Restless legs syndrome in Wilson's disease: frequency, characteristics, and mimics

Sleep Disorders in Patients with Choreic Syndromes

PURPOSE OF REVIEW

Patients with different types of choreic syndromes, specially those with Huntington's (HD) and Wilson's (WD) diseases, report frequent sleep complaints. This review focuses on the main findings of studies addressing the sleep features in these diseases, and other less frequent causes of chorea associated with sleep disorders, including a new syndrome described in the last decade associated with IgLON5 antibodies.

RECENT FINDINGS

Patients with HD and WD showed a bad quality of sleep and high frequency of insomnia and excessive daytime somnolence. WD patients also showed high scores on a specific scale for rapid eye movement sleep behavior disorders. HD and WD share decreased sleep efficiency and increased REM sleep latencies, percentage of sleep stage N1, and wake after sleep onset (WASO) among their polysomnographic features. Patients with HD and WD showed a high prevalence of different sleep disorders. Patients with other causes of chorea, including neuroacanthocytosis, parasomnia with sleep breathing disorder associated with antibodies to IgLON5, Sydenham's chorea, and choreic syndromes associated to certain genetic mutations show sleep disorders as well.

Neurological Wilson's Disease Signs-Hepatic Encephalopathy or Copper Toxicosis?

Wilson's disease (WD) is a rare autosomal recessive (AR) disorder resulting from mutations in the ATP7B gene, which is responsible for the encryption of transmembrane copper transporting ATPase. The symptomatic presentation of the disease is estimated to be about 1 in 30,000. The impairment of ATP7B function results in a copper overload in hepatocytes, which further leads to liver pathology. This copper overload also occurs in other organs, most particularly in the brain. This could then cause the occurrence of neurological and psychiatric disorders. Symptoms differ substantially and most often occur between the ages of 5 and 35 years. Early symptoms are commonly hepatic, neurological, or psychiatric. While disease presentation is most often asymptomatic, it could also range as far as to include fulminant hepatic failure, ataxia, and cognitive disorders. Various treatments are available for Wilson's disease, including chelation therapy and zinc salts, which can reverse copper overload through different mechanisms. In select cases, liver transplantation is recommended. New medications, such as tetrathiomolybdate salts, are currently being investigated in clinical trials. With prompt diagnosis and treatment, prognosis is favorable; however, diagnosing patients before the onset of severe symptoms is a significant concern. Early screening for WD could help in diagnosing patients earlier and improving treatment outcomes.

Sleep Dysfunction in Movement Disorders: a Window to the Disease Biology

PURPOSE OF REVIEW

To comprehensively summarize the sleep pathologies associated with movement disorders, focusing on neurodegenerative diseases.

RECENT FINDINGS

Mounting evidence has further implicated both sleep and circadian disruption in the pathophysiology of many movement disorders. In particular, recent data illuminate the mechanisms by which poor sleep quality and circadian dysfunction can exacerbate neurodegeneration. In addition, anti-IgLON5 disease is a recently described autoimmune disease with various symptoms that can feature prominent sleep disruption and parasomnia. Many movement disorders are associated with sleep and circadian rhythm disruption. Motor symptoms can cause sleep fragmentation, resulting in insomnia and excessive daytime sleepiness. Many neurodegenerative movement disorders involve brainstem pathology in regions close to or affecting nuclei that regulate sleep and wake. Further, commonly used movement medications may exacerbate sleep concerns. Providers should screen for and address these sleep symptoms to improve function and quality of life for patients and caregivers.

Sleep disturbances in newly diagnosed treatment-naïve patients with Wilson's disease

Introduction

Most neurodegenerative and chronic liver disorders are associated with sleep disturbances (SD). SD may be expected to occur in patients with Wilson’s disease (WD), an inherited disorder of copper metabolism that mostly affects the liver and brain; however, there is a lack of observations, particularly in treatment-naïve WD patients.

Methods

We evaluated SD in 19 newly diagnosed treatment-naïve WD patients. All patients completed the Beck Depression Inventory (BDI), the Athens Insomnia Scale (AIS) and the Epworth Sleepiness Scale (ESS), and underwent nightlong video polysomnography (vPSG). Results of vPSG in WD patients were compared with results from 19 sex- and age-matched healthy controls.

