Sequential MRI changes in Wilson's disease with de-coppering therapy: a study of 50 patients

A weighted cranial diffusion-weighted imaging scale for Wilson's disease

Objectives

Cranial magnetic resonance imaging (MRI) could be a crucial tool for the assessment for neurological symptoms in patients with Wilson's disease (WD). Diffusion-weighted imaging (DWI) hyperintensity reflects the acute brain injuries, which mainly occur in specific brain regions. Therefore, this study aimed to develop a weighted cranial DWI scale for patients with WD, with special focus on specific brain regions.

Materials and methods

In total, 123 patients with WD were enrolled, 118 of whom underwent 1.5 T-MRI on admission. The imaging score was calculated as described previously and depended on the following sequences: one point was acquired when abnormal intensity occurred in the T1, T2, and fluid-attenuation inversion recovery sequences, and two points were acquired when DWI hyperintensity were found. Consensus weighting was conducted based on the symptoms and response to treatment.

Results

Intra-rater agreement were good (r = 0.855 [0.798-0.897], p < 0.0001). DWI hyperintensity in the putamen was a high-risk factor for deterioration during de-copper therapy (OR = 8.656, p < 0.05). The high-risk factors for readmission for intravenous de-copper therapies were DWI hyperintensity in the midbrain (OR = 3.818, p < 0.05) and the corpus callosum (OR = 2.654, p < 0.05). Both scoring systems had positive correlation with UWDRS scale (original semi-quantitative scoring system, r = 0.35, p < 0.001; consensus semi-quantitative scoring system, r = 0.351, p < 0.001.). Compared to the original scoring system, the consensus scoring system had higher correlations with the occurrence of deterioration (OR = 1.052, 95%CI [1.003, 1.0103], p < 0.05) and readmission for intravenous de-copper therapy (OR = 1.043, 95%CI [1.001, 1.086], p < 0.05).

Conclusion

The predictive performance of the consensus semi-quantitative scoring system for cranial MRI was improved to guide medication, healthcare management, and prognosis prediction in patients with WD. For every point increase in the neuroimaging score, the risk of exacerbations during treatment increased by 5.2%, and the risk of readmission to the hospital within 6 months increased by 4.3%.

Genetic Movement Disorders Commonly Seen in Asians

The increasing availability of molecular genetic testing has changed the landscape of both genetic research and clinical practice. Not only is the pace of discovery of novel disease-causing genes accelerating but also the phenotypic spectra associated with previously known genes are expanding. These advancements lead to the awareness that some genetic movement disorders may cluster in certain ethnic populations and genetic pleiotropy may result in unique clinical presentations in specific ethnic groups. Thus, the characteristics, genetics and risk factors of movement disorders may differ between populations. Recognition of a particular clinical phenotype, combined with information about the ethnic origin of patients could lead to early and correct diagnosis and assist the development of future personalized medicine for patients with these disorders. Here, the Movement Disorders in Asia Task Force sought to review genetic movement disorders that are commonly seen in Asia, including Wilson's disease, spinocerebellar ataxias (SCA) types 12, 31, and 36, Gerstmann-Sträussler-Scheinker disease, PLA2G6-related parkinsonism, adult-onset neuronal intranuclear inclusion disease (NIID), and paroxysmal kinesigenic dyskinesia. We also review common disorders seen worldwide with specific mutations or presentations that occur frequently in Asians.

A Study of Dopaminergic Pathway in Neurologic Wilson Disease with Movement Disorder

Movement disorder (MD) is an important manifestation of neurologic Wilson disease (NWD), but there is a paucity of information on dopaminergic pathways. We evaluate dopamine and its receptors in patients with NWD and correlate the changes with MD and MRI changes. Twenty patients with NWD having MD were included. The severity of dystonia was assessed using BFM (Burke-Fahn-Marsden) score. The neurological severity of NWD was categorized as grades I to III based on the sum score of 5 neurological signs and activity of daily living. Dopamine concentration in plasma and CSF was measured using liquid chromatography-mass spectrometry, and D1 and D2 receptor expression at mRNA by reverse transcriptase polymerase chain reaction in patients and 20 matched controls. The median age of the patients was 15 years and 7 (35%) were females. Eighteen (90%) patients had dystonia and 2 (10%) had chorea. The CSF dopamine concentration (0.08 ± 0.02 vs 0.09 ± 0.017 pg/ml; p = 0.42) in the patients and controls was comparable, but D2 receptor expression was reduced in the patients (0.41 ± 0.13 vs 1.39 ± 1.04; p = 0.01). Plasma dopamine level correlated with BFM score (r = 0.592, p < 0.01) and D2 receptor expression with the severity of chorea (r = 0.447, p < 0.05). The neurological severity of WD correlated with plasma dopamine concentration (p = 0.006). Dopamine and its receptors were not related to MRI changes. The central nervous system dopaminergic pathway is not enhanced in NWD, which may be due to structural damage to the corpus striatum and/or substantia nigra.

Brain Atrophy Is Substantially Accelerated in Neurological Wilson's Disease: A Longitudinal Study

BACKGROUND

Although brain atrophy is common in neurological Wilson's disease, longitudinal studies are lacking.

OBJECTIVE

The objective of this study was to measure longitudinal brain atrophy rate and to relate it to the change in neurological impairment in Wilson's disease.

METHODS

We included patients with brain imaging done at diagnosis and at least 12 months later. The atrophy rate was measured as percentage change in ventricular volume, whereas the change in neurological impairment was scored on the Unified Wilson's Disease Rating Scale.

RESULTS

Of 57 patients, 36 had neurological presentation, 17 had hepatic presentation, and 4 were presymptomatic. The annualized atrophy rate was significantly greater in patients with the neurological presentation than in other patients (P = 0.001). In the neurological presentation, the atrophy rate correlated with the change in impairment (rho = 0.39, P = 0.018) and was significantly greater in those with worsening after diagnosis than in those without worsening (P < 0.001).

