letrozole)

An American study found that aromatase inhibitors (letrozole) significantly reduced pelvic pain due to endometriosis in 9 of 10 patients.

Ten (10) premenopausal patients with endometriosis who had undergone surgical and medical treatment were selected for this study.

Endometriosis was confirmed via biopsy obtained during diagnostic laparoscopy.

Oral treatment of letrozole, together with norethindrone acetate, calcium citrate (to minimize bone loss) and vitamin D (to strengthen bones), was offered daily for 6 months.

Second-look laparoscopy was done following letrozole treatment for 6 months.

The good news:

This 2nd biopsy showed nil endometriosis in all 10 patients.  Nada!  

Furthermore, pelvic pain due to endometriosis was significantly reduced in 9 out of 10 patients following letrozole treatment for 6 months.  Bone density appeared unaffected.

In conclusion, letrozole may offer effective treatment for endometriosis (Ailawadi et al, 2004).

(2) A 2nd American Study (N=15) Involving Aromatase Inhibitors (Anastrazole)

A 2nd American study led by the same doctor revealed that another aromatase inhibitor called anastrazole also decreased pelvic pain due to endometriosis.

Fifteen (15) premenopausal patients with endometriosis and pelvic pain were selected for this study.   

Oral treatment of anastrazole and oral contraceptive was offered daily for 6 months.  Anastrazole treatment led to suppression of estradiol levels.

The good news:

Fourteen of 15 endometriosis patients obtained significant pain relief following 6 months of anastrazole treatment.  Specifically, median pain levels were reduced by 55% while mean pain scores were decreased by 40%.

In conclusion, anastrazole may offer effective treatment for endometriosis (Amsterdam et al, 2005).

 

(3) A Young Italian Woman with Endometriosis Finally Found Relief from Severe Pelvic Pain Thanks to Letrozole (After Ovariectomy Failed to Offer Pain Relief)

A young Italian woman named ‘Maria’ (not her real name) with aggressive endometriosis finally found relief from severe pelvic pain thanks to daily oral aromatase inhibitor (letrozole) treatment for 9 months.

Maria had initially undergone a subtotal hysterectomy as well as removal of both ovaries in an unsuccessful bid to reduce pelvic pain.

Following 3 months of daily oral letrozole treatment, Maria’s pelvic pain including pain during sex was significantly reduced.  Her pelvic ultrasound showed nil endometrial tissue in the pelvis.  Maria’s bone density remained unchanged thanks to daily calcium and Vitamin D supplements.

Given these encouraging results, treatment was continued for another 6 months.

In summary, daily oral aromatase inhibitor (letrozole) treatment may relieve severe pain in young women with endometriosis (Razzi et al, 2004).

(4) The First Woman to be Successfully Treated for Endometriosis via an Aromatase Inhibitor (Anastrozole)

An American woman (57) named ‘Jane’ (not her real name) with aggressive postmenopausal endometriosis finally found relief from severe pelvic pain thanks to daily oral aromatase inhibitor (anastrozole) treatment for 9 months.

Jane had previously undergone a hysterectomy as well as removal of her ovaries and fallopian tubes.

Guess what happened next?

Jane’s pelvic pain completely vanished after 2 months of daily oral anastrozole treatment!

Furthermore, a large 30mm X 30mm X 20mm bright red vaginal lesion had reduced to a mere 3mm gray tissue after 9-month anastrozole treatment.

Bone density was however decreased by 6.2% following 9 months of aromatase inhibitor treatment.

Aromatase inhibitors may offer benefits including pain relief and substantial eradication of endometrial tissue (Takayama et al, 1998). 

(5) Two Sisters Successfully Treated for Severe Endometriosis via an Aromatase Inhibitor (Anastrozole)

Two sisters, aged 24 and 26, had undergone several minimally invasive surgeries (i.e. laparoscopies) that, unfortunately, failed to alleviate severe pelvic pain due to aggressive endometriosis.

Both women received oral aromatase inhibitors (anastrozole), oral contraceptives (for birth control), calcitriol (to minimise bone loss) and rofecoxib (for pain control) on a daily basis for 21 days followed by 7 days off (i.e. a cycle).  Six cycles were offered over 6 months.

Within only 3 months, pelvic pain and other symptoms of endometriosis were eliminated in both sisters.  These positive effects lasted over a year, post-treatment.  

There was nil evidence of endometriosis disease in one of the 2 sisters, as confirmed via laparoscopy done 15 months after treatment.

Bone densities remained normal in both sisters after treatment (Shippen & West, 2004).

(6) A Woman (55) Successfully Treated for Endometriosis via an Aromatase Inhibitor (Letrozole)

‘Joan’ (55) in Belgium (not her real name) underwent a total abdominal hysterectomy 10 years earlier.

Recently, Joan had right-sided sciatic pain that radiated down her right leg due to recurring endometriosis.  

A pelvic ultrasound confirmed an endometrial mass that compressed against her lumbo-sacral plexus.  This mass was 4cm X 8cm in size.   

A daily oral aromatase inhibitor (letrozole) was offered to treat this large mass.

After 12 months of letrozole treatment, Joan no longer had sciatic pain. Following 18 months of treatment, Joan’s mass had shrunk to only 1cm in size.  

Due to a successful outcome, oral letrozole was stopped after 21 months.

Recurring endometriosis may successfully be treated via an aromatase inhibitor (letrozole).  This is a less invasive treatment option than surgery (Fatemi, 2005).

THE SCIENCE BEHIND ENDOMETRIOSIS AND AROMATASE INHIBITORS

An enzyme called aromatase is important in oestrogen production.  This enzyme is absent in normal endometrium in the uterus.

However, this enzyme is aggressively produced in endometriosis, an oestrogen-dependent disease.  Increased aromatase activity leads to high estradiol levels in endometriosis.

Being potent oestrogen blockers, aromatase inhibitors ‘starve’ endometrial tissue of oestrogen.  This leads to shrinkage, and in some cases, complete elimination of endometriosis.

