Specific limb: A brief look at ‘restless legs syndrome’

Those that know me well often comment that I have a general inability to sit still and that I am a ‘fidget’. (This is not necessarily a bad thing and in fact there are some positives to fidgeting that I outlined in a previous blog on bad behaviours that are sometimes good for you). There is certainly some truth to the observation that I fidget but sometimes the fidgeting is out of my control. Every few weeks my right lower leg appears to take on a life of its own and I will get strange (uncomfortable) sensations (such as tingling, itching, and aching, and occasionally cramp-like feelings) that force me to move my right leg and foot around. It only happens when I am in a resting and relaxing state and usually lasts about 30 minutes (but can occasionally last much longer). On occasions it disrupts my work and sleep but I find that just getting up and moving around is sometimes enough to alleviate the uncomfortable feelings.

A few years ago I Googled my ‘symptoms’ and was surprised to find that I am not the only person who appears to experience such effects and that there is a whole medical literature on what has been termed ‘restless legs syndrome’ although in my case it would be in a singular rather than plural form). I’ve had the condition for about 15 years now and it may be related to some of the medication I take for an unrelated chronic degenerative health condition that I have. According to the Wikipedia entry on restless legs syndrome (RLS):

“The first known medical description of RLS was by Sir Thomas Willis in 1672. Willis emphasized the sleep disruption and limb movements experienced by people with RLS…The term ‘fidgets in the legs’ has also been used as early as the early nineteenth century. Subsequently, other descriptions of RLS were published, including those by Francois Boissier de Sauvages (1763), Magnus Huss (1849), Theodur Wittmaack (1861), George Miller Beard (1880), Georges Gilles de la Tourette (1898), Hermann Oppenheim (1923) and Frederick Gerard Allison (1943). However, it was not until almost three centuries after Willis, in 1945, that Karl-Axel Ekbom (1907–1977) provided a detailed and comprehensive report of this condition in his doctoral thesis, Restless legs: clinical study of hitherto overlooked disease. Ekbom coined the term “restless legs” and continued work on this disorder throughout his career. He described the essential diagnostic symptoms, differential diagnosis from other conditions, prevalence, relation to anemia, and common occurrence during pregnancy. Ekbom’s work was largely ignored until it was rediscovered by Arthur S. Walters and Wayne A. Hening in the 1980s. Subsequent landmark publications include 1995 and 2003 papers, which revised and updated the diagnostic criteria”.

As well as being referred to as RLS, it is sometimes referred to as Willis-Ekbom Disease or Willis-Ekbom Syndrome. Since being ‘rediscovered’ in the 1980s, there have been a lot of scientific papers published on the phenomenon although many of these are medical case studies (I don’t think my own experiences are extreme enough or strong enough to appear in any medical textbook. The Wikipedia entry on RLS provides a good summary of what is known medically and empirically:

“Restless legs syndrome (RLS) is a disorder that causes a strong urge to move one’s legs. There is often an unpleasant feeling in the legs that improves somewhat with moving them. Occasionally the arms may also be affected. The feelings generally happen when at rest and therefore can make it hard to sleep. Due to the disturbance in sleep, people with RLS may have daytime sleepiness, low energy, irritability, and a depressed mood. Additionally, many have limb twitching during sleep. Risk factors for RLS include low iron levels, kidney failure, Parkinson’s disease, diabetes, rheumatoid arthritis, and pregnancy. A number of medications may also trigger the disorder including antidepressants, antipsychotics, antihistamines, and calcium channel blockers. There are two main types. One is early onset RLS which starts before age 45 [years], runs in families and worsens over time. The other is late onset RLS which begins after age 45 [years], starts suddenly, and does not worsen. Diagnosis is generally based on a person’s symptoms after ruling out other potential causes… Females are more commonly affected than males and it becomes more common with age…Some doctors express the view that the incidence of restless leg syndrome is exaggerated by manufacturers of drugs used to treat it. Others believe it is an under-recognized and undertreated disorder…An association has been observed between attention deficit hyperactivity disorder (ADHD) and RLS or periodic limb movement disorder. Both conditions appear to have links to dysfunctions related to the neurotransmitter dopamine, and common medications for both conditions among other systems, affect dopamine levels in the brain”.

According to a review by Dr. Richard Allen and Dr. Christopher Earley in the Journal of Clinical Neurophysiology, RLS affects 2.5-15% of the US population. In another review on sleep disorder in the journal American Family Physician, Dr. Kannan Ramar and Dr. Eric Olson reported that RLS is typically characterized by four essential features: These are:

“(1) the intense urge to move the legs, usually accompanied or caused by uncomfortable sensations (e.g., “creepy crawly,” aching) in the legs; (2) symptoms that begin or worsen during periods of rest or inactivity; (3) symptoms that are partially or totally relieved by movements such as walking or stretching; and (4) symptoms that are worse or only occur in the evening or at night”.

Various online articles and papers report a variety of potential treatments based on the notion that RLS might be caused by a dopamine imbalance in the body. Some medics advise a regular sleep routine (such as that advised for those with insomnia), and cutting out the drinking of alcohol and the smoking of cigarettes. Pharmacological treatments include the use of drugs that are also used in the treatment of Parkinson’s disease such as L-DOPA and pramipexole, and the use of magnesium sulphate therapy (as reported in a 2006 paper in the Journal of Clinical Sleep Medicine – magnesium is known to be a natural muscle relaxant). In a 2011 issue of the journal Sleep Medicine, In an online article about RLS, Dr Michael Platt, author of the 2014 book Adrenalin Dominance, claims that RLS sufferers can be treated using a progesterone cream:

“Excess adrenalin during the night can cause restless leg syndrome. People often have associated symptoms also resulting from elevated adrenalin, such as teeth grinding, the need to urinate, and tossing and turning, and they often awaken in the morning with low back pain. Characteristically, RLS patients have an excess of adrenaline, may toss and turn all night, be quick to anger, might be workaholics, will usually have fibromyalgia (aches and pains – low back, side of the hips, and grind their teeth), they might drink too much, and will be hypoglycemic (sleepy between 3-4 p.m. or when in a car), and so on. There is an associated over-production of insulin and an under-production of progesterone…[By using a progesterone cream] I have had 100% success with eliminating RLS by getting hormones into balance, often within the first week. Patients feel more relaxed, they can sleep at night, rage disappears, and they can focus more easily”.

