His parents didn't know what to do:

In September[2007], David [Foster Wallace, then 45 years old] asked Amy to forgo her annual fall-break visit. He wasn't up to it. By October, his symptoms had become bad enough to send him to the hospital. His parents didn't know what to do. "I started worrying about that," Sally [his mother] says, "but then it seemed OK."

David Lipsky/Rolling Stone 30.Oct.08
via RW