Thus, in the presence of aromatase inhibitors (that block oestrogen production), endometriosis may shrink, and even vanish altogether, during daily letrozole or anastrazole treatment for a certain period of time.

Aromatase inhibitors exert their anti-oestrogen effects on ovaries and on endometrial tissue growing outside of the uterus (Bulun et al, 2001; Ailawadi et al, 2004; Bulun et al, 2004; Amsterdam et al, 2005; Fatemi, 2005).

SUMMARY

In addition to oral contraceptives* and excision, aromatase inhibitors (e.g. letrozole, anastrazole) may offer effective treatment for endometriosis (Ailawadi et al, 2004; Amsterdam et al, 2005; Hofmann-Werther)

Isn’t this exciting?

If you know someone with endometriosis, please forward this blog post to her.

 

Wishing all pain patients inspiration, hope and empowerment,

Sabina Walker

PS From a patient’s perspective, Gabrielle Jackson’ book called Pain and Prejudice offers enormous insight into endometriosis (Jackson, 2019).

 

 

Sabina Walker, Masters Appl. Science (Neuroscience)

Blogger of Pain Matters (in WordPress)

painmatters.wordpress.com

and

Author of soon-to-be published book called Pain Matters 

Twitter

@SabinaWalker18

REFERENCES

MEDIA

(1) Howarth, Angus. Lack of cash hinders research into condition affecting 10% of women. The Scotsman (8 April 2019).

https://www.scotsman.com/news-2-15012/lack-of-cash-hinders-research-into-condition-affecting-10-of-women-1-4903496

(2) Facts about endometriosis.

http://endometriosis.org/resources/articles/facts-about-endometriosis/

(3) Bulun, Serdar & Wood, Ros. Aromatase in endometriosis.  

http://endometriosis.org/resources/articles/aromatase/

* (4) Endometriosis in adolescence. Women’s Health Queensland

https://womhealth.org.au/conditions-and-treatments/endometriosis-adolescence

(5) Hofmann-Werther, Amelie. Chronic pelvic pain and endometriosis. Middle East Medical.

https://www.middleeastmedicalportal.com/chronic-pelvic-pain-and-endometriosis/

BOOK

(1) Jackson, Gabrielle. Pain and Prejudice – A Call to Arms for Women and their Bodies. Allen & Unwin (2019).

ISBN 978 1 76052 909 3

https://www.allenandunwin.com/browse/books/general-books/health-fitness/Pain-and-Prejudice-Gabrielle-Jackson-9781760529093

PEER-REVIEWED PAPERS

 (1a) Amsterdam et al. Anastrazole and oral contraceptives: a novel treatment for endometriosis. Fertility and Sterility (Aug 2005); 84(2), 300–304.

doi: https://doi.org/10.1016/j.fertnstert.2005.02.018

https://www.fertstert.org/article/S0015-0282(05)00859-9/fulltext

(1b) Ailawadi et al. Treatment of endometriosis and chronic pelvic pain with letrozole and norethindrone acetate: a pilot study. Fertility and Sterility (Feb 2004); 81(2): 290–296.

doi: https://doi.org/10.1016/j.fertnstert.2003.09.029

https://www.fertstert.org/article/S0015-0282(03)02874-7/fulltext

(1c) Bulun et al. Aromatase and endometriosis. Semin Reprod Med (Feb 2004); 22(1): 45-50.

https://www.ncbi.nlm.nih.gov/pubmed/15083380

(1d) Takayama, K, Zeitoun, K, Gunby, RT, Sasano, H, Carr, BR, Bulun, SE. Treatment of severe postmenopausal endometriosis with an aromatase inhibitor. Fertil Steril (1998); 69: 709– 713.

https://www.ncbi.nlm.nih.gov/pubmed/9548162?dopt=Abstract

(1e) Bulun et al. Role of aromatase in endometrial disease. J Steroid Biochem Mol Biol (Dec 2001); 79(1-5): 19-25.

https://www.ncbi.nlm.nih.gov/pubmed/11850203

(2) Razzi et al. Treatment of severe recurrent endometriosis with an aromatase inhibitor in a young ovariectomised woman. BJOG (Feb 2004); 111(2): 182-184.

https://doi.org/10.1046/j.1471-0528.2003.00038.x

https://obgyn.onlinelibrary.wiley.com/doi/full/10.1046/j.1471-0528.2003.00038.x

(3) Shippen & West. Successful treatment of severe endometriosis in two premenopausal women with an aromatase inhibitor. Fertil Steril (May 2004); 81(5): 1395-8.

https://www.fertstert.org/article/S0015-0282(04)00147-5/fulltext

(4) Fatemi, Human Mousavi. Successful treatment of an aggressive recurrent post-menopausal endometriosis with an aromatase inhibitor. RBM Online (2005); 11(4): 455-457. 

https://www.rbmojournal.com/article/S1472-6483(10)61140-6/pdf

SUPPORT GROUP FOR ENDOMETRIOSIS PATIENTS

There are many support groups including:

(1A) Endometriosis – Perth Sisterhood of Support.

https://www.endoperthsisters.com

Above support group is run by endometriosis sufferers, Joanne McCormick and Monique Alva (see below story).

(1B) Hedley, Kate. ‘The bad days are shocking’: Fresh hope for endometriosis sufferers. WA Today (15 Dec 2017).

https://www.watoday.com.au/national/western-australia/the-bad-days-are-shocking-fresh-hope-for-endometriosis-sufferers-20171214-h04szx.html

 

 

 

A Doctor and a Nurse who can Literally Feel Pain in Other People

Feature Image of Dr Joel Salinas sourced from:

https://nypost.com/2017/04/18/this-doctor-can-really-feel-your-pain/

Dear Pain Matters readers,

Overview

Most doctors and nurses have great empathy and compassion for their pain patients.