CONCLUSIONS

Brain atrophy rate appears as a promising marker of neurodegeneration in Wilson's disease. © 2022 International Parkinson and Movement Disorder Society.

Disrupted topological organization of the motor execution network in Wilson's disease

OBJECTIVE

There are a number of symptoms associated with Wilson's disease (WD), including motor function damage. The neuropathological mechanisms underlying motor impairments in WD are, however, little understood. In this study, we explored changes in the motor execution network topology in WD.

METHODS

We conducted resting-state functional magnetic resonance imaging (fMRI) on 38 right-handed individuals, including 23 WD patients and 15 healthy controls of the same age. Based on graph theory, a motor execution network was constructed and analyzed. In this study, global, nodal, and edge topological properties of motor execution networks were compared.

RESULTS

The global topological organization of the motor execution network in the two groups did not differ significantly across groups. In the cerebellum, WD patients had a higher nodal degree. At the edge level, a cerebello-thalamo-striato-cortical circuit with altered functional connectivity strength in WD patients was observed. Specifically, the strength of the functional connections between the cerebellum and thalamus increased, whereas the cortical-thalamic, cortical-striatum and cortical-cerebellar connections exhibited a decrease in the strength of the functional connection.

CONCLUSION

There is a disruption of the topology of the motor execution network in WD patients, which may be the potential basis for WD motor dysfunction and may provide important insights into neurobiological research related to WD motor dysfunction.

Brain magnetic resonance imaging and severity of neurological disease in Wilson's disease - the neuroradiological correlations

INTRODUCTION

Wilson's disease (WD) is a genetic disorder with pathological copper accumulation and associated clinical symptoms in various organs, particularly the liver and brain. Neurological disease is assessed with the clinical Unified Wilson's Disease Rating Scale (UWDRS). There is a lack of quantitative objective markers evaluating brain involvement. Recently, a semiquantitative brain magnetic resonance imaging (MRI) scale has been proposed, which combines acute toxicity and chronic damage measures into a total score. The relationship between MRI brain pathology and the MRI scale with disease form and neurological severity was studied in a large cohort.

METHODS

We retrospectively assessed 100 newly diagnosed treatment-naïve patients with WD with respect to brain MRI pathology and MRI scores (acute toxicity, chronic damage, and total) and analyzed the relationship with disease form and UWDRS part II (functional impairment) and part III (neurological deficits) scores.

RESULTS

Most patients had the neurological form of WD (55%) followed by hepatic (31%) and presymptomatic (14%). MRI examination revealed WD-typical abnormalities in 56% of patients, with higher pathology rates in neurological cases (83%) than in hepatic (29%) and presymptomatic (7%) cases. UWDRS part II and III scores correlated with the MRI acute toxicity score (r = 0.55 and 0.55, respectively), chronic damage score (r = 0.39 and 0.45), and total score (0.45 and 0.52) (all P < 0.01).

CONCLUSIONS

Brain MRI changes may be present even in patients without neurological symptoms, although not frequently. The semiquantitative MRI scale correlated with the UWDRS and appears to be a complementary tool for severity of brain injury assessment in WD patients.

Neuroimaging correlates of brain injury in Wilson's disease: a multimodal, whole-brain MRI study

Wilson's disease is an autosomal-recessive disorder of copper metabolism with neurological and hepatic presentations. Chelation therapy is used to 'de-copper' patients but neurological outcomes remain unpredictable. A range of neuroimaging abnormalities have been described and may provide insights into disease mechanisms, in addition to prognostic and monitoring biomarkers. Previous quantitative MRI analyses have focused on specific sequences or regions of interest, often stratifying chronically treated patients according to persisting symptoms as opposed to initial presentation. In this cross-sectional study, we performed a combination of unbiased, whole-brain analyses on T1-weighted, fluid-attenuated inversion recovery, diffusion-weighted and susceptibility-weighted imaging data from 40 prospectively recruited patients with Wilson's disease (age range 16-68). We compared patients with neurological (n = 23) and hepatic (n = 17) presentations to determine the neuroradiological sequelae of the initial brain injury. We also subcategorized patients according to recent neurological status, classifying those with neurological presentations or deterioration in the preceding 6 months as having 'active' disease. This allowed us to compare patients with active (n = 5) and stable (n = 35) disease and identify imaging correlates for persistent neurological deficits and copper indices in chronically treated, stable patients. Using a combination of voxel-based morphometry and region-of-interest volumetric analyses, we demonstrate that grey matter volumes are lower in the basal ganglia, thalamus, brainstem, cerebellum, anterior insula and orbitofrontal cortex when comparing patients with neurological and hepatic presentations. In chronically treated, stable patients, the severity of neurological deficits correlated with grey matter volumes in similar, predominantly subcortical regions. In contrast, the severity of neurological deficits did not correlate with the volume of white matter hyperintensities, calculated using an automated lesion segmentation algorithm. Using tract-based spatial statistics, increasing neurological severity in chronically treated patients was associated with decreasing axial diffusivity in white matter tracts whereas increasing serum non-caeruloplasmin-bound ('free') copper and active disease were associated with distinct patterns of increasing mean, axial and radial diffusivity. Whole-brain quantitative susceptibility mapping identified increased iron deposition in the putamen, cingulate and medial frontal cortices of patients with neurological presentations relative to those with hepatic presentations and neurological severity was associated with iron deposition in widespread cortical regions in chronically treated patients. Our data indicate that composite measures of subcortical atrophy provide useful prognostic biomarkers, whereas abnormal mean, axial and radial diffusivity are promising monitoring biomarkers. Finally, deposition of brain iron in response to copper accumulation may directly contribute to neurodegeneration in Wilson's disease.

