An ex-girlfriend of billionaire Sumner Redstone, who is 92, filed a lawsuit Wednesday, alleging that he is unable to make his own decisions and questions his mental faculties. Redstone, who is chairman of both Viacom Inc. and CBS Corp., has no succession plans in place, the Los Angeles Times reports.

The lawsuit raises questions about his overall health and whether he is capable of continuing to oversee the affairs of both companies.

However, one of Redstone’s attorneys referred to the lawsuit as “meritless” and an “invasion of privacy.”