She remembers her panic attacks at age six, whenever she lost sight of her mother at the supermarket. Later, to avoid getting lost on her way to high school, she was constantly accompanied.

Andrea* is now 47-years-old and lives with her father in Vancouver, Canada. To go to work, she follows an itinerary that is always identical. If there is roadwork or a disruption that requires a detour, she is likely to lose her way and will have to call someone to come get her. Andrea doesn't drive. Her social life is very limited.

When there was talk of moving her work place, Andrea decided to see a professional. That's how psychologist Giuseppe Iaria, a specialist of spatial orientation at the University of Calgary, got interested in her case.

Topographical disorientation is a common disorder, but until now it was considered a symptom of brain damage (after a cerebrovascular accident, a trauma, or cerebral degeneration like Alzheimer's disease), or of a mental illness like autism. Yet Andrea has normal motor and intellectual development. She doesn’t have brain damage or any other disorder. But she seems incapable of building a virtual map of her surroundings in her head.

In 2009, Giuseppe Iaria described her case more precisely in the Neuropsychologia scientific journal. "After the article, many people from around the world reached out to us, saying that they had always been suffering from the described symptoms," says the psychologist. He then created a website and perfected a series of online tests to determine if it was the same disorder.

Getting lost, even at home

In 2010, Giuseppe Iaria counted 120 people who had no other problem than getting lost, even in familiar environments. A third of them also declared that at least one other person in their family experienced the same problem, which suggests the presence of a genetic component.

The same year, psychologists at the University of Rome related a second case, even more severe than Andrea's. F.G. was a 22-year-old screenwriting student. He had never been affected by any neurologic or psychiatric illness, and cerebral imagery showed no anomalies, but he had trouble going from his room to the kitchen in his childhood home.

Finally, this year, orientation specialist neurologist Geoffrey Aguirre welcomed a young 18-year-old student with similar symptoms into his University of Pennsylvania laboratory. "He is very smart, he can play music but is completely incapable of finding his way," says the doctor.

"Some people have a specific problem with speech, which is agnosia. Others have trouble reading, which is dyslexia. Others can't recognize faces, which is prosopagnosia. Now we have discovered that some people have a specific problem with orientation. That's developmental topographical disorientation,” explains Aguirre.

No one knows how many people might be affected, or what causes the illness. Giuseppe Iaria's laboratory barely has a trail. When you observe the brain activity of these patients with MRIs as they are asked to form a mental map of their environment, a certain zone, which is normally activated with a healthy subject, stays unsolicited: the hippocampus.

Connections between neurons

The hippocampus plays an important role in spatial representation. In 1978, in animals and in 2003, with humans, biologists identified "location neurons" there. These neurons emit electric shocks when a person is in certain locations of his or her environment. For Geoffrey Aguirre, "it is possible that with disoriented people, the connections between the neurons involved in spatial representation aren't developed enough."

These hypotheses need to be tested, most notably to convince the psychologist, psychiatrist and neurologist communities of the existence of a specific disorder. For Alain Berthoz, a professor at the Collège de France, "there are disorientation symptoms in many pathologies. Orientation brings too many specialized structures and cells into play for there to be a unique disorder."

Radek Ptak, a neurologist and the section head of reeducation at the Beau-Séjour hospital in Geneva, has a more nuanced opinion. "In our department, patients who suffer from disorientation have generally been the victims of cerebrovascular accidents. But we are discovering more and more people with brain development disorders that affect very specific functions. And very clearly, some of them are affected with developmental topographical disorientation."

For now, the disorder isn't in the Diagnostic and Statistical Manual of Mental Disorders, the international reference on the topic which is currently being revised for a fifth edition. In order to qualify, many studies need to define the disorder more precisely and evaluate the importance of the affected population.

But in laboratories, psychologists are already looking for ideas to help the daily life of their patients. These strategies can use bypassing techniques: for instance, learning the list of landmarks you go by when going from one point to another as a verbal code, or testing video games that teach you how to manipulate maps in three dimensions.

*Not her real name.