Dr Joel Salinas and Megan Pohlmann, a nurse, take empathy to a new level.  They literally feel pain, physical sensations and emotions in patients.  They have heightened empathy for others that may also be viewed as ’empathy on steroids’, ’empathy in overdrive’ or ‘ultimate empathy’.

Dr Joel Salinas and Megan Pohlmann have mirror touch synesthesia.  This is when a person can perceive someone else’s pain or tactile sensation.

For some mirror touch synesthetes, this can be a curse rather than a blessing.  These people may require long periods alone after being exposed to other people’s pain and emotions.  They may even become recluses in their own homes for fear of ‘sensory overload’.

Others including Dr Joel Salinas and Megan Pohlmann embrace their mirror touch synesthesia as a special gift to help others.  These people apply their unique neurological trait in their work and personal life, when appropriate. 

Joel Salinas, Neurologist

Joel Salinas (34) is a neurologist, writer, researcher and Assistant Professor of Neurology at Harvard Medical School.  As stated, he can feel pain, physical touch and emotions in other people.  This ‘mirrored touch’ ability is automatically triggered by sight.  For example, when he sees someone’s right arm being touched, he feels a touch on his left hand, like in a mirror.  

In Dr Salinas’ words:

‘[Having mirror touch synesthesia] blurs this boundary between the self and the other’ (Kalter, 2017).

‘[Mirror touch synesthesia] is as close as I can get to literally putting myself ‘in the other person’s shoes” (Salinas, 2017).

‘… Like I’m the reflection … It’s really like I’m a reflection … Mirror touch is … like an automatic, very physical, super empathy …’ (quoted from video, below).

For more insights into Dr Salinas’ ‘super power’, see his TED Talk dated 18 May 2018:

 

Two interviews with Dr Salinas are also available:

1. What It’s Like to Have Mirror Touch Synesthesia (a 4-minute interview dated 13 Dec 2018) (https://www.thecut.com/2018/12/what-its-like-to-have-mirror-touch-synesthesia.html); and
2. Mirror Touch: Rare condition means Dr Joel Salinas feels what others feel (a 7-minute interview by Boston 25 News dated 25 May 2017) (https://www.youtube.com/watch?v=xDj5Xoi8upQ).

Finally, Dr Salinas is the author of a fascinating book called Mirror Touch: Notes from a Doctor Who Can Feel Your Pain. 

Megan Pohlmann, Nurse

As noted, Megan Pohlmann is a paediatric nurse who has mirror touch synesthesia.  This trait often enables her to feel other people’s emotions, pain and other sensations as her own. In her words,

‘If someone’s hurting, for instance, if they have a cut on their arm … when I visualise the injury, I’ll get a feeling on my spine that’s kind of similar to being on a roller coaster.  It’s that gut-dropping feeling … the electricity … shoots up my spine and out my arms and my extremities.’

See 7-minute interview called ‘Meet the nurse who feels other people’s pain – literally’.

https://www.today.com/video/meet-the-nurse-who-feels-other-people-s-pain-literally-1207330371665

Please note that Dr Salinas is also featured in this interview, together with Megan Pohlmann.

The Science of Mirror Touch Synesthesia

A study revealed that 45 of 2,351 (2%) psychology students had mirror touch synesthesia (Medina & DePasquale, 2017; University of Delaware, 2017).

Mirror neurons are said to underlie mirror touch synesthesia (Linkovski et al, 2017).

Prof Ramachandran, a respected neuroscientist, nicknamed these mirror neurons ‘Gandhi neurons’or ’empathy neurons’.  In his words:

‘… You are, in fact, connected not just via Facebook and Internet.  You’re actually quite literally connected by your neurons.  And there [are] whole chains of neurons around this room, talking to each other.  And there is no real distinctiveness of your consciousness from somebody else’s consciousness.’ 

See TEDIndia by Prof Ramachandran called The neurons that shaped civilization (2009; a 7-minute video):

 

A question:

As noted, Dr Salinas’ ‘mirrored touch’ ability is automatically triggered by sight.  For example, when he sees someone’s right arm being touched, he also feels a touch on his own left hand – just like in a mirror.

Could Dr Salina’s experience with mirror touch synesthesia offer certain insight into why mirror therapy may offer relief from phantom limb pain in many amputees? 

See my 4 blog posts for further details on mirror therapy including:

Mirror Therapy for Relief from Phantom Limb Pain Inspired By Professor Ramachandran

Summary

This world is lucky to have many doctors, nurses and other medical clinicians who show empathy and compassion for their patients.

The fact that some doctors and nurses can literally feel their patients’ pain may be one of the highest levels of empathy.

References 

Articles and Book 

Joel Salinas, Neurologist

Articles  

(1A)  Love, Shayla. The Anatomy of Empathy. Vice (8 May 2019).

https://www.vice.com/en_us/article/5973jq/joel-salinas-feels-patients-pain-mirror-touch-synesthesia

(1B) Salinas, Joel. I’m a doctor with a rare neurological condition: I can literally feel your pain. Quartz (30 April 2017).

https://qz.com/969246/mirror-touch-synethesia-doctor-who-can-literally-feel-your-pain/

(1C) Carlton, Lindsay. A doctor who can feel his patient’s pain. Fox News (26 Apr 2018).

https://www.foxnews.com/health/a-doctor-who-can-feel-his-patients-pain

This article includes a 7-minute interview with Dr Joel Salinas:

Mirror-touch synesthesia: A doctor who can feel his patient’s pain

(1D) Ridley, Jane. This doctor can really feel your pain. New York Post (18 April 2017).

https://nypost.com/2017/04/18/this-doctor-can-really-feel-your-pain/

(1E) Angley, Natalie. This doctor can feel your pain. CNN (16 June 2017).

https://edition.cnn.com/2017/06/16/health/turning-points-dr-joel-salinas/index.html

(1F) Kalter, Lindsay: This doc can feel your pain. Boston Herald (3 May 2017).

https://www.bostonherald.com/2017/05/03/kalter-this-doc-can-feel-your-pain/

(1G) Salinas, Joel & Lee, Samantha. What It’s Like to Have Mirror Touch Synesthesia. The Cut (13 Dec 2018).