Dr. Luis Marin and his colleagues reported a different treatment for RLS altogether. They reported the case of a 41-year-old male RLS sufferer who after being on medication for RLS discovered his own solution – having sex. Following sex, the man reported that all RLS symptoms would disappear. Marin and colleagues speculated that the release of dopamine following orgasm might alleviate RLS symptoms. This appears to be a reasonable speculation given the findings of research published in the Journal of Neuroscience by Dr. Gert Holstege and his colleagues who examined brain activation at the point of ejaculation. In their paper they reported the similarity between ejaculation and using heroin in terms of brain activation:

“We used positron emission tomography to measure increases in regional cerebral blood flow during ejaculation compared with sexual stimulation in heterosexual male volunteers. Manual penile stimulation was performed by the volunteer’s female partner. Primary activation was found in the mesodiencephalic transition zone, including the ventral tegmental area, which is involved in a wide variety of rewarding behaviors. Parallels are drawn between ejaculation and heroin rush”.

It could well be that the increase in dopamine following ejaculation acts in a similar way to the medications that are given to RLS sufferers. Of all the treatments for RLS that I have read about, I think I know which one I would prefer!

Dr. Mark Griffiths, Professor of Behavioural Addiction, International Gaming Research Unit, Nottingham Trent University, Nottingham, UK

Further reading

Allen, R.P., & Earley, C.J. (2001). Restless legs syndrome: A review of clinical and pathophysiologic features. Journal of Clinical Neurophysiology, 18(2), 128-147.

Bartell S1, Zallek S. Intravenous magnesium sulfate may relieve restless legs syndrome in pregnancy. Journal of Clinical Sleep Medicine, 15, 187-188.

Chaudhuri, K.R., Appiah-Kubi, L.S., & Trenkwalder, C. (2001). Restless legs syndrome. Journal of Neurology, Neurosurgery & Psychiatry, 71(2), 143-146.

Ekbom, K., & Ulfberg, J. (2009). Restless legs syndrome. Journal of Internal Medicine, 266(5), 419-431.

Holstege, G., Georgiadis, J. R., Paans, A. M., Meiners, L. C., van der Graaf, F. H., & Reinders, A. S. (2003). Brain activation during human male ejaculation. Journal of Neuroscience, 23(27), 9185-9193

Leschziner, G., & Gringras, P. (2012). Restless legs syndrome. British Medical Journal, 344, e3056.

Marin, L.F., Felicio, A.C., & Prado, G.F. (2011). Sexual intercourse and masturbation: Potential relief factors for restless legs syndrome? Sleep Medicine, 12(4), 422.

Ondo, W. G. (2009). Restless legs syndrome. Neurologic Clinics, 27(3), 779-799.

Ramar, K; Olson, EJ (Aug 15, 2013). Management of common sleep disorders. American Family Physician, 88, 231–238.

Satija, P., & Ondo, W. G. (2008). Restless legs syndrome. CNS Drugs, 22(6), 497-518.

Come undone: A beginner’s guide to Traumatic Masturbatory Syndrome

I’m not quite sure where I first read about it, but Traumatic Masturbatory Syndrome (TMS) appears to be a controversial phenomenon that is not widely accepted in the medical and sexological communities. According to the Healthy Strokes website:

“[Traumatic Masturbatory Syndrome] is the habit of masturbating in a face-down position against a bed or floor, which puts excessive pressure on the penis, and can interfere with sexual relations. The most common problems TMS sufferers have are inorgasmia – inability to reach orgasm during intercourse – or delayed orgasm. Many TMS sufferers also experience erectile dysfunction”. 

The term ‘Traumatic Masturbatory Syndrome’ originates from a 1998 paper in the Journal of Sex and Marital Therapy by Dr. Lawrence Sank. His paper described what he believed was “a previously unreported pattern of atypical masturbatory behavior, which presents as either an erectile or orgasmic disorder in men”. He outlined four case studies of men who masturbated daily in a prone position over many years. I wrote to Dr. Sank and he kindly sent me his paper. Sank’s paper began by outlining the fact that there are many texts and manuals for women on how to masturbate and how to overcome being non-orgasmic, but little for men. He pointed out that problems in erectile functioning and orgasm among males appears to result, not from their inability to masturbate but from the inability to masturbate correctly (Sank’s emphasis on the word ‘correctly’). The four cases that Sank reported on were all physically healthy and there were no problems urogenitally, neurologically, hormonally or vascularly. Here are brief summaries of the four cases Dr. Sank wrote about:

• Case 1 [Mr. A]: A 62-year old heterosexual married Black male who was referred for impotence – “He had been married over two years but the couple had not had successful intercourse…He learned at age 8, from his local priest, that any pleasure from touching his penis was the equivalent of ‘re-crucifying Jesus’…The compromise that Mr. A reached was to not use his hand but to rub his penis against his bed clothes and/or pillow without manual guidance. He believed that this would mitigate the seriousness of his sin…This method of sexual expression lasted through several decades of almost daily practice….Mr. A pursued a series of relationships with women…He would rub extremely vigorously against his partner usually to a point where any erection was lost… Mr. A’s masturbatory history is significant for the unique prone position that he engaged in daily over many years”.

• Case 2 [Mr. B]: A 35-year old gay single Asian male referred for an inability to attain or sustain any erection and an inability to achieve orgasm during intercourse – “Mr. B’s history was significant for the absence of what he called a ‘phallic oriented puberty’…He was not able to achieve orgasm until his early 20s. At that time all masturbation was accomplished by rubbing his penis against his mattress in a prone position while fantasizing about being penetrated by a male. He would do this on a daily basis, always eventuating in orgasm. In his late 20’s he found a male lover with whom he would characteristically engage in mutual, manual masturbation…Any stimulation by his partner eventuated in mutual exhaustion since no effort was sufficient, no matter how prodigious, to trigger Mr. B’s orgasm…Mr. B reported that masturbation, while in a prone position, felt ‘more natural’, was speedier, and required far less effort. Mr. B’s explanation was that he imagined his masturbatory preference to be a logical outgrowth of his shame at not having ‘good, working equipment’…Being face down allowed him to hide his embarrassment”.

• Case 3 [Mr. C]: A 24-year old gay white male referred for inability to reach orgasm – “When, on rare occasions, Mr. C did achieve orgasm, it was always with a flaccid penis and never accompanied by any pleasurable sensation…Positionally, Mr. C would invariably masturbate while lying on his stomach, his hands made into fists with his penis between his thumbs. He would thrust downward creating intense friction between the lateral portion of his penile shaft and the knuckles of his thumbs. There would be no erection. The frequency of masturbation was 5-7 times per week. Before treatment, when Mr. C tried masturbating in a more typical fashion he was capable of obtaining an erection but never a strong one nor was there any subsequent orgasm”.

