Congenital Insensitivity to Pain
Congenital insensitivity to pain (CIP), also known as congenital analgesia, is one or more extraordinarily rare conditions in which a person cannot feel (and has never felt) physical pain. CIP is an extremely dangerous condition. It is common for people with the condition to die in childhood due to injuries or illnesses going unnoticed. Burn injuries are among the more common injuries.
Congenital insensitivity to pain is considered a form of peripheral neuropathy because it affects the peripheral nervous system, which connects the brain and spinal cord to muscles and to cells that detect sensations such as touch, smell, and pain.
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 do not flinch or withdraw when exposed to pain.
Congenital insensitivity to pain is found at an abnormally high frequency in Vittangi, a village in Kiruna Municipality in Northern Sweden, where nearly 40 cases have been reported.
In this condition, cognition and sensation are otherwise normal, for example, patients can still feel different touch (though not always temperature), and there are generally no detectable physical abnormalities.
As children and adults with the disorder cannot feel pain, they are at a higher risk of more severe diseases due to not responding to problems.
Most people with congenital insensitivity to pain will show the following symptoms –
• Pain insensitivity — where there’s no reaction to painful sensations caused by cuts, burns, or injections
• Repeated severe injuries and accidental self-injury — like severe bite wounds on the tongue, mouth, and fingers
• Anhidrosis — or hypohidrosis, the reduced ability to sweat
• No reaction to extreme temperature
• Recurrent high fever — possibly with febrile seizures
• Lack of corneal reflex — which is when you blink as a reflex to something touching your cornea
• Intellectual disability
These repeated injuries often lead to a reduced life expectancy in people with congenital insensitivity to pain.
Mutations in the SCN9A gene cause congenital insensitivity to pain. The SCN9A gene provides instructions for making one part (the alpha subunit) of a sodium channel called NaV1.7. Sodium channels transport positively charged sodium atoms (sodium ions) into cells and play a key role in a cell’s ability to generate and transmit electrical signals. NaV1.7 sodium channels are found in nerve cells called nociceptors that transmit pain signals to the spinal cord and brain. The NaV1.7 channel is also found in olfactory sensory neurons, which are nerve cells in the nasal cavity that transmit smell-related signals to the brain.
The SCN9A gene mutations that cause congenital insensitivity to pain result in the production of nonfunctional alpha subunits that cannot be incorporated into NaV1.7 channels. As a result, the channels cannot be formed. The absence of NaV1.7 channels impairs the transmission of pain signals from the site of injury to the brain, causing those affected to be insensitive to pain. Loss of this channel in olfactory sensory neurons likely impairs the transmission of smell-related signals to the brain, leading to anosmia.
• CIP is often diagnosed in early childhood due to a lack of typical pain response (wincing or crying) during standard medical procedures like vaccination and treatment for common childhood injuries like falls.
•Accidental self-injury is common among young children with CIP — this includes aggressively biting the mouth, tongue, and fingers to the point of causing severe damage.
• Your health provider will diagnose congenital insensitivity to pain by testing your baby’s pain response to pricking with something that typically causes pain but doesn’t cause damage or scarring, like a needle.
• To confirm the results of this test, your doctor may recommend genetic testing.
There is currently no cure for CIP, so its treatment mainly focuses on patient education — which includes teaching the patients how to avoid injuries, check themselves for any injuries, and get treatment for these injuries as quickly as possible.
In some cases, doctors may suggest preventative medical procedures, like the removal of primary teeth, to prevent young patients from injuring themselves before they can learn how to protect themselves.
An opioid antagonist called Naloxone has been explored as a treatment option for channelopathy-associated congenital insensitivity to pain and has shown partial success in some cases.
For more informative articles on such rare diseases and other health related issues, please visit our website www.santripty.com and also feel free to consult with our experienced doctors.