MINNEAPOLIS — A lawmaker from Minnesota is pushing for a nationwide investigation into the Veterans Administration to determine how many unqualified personnel have performed traumatic brain injury exams.

The request by Democratic Rep. Tim Walz follows an investigation by KARE-TV that determined the VA Medical Center in Minneapolis didn’t use specialists to perform traumatic brain injury (TBI) exams on some veterans, in violation of Veterans Administration policy, resulting in veterans being improperly denied benefits. The station reported that the exams by underqualified personnel went on for years.

Walz has sent a letter to the Inspector General for the Department of Veterans Affairs, saying he’s concerned that the problems exposed in Minneapolis may exist “throughout the VA system.”

“It’s certainly possible if it happened in Minneapolis it’s possible, and I would argue probable, it happened elsewhere,” Walz told the station on Wednesday.

According to Veterans Administration policy, initial traumatic brain injury exams must be performed by doctors in one of four specialties, including neurology and neurosurgery.

Butch Hamersma, a Vietnam veteran who operates a farm near Spring Valley, said he was denied traumatic brain injury benefits after an exam was performed on him by a nurse practitioner, instead of a neurologist. Despite medical records showing his skull was shattered in an explosion in November 1968, Hamersma still was denied those benefits.

Shortly after KARE-TV reported Hamersma’s story, Minneapolis VA Health Care Systems Director Patrick Kelly wrote in an email to staff, “It’s true that we used the wrong type of examiner on some initial TBI exams from 2010-2014.”

Walz, who sits on the House Veterans’ Affairs Committee, believes that more than 300 veterans have been impacted by the improper exams.

Minneapolis VA Public Information Officer Ralph Heussner said last month that veterans who were not seen by specialists were being offered new examinations.

Walz calls traumatic brain injuries “the signature wound” of the wars in Iraq and Afghanistan, so he believes it’s “essential” to find out if unqualified doctors are performing these exams at other VA facilities across the country.

“I want to know that every veteran that went in to do a C & P exam and specifically being screened for TBI saw a qualified medical professional,” he said.

Citing concerns over “personal privacy” violations, the Department of Veterans Affairs has denied multiple Freedom of Information Act requests seeking the names and qualifications of medical personnel who had performed initial TBI exams at VA Medical Centers.

KARE-TV and its parent company, TEGNA, are appealing the VA’s denial of the requests, arguing that the information will allow them to learn how many veterans have been examined by unqualified personnel.