Delirium is a common and serious condition and is associated with adverse outcome. The elderly who have cognitive dysfunction are expected to show delirium more frequently. It is most likely that delirium represents a response to impaired cholinergic neurotransmission. Investigators aimed to establish the preventive effect of the cholinesterase inhibitor, rivastigmine patch, on the post-operative delirium limited to femur neck fracture operation in patients at risk of dementia.

Investigators evaluated the delirium prevention effect of rivastigmine patch in patients with femur neck fracture and cognitive impairment. Investigators measured the frequency and severity of post-operation delirium in the patch applied and non-applied subjects.

Inclusion Criteria:

• Consecutively enrolled the patients who is going to operation after femur neck fracture.
• Patients agree to the informed consent.

Exclusion Criteria:

• depressive mood and their geriatric depression scale is over 6 / 15.
• Their Korean version MMSE(minimental status examination) are over 25, or global dementia scale (GDS) are under 3 or over 5.
• any delirious state at pre-operation period by DSM IV and CAM (Confusion Assessment Method)