Epidemiology and clinical features of sleep disorders in extrapyramidal disease

Non-Motor Symptoms in Cervical Dystonia: A Review

Dystonia is a movement disorder characterized by sustained or intermittent muscle contractions causing abnormal, often repetitive movements, postures, or both. Dystonic movements are typically patterned, associated with twisting of body parts, and may have tremulousness. Dystonia is usually initiated or worsened by voluntary action and associated with overflow muscle activation. Cervical dystonia (CD) is the most prevalent form of dystonia. CD is a condition characterized by cranial muscle overactivity leading to abnormal intermittent or continuous posturing of the head. Non-motor symptoms are comorbidity of dystonia, which significantly hampers the quality of life among these patients. The symptoms can be as a result of the dystonia itself. However, studies have highlighted the involvement of cortical-striatal-thalamocortical circuits in primary dystonia that could be the pathophysiological basis for the non-motor symptoms. The non-motor symptoms that are commonly associated with dystonia are anxiety, depression, restless leg syndrome, excessive daytime sleepiness, cognitive disturbances, and poor sleep. This review attempts to summarize the literature on non-motor symptoms in patients with CD.

Sleep Disorders in Huntington's Disease

Huntington's chorea (Huntington's disease, HD) is a genetic disorder caused by autosomal dominant mutation, leading to progressive neurodegenerative changes in the central nervous system. Involuntary movements such as chorea occur typically in HD patients, accompanied by progressive cognitive and psychiatric disturbances. Other common symptoms of HD are circadian and sleep abnormalities, which are observed from the earliest stages of the disease or even before the occurrence of clinical symptoms. The most common sleep problems reported by HD patients include insomnia, difficulties in falling asleep, frequent nocturnal awakenings, and excessive daytime sleepiness. Also, specific changes in sleep architecture have been identified in HD. In this paper, we review studies on sleep and circadian rhythm disorders in HD. We outline findings concerning sleep patterns and disturbances of circadian rhythms in HD patients, as well as the role of psychiatric disorders and motor disorders in HD patients' sleep problems. We also discuss problems related to the different methods of diagnosing sleep disorders in HD. Furthermore, the adverse effects of medication used for the treatment of core HD symptoms as one of the sources of sleep disturbances in HD are emphasized. In conclusion, the diversity and complexity of the determinants of sleep and circadian rhythm disorders in HD are highlighted. Finally, the relevance of effective treatment to improve patients' functioning and quality of life as well as the potential relief of their cognitive and emotional symptoms is addressed.

Serum Levels of Melatonin and Sleep Evaluation Scales in the Diagnosis of Sleep Disorders in Patients with Idiopathic Parkinson's Disease

Introduction

Sleep disturbances, such as difficulty in initiation of sleep, decrease in total sleep duration and efficacy, frequent awakenings, and increased daytime sleepiness are among the most common non-motor symptoms in patients with idiopathic Parkinson's disease (PD). However, patients usually do not consider these symptoms as important as their motor symptoms, and do not complain. We aimed to investigate PD patients for subtle sleep disturbances using sleep evaluation scales, and to evaluate the relationship between these tests and the serum levels of melatonin during night-sleep.

Methods

A total of 40 PD patients (19, female), older than 50 years, registered in our "Movement Disorders Out-patient Clinic", and 40 healthy, age and sex-matched control subjects (20, female) were included in the study. All subjects were assessed using Pittsburg Sleep Quality Index (PSQI) and Epworth Sleepiness Scale (ESS). Serum melatonin levels during night-sleep were measured in blood samples taken at 00:00 and 05:00 hours in every subject. Both groups were compared for demographical data, sleep evaluation scales and serum levels of melatonin.

