Observation on the changes of clinical symptoms, blood and brain copper deposition in Wilson disease patients treated with dimercaptosuccinic acid for 2 years.

OBJECTIVE: To compare the clinical symptoms, brain copper deposition changes of Meso-2,3-dimercaptosuccinic acid (DMSA) and penicillamine therapy in patients with Wilson disease (WD) within 2 years. METHODS: 68 drug-naive patients with WD were enrolled. 10 WD patients treated with zinc gluconate alone were used as the control group. Neurological symptoms were scored using the modified Young Scale. Liver function tests, copper indices and sensitive weighted imaging (SWI) examination were collected. The values of corrected phase (CP) were collected. WD patients were treated with DPA (group 1) or DMSA (group 2) for two years, and followed up every 2 months. RESULTS: The ratio of neurological improvement in group 2 was higher than that in group 1 (P = 0.029). Higher rate of neurologic worsening was noticed in patients treated with DPA vs DMSA (P = 0.039). The post-treatment neurological score of DMSA group was lower than that of Zn group (P = 0.037). Hepatic function in 63.3% of patients was stable, while 16.7% was improved, and 20% was deteriorated, after DMSA therapy. Urinary copper levels were lower 1 month (p = 0.032), 4 months (p = 0.041), 12 months (p = 0.037) after initiation of treatment in group 2 than in group 1. At the first year of treatment, the CP values in globus pallidus and substantia nigra in group 2 were higher than those in group 1 (P = 0.034,0.039). At the second year of treatment, the CP values of substantia nigra in group 2 were higher (P = 0.041). Discontinuation was more common in patients on DPA therapy (P = 0 0.032). CONCLUSIONS: DMSA could remove metal from brain tissue faster than DPA. DMSA is effective for neurologic symptoms, while the outcome for hepatic symptoms is not entirely satisfactory. DMSA therapy is better tolerated than DPA.

A study of susceptibility-weighted imaging in patients with Wilson disease during the treatment of metal chelator.

OBJECTIVE: A randomized-controlled trial comparing study of the changes in brain sensitive-weighted imaging (SWI) of Wilson disease (WD) patients during the treatment with metal chelator was done. METHODS: 100 untreated WD patients (80 cases of cerebral type, 20 cases of hepatic type, age 20.13 ± 9.12 years old) and 20 normal controls were selected. Neurological symptoms were scored using the modified Young scale. Liver function tests and copper indices were collected. All study objects received SWI test of the brain. The values of corrected phase (CP) were calculated on SWI. Cerebral-type WD patients were treated with D-penicillamine (DPA) (group 1) or Dimercaptopropane Sulfonate (DMPS) + Dimercaptosuccinic Acid (DMSA) (group 2). Hepatic-type WD patients were treated with DPA (group 3). All patients received annual neurological symptom score, liver function, copper indices, and SWI examination. RESULTS: At the first year of treatment, score of the modified Young scale in group 2 was lower than that in group 1 (P = 0.023) and lower than that before treatment (P = 0.040). After 2 years of treatment, the score of the modified Young scale in group 1 was lower than that before treatment (P = 0.012). At the second year after treatment, the urinary copper in group 2 was higher than that in group 1 (P = 0.014). Urinary copper was maintained at 200 µg/day in group 1 and 300 µg/day in group 2 after 3 years of treatment. At the first year of treatment, serum copper in group 1 was lower than that in group 2 (P = 0.032). At the first year of treatment, CP values of the pallidum and substantia nigra in group 2 were higher than those in group 1 (P = 0.026, 0.040). At the second year of treatment, CP value of substantia nigra in group 2 was higher than that in group 1 (P = 0.037). After 3 years of treatment, there was no difference in CP values between WD patients and normal controls. CONCLUSIONS: Therapy with DMPS and DMSA improves neurological symptoms of WD patients more quickly and leads to less aggravation, compared with therapy with DPA. The metal content in the brain of WD patients was at a low level after 3 years of treatment. DMPS and DMSA can remove metal from brain tissue faster than DPA.

Injury factors and pathological features of toxic milk mice during different disease stages.

OBJECTIVE: To evaluate different injury factors and pathological characteristics of the brain at different disease stages in toxic milk (TX) mice, an animal model of Wilson's disease (WD). METHODS: Thirty TX mice (10 each at 3, 6 and 12 months old) and 30 age-matched C57 mice were used in this study. Corrected phase (CP) values were determined from susceptibility-weighted images. Myelin content was determined by measuring inhibition optical density values of Luxol fast blue-stained sections. Neurofilament protein 68 kDa (NF68), ß-amyloid precursor protein (ß-APP), and myelin basic protein (MBP) levels, as well as copper and iron content, in brain nuclei of the TX mouse were evaluated. Gene amplification ratios for catalase (CAT), GSH peroxidase (GSH-PX), nitric oxide synthase (NOS), and superoxide dismutase (SOD) in mouse brain were also determined. RESULTS: Compared with C57 mice, neuronal cell counts were decreased in 12-months-old TX mice (p = .011). Myelin content was decreased in the lenticular nucleus (p = .029), thalamus (p = .030), and brainstem (p = .034) of 6-months-old TX mice; decreases in the corresponding nuclei (p = .044, .037, and .032, respectively) were also found in 12-months-old TX mice. MBP values were lower in the lenticular nucleus and thalamus (p = .027 and .016, respectively) of 6-months-old TX mice and in the corresponding nuclei (p = .24 and .040) of 12-months-old TX mice. NF-68 values were lower in the lenticular nucleus and thalamus (p = .034 and .037, respectively) of 6-months-old TX mice and in the corresponding nuclei (p = .006 and .012) of 12-months-old TX mice. ß-APP values were higher in the thalamus of 6-months-old (p = .037) and 12-months-old (p = .012) TX mice. Iron content was higher in the lenticular nucleus, thalamus, and cerebellum (p = .044, .038, and .029, respectively) of 6-months-old TX mice and in the corresponding nuclei (p = .017, .024, and .029) of 12-months-old TX mice. The NOS gene amplification multiple was higher (p = .039), whereas the SOD1 gene amplification multiple was lower (p = .041) in 12-months-old TX mice. There was no correlation between metal content or oxidation index and pathological index. CONCLUSIONS: The pathological characteristics of the brains of TX mice may differ at different ages. Different pathogenic factors, including copper and iron deposition and abnormal oxidative stress, are present at different stages.

