Amy Gruenhut spent nearly a month in a coma and four months in a hospital bed after a brain infection nearly killed her. On Sunday, she is set to run the Bank of America Chicago Marathon, which would be her 10th marathon overall.
Gruenhut, who has lived with multiple sclerosis for more than 20 years, was admitted to Mount Sinai Hospital in Manhattan in January 2022 after an enterovirus infection triggered acute viral encephalitis, according to the Long Island Herald. The infection left her in a coma for nearly a month, and she stayed hospitalized for four months as doctors worked to save her, according to NBC 5 Chicago. She had completed her first New York City Marathon just two months before the emergency admission, per the Herald's reporting.
In the hospital, Gruenhut had to relearn how to walk, talk, eat and breathe independently, NBC 5 Chicago reports. Doctors saved her life, and she has said she is grateful to be alive and to the medical team that pulled her through.
Rebuilding a Body, One Lap at a Time
Part of that rebuilding happened on the running path. During her physical rehabilitation, Gruenhut re-learned basic movement by walking and running 5Ks in Long Island's Eisenhower Park alongside guide runners from Achilles International, the Herald reported in 2022. The nonprofit, founded in 1983 by Dick Traum — the first amputee to finish the New York City Marathon on a prosthetic leg — now operates 62 chapters worldwide pairing adaptive athletes with volunteer guides, according to Achilles International.
Gruenhut started running in 2018 and went on to complete a half-marathon, per NBC 5 Chicago's account. She now competes as an athlete with a disability, running with Brian, her guide and friend, who travels from New York to join her on race courses. In Chicago, Brian is expected to be one of the two guide runners she is permitted under major marathon rules, which allow up to two guides per race and set designated exchange stations near the midway point, according to Achilles International's course guidance for athletes with disabilities.
A Field Built for Record Numbers, With Strict Limits for Para Athletes
Sunday's race is scheduled to be the 48th running of the Chicago Marathon, with a record field of more than 55,000 registered runners set to cover 26.2 miles through 29 city neighborhoods, according to the Bank of America Chicago Marathon. More than 160,000 people applied through the race's lottery this year. Within that massive field, the marathon's Para Athletics Program provides an opportunity for athletes with disabilities to compete.
Encephalitis, the brain infection that nearly killed Gruenhut, is rare. Research published on PMC estimated the incidence of infectious encephalitis overall at 1.0 case per 100,000 person-years; encephalitis causes acute brain swelling and carries a high risk of permanent neurological damage. Separately, Gruenhut's multiple sclerosis places her among an estimated 1 million people in the United States living with the autoimmune condition, in which the immune system attacks the protective myelin sheaths around nerves in the central nervous system, per Medical News Today.
Ten Marathons and a Three-Week Turnaround
Chicago will be Gruenhut's 10th marathon overall. She has completed the New York City Marathon five times, along with marathons in Chicago, Boston, London and Berlin, NBC 5 Chicago reports.
She isn't done. Gruenhut plans to run the New York City Marathon again just three weeks after Chicago, per NBC 5 Chicago's reporting. She has said she would keep running despite severe illness and limited mobility, and that her recovery showed people can accomplish extraordinary things.
The marathon's charity program, meanwhile, has become its own force: participants raised a record $47.1 million for charitable causes during the 2025 race, pushing the event's cumulative charity total past $405 million since 2002, according to Funds Society.
