Effects of Bright Light to Improve Agitation and Sleep Disorders in Patients With Alzheimer's Disease

Background: Management of patients with Alzheimer's disease associated with behavioral disturbances is difficult especially in those with agitation/aggression and insomnia and nighttime behaviors. No treatment has shown any efficacy to control these disturbances and psychotropics drugs, i.e. sedatives and hypnotics have numerous adverse effects.

Objective: Assess the effect of bright light therapy on behavioral disturbances of patients with Alzheimer's disease, especially the effect on agitation/aggression and insomnia and nighttime behaviours.

Study design: Multicenter non pharmacological intervention trial, controlled, randomized, open, two-arm design : control group and intervention group.

Centres : Rehabilitation and long term-care units of 4 geriatric hospital wards.

Patients: 120 patients admitted in geriatric hospital wards (30 by centre), with probable Alzheimer's disease according to DSM-IV diagnosis criteria and agitation/aggression (associated or not with insomnia or nighttime behaviors) according to the Neuropsychiatric inventory, nurse scale (NPI-nurse).

Treatments: Intervention group: patients will participate in a program of bright light therapy realised during a one-hour sessions of occupational therapy,. These sessions will be realised for groups of 6 patients and will be done every week day, at late morning, for 4 consecutive weeks). During the session, patients will be exposed to 10000 lux-bright light. Patients of control group will participate in a program of occupational therapy of same duration and rhythm, realised in standard light conditions (about 300 lux).

Assessment: Patients with be assessed on 3 occasions: inclusion, two and four weeks after the beginning of the programs. Assessment will comprise ; NPI-nurse scale and Cohen-Mansfield scale for behaviour disturbances, wrist actimetry for sleep and nighttime behaviours (total sleep length, nocturnal wake episodes and nocturnal motor agitation).

Judgment criteria: Principal: changes in the agitation/aggression item of NPI-nurse scale. Secondary: changes of the nightime behaviours item of NPI-nurse scale, the Cohen-Mansfield, total sleep duration and numbers of nocturnal wake episodes measured by wrist actimetry.

Statistics: Changes in agitation/aggression scores od the two groups will be compared by Mann and Whitney test.

Expected results and perspectives; If bright light exposure is efficient, professional caregivers of Alzheimer's disease patients might apply this cheap and non pharmacological approach to improve behaviour and sleep of these patients. This study might contribute to better define the place of a non invasive and promising technique, wrist actigraphy, to assess sleep and behaviour disturbances in psychogeriatric patients