"It’s astonishing and challenges many assumptions about how the brain works."

FAIRFAX—In a case baffling scientists, a man was recently discovered to be missing 90% of his brain—yet remarkably, he leads a seemingly normal life, including purchasing and commuting in his Audi. The man, identified as 44-year-old Mark Harris, underwent an MRI for a routine checkup, only for doctors to find that his brain structure defied all expectations.

"To say we were stunned is an understatement," said Dr. Elaine Grossman, a neurologist who reviewed Harris’s MRI. “Mr. Harris’s scans show an extreme form of brain atrophy, yet he was still able to purchase a car—an Audi, but a car nonetheless. It’s astonishing and challenges many assumptions about how the brain works.”

Harris, an accountant by trade, said he had no idea anything was amiss. “I’ve always felt normal, I like black jelly beans as much as the next guy and I’ve been driving my Audi for years without an issue,” he said. “Sure, I forget why I bought the Audi, but don’t we all?”

The findings have drawn worldwide attention and spurred interest in how the human brain compensates for such extreme physical deficiencies. Neurologists speculate that Harris’s brain has reorganized itself to use the small amount of brain tissue he has with as much efficiency as possible. Some even suggest that this limited efficiency could explain his lifelong preference for Audi cars.

"I guess I don't know what I'm missing," Harris joked. “But if I'm in an Audi, I can't be doing that bad.”

While Harris’s case remains rare, researchers hope that studying his unique condition will deepen understanding of brain plasticity. For now, Harris is simply grateful he can keep driving his Audi and going about his life, even with 90% less brain than most people.