Congenital insensitivity to pain (CIPA) also known as congenital analgia, is a rare condition where a person cannot feel (and has never felt) physical pain.
Presentation
Cognition and
sensation is otherwise normal; for instance they can still feel discriminative touch (though not always temperature
), and there is no detectable physical abnormality.
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 can not 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 slight mental retardation, as well as an impaired corneal reflex.
Causes
There are some cases where the condition is caused by increased production of
endorphins in the
brain, in which case
naloxone may be used as treatment. This treatment does not always work.
In some cases, this disorder can be caused by mutations in the voltage-gated sodium channel SCN9A (NaV1.7). 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. NaV1.7 channels are expressed at high levels in nociceptive neurons of the dorsal root ganglia. As these channels are likely involved in the formation and propagation of action potentials in such neurons, it is expected that a loss of function mutation in SCN9A will lead to abolished nociceptive pain propagation.
One of the side effects of Hansen's Disease is the progressive destruction of the nerves; this can be passed on to offspring, remaining dormant except for nerve insensitivity.
Types of congenital pain indifference
There are generally two types of non-response exhibited.
- Insensitivity to pain means that the painful stimulus is not even perceived: a patient cannot describe the intensity or type of pain.
- Indifference to pain means that the patient can perceive the stimulus, but lacks an appropriate response: they will not flinch or withdraw when exposed to pain.
Incidence
Due to its congenital nature, the disorder is primarily found in
homogeneous societies.
For example, it is found in Gällivare, a Swedish village in Gällivare Municipality in northern Sweden, where nearly 40 cases have been reported.
In Popular Culture
- Hayden Tenno, the main character in the video game Dark Sector, suffers from Congenital Analgia, meaning he cannot feel any pain inflicted upon him during the game. It also allows him to endure the excruciatingly painful mutation on his body that would otherwise drive him insane.
- The television series House featured a patient with CIPA in the episode "Insensitive".
- The television series 'Grey's Anatomy' featured a patient with CIPA in the episode "Sometimes a Fantasy".
- In the anime Joe vs. Joe, Joe Akamine's young fan has CIPA which Akamine is unaware until the child is rushed to the hospital after taking a fall and seeming unfazed by it.
- In the anime Kinnikuman Nisei, the character Scarface suffers from this condition. It is both his greatest strength & his achilles heel, as he is not slowed down by the pain of injuries he receives in battle, he often ends up collapsing in the middle of a fight because he has no way of knowing how serious his wounds actually are and pushes himself too hard.
See also
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