• Case 4 [Mr. D]: A 35-year old heterosexual single white male referred for primary erectile dysfunction – “Mr. D masturbated on a daily basis since adolescence. The quality of the erection during masturbation was reported to be of ‘poor rigidity’…but always eventuated in orgasm. Positionally, Mr. D would be prone, lying on his face and chest, using both hands – one hand grasping his penis, the other hand placed over the first…Only subtle changes in pressure from his hand served to heighten his arousal to the point of obtaining a semi-rigid, non penetrable erection and then orgasm…He has never been able to sustain his erection beyond several seconds of intercourse nor has he achieved orgasm…When asked as to why he masturbated in this statistically unusual manner, Mr. D expressed surprise that it was so unusual and hypothesized that it must have arisen out of being a shameful activity at which he wouldn’t have wanted to be caught. In addition, the tight clutching of his penis during masturbation parallels Mr. C’s traumatizing handling of his penis during masturbation and Mr. A’s vigorous, exhaustive masturbatory rubbing against his bedding or partner”.

Dr. Sank duly acknowledged that the case material presented was anecdotal and he made it clear in his paper that he wasn’t suggesting the “distinguishing variables of position plus frequency or either, alone, are necessary or sufficient for causing the erectile or orgasmic dysfunctions described in these cases”. In the cases of A, C and D:

“The punishing handling of the penis might co-occur with these two variables because a prone position, due to its awkwardness and lack of freedom of motion, would seem to require a great deal of intensity if the subject is to derive the requisite pleasurable sensations associated with masturbatory activity. The daily regimen of masturbation might also have served to raise the threshold of sensation, thus requiring even more intense stimulatory activity to enable orgasm. Unfortunately this heightened intensity would likely raise the threshold for pleasurable sensation even higher…the proverbial vicious circle”

Dr. Sank reported that all his patients were successfully treated and overcame their presenting symptoms. Sank did not describe the treatment in any detail (saying it was beyond the scope of the paper) but involved the “re-sensitizing what the patient treats as a desensitized organ through both individualized behavioral exercises and psychotherapy when appropriate”.

On the basis of his admittedly anecdotal findings, Dr. Sank recommends that pubescent teenagers should be taught proper masturbatory techniques (either by parents, by teachers, and/or by paediatricians). However, as far as I am aware, no other academic or clinical paper has followed up the work of Sank. The Wikipedia entry relating to TMS was removed in 2009 (presumably because of lack of evidence). However, according to an article on masturbation on the Right Diagnosis website, some sources, still continue to give credence to the idea of TMS. The article cites the 1994 book by sex therapist Eva Margolies (Undressing The American Male) who condemned masturbation by rubbing against a pillow or mattress. The same article also quotes the work of and Dr. Josie Lipsith and her colleagues in a 2003 issue of Sexual and Relationship Therapy that suggests masturbation could play a part in male psychogenic sexual dysfunction (although this seems to be little more than citation of Dr. Sank’s original paper).

Dr Mark Griffiths, Professor of Behavioural Addiction, International Gaming Research Unit, Nottingham Trent University, Nottingham, UK

Further reading

Go Ask Alice (2006). Traumatic Masturbatory Syndrome. November 17. Located at: http://goaskalice.columbia.edu/traumatic-masturbatory-syndrome-tms

Healthy Strokes (2013). Facts about prone masturbation. Located at: http://www.healthystrokes.com

Lipsith, J., McCann, D. & Goldmeier, D. (2003). Male Psychogenic Sexual Dysfunction: The Role of Masturbation. Sexual and Relationship Therapy, 18, 448-471.

Margolies, E. (1994). Undressing the American Male: Men with Sexual Problems and What Women Can Do to Help Them. New York: Penguin.

Right Diagnosis (2013). Masturbation. Located at: http://www.rightdiagnosis.com/m/masturbation/wiki.htm

Sank, L.I. (1998). Traumatic masturbatory syndrome. Journal of Sex and Marital Therapy, 24, 37-42.

Coining it in: Neologisms and ‘New Syndrome’ Syndrome

One of things I am very proud of in my academic career is the coining of the term ‘technological addiction’ back in 1995 (an umbrella term that I invented to describe a number of different person-machine addictions including slot machine addictions, video game addiction, television addiction, etc.). I’m also proud of coining the term ‘aca-media’ (relating to academics like myself that use the media to disseminate our research). A neologism (i.e., the name for a newly coined term) is often (according to Wikipedia) directly attributable to a specific event, person, publication, or period.

In the 1980s and early 1990s, there seemed to be a real upsurge is the naming of ‘new syndromes’ in the medical literature including many relating to excessive use of technology (such as ‘Space Invader’s Wrist’) and other leisure activities (such as ‘Cuber’s Thumb’ relating to excessive use of the Rubik’s Cube) – both of which made their appearance in 1981 issues of the New England Journal of Medicine. Other videogame medical complaints include ‘Pseudovideoma’ (in a 1984 issue of the Journal of Hand Surgery), ‘Pac-Man Phalanx’ (in a 1983 issue of Arthritis and Rheumatism) and ‘Joystick Digit’ (in a 1987 issue of the Journal of the American Medical Association). Another videogame-related medical complaint (in this case an infection), was reported in a 1987 issue of the Western Journal of Medicine by Dr. G.B. Soe and colleagues:

“We wish to focus WJM readers’ attention on another complication associated with video games-one that originally presented as an “infected spider bite. A 17-year-old right-handed boy noted progressive swelling and redness of his left hand seven days before admission. Two days before admission he was given penicillin intramuscularly and oral cephalexin to take at home. The swelling did not subside and the hand became very painful, so he came to the medical center for treatment. On admission his mother reported that she had seen many spiders around the house with a violin pattern on their backs, and that her son had probably been bitten by a spider…After seven days of parenteral antibiotic therapy, the edema, erythema and fever had disappeared and the patient was discharged home. Further questioning revealed that the young man was spending almost all of his time playing his favorite video game, which involved a fighting kung fu character. The patient used his left hand in manipulating a ball-shaped joystick to move the figure up, down, left and right, and his right in operating buttons to kick and jab. Extensive use of the joystick resulted in blisters on his left palm. He rubbed the blisters off, and an infection resulted that progressed to abscess formation. Neuromuscular complications of video games (‘pseudovideoma’, ‘Pac-Man phalanx’, ‘firing-finger syndrome’ and ‘Space Invaders wrist’) have been reported, as well as video game-induced seizures, but we have not come across any reports of an infectious complication of video games. Perhaps video game players should wear gloves to protect their palms, similar to ones worn by golfers and baseball players, who also need to get a firm grip on their respective sticks”.