(a 4-minute interview with Dr Joel Salinas dated 13 Dec 2018)

https://www.thecut.com/2018/12/what-its-like-to-have-mirror-touch-synesthesia.html

(1H) Mirror Touch: Rare condition means Dr Joel Salinas feels what others feel

(a 7-minute interview with Dr Joel Salinas by Boston 25 News dated 25 May 2017)

https://www.youtube.com/watch?v=xDj5Xoi8upQ

A Book by Dr Joel Salinas

(1I) Salinas, Joel. Mirror Touch: Notes from a Doctor Who Can Feel Your Pain. HarperOne (18 Apr 2017); 320 pages.

ISBN-10 0062458663

ISBN-13 978-0062458667

ISBN 0062458663

Megan Pohlmann, Nurse

Articles  

(1A) Kelly, Megyn. Meet the nurse who feels other people’s pain – literally. Today (11 April 2018).

https://www.today.com/video/meet-the-nurse-who-feels-other-people-s-pain-literally-1207330371665

(1B) Seaberg, Maureen. Meet the Nurse Whose Superpower Is Feeling Your Pain—Literally. Glamour (1 Mar 2018).

https://www.glamour.com/story/meet-the-nurse-whose-superpower-is-synesthesia

(1C) Nuñez, Gabriella. People You Should Know: Megan Pohlmann and her world of many colors. krcgtv (14 May 2018).

https://krcgtv.com/news/people-you-should-know/people-you-should-know-megan-pohlmann-and-her-world-of-many-colors

Peer-Reviewed Papers

(1A) Linkovski et al.   2017). Mirror Neurons and Mirror-Touch Synesthesia. Neuroscientist (April 2017); 23(2): 103-108.

doi: 10.1177/1073858416652079

https://www.ncbi.nlm.nih.gov/pubmed/27242280

(2A) University of Delaware. ‘I feel for you: Some really do: Researchers examine unusual condition of mirror-touch synesthesia.’ ScienceDaily (6 Feb 2017).

https://www.sciencedaily.com/releases/2017/02/170206130346.htm

(2B) Medina J & DePasquale C. Influence of the body schema on mirror-touch synesthesia. Cortex (2017);  88: 53.

doi: 10.1016/j.cortex.2016.12.013

https://www.sciencedirect.com/science/article/pii/S0010945216303586?via%3Dihub

The Gall of Gallstones to Cause Pain

Feature Image sourced from:

https://consultqd.clevelandclinic.org/gallstones-watch-and-wait-or-intervene/

Dear Pain Matters readers,

INTRODUCTION

You may have heard a friend or family member say that they have an intense pain in their chest, upper right or mid abdominal area, just below their breastbone.  Alternatively, they may feel pain in their back, right shoulder blade or in between their shoulder blades.  They may feel sweaty, nauseous and an urge to vomit.  They may have to lie down due to pain, especially after a rich and fatty meal.

Patients may not understand why this is happening to them.  Could it be back pain, indigestion, ulcers or irritable bowel syndrome (IBS)?  Or are they simply over-reacting to a spicy meal?

What they do know though is that their pain is severe and repetitive.  This pain may last anywhere from a few minutes to several hours.

Here’s a thought:

Could gallstones* be responsible for the pain?  If yes, then the severe pain attacks will likely persist until properly treated.  Imaging via ultrasound, CT and/or MRI is necessary to rule out the possibility of gallstones that may otherwise lead to a blockage in a duct or gallbladder inflammation (cholecystitis).

If present, gallstones (and gallstone pain attacks) usually do not go away on their own.  Surgery to remove the gallbladder may be necessary.  Alternatively, if only 2-3 gallstones are present, shock wave treatment plus medication may offer relief from pain (although there is a risk of recurring gallstones) (more later).

TWO PATIENT STORIES

Denise Fernholz, Germany 

Denise Fernholz, an editor in Germany, had severe pain attacks for 4 long years. Despite exclusively seeing her family doctor for 4 years, her symptoms were never taken seriously nor was any ultrasound test ordered.  As such, Denise had no idea that excess gallstones were the cause of her excruciating pain.

Denise first felt an intense pain emanating from her breast area when she was 17.  She attributed this pain to her tight-fitting bra.  However, her pain only became worse after she removed her bra.  Panicking, she thought she was having a heart attack.  She felt better after laying down for an hour or so.

After her doctor ruled out any cardiac issues, it was thought that she may have done something to her back.  Unconvinced, Denise hoped for the best anyway.

However, the severe pain attacks kept returning.  Her pain attacks were so unbearable that they rendered her bedridden during these episodes.  Denise felt like she was going to die.  Her parents always wanted to call an ambulance but Denise resisted.  By now, Denise was convinced that she was ‘only suffering from back pain’.  She was worried about being ridiculed by paramedics for ‘calling an ambulance for back pain only’.

Instead, Denise continued to see her family doctor who regularly performed his manual adjustments.

One day, Denise had an MRI that, sadly, did not elucidate the cause of her pain.

As such, Denise was told that ‘her pain was likely psychosomatic’.  She was asked if she had a lot of stress in her life.  Alternatively, ‘did she do drugs?’  Her answer, ‘No.’  Denise was then asked, ‘Are you sure?’  Her answer, ‘Yes, damn it, I am sure!’  Denise added, ‘Can you please prescribe something stronger for my pain?’  

Denise thought that it seemed rather convenient to simply attribute pain as being psychological in origin if a doctor can not find anything wrong with a patient.

Nothing was offered other than Ibuprofen.  Denise felt that no one was taking her pain seriously.  Her doctors simply did not believe her.  

By now, Denise was in her early 20’s.

Denise’s pain attacks would often occur on special days such as birthdays or while away with her girlfriends.  After pizza, Denise would have to lie down in pain.  Then she’d go to the toilet to vomit.  Her concerned friends were tempted to call an ambulance.  However, by now, Denise had become accustomed to her pain attacks.  