Wilson's disease update: An Indian perspective

Wilson's disease (WD) is an autosomal recessive disorder due to ATP7B gene mutation, resulting in defective copper metabolism, with liver and brain being primarily affected. Being a treatable disorder, early diagnosis and proper management of WD may result in near complete recovery. It has received significant attention over the past 50 years, with several Indian contributions. This study collates published Indian studies on WD in Pubmed and Embase databases and puts them in perspective. Several Indian case series suggest that WD may be more prevalent than thought. Commonly detected ATP7B mutation in India is p.C271X. Although initial Indian series reported significant osseomuscular presentation, neuropsychiatric and hepatic manifestations dominated the later reports. A significant male predominance is observed in Indian series. Pure hepatic presentation starts earlier than neurological or osseomuscular WD. A positive family history may be seen in nearly 50% of Indian WD cases with a high rate of consanguinity. Up to two-third of Indian cases may be initially misdiagnosed, with a mean diagnostic delay of up to 2 years. Abnormalities in serum ceruloplasmin and 24-hour urinary copper has been reported in more than four-fifth cases. Brain MRI is abnormal in nearly all neurological WD cases. Copper chelation remains the mainstay of therapy, with D-penicillamine being the most widely used chelator in India. Global Assessment Scale for WD is a comprehensive tool for clinical monitoring. Hepatic presentation carries a five-time higher mortality risk than neurological, with up to 90% Indian neurological WD cases recovering to pre-morbid functionality with adequate therapy.

Morphometric mapping of the macrostructural abnormalities of midsagittal corpus callosum in Wilson’s disease

Background and Purpose

The corpus callosum (CC) consists of topographically arranged white matter (WM) fibers. Previous studies have indicated the CC to be discretely involved in WD. In this study, we strived to characterize the macrostructural properties of the CC using midsagittal cross-sectional area and thickness profile measurements.

Materials and Methods

This study was performed using archived magnetic resonance imaging (MRI) scans of 14 patients with WD and 14 age- and gender-matched healthy controls. Using an automated software pipeline for morphometric profiling, the midsagittal CC was segmented into five sub-regions (CC_1–5) according to the Hofer–Frahm scheme. The mean thickness and area of different CC segments and their clinical and cognitive correlates were identified.

Results

The mean area was significantly different only in CC₂ segment (94.2 ± 25.5 vs. 118.6 ± 19.7 mm², corrected P < 0.05). The mean thickness was significantly different in CC₁ (5.06 ± 1.15 vs. 6.93 ± 0.89 mm, corrected P < 0.05), CC₂ (3.73 ± 0.96 vs. 4.87 ± 1.01 mm, corrected P < 0.05), and CC₃ segments (3.42 ± 0.84 vs. 3.94 ± 0.72 mm, corrected P < 0.05). The age at onset of neurological symptoms and MMSE score was significantly correlated with the morphometric changes of CC₁ and CC₂ segments.

Conclusion

Morphological changes of the CC are discrete in WD. Morphometric loss of CC was associated with an earlier onset of neurological symptoms and cognitive dysfunction in WD.

Structural and functional brain changes in hepatic and neurological Wilson disease

Wilson disease (WD) can manifest with hepatic or neuropsychiatric symptoms. Our understanding of the in vivo brain changes in WD, particularly in the hepatic phenotype, is limited. Thirty subjects with WD and 30 age- and gender-matched controls participated. WD group underwent neuropsychiatric assessment. Unified WD Rating Scale neurological exam scores were used to determine neurological (WDN, score > 0) and hepatic-only (WDH, score 0) subgroups. All subjects underwent 3 Tesla anatomical and resting-state functional MRI. Diffusion tensor imaging (DTI) and susceptibility-weighted imaging (SWI) were performed only in the WD group. Volumetric, DTI, and functional connectivity analyses were performed to determine between-group differences. WDN and WDH groups were matched in demographic and psychiatric profiles. The entire WD group compared to controls showed significant thinning in the bilateral superior frontal cortex. The WDN group compared to control and WDH groups showed prominent structural brain changes including significant striatal and thalamic atrophy, more subcortical hypointense lesions on SWI, and diminished white matter integrity in the bilateral anterior corona radiata and corpus callosum. However, the WDH group also showed significant white matter volume loss compared to controls. The functional connectivity between the frontostriatal nodes was significantly reduced in the WDN group, whereas that of the hippocampus was significantly increased in the WDH group compared to controls. In summary, structural and functional brain changes were present even in neurologically non-manifesting WD patients in this cross-sectional study. Longitudinal brain MRI scans may be useful as biomarkers for prognostication and optimization of treatment strategies in WD.

Wilson Disease: An Overview and Approach to Management

Wilson's disease is one of the few preventable movement disorders in which there are therapies that modify disease progression. This disease is caused by copper overload caused by reduced copper excretion secondary to genetic mutations in the ATP7B gene. Copper overload can lead to a variety of clinical presentations, including neurologic symptoms, liver failure, and/or psychiatric manifestations. There is often a delay in diagnosis of Wilson disease, and awareness of the diagnosis and management is important because of the treatable nature of this condition. This article reviews the clinical presentation, epidemiology, genetics, pathophysiology, diagnosis, and management of Wilson disease.

Brain volume is related to neurological impairment and to copper overload in Wilson's disease

Introduction

To determine whether brain volume was associated with functional and neurological impairments and with copper overload markers in patients with Wilson’s disease.

Methods

In 48 treatment-naïve patients, we assessed functional and neurological impairments with the Unified Wilson’s Disease Rating Scale, measured normalized brain volumes based on magnetic resonance images, and assessed concentration of non-ceruloplasmin-bound copper. We correlated brain volume measures with functional and neurological impairment scores and copper overload indices.

Results

Functional and neurological impairments correlated with all brain volume measures, including the total brain volume and the volumes of white matter and gray matter (both peripheral gray matter and deep brain nuclei). Higher non-ceruloplasmin-bound copper concentrations were associated with greater functional and neurological impairments and lower brain volumes.

Conclusions

Our findings provided the first in vivo evidence that the severity of brain atrophy is a correlate of functional and neurological impairments in patients with Wilson’s disease and that brain volume could serve as a marker of neurodegeneration induced by copper.