Another one that I’d never heard of is ‘Nurd Knuckles’ coined by Dr. J.B. Martin in the Canadian Medical Association Journal in 1982:

“I wish to describe a case of painful knuckles associated with the use and manipulation of a new, allegedly therapeutic product, a Nurd. A Nurd is a head 10 cm across with a smiling face and large ears, reminiscent of the character Yoda of ‘Star Wars’. It is made of malleable material that can be stretched, twisted or deformed in any direction, yet with release of tension quickly resumes its original shape without a trace of distortion. A 32-year-old public school teacher presented with painful knuckles of his right hand. His students, perhaps feeling that their teacher was under increased stress during the marking of exams, had given him a Nurd for Christmas, and during a particularly trying day he had found occasion to use it. He repeatedly stretched its ears and twisted its neck without ill effect; however, on punching it he suffered sharp pain of his fourth and fifth metacarpophalangeal joints. On examination the joints were found to be reddened, with point tenderness over the fifth metacarpal head; there was no evidence of deformity. He was advised to stop beating his Nurd, and the pain subsided. While the Nurd is very plastic, yielding to the linear tension of stretching and twisting, it is very resistant to compression. Punching a Nurd does not cause the surface to give way, and, since the force of the blow is returned to the fist, it is conceivable that a fracture might result. Therefore, although stretching and twisting Nurds does not cause any harm, users should be cautioned against punching their Nurd. The Nurd is advertised as being a ‘punchable, stretchable, pushable and likeable alternative to tension, migraine headaches, drug abuse, alcoholism and manic depression’, but these claims are unsubstantiated. A MEDLINE search of the medical literature shows that no retrospective or prospective case control studies or controlled double blind crossover studies have been undertaken. Before the clinical efficacy of the Nurd can be taken seriously in the treatment of this broad spectrum of disease, full clinical trials must be completed. Subjects entering into trials must, however, be duly informed of the hazards of punching Nurds”.

Another one that caught my attention was a new affliction (‘Breaker’s Neck’) caused by the craze of ‘break dancing’ reported by Dr. Bertha Ramirez and her colleagues in a 1984 issue of the Journal of the American Medical Association. (The reason why I say it caught my eye is that I am currently involved in some research on ‘dancing addiction’ with some of my Hungarian colleagues and we have just had a new paper accepted in the journal PLoS ONE concerning the development of our ‘Dancing Motives Inventory’ – see ‘Further Reading’ below).

“To be added to the rapidly growing list of socially acquired injuries, we report a case of traumatic cervical subluxation caused by a new dance technique. This technique, labeled ‘breaking’ by its devotees, involves a modified head stand, in which the dancer, using his arms and hands for balance, spins rapidly on his head, neck, or shoulders to the rhythm of disco music. He then lowers his body to the floor and performs a series of rotational motions using his arms as a fulcrum…A 15-year-old boy was seen in our pediatric emergency room complaining that, on awakening two days previously, he felt a ‘snap’ in his neck, followed by persistent neck stiffness. He reported having ‘danced on his head’ the night prior to this incident. On physical examination, his head was tilted to the left with an inability to flex”.

Engaging in excessive sporting activity has given rise to a number of medical syndromes. One such consequence is ‘Rower’s Rump’ reported by Drs. K Tomecki and J. Mikesell in a 1987 issue of the Journal of the American Academy of Dermatology. In a previous blog I examined addiction to cycling. In the 1980s there were many medical complaints reported as a result of excessive cycling. One such complaint (given the name of ‘Bicycling nipples’) was highlighted by Dr. B. Powell in a 1983 issue of the Journal of the American Medical Association:

“Bicyclists are likely to suffer from a number of maladies, including dysuria, numb penises, and more. During cool or cold weather, another problem, bicyclist’s nipples, may occur. This condition is similar to jogger’s nipples, but it is primarily a thermal injury instead of an irritation secondary to friction, as with the jogger’s complaint. Often the rider is out in the cold weather for some time, and his or her undershirt, jersey, and jacket can become moist from perspiration. Evaporation and the chill of the wind lower the temperature of the nipples. They get downright cold, and they hurt. The pain continues after the ride is over. Indeed, it can continue for several days. The nipples are sore, sensitive to both temperature change and touch”.

After reading this I found out that Dr. Fred Levit had reported a case of ‘Jogger’s Nipples’ in a 1977 issue of the New England Journal of Medicine. All of these related nipple conditions are all examples of fissure of the nipple as they are all caused by friction resulting in soreness, dryness or irritation to, or bleeding of, one or both nipples. The Wikipedia entry also notes that “the condition is also experienced by women who breastfeed, and by surfers who do not wear rash guards”. The article also noted that:

“Jogger’s nipple is caused by friction from the repeated rubbing of a t-shirt or other upper body clothing against the nipples during a prolonged period of exercise. The condition is suffered mainly by runners. Long-distance runners are especially prone, because they are exposed to the friction on the nipple for the greatest period of time. However, it is not only suffered by athletes; the inside of a badge, a logo on normal items of clothing, or breastfeeding can also cause the friction which results in this condition”.

Outside of the leisure sphere, there were two case study reports of ‘Diaper Doer’s Hand’ in a 1987 issue of the journal Clinical Rehabilitation by Dr. J.L. Cosgrove and colleagues:

“Three cases of stenosing tenosynovitis occurred three to six months postpartum. Childcare activities aggravated the symptoms of pain and swelling in both patients. In two cases, a specific method of carrying the child was implicated as the mechanism of injury. Although there was no evidence of generalized inflammatory arthritis, all patients had very low positive titres of anti-nuclear antibodies. While it is likely that tenosynovitis was caused by mechanical factors, the possibility of increased susceptibility to inflammatory disease in the postpartum period cannot be discounted. The patients were successfully treated with a low temperature plastic splint, superficial heat and gentle mobilization”.

