Nottingham's Clinical Commissioning Groups said some services could be delivered in a "community setting".
Heather Peacock, from West Bridgford, who went into coma following the crash in 2015, said this would be a mistake.
Dr James Hopkinson, clinical lead at one CCG, said the measures were about getting "best value" for patients.
Ms Peacock was in a coma for eight weeks following the accident on 1 April which, along with her brain injury, left her with limited movement down her left side.
The 24-year-old, who has been receiving care at Nottingham's City Hospital, said the part of the proposals involved providing only 16 weeks of outpatient care for people with brain injuries.
"I'm very worried about future patients... I want everyone to get the amount of great care and support that I received," she said.
"I've been going back to outpatients for a year now and it has only been in the last few weeks that I have improved quite dramatically."
Seven hospital-based services, including neurology assessment and brain injury care, could be affected if the proposals go ahead.
The local CCG groups said those services based at Nottingham University Hospitals (NUH) could be delivered in the community, closer to patients' homes.
Dr Hopkinson said: "We're aiming to ensure all those services are fit for purpose and meets the patients' needs and give the best value for money for the public and taxpayer."
The Health Service Journal said it had seen a leaked document to staff that said 13 services would be decommissioned by the CCGs this year.
One of its senior journalists, Shaun Lintern, said it referred an additional 17 services, which are not mentioned in the online consultation, but would be "redesigned".
He said many were to be finished and signed off by July which was "extremely ambitious."
A woman who suffered a brain injury in a car crash has said she fears planned changes to hospital services could damage patient care.