For most people the idea of losing a limb is horrifying. Even worse is the idea that we would have to self-amputate in order to survive. Some films have played on this fear, for example in Saw I a man was forced to cut off his own shackled foot in order to escape from death. In the American TV series The Walking Dead, a man cut off his shackled hand to escape from hordes of the undead. Most humans experience considerable distress when faced with the loss of a limb. However, to a small minority the idea of ‘getting rid of a limb’ is desirable. In one study, an individual was reported as saying “I felt like I was in the wrong body; that I am only complete with both my arm and leg off on the right side.” . Apotemnophilia, a disorder that blurs the boundaries between neurology and psychology, describes the rare phenomenon of individuals who desire the amputation of one or more healthy limbs or who desire a paralysis. Individuals with desire for limb amputation often mimic amputation by bending their limbs out of view, using crutches extensively and wearing prostheses. Recently, the number of self-demand amputations has increased with some amputations of healthy legs being performed in hospital settings .

The obsessive need for amputation can even be deadly as those who cannot afford or find a surgeon to carry out the surgery resort to mutilating themselves, for example, by shooting into a leg, sawing off a finger or toe, placing the offensive limb in the way of an oncoming train, or freezing the limb to death by packing it in ice. Even injecting the knee with liquidized fecal matter has been reported. Patients with apotemnophilia secretly harm themselves to necessitate amputation of an injured limb and commonly have a history of repeated, unexplained injuries to the same segment of the body. This presents as a diagnostic challenge for the health care provider because of the atypical presentation of self-inflicted injury caused by the disorder.

Previous case reports have revealed that patients with apotemnophilia are fully aware that people do not approve of their desire for self-amputation. Bensler and Paauw reported the case of a patient in his 20s with apotemnophilia who presented with several conditions mimicking common medical problems and, consistent with previous cases, was secretive about his attempt to self-amputate his legs. Individuals with apotemnophilia fantasise about accomplishing great things despite having an amputation. The existence of such fantasies in individuals with apotemnophilia may explain why the patient described above by Bensler and Paauw claimed to be a world-class artist. Recently there has been a shift away from the long existing theory that this disorder is psychological in origin with some scientists hypothesising a neurological basis. So what causes some individuals to desire to get rid of a completely healthy limb?

Psychological Theories to Explain Desire for Amputation

Body Integrity Image Disorder (BIID)

More recently, the term used to describe apotemnophilia is body integrity image disorder (BIID) also known as Amputee Identity Disorder (AID). The first person to use the term BIID was US psychiatrist Michael First, Professor of Clinical Psychiatry at Columbia University. BIID, a term gaining in popularity, describes the extremely rare phenomenon of individuals who desire the amputation of one or more healthy limbs or who desire a paralysis. The majority of individuals experience disruption to their everyday life and experience distress as a result of their obsession with how to cut off or get rid of the “alien appendage”. BIID indicates that there is a mismatch between the individual’s subjective experience of their body and the actual structure of their body.

Interestingly, BIID may actually be some form of identity disorder and has in fact been compared to gender identity disorder (GID). In a report for the journal of Psychological Medicine, First and colleagues point out the similarities between BIID and GID, a disorder in which individuals are similarly distressed with some part of their anatomy because they feel it is at odds with their ‘internal sense of self’. Both disorders typically originate in childhood. They are often expressed by the imitation of the desired identity like pretending or transvestism, they induce a paraphiliac sexual arousal and are sometimes resolved with surgery. Paraphiliac is a term used to describe individuals who gain sexual arousal and gratification from objects, situations, or individuals that are atypical and extreme.

What motivates an individual to desire the amputation of a healthy limb?

So the question is what motivates an individual to desire the amputation of a perfectly healthy limb? Bayne and Levy have put forward the idea that it may be that the individuals who desire amputation are suffering from Body Dysmorphic Disorder (BDD), a condition in which the individual incorrectly believes that a part of their body is diseased or extremely ugly. Such a belief can produce intense concern by the sufferer – which is maintained even when they are faced with evidence to the contrary. There are two noteworthy distinctions between BDD and BIID patients. First, individuals with BIID do not think that the limb they want removed is ugly. Second, rather than wishing to become more beautiful, they are instead interested in becoming disabled in order to “become more authentic”.

Sexual Attraction

A second explanation for the desire for amputation is that it is a sexual attraction to amputees or a sexual arousal from the idea that they might themselves become amputees. Here, the desire for amputation derives from apotemnophilia, a type of psychosexual disorder. Strangely, it has even been argued that the underlying reason for amputation desire is the supposed phallic resemblance of an amputee’s stump .

Neurological Theories to Explain Desire for Amputation

BIID is a disorder that has long been considered as being completely psychological in origin. There is increasing popularity in the notion that it actually has a neurological basis.

