Row before and after?

[Waynn Lue]

I'm trying to find the first row before and the first row after a specific
row.  Essentially I want to do these two queries, and get each row.

SELECT * FROM Users WHERE UserId = <userId> ORDER BY UserId DESC LIMIT 1;
SELECT * FROM Users WHERE UserId = <userId> ORDER BY UserId LIMIT 1;

Is there any way to combine this into one query?  OFFSET doesn't allow a
negative number, which is essentially what I want.

Thanks,
Waynn