A 96-year-old U.S. federal appeals court judge was barred Wednesday from hearing cases for a year after a panel said she refused to undergo medical testing amid concerns that she is no longer mentally fit to serve on the bench.

It’s the latest development in an unusually public and bitter fight over whether Judge Pauline Newman should continue to serve on the Washington-based U.S. Court of Appeals for the Federal Circuit that has sparked a lawsuit and turned judges against one another.

Newman, a President Ronald Reagan appointee who has been on the court for nearly four decades, insists that she remains physically and mentally fit to decide matters of the law, and has accused her colleagues of making baseless claims in an effort to push her out because of her age.