The woman carrying the disease is not afraid

Having been pointed with a gun at the head, throwing a knife at him, facing poisonous snakes . but the 47-year-old woman was not afraid at all, because she had a rare genetic disease.

Most of us will shudder in the face of a poisonous spider or dangerous treacherous cliff, but SM doesn't have that feeling. This American woman, once referred to by SM doctors, has been placed in many life-threatening situations but still not flinched. She did not panic when she was pointed at knives and guns and did not call the police after facing these attacks.

She was beaten by her first husband almost to death but did not feel scared. When she met poisonous snakes, she was just curious, not afraid and had to restrain herself from touching them.

While doctors tried to study SM's case for more than a decade, no newspaper approached her and interviewed her. The reason is that the team of neuroscientists, University of Iowa (USA) - who conducted the study, said that if this characteristic of the patient is public, people can easily take advantage of her.

Therefore, Dr. Daniel Tranel, University of Iowa, conducted an interview and handed over to NPR radio journalists to play in Invisibilia program.

Artwork: Capitalbay.com

Dr. Tranel began by suggesting that SM, 44, the mother of three children, described what she was afraid of."Oh, that's what I'm trying to get," the woman replied. She remembered that when she was young, she was afraid that a catfish would catch her because she did not want to be bitten. It was the only time she could remember this feeling.

The fearless thing made SM many times fall into the scary situation. When the boys were young, once she walked to the store to buy things, a man was sitting on the park bench calling her back."He pulled my shirt and pressed the knife into my throat, saying he would stab me. I told him to " go ahead and stab " , the woman recounted. Go home, do not call the police after this incident because there is no danger.

SM has a rare disease called Urbach-Wiethe - which makes her brain parts become harder and weary.

What is fearless syndrome (Urbach-Wiethe)?

Urbach-Wiethe is a rare genetic disorder . Scientists have identified about 400 people worldwide suffering from this disease. The symptoms of the disease are very different in each case. This may include a hoarse voice, small bumps around the eyes, easily damaged skin with hard-to-heal wounds. Other symptoms can be dry, wrinkled skin, and the skin and film are quite thick in general. Some cases have calcium deposits in the brain. This sediment causes the parts of the brain to become calcified and hardened, which can lead to epilepsy and other abnormalities such as fearlessness, in the case of SM. The disease is usually not life-threatening and the patient is not shown to be short of life.

In SM's case, almond-like structures called amygdala are found deep in the brain that have become calcified and worn away. This lobe is located in the cerebral cortex, which handles emotional factors in humans, including fearful reactions and SM's inability to fear.

Usually, in situations that can be dangerous, the amygdala sends signals to the body to reduce the symptoms of fear, such as tachycardia and sweating palms. But for SM, because this part of the brain does not exist, she does not experience these traits in situations where others feel scared. She also could not recognize the expression of fear on the faces of others.

The doctors noted that this is a single defect: She has normal intelligence and feels other emotions like happiness, sadness, anger are like everyone else. Iowa scientists created a sense of fear for SM in 2013 when they let her inhale carbon dioxide. Even at low levels, if the amygdala detects carbon dioxide in the body, it usually causes feelings of fear and panic because it is a sign of choking. Scientists predict that SM does not panic after breathing this gas, but in fact she was afraid.

Professor Antonio Damasio, a neurologist at the University of Iowa, has spent a lot of time researching SM cases. He said that what is remarkable about this patient, when he is not afraid, means that she has no painful memories.

With things happening in her life, SM doesn't consider anything bad or dangerous. Even if she was nearly beaten to death by her husband, her memory was not considered a pain and leaving a mark of emotion could cause psychological problems like others.

"If you are not afraid, there will be more bad things happening to you but you don't think that is bad. If you are scared, you will have a few bad things happening but consider yourself my life is full of pain, then, is it better to be afraid or not afraid? " , Professor Damasio said.

Scientists are studying whether the SM case can help people with traumatic memories like soldiers suffering from post-traumatic stress disorder. They believe that finding a treatment to reduce the activity of the amygdala may help patients with this syndrome.