(CBS News) – Doctors are still learning about the long-term effects patients can face weeks and months after having the coronavirus. Now a first-of-its-kind study highlights the neurological problems for many COVID survivors.

New research from a Northwestern Medicine study looked at more than 500 hospitalized patients and found 82% had neurological issues while they were sick. According to Dr. Igor Koralnik, symptoms include: “Muscle pain, headache, encephalopathy, which means alteration of mental function, going from mild confusion all the way to coma, dizziness, disorder of smell and taste.”

Dr. Koralnik oversees the neuro COVID-19 clinic at Northwestern. Most patients are long haulers: young, previously healthy, had less severe COVID, and still suffering with issues. “Lingering and fluctuating over time, sometime lasting months. The general trend is for people to improve over time,” Dr. Koralnik says.

It’s the case for Maria Manfredini. She and her fiancé were planning their dream wedding in Italy when the pandemic hit. Forced to cancel, they took a quick trip to Arizona in June and came home with COVID-19. “No smell, no taste, horrible body aches, and it really attacked my legs. Horrible leg pains,” Manfredini says. Six months later, the 35-year-old is still not feeling well. Her worst symptoms are leg pain and brain fog. “It’s extremely frustrating because everybody, the first thing they tell me is, well, you look great. You can’t be sick. At the end of the day, I’m exhausted, I’m in pain,” Manfredini says.

“They think I’ll fully recover, which is, you know, fantastic. But at the end of my appointment with him, I just broke down again and thanked him,” Manfredini says. She and her husband were married in September. She’s trying alternative treatments like vitamin infusions and diet and says some of her symptoms are improving.

The study also found hospitalized patients had more serious neurological problems such as stroke, seizures, and movement disorders, but they were less common.