Sleep disturbances and nocturnal agitation behaviors in older adults with dementia.

STUDY OBJECTIVES

To examine nighttime sleep patterns of persons with dementia showing nocturnal agitation behaviors and to determine whether restless legs syndrome (RLS), periodic limb movements in sleep (PLMS), and obstructive sleep apnea (OSA) are associated with nocturnal agitation behaviors.

DESIGN

Cross-sectional.

SETTING

General community.

PARTICIPANTS

59 participants with geriatrician-diagnosed dementia. Participants ages ranged from 66 to 88 years (mean age 79.1; SD 6.0). Mean Mini Mental State Examination (MMSE) score was 20.1 (SD 6.6). MMSE was used to measure baseline cognitive function and not for the diagnosis of dementia.

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

Sleep was measured by 2 nights of in-home, attended, portable polysomnography (PSG). Nocturnal agitation was measured over 3 additional nights using the Cohen-Mansfield Agitation Inventory modified for direct observations. Two experts independently and via consensus identified probable RLS. Total sleep time in participants was 5.6 h (SD 1.8 h). Mean periodic limb movements in sleep index (PLMI) was 15.29, and a high percentage (49%) had moderate to severe obstructive sleep apnea. Probable RLS was present in 24% of participants. Those with more severe cognitive impairment had longer sleep latency. Severe cognitive impairment, low apnea hypopnea index (AHI), and probable RLS were associated with nocturnal agitation behaviors (R(2) = 0.35, F(3,55) = 9.40, P < 0.001).

CONCLUSIONS

It appears that probable RLS is associated with nocturnal agitation behaviors in persons with dementia, while OSA and PLMS are not. Further investigation is warranted to determine if treatment of RLS impacts nocturnal agitation behaviors in persons with dementia.