Because she’d been told countless times that ‘her pain was due to back tension’, that she was otherwise healthy, that she was ‘merely imagining her pain’ and that ‘her brain was simply fabricating pain to avoid having fun’, Denise even started believing these so-called ‘reasons’ for her pain.

It was much later when Denise finally made a connection between pizza and pain.  

Until then, Denise’s doctor had prescribed gymnastics and sent her to an orthopedist.  Denise was urged to do more sport and given new insoles for her shoes.  She even bought a new mattress for her bed.

Guess what??  None of this helped with her pain attacks!  

Four (4) years went by.

At times, Denise was pain free for a month.  At other times, her pain attacks would occur several times in a week.  However, not once did Denise call an ambulance.

One day, Denise moved to another country to study.  She regularly returned home to visit her parents.  While home, she always returned to her trusted doctor for ongoing pain treatment.  Denise did not want to seek an alternative opinion from a new doctor or hospital for ostensibly back pain in a foreign country where she studied. After all, Denise had no reason to doubt her doctor’s opinion that she had back pain.

The turning point:

Despite being sceptical of alternative medicine, Denise was finally convinced by her friends to see an osteopath.  She felt strange when the osteopath placed his hands on her body.

Denise noted however that the osteopath was the first person to take time to do a proper medical history.  Denise told him about her pain, the vomiting and her doctor’s ‘diagnosis’.

Thereafter, the osteopath was quick to conclude that Denise’s pain did not come from her back, but rather, from her organs.     

During her next visit to her doctor, Denise insisted that he check her organs.

Then came the moment of truth!  An ultrasound clearly showed that Denise’s gallbladder was chockablock full of very small gallstones!  

Diagnosis:  Biliary colic, aka gallbladder attack or gallstone attack.

Because her gallbladder was full of very small gallstones, Denise would feel excruciating pain every time a gallstone would exit her gallbladder and force its way through the bile duct.*  Generally, this would occur after a fatty meal (e.g. pizza).  

Denise’s doctor thought that her newly-revised diagnosis was rather strange given that she was young and not overweight.

Denise, on the other hand, was ecstatic to have finally received a proper diagnosis after 4 long years of suffering due to pain attacks!  FINALLY, A CORRECT DIAGNOSIS!  YIPPEE!

Treatment:  Gallbladder removal surgery

While in hospital during her gallbladder removal operation, everyone was surprised by her gallstone story.  After all, even young, slim women and children routinely presented with gallstones these days.  Furthermore, gallstones were usually easy to diagnose via ultrasonography.

Denise was merely grateful that her gallstones were finally being removed forever.

The good news:

After 4 long years of sporadic and intense pain for ostensibly back pain, Denise finally received a correct diagnosis.  Shortly after, she underwent effective treatment involving surgical removal of her gallbladder.  This led to complete relief from pain (Fernholz, 2018).

Fiona Tapp, a British Freelance Writer and Educator based in the US 

Fiona Trapp first became aware of an intense pain in her breastbone after ordering a huge amount of Chinese food one day.  Thinking that her pain was due to eating too much, she went to lie down in the hopes that her pain would pass.  Instead, her pain got worse as it spread from her chest into her stomach and back.  Fiona felt as if an iron bar had impaled her from the front of her ribs and straight through her back.  Her then-boyfriend (now-husband) tried his best to help by massaging her in between her shoulder blade area.

While enduring excruciating pain for a few hours, Fiona thought that she was having a heart attack.  Fiona’s pain finally went away after vomiting and she fell into a deep slumber.

Sadly, this was not the last of her pain attacks.  Instead, these pain attacks arose at least once every 2 weeks over the next 5 years.  Her severe pain attacks in her chest, stomach and back would wake her up in the middle of the night.  As she cried out in pain, her partner would also be awakened.

Tragically, Fiona went from one misdiagnosis to another.

Fiona’s general practitioner (GP) first suggested that she keep a food diary to help identify any food allergies.  However, her pain attacks would persist regardless whether she drank water or indulged in junk food.

When her friends and family suggested that she might have an ulcer, Fiona returned to her GP.  However, after saying it was ‘just indigestion’, he prescribed antacids (which, of course, did nothing for her pain).

Fiona decided to get a second, and even a third, opinion.  Her third doctor prescribed esomeprazole pills daily for stomach acid.  Of course, these pills also did nothing for her pain attacks.

Upon returning to her GP, Fiona discovered that a new doctor was available to see her instead.  This doctor was energetic, empathetic and cheerful.  Moreover, after reviewing her history and doing some checks, he suggested that there may be more going on than ‘just indigestion’.  He then arranged for Fiona to do some blood tests and an ultrasound.

Guess what happened next?  You guessed it!  Finally, Fiona received a proper diagnosis after 5 long years of pain attacks and vomiting!  Whew!  

Fiona was finally diagnosed with ‘a lot of gallstones’ in her gallbladder, an organ next to her liver that holds bile until it is released to help digest food.*  These gallstones were blocking her bile duct as well as causing pain attacks and vomiting episodes.

Gallbladder removal surgery was recommended.

After awakening from surgery to remove her gallbladder, her surgeon said that her gallbladder was FULL of gallstones.  He had never seen so many gallstones in his entire life!  He also added that he was sympathetic for all the pain that she had endured over 5 years.

Fiona was simply grateful that a correct diagnosis was finally made and that gallbladder removal surgery was done.  Finally, her severe pain attacks ended after 5 long years! 

Please see Fiona Tapp’s inspiring story for more details and advice:  

https://www.healthline.com/health/i-lived-in-hell-for-5-years-due-to-a-misdiagnosis#5

(Tapp, 2017; Stinton & Shaffer, 2012).    

DIAGNOSIS AND TREATMENTS FOR GALLSTONES

Overview

Gallstones are not rare.  They can affect both young and healthy people as well as the young-at-heart.  Between 10% to 15% of adults in developed societies have, or will have, gallstones including 25 million Americans.