Results

Patients with PD had significantly higher scores in PSQI and ESS than the healthy controls (p<0.001). Although the serum melatonin levels at two different time points during night sleep were lower in PD patients than the controls, these differences did not reach statistical significance (p=0.104 at 00:00 am, p=0.528 at 05:00 am). There was no significant correlation between the PSQI scores and serum melatonin levels in patient group (p>0.05). However, there was a significant but weak correlation (r=-0.353, p=0.025) between ESS scores and the serum melatonin levels measured at 05:00 hours in patients, but not between the melatonin levels measured at 00:00 hours.

Conclusion

Sleep evaluation questionnaires such as, PSQI and ESS, can provide useful information in PD patients with mild sleep disturbances. However, serum melatonin levels alone were not helpful in diagnosing the sleep disorders.

Medical comorbidity of sleep disorders

PURPOSE OF REVIEW

Recently published literature indicates that sleep disorders present with medical comorbidities quite frequently. The coexistence of a sleep disorder with a medical disorder has a substantial impact for both the patient and the health system.

RECENT FINDINGS

Insomnia and hypersomnia are highly comorbid with medical conditions, such as chronic pain and diabetes, as well as with various cardiovascular, respiratory, gastrointestinal, urinary and neurological disorders. Restless legs syndrome and periodic leg movement syndrome have been associated with iron deficiency, kidney disease, diabetes, and neurological, autoimmune, cardiovascular and respiratory disorders. Rapid eye movement behaviour disorder has been described as an early manifestation of serious central nervous system diseases; thus, close neurological monitoring of patients referring with this complaint is indicated.

SUMMARY

Identification and management of any sleep disorder in medical patients is important for optimizing the course and prognosis. Of equal importance is the search for undetected medical disorder in patients presenting with sleep disorders.

Sleep and circadian rhythm alterations correlate with depression and cognitive impairment in Huntington's disease

OBJECTIVE

Sleep disturbances are a prominent feature of Huntington's disease (HD) and can substantially impair patients' quality of life. However, sleep complaints and their association with other symptoms and signs of HD have not yet been assessed in large groups of patients or premanifest mutation carriers. Therefore, we aimed to delineate the nature of subjective sleep disturbances and identify important correlates of sleep impairment in HD patients and premanifest mutation carriers.

SUBJECTS & METHODS

Using standardized questionnaires (including Epworth's Sleepiness Scale, Pittsburgh Sleep Quality Index, SCOPA-SLEEP, and Beck's Depression Inventory), daytime sleepiness, night-time sleep, and depressed mood were assessed in 63 HD patients, 21 premanifest mutation carriers and 84 controls.

RESULTS

Night-time sleep impairment was significantly more prevalent in HD patients compared with controls (58.1% vs. 34.9%, p = 0.012), but daytime sleepiness was not (12.7% vs. 7.9%, p = 0.560). Depression was the only independent correlate of night-time sleep impairment in HD patients, accounting for 10% of the variance. Compared with controls, both sleep onset latency and wake-up time were significantly delayed in HD patients. Moreover, in HD patients, later wake-up time was significantly associated with cognitive score (r = -0.43), total functional capacity (r = -0.54) and depressive symptoms (r = +0.47). In general, the degree of sleep (phase) changes in premanifest mutation carriers lay in between those of HD patients and controls.

CONCLUSIONS

HD is primarily accompanied by night-time sleep disturbances and a delayed sleep phase, which are associated with depression and lower cognitive as well as functional performance.

Quality of sleep in primary focal dystonia: a case-control study

BACKGROUND

Sleep disturbances are common in patients with movement disorders. Evaluating quality of sleep is of primary importance because of the effect that nocturnal and daytime sleep abnormalities exert on general health status. However, quality of sleep has never been addressed in detail in patients with dystonia. The aim of this case-control study was to analyse quality of sleep in patients with the two most common forms of primary focal dystonia, blepharospasm (BSP) and cervical dystonia (CD).

METHODS

We evaluated quality of sleep (Pittsburgh Sleep Quality Index, PSQI) and excessive daytime sleepiness (Epworth Sleepiness Scale, ESS) in 98 patients with focal adult-onset dystonia (52 with BSP; 46 with CD) and in a group of 56 age-and gender-matched healthy subjects. The Beck Depression Inventory (BDI) was used for the evaluation of depressive symptomatology.

