Former Air Force reservist Gale Reid received a letter from the Veterans Affairs Department that told her she had Lou Gehrig's disease, and she immediately put herself through a battery of painful, expensive tests. Five days later, the VA said its "diagnosis" was a mistake.

Letters were sent to 1,864 veterans about disability benefits for those with ALS, also known as Lou Gehrig's disease, and a "small number" have contacted the VA indicating they received the letters in error, VA spokeswoman Katie Roberts said Monday night.

However, the National Gulf War Resource Center said Reid was among at least 1,200 veterans who received the letter, even though they hadn't been diagnosed with the illness. Veterans were initially suspicious, but still went through the pain not knowing whether they had the degenerative disease, which typically kills people within five years.

The Resource Center said at least 2,500 letters informing veterans of disability benefits for ALS sufferers were sent, with almost half a mistake. Roberts said the number sent was not that high and that only less than 10 people had called to say they had gotten an ALS benefits letter but didn't have the disease.

The veterans group president Jim Bunker said it stood by its figures.

Those who received the letters have undiagnosed neurological disorders, according to the Gulf War veterans group, which provides information, support and referrals about illnesses to people who served in the military.

No one knows for sure exactly how many letters were mailed to veterans treated at VA hospitals and how many were a mistake.

"VA is immediately reviewing the individual claims files for all the recipients of this letter to identify those who received the notification in error," the VA said in a statement Monday night.

Former Army Sgt. Samuel Hargrove cried Sunday after opening his letter.

"I can't even describe the intensity of my feelings," said the father of two from Henderson, N.C. "With so many health issues that I already have, I didn't know how to approach my family with the news."

So, at first, he didn't. Hargrove later discovered the mistake after talking with fellow veterans in the resource center and online. He was angry, as is Reid.

"I've been through a week of hell, emotionally, physically and financially," she said.

Denise Nichols, vice president of the resource center, said her group has received calls and e-mails from panicked veterans in Alabama, Florida, Kansas, North Carolina, West Virginia and Wyoming.

"Our fear was this could push somebody over the edge," said Nichols, who worried the news could lead already fragile veterans to commit suicide. "We don't want that to happen."

Jim Bunker, president of the veterans group, said he talked to someone at the VA and was told the mistake was caused by a coding error. The VA uses more than 8,000 codes for various diseases and illnesses and veterans with undiagnosed neurological disorders, which can range from mild to severe.

ALS is a rapidly progressive disease that attacks the nerve cells responsible for controlling voluntary muscles.

Nichols said she suspected something was amiss because some of the veterans she knew who received the letters did not exhibit any symptoms. Hargrove said he became suspicious because the letter didn't come from his doctor, and Reid said she sought a second opinion even though she believed the letter wasn't the right way to inform patients of a diagnosis.

The veterans groups notified the VA of the problems late last week, and the agency was in the process of calling every person who mistakenly received a letter, Bunker said.

The VA has taken some heavy criticism already this year. In June, Congress questioned the agency over botched colonoscopies at medical centers in Florida, Georgia and Tennessee that may have exposed 10,000 veterans to HIV and other infections. Last month, the VA Medical Center in Philadelphia disclosed that the number of cancer patients receiving incorrect radiation doses had risen to 98 veterans over a six-year period.

The Gulf War veterans group is urging the VA to reimburse any veteran who scheduled additional tests with civilian doctors. Reid said her tests cost about $3,000, though it may take weeks before she finds out how much her private insurance will cover.

"We are trying to work with the VA because we realize it was an error and they were trying to do something right for the people who were diagnosed with ALS," Nichols said. "Basically this was a good effort that ended badly."