these descriptions are stored in the sysproperties system table (don't know if they are also stored in any INFORMATION_SCHEMA view) along with the object id of the table...
this query should (hopefully) return the column name and the description (if any):
DECLARE @TableName Varchar(100)
SET @TableName = 'xxxxxxxx'
FROM syscolumns SC LEFT OUTER JOIN sysproperties SP ON
SP.id = SC.id
WHERE SC.id = object_id(@TableName)