M. Gjerstad

Epidemiology of Parkinson’s disease

Epidemiological research aims to provide information on the development, prevalence and progression of diseases, and their associated risk factors. Epidemiological research is thus the basis of increasing our understanding on the aetiology of diseases and as a consequence the starting point for identifying at risk groups in the population, development for novel prevention and treatment strategies, and health care planning. This review provides an overview of the epidemiology of Parkinson’s disease, the second most common neurodegenerative disorder, with special emphasis on population-based data on the clinical progression of motor and non-motor features of the disease.

Occurrence and clinical correlates of REM sleep behaviour disorder in patients with Parkinson’s disease over time

Objective: To examine the occurrence and clinical and demographic correlates of REM sleep behaviour disorder (RBD) in patients with Parkinson’s disease (PD) in a community-based cohort over 8 years. Methods: 231 patients with PD were included in a population-based prevalence study in 1993. Patients were then followed prospectively and reexamined after 4 and 8 years. Semi-structured interviews for information on clinical and demographic data were applied at all study visits. Standardised rating scales of parkinsonism, depression and cognitive impairment were used. The diagnosis of probable RBD (pRBD) was based on a sleep questionnaire. Proportional-odds ordinal logistic regression models for clustered data were used to study the relationship between pRBD and various demographic and clinical variables. Results: 231 patients were evaluated for RBD in 1993 and, after 4 and 8 years, 142 and 89 patients, respectively, were available for re-evaluation. The frequency of pRBD varied from 14.6% to 27% during the study period. Probable RBD was related to male gender, higher dopaminergic treatment and less severe parkinsonism. Conclusion: We found that the frequency of pRBD varied over time and that it is associated with male gender, less parkinsonism and higher levodopa equivalent dose. Our findings indicate that dopaminergic therapy may contribute to the expression of RBD and that RBD is symptomatic in earlier stages of PD.

Development of daytime somnolence over time in Parkinson's disease.

Abstract—The authors examined the development over time of excessive daytime sleepiness (EDS) in patients with PD by evaluating EDS among 142 patients in 1993 and 4 years later. Eleven patients were diagnosed with EDS in 1993. In all of these patients, EDS persisted 4 years later. During follow-up, 30 new patients had EDS (6% new patients per year). In 1997, 29% of the patients with PD had EDS. The development of EDS correlated with more advanced disease and dementia.

Insomnia in Parkinson's disease: frequency and progression over time

Objectives: To examine the development of nocturnal sleeping problems in patients with Parkinson’s disease (PD) over an 8-year period and to study the clinical and demographic correlates of insomnia. Methods: 231 patients were included in a population-based prevalence study in 1993, and re-examined in 1997 and 2001. At all study visits, we applied semi-structured interviews to obtain information on clinical and demographic data, as well as on nocturnal sleeping problems. Standardised rating scales of parkinsonism, depression and cognitive impairment were used. The relationship between insomnia and demographic and clinical variables was analysed using population-averaged logistic regression models for correlated data. 231 patients were included at baseline, 142 were available for re-evaluation in 1997 and 89 patients in 2001. Results: Most nocturnal sleeping problems varied little in prevalence over time, whereas problems related to turning in bed and vivid dreaming or nightmares increased. Insomnia was present in 54–60% of the patients at each of the three study visits and varied considerably in individual patients over time. The presence of insomnia was closely related to disease duration, higher Montgomery–Åsberg Depression Rating Scale scores and female sex. Conclusion: Insomnia is a highly frequent complaint in patients with PD. It fluctuates over time in individual patients, and its origin seems to be multifactorial. Physicians should be aware of the high prevalence of insomnia in patients with PD and should examine their patients for a possible coexisting depression.

Increased risk of leg motor restlessness but not RLS in early Parkinson disease

Objective: This study explores the risk and correlates of leg restlessness in drug-naive patients with Parkinson disease (PD) as compared to control subjects matched for age and gender. Methods: A total of 200 drug-naive patients with early, unmedicated PD derived from a population-based incident cohort and 173 age- and gender-matched control subjects were assessed for leg restlessness by structured interviews, clinical examination, and blood samples. All subjects were Caucasian. Restless legs syndrome (RLS) was diagnosed according to the essential diagnostic criteria. Results: More patients (81 of 200, 40.5%) than controls (31 of 173, 17.9%) reported leg restlessness (p < 0.001). Thirty-one (15.5%) of these patients with PD and 16 (9.2%) control subjects met RLS criteria (p = 0.07). A total of 21 (12.5%) patients and 12 (6.9%) controls with RLS remained after the exclusion of potential RLS mimics and 26 patients vs 10 control subjects with leg motor restlessness (LMR), leading to a relative risk for RLS of 1.76 (95% confidence interval [CI] 0.90–3.43, p = 0.089) and 2.84 for LMR (95% CI 1.43–5.61, p = 0.001) in PD. Except for increased sleep disturbances in patients with RLS and increased Montgomery and Åsberg Depression Rating Scale scores for patients with RLS or LMR there were no other major differences in relevant blood tests, motor or cognitive function between PD with and without RLS or LMR. Conclusion: LMR and not RLS occurs with a near 3-fold higher risk as compared to controls in early PD. The findings underline a need for more accurate assessments of RLS in PD and support the notion that RLS and PD are different entities.