All of these new syndromes lead to why I put this article together in the first place. I found this letter in the British Medical Journal by Dr. E.P. Hoare entitled ‘New Syndrome Syndrome’ that I found both funny and poignant:

“Your readers will be familiar with tennis elbow, brazier’s ague, and soap packer’s jig not to mention Achilles’ heel. More recently we have heard of Space Invader’s wrist, jogger’s nipples, and the ultimate futility of Cuber’s thumb. May I point out another occupational disease which I have noticed among patrons of the reading room medical journal correspondence column reader’s neck or, more succinctly, the new syndrome syndrome. Symptoms usually begin with muscular contraction of the eyebrows, hyperventilation, and involuntary utterances, which in severe cases can lead to coprolalia. These may be followed by drowsiness, disorientation, hysterical amblyopia, and double vision (of the deja vu variety). If untreated the condition can result in a chronic pain in the neck. Treatment is 200 ml of gin and tonic stat by mouth and complete rest; music can also be helpful. The long-term prognosis is poor, however, unless journal editors can be persuaded to ban further reports of occupational afflictions or at least print a health warning at the head of their correspondence columns”.

Dr. Mark Griffiths, Professor of Gambling Studies, International Gaming Research Unit, Nottingham Trent University, Nottingham, UK

Further reading

Behr, J.T. (1984). Pseudovideoma. Journal of Hand Surgery, 9(4), 613.

Cosgrove, J. L., Welch, D. A., Richardson, G. S., & Nicholas, J. J. (1987). Diaper doer’s hand: stenosing tenosynovitis in the postpartum period. Clinical Rehabilitation, 1(3), 219-223.

Gibofsky, A. (1983). Pac‐Man phalanx. Arthritis and Rheumatism, 26(1), 120.

Griffiths, M.D. (1995). Technological addictions. Clinical Psychology Forum, 76, 14-19.

Griffiths, M.D. (1995). Pop psychology and “aca-media”: A reply to Mitchell. The Psychologist: Bulletin of the British Psychological Society, 8, 537-538.

Griffiths, M.D. (2001). A moral obligation in aca-media? The Psychologist: Bulletin of the British Psychological Society, 14, 460.

Hite, P. R., Greene, K. A., Levy, D. I., & Jackimczyk, K. (1993). Injuries resulting from bungee-cord jumping. Annals of emergency medicine, 22(6), 1060-1063.

Hoare, E.P. (1982). Points: New syndrome syndrome. British Medical Journal, 285(6352), 1429.

Levit, F. (1977). Jogger’s nipples. New England Journal of Medicine, 297(20), 1127.

Maraz, A., Király, O., Urbán, R., Griffiths, M.D., Demetrovics, Z. (2015). Why do you dance? Development of the Dance Motivation Inventory (DMI). PLoS ONE, in press.

Martyn, J. B. (1983). Nurd knuckles. Canadian Medical Association Journal, 129(3), 228.

McCowan, T.C. (1981). Space Invader’s wrist. New England Journal of Medicine, 304,1368.

Osterman, A. L., Weinberg, P., & Miller, G. (1987). Joystick digit. Journal of the American Medical Association, 257(6), 782.

Powell, B. (1983). Bicyclist’s nipples. Journal of the American Medical Association, 249(18), 2457-2457.

Ramirez, B., Masella, P. A., Fiscina, B., Lala, V. R., & Edwards, M. D. (1984). Breaker’s neck. Journal of the American Medical Association, 252(24), 3366-3367.

Soe, G.B., Gersten, L. M., Wilkins, J., Patzakis, M. J., & Harvey, J.P. (1987). Infection associated with joystick mimicking a spider bite. Western Journal of Medicine, 146(6), 748.

Tomecki, K. J., & Mikesell, J. F. (1987). Rower’s rump. Journal of the American Academy of Dermatology, 16(4), 890-891.

Torre, P. R., Williams, G. G., Blackwell, T., & Davis, C. P. (1993). Bungee jumper’s foot drop peroneal nerve palsy caused by bungee cord jumping. Annals of emergency medicine, 22(11), 1766-1767.

Waugh, D. (1981). Cuber’s thumb. New England Journal of Medicine, 305, 768.

Stats entertainment (Part 2): A 2013 review of my personal blog

My last blog of 2013 was not written by me but was prepared by the WordPress.com stats helper. I thought a few of you might be interested in the kind of person that reads my blogs. I also wanted to wish all my readers a happy new year and thank you for taking the time to read my posts.

Here’s an excerpt:

The Louvre Museum has 8.5 million visitors per year. This blog was viewed about 860,000 times in 2013. If it were an exhibit at the Louvre Museum, it would take about 37 days for that many people to see it.

Click here to see the complete report.

Becoming less of a drag: The Stoptober campaign (revisited)

(The following blog is based on an article I published last year in the Nottingham Post on why I was actively supporting the Stoptober smoking campaign to get people to stop smoking for 28 days during October. I also published a blog last year outlining my 10 top tips for giving up smoking. Since that blog, my ten tips have been slightly changed and adapted in co-operation with the Department of Health running the Stoptober campaign. I make no apologies for repetition between today’s blog and that published last year, as my only aim is to help people give up smoking).

Although most of my academic research is on behavioural addiction, I have published quite a few papers on more traditional addictions such as alcohol and nicotine addiction (see ‘Further reading’ below). Last year I had to watch my mother fight a losing battle with smoking-related lung cancer and chronic obstructive pulmonary disease. She died in September 2012 aged 66 years, and had chain-smoked most of her adult life. This followed the death of my father who also died of smoking-related heart disease, aged just 54.

This October, the Department of Health (DoH) are re-launching the ‘Stoptober’ campaign for the second time, urging as many nicotine smokers as possible to give up smoking for 28 days from October 1. The DoH website claims that “people who stop smoking for 28 days are five times more likely to stay smoke free” compared to those that don’t give up for such a long period. Like last year, those that decide to try and stop for the month will be given a lot of encouragement during the campaign including access to the Smokefree Facebook page and the downloadable Stoptober app. People will also be sent daily emails providing additional encouragement.