Electronic supplementary material

The online version of this article (10.1007/s10072-019-03942-z) contains supplementary material, which is available to authorized users.

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.

Biochemical Markers for the Diagnosis and Monitoring of Wilson Disease

Wilson disease (WD) is an autosomal recessively-inherited disorder of copper metabolism and characterised by a pathological accumulation of copper. The ATP7B gene encodes for a transmembrane copper transporter essential for biliary copper excretion. Depending on time of diagnosis, severity of disease can vary widely. Almost all patients show evidence of progressive liver disease. Neurological impairments or psychiatric symptoms are common in WD patients not diagnosed during adolescence. WD is a treatable disorder, and early treatment can prevent the development of symptoms in patients diagnosed while still asymptomatic. This is why the early diagnosis of WD is crucial. The diagnosis is based on clinical symptoms, abnormal measures of copper metabolism and DNA analysis. Available treatment includes chelators and zinc salts which increase copper excretion and reduce copper uptake. In severe cases, liver transplantation is indicated and accomplishes a phenotypic correction of the hepatic gene defect. Recently, clinical development of the new copper modulating agent tetrathiomolybdate has started and direct genetic therapies are being tested in animal models. The following review focuses especially on biochemical markers and how they can be utilised in diagnosis and drug monitoring.

Predictors of seizure in Wilson disease: A clinico-radiological and biomarkers study

BACKGROUND

There is paucity of studies on predictors of seizures in Wilson disease with neurological manifestation (WDNM), and none has evaluated the role of copper (Cu) induced oxidative stress, proinflammatory and excitotoxicity in the genesis of seizure.

OBJECTIVES

To report frequency, refractoriness, and outcome of seizure in WDNM. We also evaluate role of Cu induced oxidative stress, excitotoxicity and cytokines in predicting seizures.

METHODS

The diagnosis of WDNM was based on clinical, MRI, KF ring and 24 h urinary Cu. Detailed clinical examination including severity of WD, occurrence of seizure, seizure semiology, antiepileptic drug (AED) and breakthrough seizures were noted. Cranial MRI and electroencephalography findings were noted. Serum free-Cu, oxidative stress markers (glutathione, total antioxidant capacity, malondialdehyde), glutamate and cytokines (interleukin 6, 8 and 10 and tumour necrosis factor α) were measured by atomic absorption spectrophotometer, spectrophotometer, fluorometer and flow cytometer respectively, and correlated with seizures. Patients were treated with zinc with or without penicillamine, and those with epilepsy received second-generation antiepileptic drugs (AEDs).

RESULTS

Out of 110 patients with WDNM, 16(14.5%) had seizures; focal in 11(68.7%) and generalized in 5(31.3%). Patients with seizure had higher serum free-Cu (35.87 ± 1.34 vs 31.72 ± 0.68; P = 0.02), severe dystonia (P = 0.04), and more frequent cortical (100% vs 6.4%; P < 0.01) and subcortical (81.3% vs 20.2%; P < 0.01) lesions on MRI compared to those without seizure. Oxidative stress markers (glutathione, total antioxidant capacity, malondialdehyde), cytokines and glutamate were elevated in WDNM compared to controls. On multivariate logistic regression analysis, cortical involvement (OR = 105.49; 95%CI = 8.74-1272.39; P < 0.01) and number of MRI lesions (OR = 1.99; 95% CI = 1.11-3.57; P = 0.02) were independent predictors of seizure. The seizures were controlled with single and dual AEDs in seven patients each, and two patients needed three AEDs. All the patients had seizure remission for a median follow up of 66(24-180) months.

CONCLUSION

About one-sixth WDNM patients have seizures especially in those with cortical and extensive MRI lesions. Seizures are easily controlled by AEDs.

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.

Magnetic resonance imaging findings in diagnosis and prognosis of Wilson disease

Wilson disease (WD) is a rare autosomal recessive disorder characterized by excessive copper deposition in the body, principally in the liver and the brain. There is a wide spectrum of clinical presentations, but the most significant and basic symptoms of the disease can be divided into hepatic, neurologic, and psychiatric manifestations. Magnetic resonance imaging (MRI) provides more detailed anatomical information than computed tomography of the brain, especially of the structure of the basal ganglia and brain stem. In this review, we want to evaluate the correlation between MRI findings and clinical features of WD.

Wilson disease: neurologic features

Wilson disease (WD) is a neurodegenerative disorder, which presents as a spectrum of neurologic manifestations that includes tremor, bradykinesia, rigidity, dystonia, chorea, dysarthria, and dysphagia, together with a combination of neurologic symptoms that can easily lead to misdiagnosis. An early diagnosis of WD, and appropriate anticopper treatment, usually leads to a marked improvement in patient health. Conversely, delayed diagnosis can result in persistent pathology, which, left untreated, can ultimately prove lethal. The aim of this chapter is to present a detailed description of the neurologic features of WD, including their evaluation, together with relevant ophthalmologic examinations, brain neuroimaging, and other laboratory measurements that show the extent of the involvement of the nervous system.

Wilson disease: At the crossroads between genetics and epigenetics-A review of the evidence

Environmental factors, including diet, exercise, stress, and toxins, profoundly impact disease phenotypes. This review examines how Wilson disease (WD), an autosomal recessive genetic disorder, is influenced by genetic and environmental inputs. WD is caused by mutations in the copper-transporter gene ATP7B, leading to the accumulation of copper in the liver and brain, resulting in hepatic, neurological, and psychiatric symptoms. These symptoms range in severity and can first appear anytime between early childhood and old age. Over 300 disease-causing mutations in ATP7B have been identified, but attempts to link genotype to the phenotypic presentation have yielded little insight, prompting investigators to identify alternative mechanisms, such as epigenetics, to explain the highly varied clinical presentation. Further, WD is accompanied by structural and functional abnormalities in mitochondria, potentially altering the production of metabolites that are required for epigenetic regulation of gene expression. Notably, environmental exposure affects the regulation of gene expression and mitochondrial function. We present the "multi-hit" hypothesis of WD progression, which posits that the initial hit is an environmental factor that affects fetal gene expression and epigenetic mechanisms and subsequent "hits" are environmental exposures that occur in the offspring after birth. These environmental hits and subsequent changes in epigenetic regulation may impact copper accumulation and ultimately WD phenotype. Lifestyle changes, including diet, increased physical activity, stress reduction, and toxin avoidance, might influence the presentation and course of WD, and therefore may serve as potential adjunctive or replacement therapies.