Results

Depressive symptoms were not reported by patients on routine examination although three patients were diagnosed with mild depression. No patients reported SD during routine examination; three patients had insomnia according to the AIS and all patients scored 0 on the ESS. Despite the lack of reporting of SD by patients, significant differences were observed between WD patients and controls following vPSG analysis: WD patients had shorter mean total sleeping time (366.2 vs. 451.7 min), a lower percentage of rapid-eye movement (15.4 vs. 20.6%), longer sleep latency (36.7 vs. 10.4 min) and lower sleep efficiency (76.2 vs. 93.8%) (all P ≤ 0.01). SD tended to be worse in patients with neurological WD compared with hepatic WD.

Conclusions

As SD may precede depression and severely affect quality of life, our findings suggest that patients with WD should be screened for SD with suitable methods.

Sleep disturbance in movement disorders: insights, treatments and challenges

Sleep and circadian rhythm disturbances are central features of many movement disorders, exacerbating motor and non-motor symptoms and impairing quality of life. Understanding these disturbances to sleep is clinically important and may further our understanding of the underlying movement disorder. This review evaluates the current anatomical and neurochemical understanding of normal sleep and the recognised primary sleep disorders. In addition, we undertook a systematic review of the evidence for disruption to sleep across multiple movement disorders. Rapid eye movement sleep behaviour disorder has emerged as the most reliable prodromal biomarker for the alpha synucleinopathies, including Parkinson's disease and multiple system atrophy, often preceding motor symptom onset by several years. Abnormal sleep has also been described for many other movement disorders, but further evidence is needed to determine whether this is a primary or secondary phenotypic component of the underlying condition. Medication used in the treatment of motor symptoms also affects sleep and can aggravate or cause certain sleep disorders. Within the context of movement disorders, there is also some suggestion of a shared underlying mechanism for motor and sleep pathophysiology, with evidence implicating thalamic and brainstem structures and monoaminergic neurotransmission. This review highlights the need for an understanding of normal and abnormal sleep within the movement disorder clinic, an ability to screen for specific causes of poor sleep and to treat sleep disturbance to improve quality of life. Key sleep disorders also act as important biomarkers and have implications in diagnosis, prognosis and the development of future therapies.

Comprehensive Overview of Sleep Disorders in Patients with Chronic Liver Disease

The impact of sleep disorders (SDs) on patients with chronic liver diseases (CLD) is tremendous. SDs are frequently encountered among these patients and interfere with their quality of life. This review aims to present the data available so far about the prevalence, phenotypes, and proposed pathophysiological mechanisms of SDs in CLD. Moreover, we proposed to search the literature regarding the most reliable methods to assess SDs and the possible therapeutic options in patients with CLD. The main results of this review show that when it comes to prevalence, the percentages reported vary widely between studies performed among populations from the USA or Europe and those coming from Asian countries. Furthermore, it has been proven that SDs may also be present in the absence of neurocognitive disorders attributable to hepatic encephalopathy (HE), which contradicts traditional suppositions where SDs were considered part of the clinical scenario of HE. Currently, there are no specific recommendations or protocols to assess SDs in CLD patients and data about the therapeutic management are limited. Taking into consideration their impact, a protocol for diagnosing and managing SDs should be developed and included in the daily practice of hepatologists.

Sleep disorders in Wilson's disease

BACKGROUND/OBJECTIVES

Wilson's disease (WD) is a rare genetic disorder that leads to copper overload, mainly in the liver then, in the brain. Patients with WD often complain about sleep disorders. We aimed to explore them.

PATIENTS/METHODS

Sleep complaints and disease symptoms were compared in 40 patients with WD (20 patients with hepatic phenotype matched to 20 neurologic one) and 40 age, sex and BMI matched healthy controls.