Development of excessive daytime sleepiness in early Parkinson disease

Objective: To examine the frequency, development, and risk factors of excessive daytime sleepiness (EDS) in a cohort of originally drug-naive patients with incident Parkinson disease (PD) during the first 5 years after diagnosis. Methods: One hundred fifty-three drug-naive patients with early PD derived from a population-based incident cohort and 169 control participants were assessed for EDS and reevaluated after 1, 3, and 5 years on medication. EDS was diagnosed according to the Epworth Sleepiness Scale. Cutoff score above 10 was applied. Generalized estimating equation models for correlated data were used to examine associated and risk factors for EDS. Results: Patients reported EDS more often than control participants at the time of diagnosis and during follow-up. The frequency of EDS in PD increased from 11.8% at baseline to 23.4% after 5 years. Associated factors were male sex, the use of dopamine agonists, and higher Montgomery-Åsberg Depression Rating Scale and Unified Parkinsons Disease Rating Scale–activities of daily living scores. Main risk factor for developing EDS was an increased Epworth Sleepiness Scale score at baseline. Conclusion: EDS is more frequent in PD even before treatment initiation compared with control participants and increases in occurrence with disease progression. The main risk factor for developing EDS with time is an early predisposition for sleepiness. In addition, the use of dopamine agonists was associated with the development of EDS. These findings necessitate caution in patients with PD and early increased sleep propensity and when using dopamine agonists.

European guideline for the diagnosis and treatment of insomnia

This European guideline for the diagnosis and treatment of insomnia was developed by a task force of the European Sleep Research Society, with the aim of providing clinical recommendations for the management of adult patients with insomnia. The guideline is based on a systematic review of relevant meta‐analyses published till June 2016. The target audience for this guideline includes all clinicians involved in the management of insomnia, and the target patient population includes adults with chronic insomnia disorder. The GRADE (Grading of Recommendations Assessment, Development and Evaluation) system was used to grade the evidence and guide recommendations. The diagnostic procedure for insomnia, and its co‐morbidities, should include a clinical interview consisting of a sleep history (sleep habits, sleep environment, work schedules, circadian factors), the use of sleep questionnaires and sleep diaries, questions about somatic and mental health, a physical examination and additional measures if indicated (i.e. blood tests, electrocardiogram, electroencephalogram; strong recommendation, moderate‐ to high‐quality evidence). Polysomnography can be used to evaluate other sleep disorders if suspected (i.e. periodic limb movement disorder, sleep‐related breathing disorders), in treatment‐resistant insomnia, for professional at‐risk populations and when substantial sleep state misperception is suspected (strong recommendation, high‐quality evidence). Cognitive behavioural therapy for insomnia is recommended as the first‐line treatment for chronic insomnia in adults of any age (strong recommendation, high‐quality evidence). A pharmacological intervention can be offered if cognitive behavioural therapy for insomnia is not sufficiently effective or not available. Benzodiazepines, benzodiazepine receptor agonists and some antidepressants are effective in the short‐term treatment of insomnia (≤4 weeks; weak recommendation, moderate‐quality evidence). Antihistamines, antipsychotics, melatonin and phytotherapeutics are not recommended for insomnia treatment (strong to weak recommendations, low‐ to very‐low‐quality evidence). Light therapy and exercise need to be further evaluated to judge their usefulness in the treatment of insomnia (weak recommendation, low‐quality evidence). Complementary and alternative treatments (e.g. homeopathy, acupuncture) are not recommended for insomnia treatment (weak recommendation, very‐low‐quality evidence).

Drug costs for patients with Parkinson's disease in two different European countries

Objective –  To examine factors that influence drug costs in patients with Parkinsons disease (PD) and to compare the costs in two different countries.

Subjective sleep problems in patients with early Parkinson's disease.

Sleep problems are common in Parkinsons disease (PD) and increasingly so with disease progression. The frequency of these problems and the influence of dopaminergic treatment on sleep in early stages of PD remain unclear. We have therefore in this study examined the subjective experience of sleep problems in drug‐naïve patients with early PD and how these problems developed after 1 year on dopaminergic treatment using the Parkinsons Disease Sleep Scale (PDSS).

The long-term development of non-motor problems after STN-DBS.

Stimulation of the subthalamic nucleus (STN‐DBS) is an established treatment with long‐term beneficial effects on motor symptoms in patients with Parkinsons disease (PD). The long‐term development of non‐motor problems after STN‐DBS is not fully understood. In this study, we have studied how non‐motor problems develop in patients with and without STN‐DBS.