Memory and Learning Dysfunction Following Copper Toxicity: Biochemical and Immunohistochemical Basis

The prototype disease of Cu toxicity in human is Wilson disease, and cognitive impairment is the presenting symptom of it. There is no study correlating Cu-induced excitotoxicity, apoptosis, and astrocytic reaction with memory dysfunction. We report excitotoxicity, apoptosis, and astrocytic reaction of the hippocampus and frontal cortex with memory dysfunction in rat model of Cu toxicity. Thirty-six rats were divided into group I (control) and group II (100 mg/kgBwt/day CuSO₄ orally). Y-maze was performed for memory and learning at 0, 30, 60, and 90 days. Frontal and hippocampal free Cu concentration, oxidative stress markers [glutathione (GSH), total antioxidant toxicity (TAC), and malondialdehyde (MDA)], and glutamate were measured by atomic absorption spectroscopy, spectrophotometry, and ELISA, respectively. N-methyl-D-aspartate receptors (NMDARs) NR1, NR2A, and NR2B were done by real-time polymerase chain reaction. Immunohistochemistry for caspase-3 and glial fibrillary acidic protein (GFAP) were done and quantified using the ImageJ software. The glutamate level in hippocampus was increased, and NMDAR expression was decreased at 30, 60, and 90 days in group II compared to group I. In the frontal cortex, glutamate was increased at 90 days, but NMDARs were not significantly different in group II compared to group I. Caspase-3 and GFAP expressions were also higher in group II compared to group I, and these changes were more marked in hippocampus than frontal cortex. These changes correlated with respective free tissue Cu, oxidative stress, and Y-maze attention score. Cu toxicity induces apoptosis and astrocytosis of the hippocampus and frontal cortex through direct or glutamate and oxidative stress pathways, and results in impaired memory and learning.

Update on the clinical management of Wilson's disease

Wilson's disease (WD), albeit relatively rare, is an important genetic metabolic disease because of highly effective therapies that can be lifesaving. It is a great imitator and requires a high index of suspicion for correct and timely diagnosis. Neurologic, psychiatric and hepatologic problems in WD are very nonspecific, and we discuss the most common clinical phenotypes. The diagnosis remains laboratory based, and here we review the most important challenges and pitfalls in laboratory evaluation of WD, including the emerging role of genetic testing in WD diagnosis. WD is a monogenic disorder but has very high allelic heterogeneity with >500 disease-causing mutations identified, and new insights into phenotype-genotype correlations are also reviewed. The gold standard of therapy is chelation of excessive copper, but many unmet needs exist because of possible clinical deterioration in treated patients and potential adverse effects associated with currently available chelating medications. We also review the most promising novel therapeutic approaches, including chelators targeting specific cell types, cell transplantation and gene therapy.

Contribution of metals to brain MR signal intensity: review articles

Various metals are essential nutrients in humans, and metal shortages lead to a variety of deficiency diseases. Metal concentration abnormalities may cause metal deposition in the brain, and magnetic resonance imaging (MRI) is the most potent and sensitive technique now available for detecting metal deposition given the difficulties associated with performing brain tissue biopsy. However, the brain contains many kinds of metals that affect the signal intensity of MRI, which has led to numerous misunderstandings in the history of metal analysis. We reviewed the history of brain metal analysis with histologic findings. Typically, manganese overload causes high signal intensity on T1-weighted images (T1WI) in the globus pallidus, iron overload causes low signal intensity in the globus pallidus on T2-weighted images, and gadolinium deposition causes high signal intensity in the dentate nucleus, globus pallidus, and pulvinar of thalamus on T1WI. However, because nonparamagnetic materials and other coexisting metals also affect the signal intensity of brain MRI, the quantitative analysis of metal concentrations is difficult. Thus, when analyzing metal deposition using MRI, caution should be exercised when interpreting the validity and reliability of the obtained data.

Wilson's disease with cognitive impairment and without extrapyramidal signs: improvement of neuropsychological performance and reduction of MRI abnormalities with trientine treatment

Extrapyramidal signs are neurological dysfunction commonly associated with Wilson's disease (WD). In addition, cognitive dysfunction has been reported in the early stages of WD. In this report, we describe a 49-year-old woman presenting with memory impairments and without Parkinsonian or extrapyramidal signs. She was diagnosed with WD based on the presence of Kayser-Fleischer rings around the irises of her eyes and two ATP7B gene mutations, R778L at exon 8 and A874V at exdyon 11. Serial magnetic resonance imaging analysis and neuropsychological tests showed improvements following treatment with trientine.

Combination Therapy Using Chelating Agent and Zinc for Wilson's Disease

There is no clear international consensus regarding the optimal medication therapy for treating Wilson's disease (WD). This study systematically reviews the effectiveness of various medication therapies in common use, specifically focusing on preliminary findings concerning the combination of a chelating agent and zinc. A systematic PubMed search was executed to locate original studies on the effectiveness of commonly used medications for WD published between January 1989 and August 2014. The results were used to conduct a systematic review of studies on combination therapies. A total of 17 combination therapy studies involving 1056 patients were reviewed. These were analyzed in terms of data on effectiveness, adverse effects, and mortality. Results from a pooled analysis indicate that combination therapies for hepatic patients were significantly less effective than the same therapies for neurological manifestations (47.1 vs. 78.6 %; pooled relative risk ratio (RR): 0.63, 95 % confidence interval CI 0.43-0.94; p = 0.02). Data from a subgroup analysis show that the combination therapy of penicillamine plus zinc sulfate resulted in a significantly higher mortality rate compared to all other combination therapy types (16.3 vs. 4.7 %; RR: 3.51, 95 % CI 1.54-8.00; p < 0.001). The use of combination therapies involving zinc and a chelator should be carefully monitored with close clinical observations and frequent biochemical tests, especially for WD patients with hepatic manifestations.

