WASHINGTON — A massive stroke that kept Sen. Mark Kirk, R-Ill., out of the Senate for nearly a year has left him with impaired vision in one eye, occasional halting speech, no use of an arm and limited use of a leg, according to a short medical letter his campaign released on Wednesday.

The Kirk campaign issued a three-paragraph letter dated July 19, 2016, from Dr. Richard Fessler, the Chicago neurosurgeon who performed Kirk’s brain surgery after his Jan. 21, 2012, stroke.

Politically, Kirk’s campaign believes the big question voters have is about the mental state of Kirk, who turns 57 on Thursday, and what the lingering fallout of the stroke has on his judgment.

Some of Kirk’s controversial remarks — such as calling his colleague, Sen. Lindsey Graham, R-S.C., a “bro with no ho” in 2015 — have fueled speculation about Kirk’s mental status.

Kirk’s stroke did not affect “the left side of his brain, which controls cognitive and verbal functions,” Fessler wrote, concluding Kirk “has made a full cognitive recovery.”

Fessler’s letter omits basic information yielded in routine physical exams: what medications Kirk takes; the results of basic lab tests; his blood pressure; electrocardiogram results.

The letter is titled by Fessler as a “Summary of Mark Kirk Medical History” and does not discuss what medical specialists Kirk may be seeing or has seen since his stroke.

The fitness of candidates is in the news on the presidential front, and it’s a potential factor in the Illinois Senate contest between Kirk and Rep. Tammy Duckworth, D-Ill., because both contenders are disabled.

Donald Trump has yet to release a detailed medical report. Hillary Clinton, who last Friday was diagnosed with pneumonia, in July 2015 released a medical report from the internist who treats her, and on Wednesday that doctor issued another letter with the latest Clinton health details.

The Illinois Senate race is unique in that Kirk and Duckworth have strong comeback stories after facing daunting physical challenges.

Kirk and Duckworth use canes and wheelchairs, and have been observed getting around with the assistance of an attendant.

Duckworth was a member of the Illinois National Guard when she lost both legs and shattered her right arm when her Blackhawk helicopter was shot down in Iraq on Nov. 12, 2004.

Since early this year, the Chicago Sun-Times has been requesting detailed medical records from the Kirk and Duckworth campaigns. A Duckworth spokesman said the information is being compiled but could not say when a medical report would be released.

Fessler performed a craniotomy on Kirk at Northwestern Memorial Hospital after he “suffered an ischemic stroke caused by a dissection of his right carotid artery,” the neurosurgeon wrote.

Kirk benefited from being part of trial studies on stroke victims conducted by the Rehabilitation Institute of Chicago. The pilot program of intensive physical therapy research started, by coincidence, at the time of his stroke.

Kirk “has made a full cognitive recovery and has made rapid improvements in his physical recovery,” Fessler wrote.

“Mr. Kirk’s stroke was on the right side of his brain, affecting the portions of his brain that regulate movement on the left side of his body. As a result, he has no use of his left arm or hand and limited use of his left leg, which is the strongest near the hip and weakest near the foot. He walks with the assistance of a cane and a brace on his lower left leg.

“He is unlikely to regain further range of motion on his left side, but he continues to undergo regular exercise and physical therapy to maintain his strength. His speech is occasionally halting but has vastly improved. The stroke did not effect the left side of his brain, which controls cognitive and verbal functions. His vision on the left is impaired.

“Aside from the lingering physical effects of the stroke, Mr. Kirk is a health 56-year-old male,” Fessler wrote.

After the Fessler letter was released, the Chicago Sun-Times asked the Kirk campaign for more information about his physical therapy.

Campaign manager Kevin Artl said in an email, “Kirk performs physical training and rehab 3-5 times per week, depending on the schedule, to continue his rehabilitation and to stay in shape. For the most part his exercises are treadmill-based along with a heavy regimen of stair climbing. He does his physical training and rehab at the Senate Gym and also at his residences in both D.C. and Highland Park.”

Kirk lives in a residential development on the grounds of the old Fort Sheridan in the northern suburb.

“He has a walking and stair route on the grounds of Fort Sheridan that he continues to time himself on to assess improvement and set goals.

“Because of mobility issues with his left arm, at the Capitol, Senator Kirk does have a staffer that among other duties pushes his wheelchair, but he does not require 24-hour assistance,” Artl said.

Mark Kirk Time Line

Nov. 2, 2010: In a close contest, then-Rep. Mark Kirk, R-Ill., beats Democrat Illinois Treasurer Alexi Giannoulias for a six-year term and to fill the small unexpired portion remaining of President Barack Obama’s Illinois Senate term. Kirk gets 48 percent of the vote to Giannoulias’ 46.4 percent.

Nov. 29, 2010: Kirk sworn into office.

Jan. 21, 2012: Kirk checks himself into Lake Forest Hospital. He suffers a stroke to right brain. Transfers to Northwestern Hospital.

Feb. 10, 2012: Transfers from Northwestern Hospital to the Rehabilitation Institute of Chicago. Becomes a patient in the new RIC Patient Recovery Unit and AbilityLab, which opened in January 2012.

April 27, 2012: Kirk discharged from inpatient RIC care.

April 30, 2012: Kirk is enrolled in “one of a kind” gait trial at the RIC.

July 16, 2012: Gait trial ends. Kirk goes to the RIC Day Rehabilitation Center in Wheeling for multiple therapies.

Dec., 2012: Kirk discharged from RIC.

Jan. 4, 2013: Returns to the Capitol, climbing the 45 steps to the Senate chamber.

Nov. 8, 2016: Election Day. Kirk battles for second term against Rep. Tammy Duckworth, D-Ill.