Can Previous Cases of Brain Tumors Shed Any Light on this Strange Disorder?

Body-image distortions have been found to be caused by tumors or strokes in the parietal lobe, which “contains the body image that is derived from sensory inputs”. Patients with Pötzl syndrome suddenly ignore parts of their body or are convinced that they are alien, unreal or even someone else’s body part. Sacks describes a young man who woke up to find that someone else’s leg was in bed with him and believed it to be from a corpse, a counterfeit of his own, which mysteriously had vanished. In an attempt to throw it out of the bed, the patient himself landed on the floor. The patient was found to have a tumor in the right side of his brain (parietal lobe) that had begun to bleed during the night. Sacks argued that the tumor was disrupting the patient’s body map in the brain, since the leg “came back” after the tumor was removed.

However, unlike for Pötzl syndrome patients, the onset of the symptoms of BIID usually dates to childhood. This early onset suggests a defect present in the brain of the baby at birth (e.g., a blood vessel anomaly), an early brain trauma (e. g., shaken baby syndrome – where shaking of the baby can cause brain swelling, damage to the retinas and tearing of the veins that drain blood away from the brain) or an incomplete development of nerves in either the regions involved in sensory and motor function (the sensorimotoric cortex) or the large bundle of nerve fibres which connects our left brain hemisphere with our right – the corpus callosum. In individuals with BIID the early onset of the disturbance of body image means that they cannot recall a life where the affected limb was integrated into their body image.

‘I Feel Like an Amputee with Natural Prostheses’

Neuroscientists Ramachandran and McGeoch suggest that a dysfunction of the right parietal lobe gives rise to BIID, resulting in “an uncoupling of the construct of one’s body image in the right parietal lobe from how one’s body physically is”. A good quote from individual with this disorder captures the meaning of this argument well: “I feel like an amputee with natural

prostheses – they’re my legs but I want to get rid of them – they don’t fit my body image”. Here, the individual’s own internally represented body image is at odds with their actual body. Additionally, Smith and Fisher argue that in BIID patients a physical limb has developed without the sensory consciousness for it. Ramachandran and McGeoch also highlight the similarity of BIIB to a disorder which can occur after a stroke in the right parietal lobe. Individuals suffering with somatoparaphrenia are convinced that one of their limbs (typically the left arm) belongs to someone else and sometimes develop an aversion to the offending limb and saying things like, “It’s a communist” or “It’s hideous”. Ramachandran and McGeoch’s argument of a right parietal lobe dysfunction is based on the tendency for the individuals to desire amputation of limbs on the left side of their body. This supports the idea of a dysfunction of the right parietal lobe (the right hemisphere) because it is this side of the brain that controls movements on the left side of the body.

Somatoparaphrenia is associated but not obligatorily with anosognosia (denial), which is also a result of right parietal lobe damage. In somatoparaphrenia, the individual denies ownership of the limb, whereas in anosognosia, the individuals may be convinced that there is nothing wrong with his/her paralysed left side. Interestingly there has been some progress with the treatment of these disorders. They have both been treated temporarily with cold-water vestibular caloric simulation – a process involving the infusion of cold-water into the external canal of a patient’s ear. Due to the similarity between these disorders and BIID, this treatment may also alleviate the symptoms of BIID in the same way. This treatment produces activation of the right parietal lobe as well as numerous other areas. Blanke, Morgenthaler, Brugger and Overney examined twenty participants with desire for limb amputation and found that amputation desire usually affects the limbs of the left side of the body. Similarly, First found that the desire for amputation is almost three times more common for the left leg as for the right leg alone and it is unlikely that such an asymmetry in the affected limbs would be present if the disorder was purely psychological in origin.

The hypothesis put forth by Ramachandran and McGeoch, that desire for amputation on limbs on the left-side is more predominant than desire for right-sided limb amputation, was investigated by Brang et al. by measuring skin conductance response (SCR) to a pinprick above and below the line of desired amputation on each leg of two right-handed individuals with apotemphilia dating right back to childhood. Skin conductance – which is mediated by regions in the right forebrain – is the measure of change in the conductivity of the skin to a weak electric current. The more you sweat (that is, to an arousing or threatening stimulus), the greater the change in skin conductivity. Findings revealed heightened skin conductance response to pinprick below the desired line of amputation which Brang et al. argue provides evidence consistent with the hypothesis that apotemnophilia is derived from a dysfunction of the right parietal lobe, since this lobe receives and integrates input from numerous sensory areas and the insula to produce a coherent sense of body image.

Conclusion

If this theory for the neurological basis for the desire for amputation is correct, then it not only suggests why BIID arises but it also indicates that caloric stimulation may be a therapeutic avenue for this chronic and currently untreatable condition.