The discrepancy between the absence of copper deposition and the presence of neuronal damage in the brain of Atp7b(-/-) mice

Wilson's disease (WD) is caused by mutations within the copper-transporting ATPase (ATP7B), characterized by copper deposition in various organs, principally the liver and the brain. With the availability of Atp7b(-/-) mice, the valid animal model of WD, the mechanism underlying copper-induced hepatocyte necrosis has been well understood. Nonetheless, little is known about the adverse impact of copper accumulation on the brain in WD. Therefore, the aim of this study was to identify copper disturbances according to various brain compartments and further dissect the causal relationship between copper storage and neuronal damage using Atp7b(-/-) mice. Copper levels in the liver, whole brain, brain compartments and basal ganglia mitochondria of Atp7b(-/-) mice and age-matched controls were measured by atomic absorption spectroscopy. Delicate electron microscopic studies on hepatocytes and neurons in the basal ganglia were performed. Here we further confirmed the remarkably elevated copper content and abnormal ultrastructure findings in livers of Atp7b(-/-) mice. Interestingly, we found the ultrastructure abnormalities in neurons of the basal ganglia of Atp7b(-/-) mice, whereas copper deposition was not detected in the whole brain, even within the basal ganglia and its mitochondria. The disparity provided a new understanding of neuronal dysfunction in WD, and strongly indicated that copper might not be the sole causative player and other unidentified pathogenic factors could enhance the toxic effects of copper on neurons in WD.

Improvement of Diffusion Tensor Imaging (DTI) Parameters with Decoppering Treatment in Wilson's Disease

OBJECTIVE

This study was undertaken to analyse serially the effects of decoppering therapy on the clinical features, disability and MRI brain including DTI metrics in patients with Wilson's disease.

METHODS AND RESULTS

Thirty-five patients with clinically and serologically confirmed neuropsychiatric form of Wilson's disease (WD) on decoppering therapy were followed for a minimum duration of 1 year with serial assessment of their clinical features, disability status and serial MR imaging of the brain including DTI. The cohort included 18 treatment-naïve patients and 17 patients already on decoppering therapy (M/F = 2.18:1). The mean age at which they underwent baseline assessment for this study was 18.6 ± 7.6 years, and follow-up assessment was done after a mean duration of 23.5 ± 8.8 months (range, 12 to 45 months). Along with the overall clinical improvement noted at follow-up, the disability assessed using Chu staging and MSEADL showed significant reduction in the number of patients with severe disability and the mean NSS reducing from 9.74 to 6.37 (p = 0.002). The mean MRI scores showed significantly reduced disease burden from a baseline score of 5.9 (±4.2) to 4.9 (±4.7) in follow-up scans (p < 0.05). Voxel-wise comparison of serial DTI metrics on TBSS (tract-based spatial statistics) analysis showed that the entire cohort had significant (p < 0.05) improvement in all the four parameters (MD, FA, DA and RD) indicated by a decrease in MD, DA and RD values and increase in FA values. Comparison of whole-brain white matter DTI measures between pre- and posttreatment did not show any significant difference (p < 0.05).

CONCLUSION

Patients with Wilson's disease on decoppering therapy showed clinical improvement accompanied with improvement in DTI metrics. Quantitative DTI metrics may be used as surrogate markers of clinical status following initiation of medical therapy in Wilson's disease.

MRI and oxidative stress markers in neurological worsening of Wilson disease following penicillamine

BACKGROUND AND AIM

There is no report of MRI correlation with neurological worsening following chelating treatment in Wilson disease with neurological manifestation (WDN). We report radiological changes in four patients with WDN who worsen after penicillamine.

METHODS

WDN was diagnosed on the basis of clinical, KF ring, serum ceruloplasmin and 24h urinary copper. Hematological, biochemical and cranial MRI were repeated at the time of clinical deterioration following chelating treatment.

RESULTS

Four WDN patients had neurological deterioration within 4-8 weeks of penicillamine therapy. This was associated with new lesions in white matter, thalamus, pons and mid brain and these lesions showed diffusion restriction. The neurologic deterioration was associated with increased free serum copper and malanodialdehyde and reduced glutathione. Clinical conditions stabilized after few weeks of penicillamine discontinuation.

CONCLUSION

Neurological worsening was associated with new lesions on MRI which revealed diffusion restriction. Increased free copper induced oxidative stress may be responsible for these changes.

Toxic and metabolic encephalopathies: iconographic essay

Generally, toxic-metabolic diseases affecting the central nervous system can hardly be differentiated just on the basis of their clinical presentation. However, some typical neuroradiological features can guide the correct diagnosis. In this context, magnetic resonance imaging is an important tool which, in association with clinical and laboratory data, can establish an early and specific treatment. The present pictorial essay with selected cases from the archives of the authors' institution describes imaging findings which might help in the etiologic diagnosis of toxic-metabolic diseases.

Reversible lesions in the brain parenchyma in Wilson's disease confirmed by magnetic resonance imaging: earlier administration of chelating therapy can reduce the damage to the brain

The aim of this study was to evaluate the resolution of brain lesions in patients with Wilson's disease during the long-term chelating therapy using magnetic resonance imaging and a possible significance of the time latency between the initial symptoms of the disease and the introduction of this therapy. Initial magnetic resonance examination was performed in 37 patients with proven neurological form of Wilson's disease with cerebellar, parkinsonian and dystonic presentation. Magnetic resonance reexamination was done 5.7 ± 1.3 years later in 14 patients. Patients were divided into: group A, where chelating therapy was initiated < 24 months from the first symptoms and group B, where the therapy started ≥ 24 months after the initial symptoms. Symmetry of the lesions was seen in 100% of patients. There was a significant difference between groups A and B regarding complete resolution of brain stem and putaminal lesions (P = 0.005 and P = 0.024, respectively). If the correct diagnosis and adequate treatment are not established less than 24 months after onset of the symptoms, irreversible lesions in the brain parenchyma could be expected. Signal abnormalities on magnetic resonance imaging might therefore, at least in the early stages, represent reversible myelinolisis or cytotoxic edema associated with copper toxicity.

