MUSKEGON, Mich. — A Muskegon teenager woke up one morning in March with what felt like a stiff neck — by that night, he couldn't feel his legs.
WATCH: 'It was terrifying': Muskegon teen relearning to walk after rare autoimmune diagnosis
Fifteen-year-old Lenni Mendez initially brushed off the discomfort.
"Kind of when I woke up, I had a neck pain, but it was kind of like something you feel, like you slept on it wrong," Lenni said.
By that evening, Lenni was struggling to move his hands. His mother, Erin, noticed something was seriously wrong.
"It wasn't until he came in my room complaining that he couldn't make a fist with his hands or any of that, and that he had chest pain and neck pain," Erin said.
As she prepared to take him to the hospital, his condition worsened rapidly.
"I started to try to walk him down the steps, and that's when he was like, I can't feel my legs, call 911," Erin said.
Lenni was taken to Trinity Health Muskegon and then transferred to Helen DeVos Children's Hospital, where an MRI showed signs of transverse myelitis, a neurological disorder that causes inflammation of the spinal cord.
"That can cause things like weakness in the body, it can cause pain, it can cause sensory disturbances and impairments in bowel and bladder function," said Dr. Marianne Mousigian, Lenni's pediatric rehabilitation physician at Mary Free Bed.
Lenni's transverse myelitis was caused by a rare autoimmune disorder known as MOGAD.
"I think MOGAD, I think I'm living with that for the rest of my life, sadly, unfortunately. Transverse myelitis can be treated, but so far, right now, I still have it," Lenni said.
Transverse myelitis affects approximately 1,400 people per year in the United States. Dr. Mousigian said the condition is rare, adding, "There can be anywhere between one to eight cases per million people."
Lenni was admitted to Mary Free Bed in late March and began intensive rehabilitation, including physical therapy focused on day-to-day mobility and generalized strengthening after an extended period without walking, as well as occupational therapy covering activities of daily living such as bathing and dressing.
Through online support groups, Erin learned about additional treatment options — PLEX and IVIG. Lenni returned to Helen DeVos for a week and a half in May to receive those treatments and began noticing significant improvements almost immediately, progressing rapidly after returning to Mary Free Bed for rehabilitation.
"I think it's a matter of relearning how to do things again," Lenni said.
He is now able to feed himself and take steps toward walking on his own. The progress has been remarkable, according to Dr. Mousigian.
"We went from, with Lenni, celebrating trace twitches in his fingers and toes to now, I was just talking with his physical therapist today, and he is walking up to 400 feet with a walker, just on his own," Dr. Mousigian said.
Erin said the experience has been overwhelming, but she wants other families to know what to watch for.
"It was terrifying as a mother, because you can't treat or help your child in this," Erin said. "Awareness is key, because there's not enough awareness about MOGAD, and it is very scary when it happens to your child, and especially when your child's completely healthy."
Lenni is expected to return home July 16 after more than a three month stay at Mary Free Bed.
He plans to begin 10th grade in the fall.
This story was reported on-air by a journalist and has been converted to this platform with the assistance of AI. Our editorial team verifies all reporting on all platforms for fairness and accuracy.
