Washington, May 19 (Inditop) The 57-year-old lawyer had completed the tough New York Times’ Saturday crossword puzzle for years. But one Saturday morning, he just couldn’t find words to fill in the squares. He had been attacked by a brain virus.

In Chicago, an 83-year-old woman began parroting the same phrases over and over. When her doctor asked her how she was, she replied, “I am fine. I am fine. I am fine.”

The symptoms of the New York lawyer and the Chicago woman could have been mistaken for early dementia. But an MRI brain scan and biopsy revealed like their brains had been eaten away.

A brain biopsy and a spinal tap confirmed the diagnosis of a swiftly moving and often fatal viral brain infection called progressive multifocal leukoencephalitis (PML) that attacks the brain’s white matter.

Both had lymphoma and had been taking the popular cancer drug rituximab (brand name Rituxan) before they developed the brain infection.

Like other cancers, lymphoma occurs when lymphocytes or white blood cells are in a state of uncontrolled cell growth and multiplication.

The two patients are part of a new study from the Northwestern University Feinberg School of Medicine RADAR project, led by Charles Bennett, that links rituximab to PML.

Rituximab is the most important and widely used cancer drug for lymphoma. It is also approved for treatment of rheumatoid arthritis and is widely used off-label to treat multiple sclerosis, lupus and auto-immune anaemias.

Bennett reports on 57 cases from 1997 to 2008 in which patients with anemia, rheumatoid arthritis or lymphoma developed the fatal brain disease after taking rituximab.

They died an average of two months after being diagnosed, said a Northwestern release.

Bennett said the brain infection is often overlooked and undiagnosed because it is so subtle at first. “People may think it’s early Alzheimer’s disease or depression,” he said. “Many of these patients have cancer and when they die, people assume it’s the cancer that killed them.”

It is not yet known how rituximab is connected to the brain virus and who may be at risk.

The study was published in the May 14 issue of the journal Blood.

By rounak