The neurotoxicity of iron, copper and manganese in Parkinson's and Wilson's diseases

Impaired cellular homeostasis of metals, particularly of Cu, Fe and Mn may trigger neurodegeneration through various mechanisms, notably induction of oxidative stress, promotion of α-synuclein aggregation and fibril formation, activation of microglial cells leading to inflammation and impaired production of metalloproteins. In this article we review available studies concerning Fe, Cu and Mn in Parkinson's disease and Wilson's disease. In Parkinson's disease local dysregulation of iron metabolism in the substantia nigra (SN) seems to be related to neurodegeneration with an increase in SN iron concentration, accompanied by decreased SN Cu and ceruloplasmin concentrations and increased free Cu concentrations and decreased ferroxidase activity in the cerebrospinal fluid. Available data in Wilson's disease suggest that substantial increases in CNS Cu concentrations persist for a long time during chelating treatment and that local accumulation of Fe in certain brain nuclei may occur during the course of the disease. Consequences for chelating treatment strategies are discussed.

Seven-tesla magnetic resonance imaging in Wilson disease using quantitative susceptibility mapping for measurement of copper accumulation

OBJECTIVES

In Wilson disease (WD), the copper content of cerebral tissue is increased, particularly in the basal ganglia. This study investigated whether a change in magnetic susceptibility can be detected using quantitative susceptibility mapping of the brain in patients with WD compared with healthy controls.

MATERIALS AND METHODS

Eleven patients with WD (6 with the neurological form, 5 with the hepatic form) and 10 age-matched healthy controls who gave informed consent were examined at 7 T in a whole-body scanner (MAGNETOM; Siemens Medical Solutions, Erlangen, Germany) using a 24-channel phased array coil (Nova Medical). For imaging, a 3-dimensional spoiled gradient multiecho sequence (repetition time, 40 milliseconds; echo time, 9.76/19.19/28.62 milliseconds; bandwidth, 150 hertz per pixel; voxel size, 0.6 × 0.6 × 0.8 mm) was used. The susceptibility of selected regions (substantia nigra, red nucleus, pallidum, putamen, caudate nucleus) was analyzed in susceptibility maps.

RESULTS

The patients with WD showed significantly increased susceptibility (P value, 0.001-0.05) in all analyzed regions compared with healthy controls. This was evident not only in patients with a neurological syndrome but also, with lower values, in patients with isolated hepatic manifestations. The distribution patterns of copper accumulation were different between the patients with neurological and non-neurological manifestations of the disease.

CONCLUSIONS

In neurologically symptomatic and asymptomatic patients with WD, we found increased magnetic susceptibility in the brain tissue using quantitative susceptibility mapping.

Effect of liver transplantation on brain magnetic resonance imaging pathology in Wilson disease: a case report

The authors present a case report of a 28-year-old patient with hepatic, but no neurological, signs of Wilson disease, with pathological changes in both the globi pallidi and caudate found with routine brain magnetic resonance imaging (MRI). The patient was recommended for liver transplantation by hepatologists, and during the two years of observation after liver transplantation, MRI brain abnormalities due to Wilson disease completely regressed. On the basis of this case, the authors present an argument for the prognostic significance of brain MRI in Wilson disease as well as current recommendations concerning liver transplantation in Wilson disease.

Diffusion tensor imaging (DTI) and its clinical correlates in drug naïve Wilson's disease

The purpose is to evaluate white matter (WM) abnormalities in Wilson's disease (WD) using the technique of diffusion tensor imaging (DTI). The prospective case-control study comprised of 15 drug-naïve patients with WD and 15 controls. The phenotype of subjects was evaluated. The DTI/conventional MRI was acquired (3T MRI): Fractional anisotropy (FA) and mean diffusivity (MD) values were extracted from regions of interest placed in pons, midbrain, bilateral frontal and occipital cerebral white matter, bilateral internal capsules (IC), middle cerebellar peduncles (MCP) and corpus callosum (CC). Six patients showed lobar WM signal changes on T(2)-Weighted (T2W)/Fluid attenuation inversion recovery (FLAIR) images while remaining had normal appearing WM. MD was significantly increased in the lobar WM, bilateral IC and midbrain of WD patients. FA was decreased in the frontal and occipital WM, bilateral IC, midbrain and pons. Normal-appearing white matter on FLAIR images showed significantly increased MD and decreased FA values in both frontal and occipital lobar WM and IC compared with those in controls. Correlation of clinical scores and DTI metrics revealed positive correlation between neurological symptom score (NSS) and MD of anterior limb of right internal capsule, Chu stage and MD of frontal and occipital WM. Negative correlation was observed between the Modified Schwab and England Activities of Daily Living (MSEADL) score and MD of bilateral frontal and occipital WM and IC. This is the probably the first study to reveal widespread alterations in WM by DTI metrics in drug naïve WD. DTI analysis revealed lobar WM abnormalities which is less frequently noted on conventional MRI and suggests widespread WM abnormalities in WD. It may be valuable in assessing the true extent of involvement and therefore the severity of the illness.

Cognitive impairment and magnetic resonance imaging correlations in Wilson's disease

OBJECTIVES

To evaluate the cognitive performance of a group of patients with Wilson's disease (WD) and to correlate the cognitive findings with changes in magnetic resonance imaging (MRI).