In the UK smoking accounts for approximately one in four cancer deaths, and as I said, it’s something I’ve witnessed first-hand. I’m sure most people reading this are aware of the addictive nature of nicotine. As soon as nicotine is ingested via cigarettes, it can pass from lungs to brain within ten seconds and stimulates the release of the neurotransmitter dopamine. The release of dopamine into the body provides reinforcing mood modifying effects. Despite nicotine being a stimulant, many people use cigarettes for both tranquillising and euphoric effects. Most authorities accept that nicotine is one of the most addictive drugs on the planet and that smokers can become hooked quickly. One of the reasons my own parents were never able to give up was because of the prolonged withdrawal effects they experienced whenever they went more than a few hours without smoking. This would lead to intense cravings for a cigarette. Watching both my parents’ die of smoking-related diseases is enough incentive for me to never smoke a cigarette. Hopefully, others can find the incentives they need to help them give up permanently. Here are my top ten tips to help you (or someone you know and love) stop smoking:

• (1) Develop the motivation to stop smoking: Many smokers say they would like to stop but don’t really want to. When you take stock, make sure you are clear as to why you want to give up. It may be to save money, to improve your health, to prevent yourself getting a smoking-related disease, or to protect your family from passive smoking. (It could of course be all of the above). Really wanting to give up is the best predictor of successful smoking cessation.
• (2) Get all the emotional support you can: Another good predictor of whether someone will overcome their addiction to nicotine is having a good support network. You need people around you that will support your efforts to quit. Tell as many people that you know that you are trying to quit. It could be the difference between stopping and starting again.
• (3) Avoid ‘cold turkey’: Although some people can stop through willpower alone, most people will need to reduce their nicotine intake slowly. The best way of doing this is to replace cigarettes with a safe form of nicotine such as those available from the pharmacy, or on prescription from the doctor.
• (4) Get support from a professional: Even if you are using a safe form of nicotine from your pharmacist or doctor, cutting out cigarettes completely can be hard. Getting support from a trained NHS stop smoking adviser can double your chances of stopping smoking. To find your nearest free NHS stop smoking service (in the UK call 0800-1690169) or visit the smokefree website and click on the ‘ways to quit’ tab.
• (5) Use non-nicotine cigarette shaped substitutes: Smoking is also a habitual behaviour where the feel of it in your hands may be as important as the nicotine it contains. The use of plastic cigarettes or e-cigarettes will help with the habitual behaviour associated with smoking but contain none of the addictive nicotine.
• (6) Use relaxation techniques: When cravings strike, use relaxation exercises to help overcome the negative feelings. At the very least take deep breaths. There are dozens of relaxation exercises online. Practice makes perfect.
• (7) Treat yourself: One of the immediate benefits of stopping smoking will be the amount of money you save. At the start of the cessation process, treat yourself to rewards with the money you save.
• (8) Focus on the positive: Giving up smoking is one of the hardest things that anyone can do. Write down lists of all the positive things that will be gained by stopping smoking. Constantly remind yourself of what the long-term advantages will be that will outweigh the short-term benefits of smoking a cigarette. In short, focus on the gains of stopping rather than what you will miss about cigarettes.
• (9) Know the triggers for your smoking: Knowing the situations in which you tend to smoke can help in overcoming the urges. Lighting up a cigarette can sometimes be the result of a classically-conditioned response (e.g. having a cigarette after every meal). These often occur unconsciously so you need to break the automatic response and de-condition the smoking. You need to replace the unhealthy activity with a more positive one and re-condition your behaviour.
• (10) Fill the void: One of the most difficult things when cigarette craving and withdrawal symptoms strike is not having an activity to fill the void. Some things (like engaging in physical activity) may help you in forgetting about the urge to smoke. Plan out alternative activities and distraction tasks to help fill the hole when the urge to smoke strikes (e.g. chew gum, eat something healthy like a carrot stick, call a friend, occupy your hands, do a word puzzle, etc.). However, avoid filling the void with other potentially addictive substances (e.g. alcohol) or activities (e.g. gambling).

Dr Mark Griffiths, Professor of Gambling Studies, International Gaming Research Unit, Nottingham Trent University, Nottingham, UK

Further reading

Griffiths, M.D. (1994). An exploratory study of gambling cross addictions. Journal of Gambling Studies, 10, 371-384.

Griffiths, M.D.  (2005). A ‘components’ model of addiction within a biopsychosocial framework. Journal of Substance Use, 10, 191-197.

Griffiths, M.D. (2012). First person: Highly-addictive drug killed both of my parents. Nottingham Post, October 1, p.13.

Griffiths, M.D., Parke, J. & Wood, R.T.A. (2002). Excessive gambling and substance abuse: Is there a relationship? Journal of Substance Use, 7, 187-190.

Griffiths, M.D., Wardle, J., Orford, J., Sproston, K. & Erens, B. (2010). Gambling, alcohol consumption, cigarette smoking and health: findings from the 2007 British Gambling Prevalence Survey. Addiction Research and Theory, 18, 208-223.

Griffiths, M.D., Wardle, J., Orford, J., Sproston, K. & Erens, B. (2011). Internet gambling, health. Smoking and alcohol use: Findings from the 2007 British Gambling Prevalence Survey. International Journal of Mental Health and Addiction, 9, 1-11.

Resnick, S. & Griffiths, M.D. (2010). Service quality in alcohol treatment: A qualitative study. International Journal of Mental Health and Addiction, 8, 453-470.

Resnick, S. & Griffiths, M.D. (2011). Service quality in alcohol treatment: A research note. International Journal of Health Care Quality Assurance, 24, 149-163.

Resnick, S. & Griffiths, M.D. (2012). Alcohol treatment: A qualitative comparison of public and private treatment centres. International Journal of Mental Health and Addiction, 10, 185-196.

Sussman, S., Lisha, N. & Griffiths, M.D. (2011). Prevalence of the addictions: A problem of the majority or the minority? Evaluation and the Health Professions, 34, 3-56.

Umeh, K. & Griffiths, M.D. (2001). Adolescent smoking: Behavioural risk factors and health beliefs. Education and Health, 19, 69-71.

Identity marred: A ‪beginner’s guide to Delusional Misidentification Syndrome‬s

Some of the strangest mental and neurological syndromes that exist involve delusional misidentification. There are many different types and they all come under the umbrella term Delusional Misidentification Syndrome (DMS)‬. It was Dr. Nikos Christodoulou who introduced the term in his 1986 edited collection The Delusional Misidentification Syndromes. All DMSs involve a belief by the affected individual that the identity of something (i.e., a person, place, object, etc.) has altered or changed in some way. There are many variants of DMS, and in most cases the delusion is monothematic (i.e., it only concerns one particular topic). Here is a brief summary of the different types:

The Fregoli delusion: This refers to an individual who has the belief that more than one person that they have met is the same person in more than one disguise. The disorder is named after Leopoldo Fregoli an Italian theatre actor who was known for his remarkable ability to quickly change his physical appearance while on stage. The first reported case was in 1927 (by Dr P. Courbon and Dr. G. Fail in a French psychiatry journal) when a female schizophrenic (aged 27 years) claimed that she was being persecuted by two actors that she had seen at the theatre. According to the woman the actors “pursued her closely, taking the form of people she knows or meets”. Compared to other forms of delusional misidentification, the Fregoli delusion is thought to be the least common.