Despite being common, gallstones are sometimes mistaken for back pain, food allergies, ulcers, indigestion, excess stomach acid and even irritable bowel syndrome (IBS).

Diagnosis

Ultrasonography is done to diagnose gallstones.  Other imaging techniques (e.g. CT, MRI) may also be useful.

Two Treatment Options

(1) Gallbladder Removal Surgery (Cholecystectomy)

Treatment usually involves gallbladder removal surgery (cholecystectomy).

Risk of Ongoing Pain Despite Surgery in Some Patients

After gallbladder removal surgery, some patients may still suffer from ongoing pain.  As such, the risk of a poor outcome following surgery needs to be discussed with patients prior to surgery (Dijk et al, 2019; Guest & Søreide, 2019; Rapaport, 2019).

(2) Extracorporeal Shock Wave Lithotripsy (ESWL)

Alternatively, extracorporeal shock wave lithotripsy (ESWL) may be offered if there are only a few gallstones (i.e. no more than 3).  This treatment involves generating sound waves (shock waves) from outside of the body.  Produced by a machine called a lithotripter, these shock waves are aimed directly at the gallstones until they shatter.  Medication is usually necessary to dissolve the remaining shattered fragments.

While shock waves shatter gallstones, they are not harmful to muscle, bone or skin.

Risk of Recurrent Gallstones

Despite ESWL being less invasive than gallbladder removal surgery, there is a risk of recurrent gallstones (mydr; Barhum, 2018).

SUMMARY

What lessons can be learned here?

According to Denise Fernolz, if a diagnosis and treatment(s) are not effective, please urgently seek a second medical opinion.  Importantly, always trust your own instincts and feelings (Fernholz, 2018).

According to Fiona Tapp, if your gut feeling tells you that there is something wrong with your body, please persist in trying to get to the bottom of this. Please don’t ever give up.  

Most doctors do want to help their patients get better.  However, sometimes it is up to the patients to also insist on getting further tests done right from the start.   

Patients have to learn to become better advocates for their own health.  They have to learn to become more assertive and take responsibility for their well-being.  After all, they know their own bodies better than anyone else does.   

Patients should never feel as if they are wasting their doctors’ time.  After all, that is what the doctors are there for – to help diagnose medical problems.

Patients and doctors need to work together as a team to properly diagnose medical problems including the cause(s) for any pain.  A patient-doctor team approach will lead to more effective and timely treatments as well as better results and outcomes.

If necessary, patients may need to pursue a 2nd, 3rd or even 4th medical opinion (as Fiona did).  

I hope these 2 stories inspire.

KEY

* Gallstones (aka cholelithiasis) are solid masses, or crystals, of cholesterol or pigment that sometimes form in the gallbladder.  Gallstones may be as small as a grain of sand or as big as a golf ball.  While gallstones are asymptomatic in some people, they may cause excruciating pain in others.

Bile is a yellow-green digestive fluid made in the liver and stored in the gallbladder.  During digestion, bile is released into the bile duct and upper part of the small intestine to help break down the fat in food.

 

REFERENCES

MEDIA

(1) Tapp, Fiona. I Lived in Hell for 5 Years Due to a Misdiagnosis. Healthline (9 June 2017).

https://www.healthline.com/health/i-lived-in-hell-for-5-years-due-to-a-misdiagnosis#1 

(2) Gallstones: Treatment.

https://www.mydr.com.au/gastrointestinal-health/gallstones-treatment

(3) KevinMD (15 March 2005).

https://www.kevinmd.com/blog/2005/03/malpractice-trial-where-physician.html

(4) Rapaport, Lisa. Gallbladders may be removed too often. Reuters (10 May 2019).

https://www.reuters.com/article/us-health-gallstones-surgery/gallbladders-may-be-removed-too-often-idUSKCN1SF28F?feedType=RSS&feedName=healthNews

MEDIA (In German)

(1) Fernholz, Denise. Vier Jahre Schmerzen – Weil ich meinem Arzt vertraute. Protokoll einer Fehldiagnose – Angeblich nur Rückenprobleme. Stern (20 April 2018).

https://www.stern.de/neon/herz/psyche-gesundheit/fehldiagnose–vier-jahre-schmerzen–weil-ich-meinem-arzt-vertraute-7950602.html

PEER-REVIEWED SCIENCE PAPERS AND ARTICLES

(1) Gallstones. Mayo Clinic.

https://www.mayoclinic.org/diseases-conditions/gallstones/diagnosis-treatment/drc-20354220

(2) Fletcher, Jenna. What are the most common gallbladder problems? Medical News Today (16 Nov 2018).

https://www.medicalnewstoday.com/articles/311357.php

(3) Stinton & Shaffer. Epidemiology of gallbladder disease: cholelithiasis and cancer. Gut Liver (2012); 6(2): 172–187.

doi:10.5009/gnl.2012.6.2.172

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3343155/

(4) Barhum, Lana. Lithotripsy for stones: What to expect. Medical News Today (3 July 2018).

https://www.medicalnewstoday.com/articles/322355.php

(5) AIHW. Gallstone lithotripsy. Australian Institute of Health and Welfare (1 Dec 1988).

https://www.aihw.gov.au/reports/corporate-publications/gallstone-lithotripsy/contents/summary

(6A) Dijk et al. Restrictive strategy versus usual care for cholecystectomy in patients with gallstones and abdominal pain (SECURE): a multicentre, randomised, parallel-arm, non-inferiority trial. The Lancet (26 Apr 2019).

https://doi.org/10.1016/S0140-6736(19)30941-9

https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(19)30941-9/fulltext

(6B) Guest & Søreide. Pain after cholecystectomy for symptomatic gallstones. The Lancet (26 Apr 2019).

https://doi.org/10.1016/S0140-6736(19)30959-6

https://www.reuters.com/article/us-health-gallstones-surgery/gallbladders-may-be-removed-too-often-idUSKCN1SF28F?feedType=RSS&feedName=healthNews

‘Off-Label’ Use of Epidiolex (Cannabidiol; CBD) and Tilray 2:100 for Pain?