RESULTS

Quality of sleep was impaired (significantly higher PSQI scores) in both groups of patients. However, differences in PSQI scores between patients with CD and control subjects were partly confounded by BDI scores, whereas differences in PSQI scores between patients with BSP and control subjects were not influenced by BDI. Excessive daytime sleepiness was not significantly more frequent than in control subjects in either patients with BSP or patients with CD.

CONCLUSIONS

This study suggests that the assessment and treatment of insomnia-related complaints should be considered in global management plans of patients with focal dystonia, particularly in those affected by BSP.

Sleep patterns in patients with Huntington's disease and their unaffected first-degree relatives: a brief report

Polysomnographic sleep patterns in Huntington's disease (HD) have been studied sporadically in small groups of patients, providing variable results. In this study, by comparing the polysomnographic sleep patterns of HD patients and their unaffected relatives, identifying sleep traits more specifically related to the HD gene was attempted. The results corroborated previously reported findings of prolonged sleep latency and the virtual absence of nocturnal respiratory disturbances in early HD. Sleep latency in the HD patients positively correlated with the results of a screening test for frontal lobe dysfunction. Larger, more standardized studies will be needed to correlate genetic markers and sleep patterns in HD.

Functional connectivity between motor cortex and globus pallidus in human non-REM sleep

Recent evidence suggests that the motor system undergoes very specific modulation in its functional state during the different sleep stages. Here we test the hypothesis that changes in the functional organization of the motor system involve both cortical and subcortical levels and that these distributed changes are interrelated in defined frequency bands. To this end we evaluated functional connectivity between motor and non-motor cortical sites (fronto-central, parieto-occipital) and the globus pallidus (GP) in human non-REM sleep in seven patients undergoing deep brain stimulation (DBS) for dystonia using a variety of spectral measures (power, coherence, partial coherence and directed transfer function (DTF)). We found significant coherence between GP and fronto-central cortex as well as between GP and parieto-occipital cortex in circumscribed frequency bands that correlated with sleep specific oscillations in 'light sleep' (N2) and 'slow-wave sleep' (N3). These sleep specific oscillations were also reflected in significant coherence between the two cortical sites corroborating previous studies. Importantly, we found two different physiological activities represented within the broad band of significant coherence between 9.5 and 17 Hz. One component occurred in the frequency range of sleep spindles (12.5-17 Hz) and was maximal in the coherence between fronto-central and parieto-occipital cortex as well as between GP and both cortical sites during N2. This component was still present between fronto-central and parieto-occipital cortex in N3. Functional connectivity in this frequency band may be due to a common input to both GP and cortex. The second component consisted of a spectral peak over 9.5-12.5 Hz. Coherence was elevated in this band for all topographical constellations in both N2 and N3, but especially between GP and fronto-central cortex. The DTF suggested that the 9.5-12.5 Hz activity consisted of a preferential drive from GP to the fronto-central cortex in N2, whereas in N3 the DTF between GP and fronto-central cortex was symmetrical. Partial coherence supported distinctive patterns for the 9.5-12.5 and 12.5 and 17 Hz component, so that only coherence in the 9.5-12.5 Hz band was reduced when the effects of GP were removed from the coherence between the two cortical sites. The data suggest that activities in the GP and fronto-central cortex are functionally connected over 9.5-12.5 Hz, possibly as a specific signature of the motor system in human non-REM sleep. This finding is pertinent to the longstanding debate about the nature of alpha-delta sleep as a physiological or pathological feature of non-REM sleep.

Sleep symptoms and their clinical correlates in Machado-Joseph disease

OBJECTIVE

To evaluate the presence of sleep symptoms in Machado-Joseph disease/spinocerebellar ataxia type 3 (MJD/SCA3).

SUBJECTS/METHODS

We used a sleep questionnaire and the Epworth Sleepiness Scale to compare 53 patients with MJD/SCA3 and 106 controls.