The Capgras delusion: This refers to an individual who has the belief that someone (typically a spouse or close relative) has been replaced by an identical-looking imposter. The delusion was named in 1923 after a French psychiatrist (Dr. Joseph Capgras) reported the case of a French woman who believed that her husband (and some other people she knew) had been replaced by identical looking doubles. Females are slightly more likely than males to have the delusion (approximately 60% females and 40% males). The disorder is most likely to found in individuals that have a brain injury, schizophrenia and/or dementia, but has also been associated with other medical conditions including hypothyroidism, diabetes, and migraines. There was also a case study published in a 2010 issue of the journal Biological Psychiatry (by Dr. P.R. Corlett and colleagues) who reported that the delusion had been induced by a psychologically healthy following the taking of the drug ketamine.

Subjective doubles (aka Christodoulou syndrome): This refers to individuals who have the belief that there are (one or more) doubles of themselves (i.e., doppelgangers) that carry out actions and behaviours independently and lead a life of their own. The disorder was first identified by Dr. Nikos Christodoulou in a 1978 issue of the American Journal of Psychiatry. As with other DMSs, subjective doubles syndrome typically arises as a consequence of a mental disorder, brain injury (typically the right central hemisphere) or a neurological disorder. In rare instances, there may be comorbidity with the Capgras delusion and is then referred to ‘subjective Capgras syndrome’.

Intermetamorphosis: This refers to an individual who has the belief that people in their immediate vicinity change identities with each other but keep the same appearance. The disorder was first reported in 1932 by Dr. P. Courbon and Dr. J. Tusques (again in a French psychiatry journal), and again shares comorbidity with mental and/or neurological disorders. An interesting case study was published in a 2002 issue of the journal Cognitive Neuropsychiatry by Dr. M.F. Shanks and Dr. A. Venneri. They described a man with Alzheimer’s disease who mistook his wife for his dead mother and (at a later date) his sister. He later mistook his son for his brother and his daughter for another sister. As the delusion occurred when speaking on the telephone to these misidentified individuals he was not diagnosed with either visual agnosia (i.e., an inability of the brain to recognize or understand visual stimuli) or prosopagnosia (i.e., ‘face-blindness’ – the inability to recognize faces).

There are also some other conditions that could feasibly be classed as DMSs including (i) mirrored-self misidentification, (ii) reduplicative paramnesia, (iii) delusional companion syndrome, (iv) clonal pluralization of the self, and (v) the Cotard delusion (which I covered in a previous blog). Very briefly:

• Mirrored-self misidentification: This refers to an individual who has the belief that when they look in the mirror they see someone else.
• Reduplicative paramnesia: This refers to an individual who has the belief that something (e.g., a person, a body part, an object, or a place has been duplicated.
• Delusional companion syndrome: This refers to an individual who has the belief that inanimate objects are actually alive.
• Clonal pluralization of the self: This refers to individuals who have the belief that there are multiple copies of themselves (both physically and psychologically identical).
• The Cotard delusion: This refers to an individual who has the belief that they are dead, don’t exist and/or immortal.

There are some cases reported where individuals have more than one DMS simultaneously. For instance, in very rare cases, a person may suffer from both the Fregoli delusion and the Capgras delusion at the same time. Such individuals often experience both depersonalization and derealization and typically co-occur with other mental disorders such as bipolar disorder, schizophrenia, obsessive-compulsive disorders, and/or other mood disorders. In general, DMS is thought to arise because of a dissociation between identification and recognition processes. The Wikipedia entry on the Fregoli delusion (which also examines other DMSs) concludes:

“The study of DMS currently remains controversial…Although there is a plethora of information on DMS, there are still many mysteries of the physiological and anatomical details of DMS. An accurate semiological analysis of higher visual anomalies and their corresponding topographic sites may help elucidate the aetiology of Fregoli’s and other misidentification disorders”.

Dr Mark Griffiths, Professor of Gambling Studies, International Gaming Research Unit, Nottingham Trent University, Nottingham, UK

Further reading

Christodoulou G.N. (1986). Delusional Misidentification Syndromes. Basel: Karger.

Christodoulou G.N. (1977). The syndrome of Capgras, British Journal of Psychiatry, 130, 556.

Christodoulou G.N. (1978). Syndrome of subjective doubles. American. Journal of Psychiatry, 135, 249.

Corlett, P.R., D’Souza, D.C. & Krystal, J.H. (2010). Capgras Syndrome induced by ketamine in a healthy subject. Biological Psychiatry, 68(1), e1–e2.

Ellis HD, Luauté JP, Retterstøl N (1994). “Delusional misidentification syndromes”. Psychopathology 27 (3-5): 117-120.

Benson DF, Gardner H, Meadows JC (February 1976). Reduplicative paramnesia. Neurology 26, 147-151.

Berrios G.E., Luque R. (1995). Cotard Syndrome: clinical analysis of 100 cases. Acta Psychiatrica Scandinavica 91, 185-188.

Shanks MF, Venneri A (2002). The emergence of delusional companions in Alzheimer’s disease: An unusual misidentification syndrome. Cognitive Neuropsychiatry, 7, 317-328.

Vörös, V., Tényi, T., Simon, M. & Trixler, M. (2003). Clonal pluralization of the self: A new form of delusional misidentification syndrome. Psychopathology 36, 46-48.

Sno, H.N. (1994). A continuum of misidentification symptoms. Psychopathology, 27, 144-147.

No pain, no gain: A beginner’s guide to congenital analgesia

Arguably one of the most extreme of human conditions is having congenital insensitivity to pain (CIP). One of the most high profile portrayals of CIP (which is where I first became aware of the condition) was in The Girl Who Played With Fire (the sequel of The Girl With The Dragon Tattoo), where one of the peripheral characters (Ronald Niedermann – ‘The Giant’) had CIP and was seen as physically invulnerable by those around him.

CIP was first reported by Dr. G. Dearborn in 1932 (in the Journal of Nervous and Mental Diseases) and is also known as congenital analgesia. Those with CIP have no capacity to feel physical pain, usually because of a hereditary genetic mutation associated with the body’s pain receptors. However, there are also cases where the causes are non-genetic. For instance, there are a few cases of CIP that appear to be due to an increase in endorphins (the body’s own morphine-like chemicals) in the brain.