METHODS

All patients with WD consecutively attended in a Movement Disorders Clinic between September 2006 and October 2007 were invited to participate in the study, together with a group of matched healthy controls. Patients and controls were submitted to comprehensive neuropsychological assessment. MRI was performed in all patients, and abnormalities (high-intensity signal, low-intensity signal and atrophy) were semi-quantitatively rated. Performance of patients and controls in each cognitive test was compared, and correlations between cognitive scores and MRI changes were investigated within the patients' group.

RESULTS

Twenty patients with WD (11 men) and 20 controls (nine men) were evaluated. Mean age in the WD and control groups was 30.05 ± 7.25 and 32.15 ± 5.37 years, respectively. Mean schooling years were 11.15 ± 3.73 among WD cases and 10.08 ± 2.62 among controls. Patients with WD performed significantly worse than controls in the Mini-Mental State Examination, Dementia Rating Scale, phonemic verbal fluency (FAS), verb generation, digit span forward, Stroop test, Frontal Assessment Battery and in the Brief Cognitive Screening Battery. A significant correlation emerged between global cognitive impairment and MRI scale (r = 0.535), being higher for high-intensity signal plus atrophy (r = 0.718).

CONCLUSION

Patients with WD presented cognitive impairment, especially in executive functions, with good correlation between cognitive abnormalities and MRI changes.

Brain metal accumulation in Wilson's disease

INTRODUCTION

Brain metal accumulation is suggested in the pathogenesis of numerous neurodegenerative disorders. In Wilson's disease (WD), only copper has been examined. The aim of the present study was to evaluate the copper, iron, manganese, and zinc concentrations in autopsy tissue samples from the brains of WD patients.

METHODS

The study material consisted of 17 brains (12 WD patients, 5 controls) obtained at autopsy. Samples were taken from four different regions of each brain: frontal cortex, putamen, pons, and nucleus dentatus. The copper, manganese, and zinc content were determined using inductively coupled plasma mass spectrometry, and iron was assessed using flame atomic absorption spectroscopy. The results were analyzed according to select clinical variables.

RESULTS

Copper content was increased homogenously in all investigated structures of the WD brains compared to controls (41.0 ± 18.6 μg/g vs.5.4 ± 1.8 μg/g; P<0.01). The mean concentrations of iron, manganese, and zinc were similar in WD and controls, but the iron level in the nucleus dentatus was higher in WD compared to controls (56.8 ± 14.1 μg/g vs. 32.6 ± 6.0 μg/g; P<0.05). Gender, age, and type and duration of WD treatment did not impact brain metals storage, but some correlations between the duration of the disease and copper and iron accumulation were observed.

CONCLUSIONS

During the course of WD, copper accumulates equally in different parts of the brain. Zinc and manganese do not seem to be involved in WD pathology, but increased levels of iron were found in the nucleus dentatus. Thus, additional studies of brain iron accumulation in WD are needed.

The effect of gender on brain MRI pathology in Wilson's disease

Gender influence on the clinical manifestations of Wilson's Disease (WD) has been suggested; however, brain MRI pathology based on sexual dimorphism in WD has not yet been examined. The aim of this study was to analyse the effect of gender on brain MRI pathology according to the predominant form of WD. We retrospectively analysed the brain MR images of 204 newly diagnosed and untreated WD patients. The predominant form of the disease was neuropsychiatric (n = 105), hepatic (n = 67) or presymptomatic (n = 32). Overall, neuroimaging pathologies were found in 64.2 % WD patients. The clinical form analysis revealed significant gender-related differences. In the neuropsychiatric form, men presented with cerebellar atrophy and cortical brain atrophy more often than women (25/58 vs. 11/47; p < 0.05) and (23/58 vs. 12/47; p = 0.09), respectively. In contrast, women tended to present with globus pallidus lesions more often than men (25/47 vs. 20/58; p = 0.054). There were no gender differences observed in the hepatic form, but cortical brain atrophy presented more often in men than women (3/12 vs. 0/20; p < 0.05) in the presymptomatic form. According to our findings, there is a gender-dependent brain vulnerability to copper toxicity. We speculate that these differences are potentially related to an oestrogen protective effect and are due to differences in gender-related clinical forms.

Wilson disease: Canadian perspectives on presentation and outcomes from an adult ambulatory setting

BACKGROUND

Wilson disease (WD) is a rare disorder of copper metabolism.

OBJECTIVE

To describe the authors' clinical experience with a cohort of 48 adult patients followed in an ambulatory setting.

METHODS

A retrospective chart review of patients with a diagnosis of WD was performed.

RESULTS

Fifty-nine charts were identified and 11 were excluded on further review. At diagnosis, 14 patients were asymptomatic, with 13 hepatic, 15 neurological and six mixed hepatic⁄neurological presentations. Ceruloplasmin levels were low (<0.20 g⁄L) in 94%, and 24 h urinary copper levels high (>0.60 µmol⁄L) in 95% of cases. D-penicillamine was the most common initial therapy (48%), with zinc the most common at review (65%). Overall, biopsy and ultrasound reports documented cirrhosis in 53%. Portal hypertension, defined as splenomegaly (>12.0 cm), reversed portal venous flow on ultrasound or varices⁄gastropathy on endoscopy was seen in 63%. At last review, 39% had elevated aspartate aminotransferase (>34 U⁄L) and⁄or alanine aminotransferase levels (>40 U⁄L). One death and one transplant occurred, while three patients had encephalopathy, two became jaundiced, two developed ascites and one experienced variceal bleed. Of 21 neurological presenting patients, 14 improved compared with baseline, with four making almost complete recovery. Eleven patients experienced documented episodes of neurological decline, including four with non-neurological presentation. Diagnostic magnetic resonance imaging showed basal ganglia (64%), brainstem (64%) abnormalities and atrophy (36%); follow-up showed basal ganglia lesions (50%) and atrophy (55%).

CONCLUSION

WD is a diverse chronic disease with generally favourable outcomes for patients who respond to initial therapy, which can be managed predominantly in an ambulatory setting.