RESULTS

Patients with MJD/SCA3 reported more symptoms of insomnia, restless leg syndrome and REM sleep behavior disorder as well as nocturnal cramps, snoring and nocturnal apnea. Insomnia was the most frequently reported sleep-related complaint in the MJD/SCA3 group.

CONCLUSIONS

Our results indicate that sleep disorders are common in patients with MJD/SCA3 and probably have a multifactorial etiology, with components of a primary sleep disorder in addition to sleep-disrupting symptoms such as nocturia and cramps.

Learning and consolidation of visuo-motor adaptation in Parkinson's disease

We have previously shown in normal subjects that motor adaptation to imposed visual rotation is significantly enhanced when tested few days later. This occurs through a process of sleep-dependent memory consolidation. Here we ascertained whether patients with Parkinson's disease (PD) learn, improve, and retain new motor skills in the same way as normal subjects. We tested 16 patients in early stages of PD and 21 control subjects over two days. All subjects performed reaching movements on a digitizing tablet. Vision of the limb was precluded with an opaque screen; hand paths were shown on the screen with the targets' position. Unbeknownst to the subjects, the hand path on the screen was rotated by 30 degrees . In experiment 1, patients taking dopaminergic treatment and controls adapted to rotation with targets appearing in an unpredictable order. In experiment 2, drug-naïve patients and controls adapted to rotation in a less challenging task where target's appearance was predictable. Patients and controls made similar movements and adapted to rotation in the same way. However, when tested again over the following days, controls' performance significantly improved compared to training, while patients' performance did not. This lack of consolidation, which is present in the early stages of the disease and is independent from therapy, may be due to abnormal homeostatic processes that occur during sleep.

Sleep and vigilance in corticobasal degeneration: a descriptive study

INTRODUCTION

Sleep disorders are common in extrapyramidal diseases, but have rarely been demonstrated in corticobasal degeneration (CBD).

METHODS

Here, we describe sleep and vigilance in five consecutive patients with CBD.

RESULTS

All five patients had insomnia, four displayed periodic limb movements during sleep (PLMS) and/or restless leg syndrome (RLS), and two had sleep respiratory disorders. None had REM sleep behaviour disorders or excessive daytime sleepiness.

CONCLUSIONS

Polysomnography is useful for diagnosing treatable sleep disorders in CBD.

Sleep and aging: 1. Sleep disorders commonly found in older people

Aging is associated with several well-described changes in patterns of sleep. Typically, there is a phase advance in the normal circadian sleep cycle: older people tend to go to sleep earlier in the evening but also to wake earlier. They may also wake more frequently during the night and experience fragmented sleep. The prevalence of many sleep disorders increases with age. Insomnia, whether primary or secondary to coexistant illness or medication use, is very common among elderly people. Rapid eye movement (REM) sleep behaviour disorder and narcolepsy, although less common, are frequently not considered for this population. Periodic leg-movement disorder, a frequent cause of interrupted sleep, can be easily diagnosed with electromyography during nocturnal polysomnography. Restless legs syndrome, however, is diagnosed clinically. Snoring is a common sleep-related respiratory disorder; so is obstructive sleep apnea, which is increasingly seen among older people and is significantly associated with cardio-and cerebrovascular disease as well as cognitive impairment.

Drug Insight: new drugs in development for Parkinson's disease

For many years, levodopa has given most patients with Parkinson's disease excellent symptomatic benefit. This agent does not slow down the progression of the disease, however, and it can induce motor fluctuations and dyskinesias in the long term. The other available antiparkinsonian agents also have drawbacks, and as a consequence research into antiparkinsonian drugs is expected to take new and different directions in the coming years. The most promising approaches include the development of 'neuroprotective' drugs that are capable of blocking or at least slowing down the degenerative process that is responsible for cellular death; 'restorative' strategies intended to restore normal brain function; more-effective agents for replacing dopamine loss; and symptomatic and antidyskinetic drugs that act on neurotransmitters other than dopamine or target brain areas other than the striatum. In this Review, we discuss the numerous drugs in development that target the primary motor disorder in Parkinson's disease.

