Inside Sandra Bullock's Partner Bryan Randall's Quiet ALS Battle: Medical Expert Explains Condition

ET spoke with Dr. Jeffrey Rosenfeld about Randall's health battle and what he faced during his private illness.

Sandra Bullock's longtime partner, Bryan Randall, died on Saturday after a private battle with ALS. Randall had been battling ALS for several years, and Bullock was by his side, caring for him in his time of need.

In the wake of Randall's tragic death at age 57, ET spoke with Dr. Jeffrey Rosenfeld, MD/PhD and professor of neurology at Loma Linda University Health, who provided some insight on what the disease is, and what Randall may have faced in his battle with the illness.

"ALS is a progressive disorder that involves motor nerve cells," Dr. Rosenfeld explained. "Motor nerve cells in the body live in both the brain and the spinal cord and in the disease of ALS, both areas are affected in a progressive way."

According to Dr. Rosenfeld, one of the primary symptoms for most ALS patients presents as "some form of [physical] weakness." 

"It might be weakness in an arm, or a hand, or a leg, or their ability to walk, lift, carry through their regular workout. For others, it might be some change in speech, or swallowing or breathing, and for yet others, it's both, or combinations in various forms," Dr. Rosenfeld explained. "So it's quite variable, and how it presents, and also how the disease runs."

Because of these symptoms, many who are battling the disease often need additional help, and can sometimes retreat from the public eye.

"Almost all folks that have progressive motor neuron disease need some form of assistance that they certainly did not need before, and that also tends to keep folks more in the home, on the sidelines," Dr. Rosenfeld said, "as much as we do try to encourage them to stay involved in the community."

While ALS is a complex illness, and there's no known cure, there are new avenues of treatment and ways to try to deal with the symptoms and battle the condition.

"Currently, today, we have more treatment options for ALS than we've ever had before. We can modify the course of the disease," Dr. Rosenfeld explained. "Now, we can't yet take away the disease. It isn't for lack of trying. We're trying that, very aggressively. But we have disease modifying therapies."

One point Dr. Rosenfeld stressed was that the disease impacts and progresses in everyone differently, and there's no specific life expectancy when diagnosed.

"I've had patients that, despite best efforts, they do progress, rather rapidly, in three years," he shared. "I've had others that I'm following up with for more than 15 years with this diagnosis."

"There are so many factors that balance in to how a person does [when dealing] with this disease. For example, where your head is, or what your mindset is, or how aggressive is the disease? What kind of support do you have around you?" Dr. Rosenfeld said. "So I really feel like it's difficult to put an average number on it."

Randall's death was confirmed in a statement released by his family over the weekend.

"It is with great sadness that we share that on Aug. 5, Bryan Randall passed away peacefully after a three-year battle with ALS," his family told ET. "Bryan chose early to keep his journey with ALS private and those of us who cared for him did our best to honor his request."

"We are immensely grateful to the tireless doctors who navigated the landscape of this illness with us and to the astounding nurses who became our roommates, often sacrificing their own families to be with ours," his family added.

"At this time we ask for privacy to grieve and to come to terms with the impossibility of saying goodbye to Bryan," the statement concluded, signed, "His Loving Family."

Randall's family said that donations can be made in his honor to ALS Research and Massachusetts General Hospital.

Bullock, 59, first met Randall, a photographer and model, when he photographed her son Louis' birthday in January 2015. Louis is now 13, and Bullock is also mom to Laila, 11. They went public with their romance later that year, but largely kept their relationship private. In 2017, the couple reportedly exchanged vows in an intimate, albeit not legally binding, ceremony in the Bahamas.

On Monday, Gesine Bullock-Prado, Bullock's sister, took to Instagram to pay tribute to the late photographer.

"I'm convinced that Bry has found the best fishing spot in heaven and is already casting his lure into rushing rivers teaming with salmon," Bullock-Prado wrote alongside a smiling photo of Randall. "ALS is a cruel disease but there is some comfort in knowing he had the best of caretakers in my amazing sister and the band of nurses she assembled who helped her look after him in their home."