The procedure, the surgeon explained, was relatively low risk. It was sensitive — any procedure that goes through the nose and toward the brain is bound to be — but it was also fairly straightforward. Just a biopsy. Perry Lynch, a 59-year-old Texan, turned out to be the exception. In his case , the biopsy of a mass at the base of his skull resulted in a rare complication and marked the beginning of a cascade of medical events that have fundamentally changed his life. Before the procedure, Lynch was active. He played tennis when he had time, he said, and he regularly rode his mountain bike. Since February 2025, when he underwent the biopsy at UT Southwestern Medical Center in Dallas, that’s changed. He described his most troubling symptoms like this: He has double vision. He’s sometimes gripped by searing pain through the back of his head. He struggles so much with balance that it is, some days, a Herculean feat to walk to the mailbox and back. You can read more from our media partner, The Dallas Morning News. ...read more read less