The 70-year-old Georgia Republican said in a statement the disease has not impeded his senatorial duties and pointed to the fact he sits on five committees, two of which he chairs.

“I am busier and have more responsibility today than ever before in my political career, and I couldn’t be happier about that,” Isakson said. “I remain devoted to public service, to my state and to my constituents. I am eager to take my record of results to the voters of Georgia as I run for re-election in 2016.”

Following the announcement, the Senate’s leaders voiced their support for Georgia’s senior senator.

“No one works harder than Johnny Isakson, who is the only Senator chairing two committees in the Senate,” Majority Leader Mitch McConnell, R-Ky., said in a statement. “This diagnosis will not slow him down one bit.”

Minority Leader Harry Reid expressed similar sentiments in his own written statement.

“Senator Isakson is tough. Johnny has represented the people of Georgia with distinction and honor in the Senate. Today’s announcement has shown his tremendous courage in his fight against Parkinson’s and his resolute determination to not let it take control of him,” the Nevada Democrat said.

The Georgia Senate race is rated Republican Favored by The Rothenberg & Gonzales Political Report/Roll Call.

Isakson said he was diagnosed in 2013, but first went to see a neurologist for stiffness in his left arm in 2012. He noted the disease is still in the early stages and said the arm stiffness and his slow, shuffling walk are two of the more prominent signs.

Isakson only recently told his children of the diagnosis and struggled with whether to make a public announcement.

“While I am facing this health challenge head on, I have wrestled with whether to disclose it publicly,” Isakson wrote. “In the end, I decided I should handle my personal health challenge with the same transparency that I have championed throughout my career.”

Isakson’s statement quoted his physician, Thomas M. Holmes, who confirmed he treats Isakson, that Isakson complies with treatment recommendations and that the Parkinson’s should not inhibit his ability to run for and serve another term.

“I believe he is fully capable of continuing to perform his duties as a U.S. Senator, and I believe he is fully capable of running for re-election and serving for another term,” Holmes said.