Media tycoon Sumner Redstone is suffering from dementia, according to an expert witness physician who testified today in Los Angeles Superior Court.

The report on the billionaire’s ailing mental health was provided by Dr. Stephen Read, a geriatric psychiatrist who examined the billionaire at the end of January at the request of Redstone’s former companion, Manuela Herzer. Redstone stepped down as chairman of both Viacom and CBS just a week later.

Herzer filed the claims that launched today’s trial in November of last year, alleging that Redstone was not mentally competent when he removed her from his estate plan in October. She would have gained $70 million before the change, and was also acting as his health-care agent.

“He didn’t have the requisite mental capacity to understand the changing of his health care directive of Oct. 16, 2015,” Read testified. He said he believe that Redstone is “severely impaired” and is suffering from delusions and poor reasoning skills, which are signs of moderate to high dementia, according to Read.

But Redstone’s videotaped deposition told a different story. When he was asked by his attorney, Gabrielle Vidal, who should be his health care representative, he responded, “Shari,” in reference to his daughter, Shari Redstone, prompting the judge to say he has given “strong testimony” that should be respected. The younger Redstone controls 20 percent of both companies while Sumner still controls 80 percent.

The trial is expected to continue through May 16.