RESULTS

Patients with WD had more frequently (32.5 vs 10.0%, p < 0.05) and more severe (10.5 ± 6.0 vs 7.6 ± 4.8, p < 0.01) insomnia than controls and insomnia was more severe in neurologic than hepatic form of the disease (12.25 ± 5.89 vs 8.73 ± 5.8, p < 0.05). Insomnia severity was correlated with the severity of depressive symptoms (r = 0.53, p < 0.001). Compared to controls, patients reported more difficulties staying asleep and more consequences of insomnia on their quality of life. REM sleep behavior disorder was more frequent in WD (20 vs 0%, p = 0.005) than controls. Patients complained more frequently of nycturia (22.8 vs 7.6%, p = 0.003) than controls. Patients did not differ from controls for sleepiness, restless legs syndrome and obstructive sleep apnea syndrome. Patients did not report cataplexia.

CONCLUSION

In patients with WD, insomnia and REM sleep behavior disorder are the two main sleep complaints. Insomnia is more frequent in neurologic than hepatic form of the disease. Severity of insomnia is associated with the severity of depressive symptoms.

Wilson disease

PURPOSE OF REVIEW

The aim of this article is to review recent developments in the areas of the disease features and treatment of Wilson disease, and survey disorders that share its pathophysiology or clinical symptoms.

RECENT FINDINGS

Knowledge of the clinical spectrum of Wilson disease has expanded with recognition of patients who present in atypical age groups - patients with very early onset (<5 years) and those in whom symptoms present in mid-to-late adulthood. A disease phenotype with dominant psychiatric features and increased risk of cardiac problems and various sleep disorders have been identified.In addition to a better understanding of the phenotype of Wilson disease itself, features of some related disorders ('Wilson disease-mimics') have been described leading to a better understanding of copper homeostasis in humans. These disorders include diseases of copper disposition, such as mental retardation, enteropathy, deafness, neuropathy, ichthyosis, keratoderma syndrome, Niemann-Pick type C, and certain congenital disorders of glycosylation, as well as analogous disorders of iron and manganese metabolism.Outcomes for existing treatments, including in certain patient subpopulations of interest, are better known. Novel treatment strategies being studied include testing of bis-choline tetrathiomolybdate in phase 2 clinical trial as well as various preclinical explorations of new copper chelators and ways to restore ATP7B function or repair the causative gene.

SUMMARY

Recent studies have expanded the phenotype of Wilson disease, identified rare inherited metal-related disorders that resemble Wilson disease, and studied long-term outcomes of existing treatments. These developments can be expected to have an immediate as well as a long-term impact on the clinical management of the disease, and point to promising avenues for future research.

Sleep disorders in Wilson disease: a systematic review and meta-analysis

STUDY OBJECTIVES

Wilson disease (WD) is an autosomal recessive inherited disorder of copper metabolism resulting in pathologic accumulation of copper in many organs and tissues. Sleep disorders are highly prevalent in patients with WD. However, both prevalence rates and severity of different sleep disorders in patients with WD vary widely. The aims of the current study were to systematically review and perform a meta-analysis of the association between WD and prevalent sleep disorders, including insomnia, rapid eye movement (REM) sleep behavior disorder (RBD), excessive daytime sleepiness (EDS), sleep-disordered breathing (SDB), restless legs syndrome (RLS), periodic limb movement in sleep (PLM), cataplexy-like episodes (CLEs) and sleep paralysis, and objective sleep characteristics.

METHODS

We performed a systematic search of PubMed, EMBase, the Cochrane Library, PsycINFO and ISI Web of Science for case-control studies. A total of 7 studies with 501 participants were included.

RESULTS

We found that 54.1% of patients with WD experience sleep disorders and up to 7.65-fold higher odds compared to control patients. Specifically, patients with WD had higher rates of RBD, insomnia, and EDS based on self-reported questionnaires. No differences were observed in terms of RLS, PLM, or SDB between patients with WD and control patients. Furthermore, objective sleep disruptions based on polysomnographic studies included prolonged sleep onset latency and REM sleep onset latency, reduced total sleep time and sleep efficiency, higher percentage of stage N1 sleep and lower percentage of stage N2 sleep were observed in patients with WD.

