MINNEAPOLIS (AP) - A Minnesota lawmaker 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 that determined the VA Medical Center in Minneapolis didn't use specialists to perform traumatic brain injury exams on some veterans, in violation of Veterans Administration policy.

The investigation said 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."