A schizophrenic patient with an arrhythmic circadian rest-activity cycle

Actigraphy to measure day structure as a therapeutic variable in the treatment of schizophrenic patients

OBJECTIVE

A component of social skills is the ability to adapt to the social rhythms of the environment. Patients with schizophrenia are often disabled in this adaptation. Thus, structuring activities throughout the day has long been known as part of psychosocial treatments. Actigraphy as a tool to measure acitvity and circadian rhythms may even serve as an indicator for the day-structuring of schizophrenic patients.

METHOD

Actigraphy was used in a patient with affective disorder and one with chronic schizophrenia for more than 2 weeks.

RESULTS

In comparison to a regular 24-hour rest-activity cycle in a depressed patient, the actigraph of the patient with schizophrenia presents active phases at night, irregular activity levels at day and signs of a delayed-sleep-phase syndrome.

CONCLUSION

Actigraphy could serve as a tool to investigate activity levels and circadian rest-activity phases, even in schizophrenia. There may be some further benefit of actigraphy as a tool in psychosocial treatments.

Actigraphic estimates of circadian rhythms and sleep/wake in older schizophrenia patients

Twenty-four hour circadian activity rhythms and light-exposure levels of 28 older schizophrenia patients (mean age=58years) were examined using an Actillume recorder. Sleep and wake were scored using the algorithm of the ACTION3 software which revealed that the patients slept for 67% of the night and napped for 9% of the day. Patients with more disturbed sleep and less robust circadian rhythms performed more poorly on neuropsychological tests. Patients with higher cognitive functioning and fewer extrapyramidal symptoms were more alert during the day. Few patients were exposed to high levels of illumination during the day, and older age was associated with lower levels of light exposure. Duration of antipsychotic use and higher antipsychotic doses were associated with decreased daytime alertness and less robust circadian activity rhythms. Patients taking antipsychotics were more sleepy both during the day and night than patients not taking antipsychotics. The circadian rhythm disturbances found in these patients did not seem to be due solely to low levels of illumination exposure. Life-style factors, behavioral factors, psychiatric symptoms and medications were likely contributors to the disturbed rhythms. The effects of the sleep disturbances did not seem to be benign. There were strong relationships between sleep and circadian rhythms and functioning.

Treatment of sleep disturbance in Alzheimer's disease

The prevalence of Alzheimer's disease (AD) is rapidly increasing as growing numbers of people around the world are living to old age. Sleep disturbances are a common, and often highly disruptive, behavioral symptom associated with AD. Nevertheless, the study of sleep in AD is relatively new. Little is known about the moderating factors that may alter a given patient's risk for developing sleep problems, or that may influence severity of presentation and persistence. Current treatments for improving sleep in AD fall into three broad categories: (i) pharmacological; (ii) cognitive-behavioral or psycho-educational strategies; and (iii) biological/circadian therapies. There are few studies demonstrating the efficacy of these treatments with community-dwelling AD patients, although studies with persons in institutional settings are promising. In this review, it is suggested that sleep problems in AD are multi-factorial, and influenced by a variety of demographic, physical, psychiatric and situational factors. These factors vary in how readily they can be modified and in how relevant they are to any individual case. Thus, when developing a treatment plan for sleep problems in a dementia patient, it is important to evaluate the underlying causes as well as the context in which the problems are occurring, and to target the intervention accordingly.

Haloperidol disrupts, clozapine reinstates the circadian rest-activity cycle in a patient with early-onset Alzheimer disease

Measurement of the circadian rest-activity cycle in a patient with early-onset Alzheimer disease for 555 days revealed marked changes in the timing and amount of nocturnal activity. After neuroleptic medication was changed to haloperidol, the rest-activity cycle became completely arrhythmic for two months, concomitant with a marked worsening of cognitive state. Circadian integrity returned together with clinical improvement when the patient was subsequently treated with clozapine. This observation suggests that the known tendency for patients with Alzheimer disease to develop sleep-wake cycle disturbances may be aggravated by a classic neuroleptic; in contrast, the atypical neuroleptic clozapine may consolidate it. Similar observations in schizophrenic patients indicate that this chronobiological finding is drug- and not illness-related.

Diurnal variation in spontaneous eye-blink rate

The daily pattern of spontaneous eye-blink rate (BR), a non-invasive peripheral measure of central dopamine activity, was investigated in 24 healthy subjects. The spontaneous eye-blink rate showed a stable pattern in morning, midday and afternoon hours. A significant increase was found at the evening time point (20.30 h). The finding is suggestive of a late evening increase of central dopamine activity. An increased level of subjective sleepiness was also found at the same evening point, at a time corresponding to the 'evening wake maintenance zone' or the 'forbidden zone for sleep'. A possible hypothesis is that the 'forbidden zone for sleep' may reflect a dopamine-mediated activation that counteracts a rising sleep drive. The role of diurnal variation of dopamine function should be considered both in the choice of the drug treatment regimen, and in the evaluation of biological and neuropsychological parameters.