Good practice in the assessment and management of nocturnal Parkinson’s disease symptoms

Abstract

The disability associated with Parkinson’s disease (PD) is classically attributed to a range of motor symptoms, but people with PD also experience non-motor symptoms, ranging from cognitive and psychiatric problems including depression, apathy and anxiety, to sleep disorders, nocturia, sexual dysfunction, and faecal and urinary incontinence. Individuals have different experiences of PD, but in a recent survey of patients attending a UK PD clinic, sleep disturbance was the second most common non-motor symptom reported after balance problems [1]. Other studies have reported that 67–98% of patients are affected by sleeprelated problems and that these become increasingly prevalent as the disease progresses [2]. People with PD experience a wide range of sleeprelated symptoms, but in a recent pilot survey of members of the UK Parkinson’s Disease Society, 41% of patients reported tiredness, fatigue and a lack of energy, while 30% said that they experienced frequent waking during the night and difficulty in sleeping, falling asleep and manoeuvring in bed [3]. Although advancing disease and the adverse effects of some drug treatments are contributory factors, disruption of nocturnal sleep is undoubtedly an important cause of excessive daytime sleepiness, which can be objectively verified in half the patients included in sleep laboratory studies [4]. Obstructive sleep apnoea syndromes are a common and treatable cause of disrupted sleep and daytime sleepiness in the elderly PD population [5]. Sleepiness during the day results in impaired quality of life, and may be associated with cardiovascular risk [6], dementia or cognitive impairment [7], and an increased risk of accidents [8]. Conversely, studies of treatments designed to alleviate nocturnal symptoms have reported improvements in clinical global state, as well as reduction in painful dyskinesias, dystonia and nocturnal akinesia [9]. Improvement in nocturnal symptoms also has the potential to reduce caregiver burden, since sleep disturbance among PD patients commonly has a negative impact on the sleep of their spouses. Indeed, the impact of specific effects of PD on sleep may be at least as profound on the spouses as on the patients themselves. In one study of caregivers, sleep disturbance was reported by 90%, poor subjective sleep quality by 65% and sleep latency by 55%. Daytime dysfunction was also reported by 80%, though this was generally due to ‘reduced enthusiasm’ rather than actual difficulty in staying awake (80% versus 5%) [10]. Two types of sleep disturbance have been reported among PD spouses: the first is associated with awakening during the night to help the patient and is predicted by the disease severity and the patient’s sleep disturbance, while the second is predicted by the spouse’s own level of stress and depression [11]. The negative impact of PD-related sleep disturbance on both patients and their family caregivers warrants aggressive intervention, but the approach to treatment will be influenced by the aetiology of the symptoms in each patient.