Sleep Abnormalities in Wilson’s Disease

The physiological and pathophysiological roles of copper in the nervous system

Copper is a critical trace element in biological systems due the vast number of essential enzymes that require the metal as a cofactor, including cytochrome c oxidase, superoxide dismutase and dopamine-β-hydroxylase. Due its key role in oxidative metabolism, antioxidant defence and neurotransmitter synthesis, copper is particularly important for neuronal development and proper neuronal function. Moreover, increasing evidence suggests that copper also serves important functions in synaptic and network activity, the regulation of circadian rhythms, and arousal. However, it is important to note that because of copper's ability to redox cycle and generate reactive species, cellular levels of the metal must be tightly regulated to meet cellular needs while avoiding copper-induced oxidative stress. Therefore, it is essential that the intricate system of copper transporters, exporters, copper chaperones and copper trafficking proteins function properly and in coordinate fashion. Indeed, disorders of copper metabolism such as Menkes disease and Wilson disease, as well as diseases linked to dysfunction of copper-requiring enzymes, such as SOD1-linked amyotrophic lateral sclerosis, demonstrate the dramatic neurological consequences of altered copper homeostasis. In this review, we explore the physiological importance of copper in the nervous system as well as pathologies related to improper copper handling.

Assessment of sleep disturbance in patients with Wilson's disease

BACKGROUND

Wilson's disease (WD) is frequently manifested with anxiety, depression and sleep disturbance; this investigation aimed to elucidate these manifestations and identify the influencing factors of sleep disturbance.

METHODS

Sleep disturbance, anxiety and depression were compared in 42 WD and 40 age- and gender-matched healthy individuals. 27 individuals indicated a neurological form of the disease (NV), and 15 had a non-neurological variant (NNV).

RESULTS

This investigation revealed that the Parkinson's disease sleep scale (PDSS) score of WD individuals was lower, whereas their Epworth Sleepiness Scale (ESS), Pittsburgh sleep quality index (PSQI), Hamilton Anxiety Scale (HAMA), and Hamilton Depression Scale (HAMD) scores were higher than the healthy individuals (p < 0.05). Furthermore, the WD subjects had markedly increased prevalence of poor sleep quality, anxiety, and depression than healthy individuals (p < 0.05). Subgroup analysis showed that NV subjects had significantly higher scores on the UWDRS, PSQI, HAMA, and HAMD scales than those in the NV group, as well as higher rates of EDS, anxiety, and depression (p < 0.05). In patients with sleep disturbance, we identified UWDRS, neurological variant, and depression as associated factors. The linear regression model demonstrated depression as the dominant risk factor.

CONCLUSIONS

Depression is highly correlated with and is a determinant of sleep disturbance in WD patients.

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.

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.

Women's experiences of surviving severe obstetric complications: a qualitative inquiry in southern Ghana

Women who survive severe obstetric complications (SOC) have health and well-being issues even up to 1 year postpartum and have challenges in their quality-of-life (QoL). However, little is known about their predicaments. This study aimed to describe the impact of severe obstetric complications on women’s QoL and well-being after surviving severe obstetric complications. Using the WHO standards for near-miss, twelve (12) women who survived severe obstetric complications were recruited between January and March 2019. The study adopted a qualitative approach with an exploratory descriptive design to explore the experiences of women who survived SOC in Southern Ghana. The participants were purposively sampled and were interviewed face to face in their homes and healthcare facility after discharge from the Hospital. Recorded interviews were transcribed and analyzed. Two (2) major themes and nine (9) sub-themes emerged. The findings revealed that women who suffered SOC are unable to perform functional activities, have financial constraints, residual hypertension, signs and symptoms of anaemia, pain, and mostly have difficulty in sleeping due to fear of death when they fall asleep. Anxiety, sadness, and emotional trauma was a common phenomenon. The study findings offer insights and directions on measures to improve the care and QoL of women who have survived severe obstetric complications in Ghana.

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.

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.

Challenges in the diagnosis of Wilson disease

The understanding and management of Wilson disease (WD) have dramatically improved since the first description of the disease by K. Wilson more than a century ago. However, the persistent long delay between the first symptoms and diagnosis emphasizes challenges in diagnosing earlier this copper overload disorder. As a treatable disease, WD should be detected early in the course of the disease by any health professionals at any care level, but the rare prevalence of the disease explains the lack of awareness of referring physicians. The most important challenge is to train physicians to recognize atypical or rare symptoms of WD that will lead to discuss the diagnosis more systematically. Atypia can come from the age of onset, the liver [non-alcoholic steatohepatitis (NASH) presentation], the central or peripheral nervous system (neuropathy, epilepsy, sleep disorders…) or may be due to lesions of other organs (renal manifestations, osteo-articular disorders or endocrine disturbances). Isolated biological anomalies, rare radiological findings or inadequate interpretation of copper test may also lead to misdiagnosis. The second challenge is to confirm the diagnosis faster and more effectively so as not to delay the initiation of treatment, and expand family screening as the genetic prevalence is higher than previously expected. Generalization of the exchangeable copper assay and the next generation sequencing (NGS) are two promising ways to overcome this ultimate challenge. By drawing attention to the earliest and rare symptoms and to new biomarkers and diagnostic tools, we hope that this article will increase diagnostic awareness and reduce delays so that patients can start their treatment earlier in the course of the illness and thus have a better disease prognosis.