SQL Server 2008 :: How To Subtract Dates From Previous Date On Same Patient

I have a list of patient encounter dates ordered by the date. I need to subtract the previous date in order to get the number of days between each date for the same patient.

create table TEST
(
MRN varchar(10),
EncDTTM datetime,
Sequence int
)
insert into TEST(MRN, EncDTTM, Sequence) values( '00000203','2014-01-24','1')
insert into TEST(MRN, EncDTTM, Sequence) values( '00000203','2014-02-03','2')

[code]....