Affiliations:Saint-Joseph University of Beirut, Lebanon
Journal reference: https://doi.org/10.2147/NDT.S53385
Summary: Losing a body part is one of many people’s biggest fears. This however is not the case for people with apotemnophilia who have a strong desire to amputate a healthy member of their body. In this article, we review all potential causes of apotemnophilia as well as relevant psychiatric and neurological factors.
What is apotemnophilia?
Losing a body part is one of many people’s biggest fears. This however is not the case for people with apotemnophilia who have a strong desire to amputate a healthy member of their body. In this article, we review all potential causes of apotemnophilia as well as relevant psychiatric and neurological factors.
Potential causes for apotemnophilia
There are three hypotheses focusing on the psychiatric etiologies for apotemnophilia: sexual desire, personal identity, and psychosis.
1) Sexual desire:
The desire to amputate one’s own limb can be related to a sexual disorder called paraphilia. Paraphilia is a type of fetishism in which individuals have strong sexual fantasies of amputating another individual’s limb, or their own body parts. For these individuals, sexual arousal increases whenever the subject is exposed to images of amputations.
While sexual arousal is not the most common mechanism behind apotemnophilia, “pure” cases of apotemnophilia (i.e. subjects in whom the sexual aspect is totally absent) are also rare, as they represent only 10% of the participants.
2) Personal identity disorder
This mechanism relates to personal identity or body integrity identity disorder (BIID). In this case, subjects seek to dismember their bodies in order to stand out from the rest and make an impression. Individuals with apotemnophilia claim to feel complete after committing this act.
3) Psychosis
A third proposed mechanism is psychosis. Participants affected by this condition have a distorted perception of reality characterized by symptoms such as hallucinations and delusions. Patients might thus see, hear, or believe things that are not real. Patients diagnosed with a psychosis such as schizophrenia do not have amputation fantasies, but this act seems to be forced upon them. For example they may hold the belief that a “divine force” (Devil/God) is imposing this act of amputation upon them and they must follow it through to avoid negative consequences. Interestingly, although medication for psychosis reduces psychotic symptoms such as hallucinations, they don’t seem to reduce amputation in patients.
What part of the brain could push an individual to amputation?
Many neurobiological mechanisms can be correlated to apotemnophilia but two main brain structures are most likely to be implicated in this condition: the right parietal lobe and the somatosensory system.
1) The right parietal lobe
Indeed, using a neuroimaging technique called magnetoencephalography (MEG) that allows to examine changes in brain activity, researchers found an alteration in the activity of the right parietal lobe in individuals with apotemnophilia. The parietal lobe processes sensory information including touch, and taste and allows the formation of perceptions. Therefore, any impairment or injury in the parietal lobe may result in a dysfunction in the senses and perceptions.
2) The somatosensory system
A dysfunction in the somatosensory system (composed of neurons that make sensing touch, temperature and position in space possible) is reported to be a second neurobiological etiology of apotemnophilia. Using functional Magnetic Resonance Imaging (fMRI) – another form of neuroimaging – researchers found that responsiveness to tactile stimuli exhibited different brain activity patterns in individuals with body integrity disorder compared to healthy controls. No differences were found when examining neural activity related to a motor exaction task. This indicates that apotemnophilia could be related to somatosensory dysfunction.
A new variant of apotemnophilia: the desire to be paralyzed
Finally, recent studies discovered a new variant of apotemnophilia in which patients wish to be paralyzed that is, to be disabled without any act of amputation. This variant seems to be related to the corpus callosum, i.e. the bundle of fibers in the middle of the brain that connect the left and right hemispheres. Although the left and right hemispheres process similar information, they are different: a distinction referred to as brain lateralization. The corpus callosum fibers are cross wired, meaning that the information from the left side of the body is transmitted to the right hemisphere, and vice versa, thus allowing both halves to communicate. Differences in corpus callosum size often alters lateralization. Interestingly, the majority of the patients wishing to be disabled without amputation are women, which is coherent with the fact that they have a less marked lateralization of the corpus callosum.
Take-home message
In conclusion, apotemnophilia or the desire to amputate a healthy limb, has three psychiatric hypotheses (sexual desire, personality identity disorder and psychosis) and various neurobiological correlates (among which a dysfunction in the right parietal lobe or in the somatosensory cortex). However, despite the significant amount of research done on this subject, apotemnophilia’s causes are still unclear and further research ought to be conducted to better understand this condition.