Expanded motor and psychiatric phenotype in autosomal dominant Segawa syndrome due to GTP cyclohydrolase deficiency

BACKGROUND

Segawa syndrome due to GTP cyclohydrolase deficiency is an autosomal dominant disorder with variable expression, that is clinically characterised by l-dopa responsive, diurnally fluctuating dystonia and parkinsonian symptoms.

OBJECTIVE

To delineate the neurological and psychiatric phenotype in all affected individuals of three extended families.

METHODS

GTP cyclohydrolase deficiency was documented by biochemical analyses, enzymatic measurements in fibroblasts, and molecular investigations. All affected individuals were examined neurologically, and psychiatric data were systematically reviewed.

RESULTS

Eighteen affected patients from three families with proven GTP cyclohydrolase deficiency were identified. Eight patients presenting at less than 20 years of age had typical motor symptoms of dystonia with diurnal variation. Five family members had late-presenting mild dopa-responsive symptoms of rigidity, frequent falls, and tendonitis. Among mutation carriers older than 20 years of age, major depressive disorder, often recurrent, and obsessive-compulsive disorder were strikingly more frequent than observed in the general population. Patients responded well to medication increasing serotonergic neurotransmission and to l-dopa substitution. Sleep disorders including difficulty in sleep onset and maintenance, excessive sleepiness, and frequent disturbing nightmares were present in 55% of patients.

CONCLUSION

Physicians should be aware of this expanded phenotype in affected members of families with GTP cyclohydrolase deficiency.

Melatonin for sleep disturbances in Parkinson's disease

BACKGROUND AND PURPOSE

Many patients with Parkinson's disease (PD) experience sleep-related symptoms. Studies in other populations indicate that melatonin can increase sleep efficiency, decrease nighttime activity, and shorten sleep latency, but there has been little research on the use of melatonin in PD. The purpose of this study was to compare the effects of two doses of melatonin to placebo on sleep, daytime sleepiness, and level of function in patients with PD who complained of sleep disturbances.

PATIENTS AND METHODS

A multi-site double-blind placebo-controlled cross-over trial was employed; 40 subjects completed the 10-week protocol. There was a 2-week screening period, 2-week treatment periods, and 1-week washouts between treatments. Nocturnal sleep was assessed by actigraphy and diaries, whereas daytime sleepiness and function were assessed by the Epworth Sleepiness Scale (ESS), Stanford Sleepiness Scale (SSS), and General Sleep Disturbance Scale (GSDS).

RESULTS

Repeated measures analysis of variance revealed a significant improvement in total nighttime sleep time during the 50 mg melatonin treatment compared to placebo. There was significant improvement in subjective sleep disturbance, sleep quantity, and daytime sleepiness during the 5 mg melatonin treatment compared to placebo as assessed by the GSDS.

CONCLUSIONS

Although we found a statistically significant improvement in actigraphically measured total sleep time on 50 mg melatonin compared to 5 mg or placebo, this small improvement (10 min) may not be clinically significant. However, the significant improvement found in subjective sleep disturbance suggests that these modest effects may be clinically relevant in this patient population.

Periodic limb movements and other movement disorders in sleep: neuropsychiatric dimensions

Movement disorders such as Parkinson's disease and Tourette's syndrome, primarily manifest during wakefulness, intrude into sleep. There are some disorders, however, such as periodic limb movements in sleep, restless legs syndrome, paroxysmal nocturnal dystonia, bruxism, and somnambulism, which occur primarily during sleep. The diagnosis and management of these disorders pose a challenge to neuropsychiatric practice, not only because they may be difficult to distinguish from other neuropsychiatric disorders, but also because psychiatric disorders are often co-morbid with them. Study of these disorders is necessary for an understanding of the interaction of sleep and movement, and how disturbance in one may affect the other.