Here are a couple of things to remember when you want to use a parameterized LIKE clause in a SELECT statement.

When using a parameter to an integer ID column, you need to break the statement apart so that the parameter stands apart from the wildcard characters:

string sql = 
  @"SELECT * FROM myTable WHERE iId like '[%]' + @iId + '[%]'";

However, that same syntax will not work if you are using a varchar column. Instead, you need to embed the wildcard characters directly into the paramter's value:

string sql =
  @"SELECT * FROM myTable WHERE vcDesc like @iId";

cmd.Parameters.Add(new SqlParameter("@vcDesc", "%" + desc + "%"));

The second syntax works in both cases, so it probably just makes sense to use that everywhere and not worry