Favre played in 20 NFL seasons and previously shared on The Bubba Army radio show that he sustained “thousands” of concussions during his football career. “Every time my head hit the turf, there was ringing or stars going, flash bulbs, but I was still able to play,” he said in the interview. “That’s what’s kind of frightening about the concussion thing. It’s the ones that seem minor that do the damage, because you’re able to keep going, and still today there’s probably guys that have them, they’re [saying] ‘I’m not going out.’” Favre also produced the new Apple TV movie Concussed: The American Dream.

Favre later spoke to TMZ Sports about his diagnosis, which he said he received on Jan. 3, 2024. According to the former football star, he met with five specialists, who, he claims, told him the same thing: "If [Parkinson's is] not in your family — and there's none on either side of my family — then the first thing we look at is head trauma." Says Favre: "Well, hell. I wrote the book on head trauma."

Favre added that he had "very minor symptoms" prior to his diagnosis. "I had two symptoms, and they went on for about a year," he told TMZ Sports. The first was his right arm raising up and being "stuck" in a right-angle position by his side. Favre, who is right-handed, said the strength in both his arms and hands are "fine," but he noticed that he would need to use two hands to, say, use a screwdriver. "The weirdest one was, like, a long-sleeved shirt or a jacket," he said. "I would go put my right arm in it, and I couldn't get it through the hole for nothing. ... I felt my arm, the strength was there, but I could not guide it. And it was the most frustrating thing."

On Tuesday night the ex-Green Bay Packer took to X to thank fans for their support regarding his diagnosis, which he said has "been an ordeal."

Favre’s revelation has raised a lot of questions about Parkinson’s disease, including a potential connection to concussions. Here’s what neurologists want you to know.

Can concussions raise your risk of Parkinson’s disease?

That’s not entirely clear at this point. Research has found a link between head trauma and the risk of developing Parkinson’s disease. One study published in the journal Neurology found that even having a mild brain injury raised the risk of developing Parkinson’s disease by up to 56%. Another study published in the journal Family Medicine and Community Health found that people who had experienced a concussion were 57% more likely to develop Parkinson’s disease.

“There is a potential link,” says Dr. Daniel Truong, a neurologist and medical director of the Truong Neuroscience Institute at MemorialCare Orange Coast Medical Center in Fountain Valley, Calif.

"Parkinson's disease is linked with higher levels of tau, a protein, in the brain," Dr. Amit Sachdev, medical director in the Department of Neurology at Michigan State University, tells Yahoo Life. "It is hard to know for sure if concussion is associated with elevated tau and, if so, if this deposits on the brain in a pattern to cause the disease."

Pal also notes that a JAMA study that was released last year found that playing football was linked with a greater chance of having a diagnosis of parkinsonism (a group of conditions that cause similar Parkinson’s-like symptoms) or a Parkinson’s disease diagnosis — and the odds were greater the longer a person played the sport. Still, this link isn’t definitive. “Playing football might be a risk factor for Parkinson’s, but the evidence is still mixed,” Pal says.

Parkinson’s disease symptoms

Symptoms of the disease can vary by person, but the NIA says these are the four main symptoms of Parkinson’s:

• Tremor in hands, arms, legs, jaw or head

• Muscle stiffness

• Slowness of movement

• Trouble with balance and coordination

Aside from medication, physical activity can also be helpful for managing symptoms, Pal says.

If you’re having symptoms of Parkinson’s disease, Pal recommends getting an evaluation with a movement disorder specialist as soon as possible to see if it could be the disease or something else entirely. “Then they will better understand what the long-term outlook would look like,” he says.

"Parkinson's is a progressive disorder with many features," adds Sachdev. "Early diagnosis is important."

Pal stresses that there are medications and treatments to help. “Generally, Parkinson’s is a slow, progressive disease,” he says. “We have a lot of treatments available.”