Feature Image of Epidiolex (cannabidiol; CBD) bottles sourced from:

https://www.bloomberg.com/news/photo-essays/2018-10-31/gw-pharmaceuticals-s-epidiolex-cannabis-based-epilepsy-drug

Dear Pain Matters readers,

Epidiolex (Cannabidiol; CBD)

Overview

An oral solution called Epidiolex (cannabidiol; CBD) was approved on 25 June 2018 by the US Food and Drug Administration (FDA).  Made by GW Pharmaceuticals, Epidiolex may be used for the treatment of epileptic seizures in patients with Lennox-Gastaut syndrome and Dravet syndrome aged 2 and above.

Epidiolex is the first FDA-approved drug that is based on a molecule (i.e. CBD) derived from marijuana (in this instance, CBD-rich cannabis).  Contrary to tetrahydrocannabinol (THC) that may lead to a ‘high’, the CBD molecule does not exert psychoactive effects.

For more information about CBD and pain, please visit my blog post called:

Cannabidiol (CBD) – ‘Cannabis With the Fun Bit Taken Out’ – For Severe Chronic Pain

Possible ‘Off-Label’ Use of Epidiolex (Cannabidiol; CBD) for Pain

Given that:

• Cannabidiol (CBD) may offer pain relief; and
• Epidiolex virtually is CBD,

‘off-label’ use of Epidiolex for pain may be warranted (Anson, 2018; Urits et al, 2019).

Thus, while specifically approved for the treatment of certain epileptic conditions, ‘off-label’ prescription by doctors for Epidiolex for pain may be possible.

Tilray 2:100

Tilray 2:100 (that is comparable to Epidiolex) is now available in Canada for patients with epilepsy.  Tilray 2:100 offers a target concentration of 100 mg/ml of CBD and 2 mg/ml of THC (Henriques, 2019; Tilray, 2018).

Similar to Epidiolex, ‘off-label’ prescription by doctors for Tilray 2:100 for pain may be warranted.

Summary

You may ask yourself,

‘Why would anyone request an ‘off-label’ prescription for Epidiolex or Tilray 2:100 when one could simply buy CBD for pain online (where legal)?’

According to Kyle Varner, MD, Internal Medicine Specialist in Washington:

‘CBD oil has tremendous therapeutic potential.  Epidiolex is just CBD— but sold at a price tag of over $30,000 per year’ (Tapp, 2019).

The answer is that many CBD products sold online are mislabeled and unregulated.  This may lead to ineffective treatments and/or side effects (Bonn-Miller et al, 2017).

As such, Epidiolex and Tilray 2:100 may be prescribed ‘off-label’ for pain in the US and Canada, respectively (in addition to, or instead of, CBD).

This is great news!  Now there are more treatment options available for pain!

Please forward to anyone who may benefit from this blog post.

Sabina Walker

Blogger, Pain Matters (in WordPress)

REFERENCES

Epidiolex

(1) Urits et al. An Update of Current Cannabis-Based Pharmaceuticals in Pain Medicine. Pain Ther (5 Feb 2019).

doi: 10.1007/s40122-019-0114-4.

https://www.ncbi.nlm.nih.gov/pubmed/30721403

(2) Anson, Pat. FDA Approves First Marijuana-Based Prescription Drug. Pain News Network (25 June 2018).

https://www.painnewsnetwork.org/stories/2018/6/25/fda-approves-first-marijuana-based-prescription-drug

(3) van der Walt, Eddie & Dawson, Rob. America’s First Cannabis-Based Medicine Is Made in England. Bloomberg (31 October 2018).

https://www.bloomberg.com/news/photo-essays/2018-10-31/gw-pharmaceuticals-s-epidiolex-cannabis-based-epilepsy-drug

(4) FDA. FDA approves first drug comprised of an active ingredient derived from marijuana to treat rare, severe forms of epilepsy. FDA (25 June 2018).

https://www.fda.gov/newsevents/newsroom/pressannouncements/ucm611046.htm

(5) Tapp, Fiona. Businesses envision a boom in CBD, the non-intoxicating oil from hemp. Boston Globe (24 Jan 2019).

https://www.bostonglobe.com/news/marijuana/2019/01/24/businesses-envision-boom-cbd-non-intoxicating-oil-from-hemp/TQhuB0EErYvrpNxpTXTXxJ/story.html

Tilray 2:100

(1A) Henriques, Carolina. Tilray Launches New High-CBD Cannabis Oil for Seizure Treatment in Canada. Dravet Syndrome News (29 May 2019).

https://dravetsyndromenews.com/2018/05/29/tilray-launches-new-high-cbd-cannabis-oil-seizure-treatment-canada/

(1B) Tilray Introduces New High-CBD Extract. Tilray (06/19/2018).

https://www.tilray.ca/en/blog/post/tilray-introduces-new-high-cbd-extract/

Labelling Accuracy of Cannabidiol Available Online

(1A) University of Pennsylvania School of Medicine. Nearly 70 percent of cannabidiol extracts sold online are mislabeled, study shows. Science Daily (7 Nov 2017).

https://www.sciencedaily.com/releases/2017/11/171107112244.htm

(1B) Royal Queen Seeds. The Recent Approval of Epidiolex and its Implications. 

https://www.royalqueenseeds.com/blog-the-recent-approval-of-epidiolex-and-its-implications-n1014

(1C) Bonn-Miller et al. Labeling Accuracy of Cannabidiol Extracts Sold Online. JAMA (2017); 318(17): 1708.

doi: 10.1001/jama.2017.11909

https://jamanetwork.com/journals/jama/fullarticle/2661569

The Woman with No Pain

Feature Image of Jo Cameron sourced from:

https://www.abc.net.au/news/2019-03-28/scientists-discover-genetic-mutation-that-blocks-pain/10950380

Dear Pain Matters readers,

Jo Cameron

A Scottish woman named Jo Cameron (71), a retired teacher, has never felt pain, fear nor anxiety.  In her words,

‘I was just a happy soul who didn’t realise there was anything different about me.