Although CIP might sound like a great (almost superhuman) condition to have, individuals with CIP are much more susceptible to death via trauma as they are completely unaware of what damage has been done to their body following accidents (so they can’t feel cuts, know if they have bitten their tongue, or know if they have broken bones). Furthermore, one of the behaviours associated with CIP is self-mutilation (as highlighted in a 2010 case study of a young boy in the Online Journal of Health and Allied Sciences by Dr. Praveen Kumar and his colleagues). Evolutionary psychologists would therefore argue that pain perception is an evolutionary necessity to avoid injury and/or death.

The condition is very rare (for instance, in the US, it is estimated that only around 100 people have the condition). However, there is a higher incidence of the disorder in societies where there is less biodiversity (so-called ‘homogenous societies’). For instance, an interesting 2006 paper by Dr. Jan Minde in the journal Acta Orthopaedica Supplementum reported that in the village of Vittangi (in the north Swedish Municipality of Kiruna) had documented 43 cases. Given the hereditary nature of CIP, many papers tend to report case studies within families. For instance, Dr. D.C. Thrush reported across two papers in a 1973 issue of the journal Brain, the case of four siblings with CIP that all reported numerous painless injuries, bone fractures, and autonomic dysfunction. Similarly, Dr. Karmani and colleagues reported on a family where three out of four children all had CIP in the Journal of the Royal Society for Medicine in 2001. They reported that in relation to the condition:

“Presentation in childhood is commonly at the time of tooth eruption, with biting and self-mutilation of lips, tongue and digits. Pyrexia of unknown origin is another way the condition can show itself in early infancy. Cuts, abrasions and burns of the limbs are common”.

CIP is different from the group hereditary sensory and autonomic neuropathy (HSAN) disorders that inhibit specific sensations (which I’ll hopefully cover in a future blog). A 2002 paper in the Journal of Bone and Joint Surgery by Dr. E. Bar-On and colleagues reported that among those with CIP “musculoskeletal manifestations are very common although the pathology, inheritance, and pathophysiology of these, as well as their relationship to the different subtypes, have only been partially clarified, mainly in case reports”. Other than the incapacity to feel pain, those with CIP are physically normal (although some individuals have difficulty in experiencing different temperatures). The Wikipedia entry on CIP also notes that:

“Children with this condition often suffer oral cavity damage both in and around the oral cavity (such as having bitten off the tip of their tongue) or fractures to bones. Unnoticed infections and corneal damage due to foreign objects in the eye are also seen. Because the child cannot feel pain they may not respond to problems, thus being at a higher risk of more severe diseases or otherwise. In some people with this disorder, there may be a mild intellectual disability”.

Another minority may have CIP in the ‘voltage-gates sodium channel SCN9A’ (and in the words of Vienna by Ultravox, “this means nothing to me”). There is a series of papers published by Dr. James Cox and his colleagues in journals like Nature and Human Mutation examining the hard-core genetics of CIP. I had hoped that the Wikipedia entry on the genetics of CIP might dumb things down a little but after reading the following, I am still generally none-the-wiser:

“Patients with such mutations are congenitally insensitive to pain and lack other neuropathies. There are three mutations in SCN9A: W897X, located in the P-loop of domain 2; I767X, located in the S2 segment of domain 2; and S459X, located in the linker region between domains 1 and 2. This results in a truncated non-functional protein…it is expected that a loss of function mutation in SCN9A will lead to abolished nociceptive pain propagation”.

Some people working in the field distinguish between pain insensitivity and pain indifference. Pain insensitivity refers to individuals who have absolutely no perception of the stimulus to pain (i.e., they are unable to describe the type or intensity of pain). Pain indifference refers to individuals that have perception of the stimulus to pain have inappropriate responses to the pain stimulus (e.g., they wouldn’t flinch if something very hot or on fire touched their flesh).

Finally, Dr. Praveen Kumar and colleagues report in the Online Journal of Health and Allied Sciences that there is “no single gold standard treatment available” for CIP and that there are some studies suggesting (the opioid antagonists) naloxone and naltrexone (most often used in the treatment of drug addictions) can be used to reverse the analgesic effects of CIP. However, they also note that treatment with opioid antagonists “lacks evidence and further support” and that most treatments are concerned with other associated conditions.

Dr Mark Griffiths, Professor of Gambling Studies, International Gaming Research Unit, Nottingham Trent University, Nottingham, UK

Further reading

Bar-On, E., Weigl, D., Parvari, R., Katz, K., Weitz, R. & Steinberg, T. (2002). Congenital insensitivity to pain. Journal of Bone and Joint Surgery, 84, 252-257.

Cox, J.J., Reimann, F. & Nicholas, A.K. (2006). An SCN9A channelopathy causes congenital inability to experience pain. Nature, 444, 894–8.

Cox, J.J., Sheynin, J., Shorer, Z., et al (2010). Congenital insensitivity to pain: Novel SCN9A missense and in-frame deletion mutations. Human Mutation, 31, E1670-E1686.

Dearborn, G. (1932). A case of congenital general pure analgesia. Journal of Nervous and Mental Diseases, 75, 612–615.

Karmani, S., Shedden, R. & De Sousa, C. Orthopaedic manifestations of congenital insensitivity to pain. Journal of the Royal Society of Medicine, 94, 139-140

Kumar, P.B, Sudhakar S. & Prabhat, M.P.V. (2010). Case report: Congenital insensitivity to pain. Online Journal of Health and Allied Sciences, 9(4).

Manfredi, M., Bini, G., Cruccu, G., Accornero, N., Berardelli, A. & Medolago, L. (1981). Congenital absence of pain”. Archives of Neurology, 38, 507-511.

Minde J (2006). Norrbottnian congenital insensitivity to pain. Supplementum 77, 2-32.

Nagasakoa, E.M., Oaklanderb, A.L., Dworkin, R.H. (2003). Congenital insensitivity to pain: an update. Pain, 101, 213–219.

Thrush, D.C. (1973). Congenital insensitivity to pain: A clinical, genetic and neurophysiological study of four children from the same family. Brain, 96, 369-86.

Thrush, D.C. (1973). Autonomic dysfunction in four patients with congenital insensitivity to pain. Brain, 96, 591-600.

Wikipedia (2012). Congenital insensitivity to pain. Located at: http://en.wikipedia.org/wiki/Congenital_insensitivity_to_pain