CONCLUSIONS

Our study indicates that sleep disorders are frequent in patients with WD. Future studies should examine the longitudinal association of WD with sleep disturbances.

Neurologic impairment in Wilson disease

Neurologic symptoms in Wilson disease (WD) appear at an older age compared to hepatic symptoms and manifest in patients with misdiagnosed liver disease, in patients when the hepatic stage is clinically silent, in the case of non-compliance with anti-copper treatment, or with treatment failure. Neurologic symptoms in WD are caused by nervous tissue damage that is primarily a consequence of extrahepatic copper toxicity. Copper levels in brain tissues as well as cerebrospinal fluid (CSF) are diffusely increased by a factor of 10 and its toxicity involves various mechanisms such as mitochondrial toxicity, oxidative stress, cell membrane damage, crosslinking of DNA, and inhibition of enzymes. Excess copper is initially taken-up and buffered by astrocytes and oligodendrocytes but ultimately causes dysfunction of blood-brain-barrier and demyelination. Most severe neuropathologic abnormalities, including tissue rarefaction, reactive astrogliosis, myelin palor, and presence of iron-laden macrophages, are typically present in the putamen while other basal ganglia, thalami, and brainstem are usually less affected. The most common neurologic symptoms of WD are movement disorders including tremor, dystonia, parkinsonism, ataxia and chorea which are associated with dysphagia, dysarthria and drooling. Patients usually manifest with various combinations of these symptoms while purely monosymptomatic presentation is rare. Neurologic symptoms are largely reversible with anti-copper treatment, but a significant number of patients are left with residual impairment. The approach for symptomatic treatment in WD is based on guidelines for management of common movement disorders. The vast majority of WD patients with neurologic symptoms have abnormalities on brain magnetic resonance imaging (MRI). Pathologic MRI changes include T2 hyperintensities in the basal ganglia, thalami and white matter, T2 hypointensities in the basal ganglia, and atrophy. Most importantly, brain damage and neurologic symptoms can be prevented with an early initiation of anti-copper treatment. Introducing population WD screening, e.g., by exome sequencing genetic methods, would allow early treatment and decrease the neurologic burden of WD.

Update on the Diagnosis and Management of Wilson Disease

PURPOSE OF REVIEW

Exciting developments relating to Wilson disease (WD) have taken place with respect to both basic biological and clinical research. This review critically examines some of these findings and considers their implications for current thinking about WD. It is not a comprehensive review of WD as a clinical disorder.

RECENT FINDINGS

The structure of the gene product of ATP7B, abnormal in WD, is being worked out in detail, along with a broader description of how the protein ATP7B (Wilson ATPase) functions in cells including enterocytes, not only in relation to copper disposition but also to lipid synthesis. Recent population studies raise the possibility that WD displays incomplete penetrance. Innovative screening techniques may increase ascertainment. New strategies for diagnosing and treating WD are being developed. Several disorders have been identified which might qualify as WD-mimics. WD can be difficult to diagnose and treat. Insights from its pathobiology are providing new options for managing WD.

Wilson disease

Wilson disease (WD) is a potentially treatable, inherited disorder of copper metabolism that is characterized by the pathological accumulation of copper. WD is caused by mutations in ATP7B, which encodes a transmembrane copper-transporting ATPase, leading to impaired copper homeostasis and copper overload in the liver, brain and other organs. The clinical course of WD can vary in the type and severity of symptoms, but progressive liver disease is a common feature. Patients can also present with neurological disorders and psychiatric symptoms. WD is diagnosed using diagnostic algorithms that incorporate clinical symptoms and signs, measures of copper metabolism and DNA analysis of ATP7B. Available treatments include chelation therapy and zinc salts, which reverse copper overload by different mechanisms. Additionally, liver transplantation is indicated in selected cases. New agents, such as tetrathiomolybdate salts, are currently being investigated in clinical trials, and genetic therapies are being tested in animal models. With early diagnosis and treatment, the prognosis is good; however, an important issue is diagnosing patients before the onset of serious symptoms. Advances in screening for WD may therefore bring earlier diagnosis and improvements for patients with WD.