Recently, pain geneticists helped unravel the mystery why this was so. They found that Jo was born with 2 genetic mutations.

The first mutation is common and causes decreased FAAH activity.  A second mutation is rare and involves an as-of-yet undiscovered pseudogene dubbed FAAH-OUT that affects FAAH expression (Habib et al, 2019).  (Don’t you just love a scientist’s warped sense of humour?  i.e. FAAH OUT, for ‘far out’??)

Due to these mutations, Jo’s body is constantly flooded with a natural cannabinoid called anandamide.

Jo may have inherited these 2 genetic mutations from her father.  In her words:

‘[He] had little requirement for painkillers’.

Jo found it enlightening that after 65 years, she finally found out why she reacted so differently to certain events than others might.

This was because she feels no pain!

Furthermore, Jo does not feel anxiety, stress, depression nor fear.  Jo has never had a panic attack during a dangerous or scary incident.

In Jo’s words,

I knew that I was happy-go-lucky, but it didn’t dawn on me that I was different … I didn’t know anything strange was going on until I was 65.”

There is a lot of truth to the saying:

‘What you don’t know, you don’t miss.’ 

In Jo’s case, she did not know pain.  Therefore, she did not ‘miss’ pain.

Jo had many injuries throughout her life including cuts, burns, broken bones and numerous surgeries, all without pain.  At times, she would accidentally iron herself.  At other times, she would smell her own burning flesh before noticing that anything was amiss.

The good news is that Jo’s wounds always healed very quickly with very little scarring.

Following complex double hand surgery, her doctor found out that Jo did not require painkillers.  Stunned, he checked her medical history only to learn that she had never requested painkillers.

Jo clarified:

‘If you don’t need [painkillers], you don’t question why you don’t … you are what you are … until someone points it out.’

Referring to a hip replacement surgery, Jo stated (quoting):

‘I didn’t know my hip was gone until it was really gone.  I physically couldn’t walk with my arthritis.’

‘I’d not had a twinge.’

Jo added:

‘It would be nice to have warning when something’s wrong.’

Two years ago, a young driver cut in front of her by mistake, causing Jo’s car to flip onto its roof in a ditch.  Instead of panicking, Jo calmly got out of her car and walked over to comfort the shaking driver.

Many years earlier, Jo found childbirth ‘quite enjoyable really’.  (OMG! Really???)

Jo enjoyed eating hot chili peppers, saying that they left her with a brief ‘pleasant glow’ in her mouth (Habib et al, 2019; Judd, 2019; Sample, 2019).

For more details, please see References that include a 2-minute video called:

Die Frau, die keine Schmerzen fühlt.  [The woman who feels no pain.]  Spiegel Online (29.03.2019).

http://www.spiegel.de/video/seltene-gen-mutation-jo-cameron-fuehlt-keinen-schmerz-video-99026124.html

Ashlyn Blocker

Whilst rare, Jo Cameron is not the only person who can not feel pain.  Amongst others who do not know pain is a teenage girl from Georgia, US, named Ashlyn Blocker.

Ashlyn was diagnosed with congenital insensitivity to pain with reduced ability to sweat.  Gene testing revealed that Ashlyn was born with 2 novel SCN9A (Nav1.7 sodium channel) mutations.

Given that this blog focuses on stories about people living with pain, and not on those who do not know pain, curious readers can find further details about Ashlyn Blocker (whose gene mutations block pain … pardon the pun) in the References below.

 

In closing, wouldn’t it be great if not feeling pain was an option for as long as desired?

Sabina Walker

Blogger, Pain Matters (in WordPress)

REFERENCES

Jo Cameron

Media

(1) Judd, Bridget. Scientists discover genetic mutation that helps block pain and improve healing. ABC News (28 March 2019).

https://www.abc.net.au/news/2019-03-28/scientists-discover-genetic-mutation-that-blocks-pain/10950380 

NB Above link only works if you ‘copy and paste’ manually.

(2) Sample, Ian. Scientists find genetic mutation that makes woman feel no pain. The Guardian (28 March 2019).

https://www.theguardian.com/science/2019/mar/28/scientists-find-genetic-mutation-that-makes-woman-feel-no-pain

Peer-Reviewed Paper

(3) Habib et al. Microdeletion in a FAAH pseudogene identified in a patient with high anandamide concentrations and pain insensitivity. BJA (2019).

doi.org/10.1016/j.bja.2019.02.019

https://bjanaesthesia.org/article/S0007-0912(19)30138-2/fulltext

Video (in German, Subtitled in English)

(4) Spiegel Online. Seltene Genmutation – Die Frau, die keine Schmerzen fühlt. [The Woman Who Feels No Pain.] Spiegel Online (29.03.2019).

http://www.spiegel.de/video/seltene-gen-mutation-jo-cameron-fuehlt-keinen-schmerz-video-99026124.html

Ashlyn Blocker

Media

(1) Agresz, Patrick. The Girl Who Has Never Felt Pain. Patrick’s Case Studies (31/10/2017).

https://patrickscasestudies.wordpress.com/2017/10/31/the-girl-who-lives-without-pain/

(2) Heckert et al. The Hazards of Growing Up Painlessly. The New York Times (15/11/2012).

(3) Associated Press. Rare disease makes girl unable to feel pain. NBC News (11/1/2004).

http://www.nbcnews.com/id/6379795/ns/health-childrens_health/t/rare-disease-makes-girl-unable-feel-pain/#.XKYH0S2B1Z1

Peer-Reviewed Paper

(4) Staud et al. Two Novel Mutations of SCN9A (Na_v1.7) are Associated with Partial Congenital Insensitivity to Pain. Eur J Pain (2010);15(3):223–230.

doi:10.1016/j.ejpain.2010.07.003

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2978801/