The asymmetry of neural symptoms in Wilson's disease patients detecting by diffusion tensor imaging, resting-state functional MRI, and susceptibility-weighted imaging.

Objective: To investigate the cause of the motor asymmetry in Wilson's disease (WD) patients using functional MRI. Methods: Fifty patients with WD and 20 age-matched healthy controls were enrolled. Neurological symptoms were scored using the modified Young Scale. All study subjects underwent diffusion tensor imaging (DTI), susceptibility-weighted imaging (SWI), and resting-state functional MRI (rs-fMRI) of the brain. Six regions of interest (ROI) were chosen. Fiber volumes between ROIs on DTI, corrected phase (CP) values on SWI, amplitude of low-frequency fluctuation (ALFF), and regional homogeneity (REHO) values on rs-fMRI were determined. Asymmetry index (right or left value/left or right value) was evaluated. Results: Asymmetry of rigidity, tremor, choreic movement, and gait abnormality (asymmetry index = 1.33, 1.39, 1.36, 1.40), fiber tracts between the GP and substantia nigra (SN), GP and PU, SN and thalamus (TH), SN and cerebellum, head of the caudate nucleus (CA) and SN, PU and CA, CA and TH, TH and cerebellum (asymmetry index = 1.233, 1.260, 1.269, 1.437, 1.503, 1.138, 1.145, 1.279), CP values in the TH, SN (asymmetry index = 1.327, 1.166), ALFF values, and REHO values of the TH (asymmetry index = 1.192, 1.233) were found. Positive correlation between asymmetry index of rigidity and fiber volumes between the GP and SN, SN and TH (r = .221, .133, p = .043, .036), and tremor and fiber volumes between the CA and TH (r = .045, p = .040) was found. Conclusions: The neurological symptoms of patients with WD were asymmetry. The asymmetry of fiber projections may be the main cause of motor asymmetry in patients with WD.

Oculomotor deficits in spinocerebellar ataxia type 3: Potential biomarkers of preclinical detection and disease progression.

AIMS: To detect specific oculomotor deficits in preclinical stage of spinocerebellar ataxia type 3 (SCA3) and evaluate whether these abnormalities prove useful as potential biomarkers of disease progression. METHODS: A Chinese cohort of 56 patients with SCA3, including 12 preclinical carriers of SCA3 (pre-SCA3) and 44 manifest SCA3, and 26 healthy control individuals were recruited. We performed a detailed investigation on central oculomotor performance including fixation, gaze, smooth pursuit, prosaccade, and antisaccade using video-oculography. RESULTS: Common oculomotor features of pre-SCA3 included square-wave jerk during central fixation and gaze holding, impaired vertical smooth pursuit, slow upward saccade, and increased antisaccade error rate. In our SCA3 cohort, all oculomotor parameters were correlated with the score of the Scale for the Assessment and Rating of Ataxia, whilst some of them were correlated with disease duration. CONCLUSION: This study showed that a series of neuropathological changes reflected by oculomotor abnormalities appeared preferentially in preclinical stage of SCA3. Accordingly, objective oculomotor preclinical signs may be useful to detect the optimum time-point for therapeutic interventions in future clinical trials of SCA3. Larger and longitudinal data are warranted to confirm our results.

Effects of tetrathiomolybdate and penicillamine on brain hydroxyl radical and free copper levels: a microdialysis study in vivo.

Wilson disease is an inherited disorder of excessive copper accumulation. The commonly used drug d-penicillamine (PA) or trientine both cause a high incidence (10-50%) of neurological worsening, which rarely occurs with tetrathiomolybdate (TM) treatment. To investigate the mechanisms of neurologic deterioration after the initiation of chelation therapy, brain hydroxyl radical and free copper were assessed in vivo in this study. On days 3, 7, 14, and 21 after PA or TM administration, striatal hydroxyl radical levels of both TX mice and controls were assessed by terephthalic acid (TA) combined with microdialysis and high-performance liquid chromatography (HPLC). Within the same microdialysis samples, free copper was measured by inductively coupled plasma mass spectrometry (ICP-MS). The results showed that both hydroxyl radical and free copper markedly increased in the striatum of TX mice during PA administration but were not elevated when administering TM. These results suggested that the further increased free copper in the brain and oxidative stress caused by some chelators might contribute to the neurological deterioration.

Cognitive impairment in native Chinese with spinocerebellar ataxia type 3.

BACKGROUND: Previous studies have shown cognitive impairment in patients with spinocerebellar ataxia type 3 (SCA3). However, there is a lack of data on Chinese patients with SCA3. METHOD: We investigated 22 native Chinese with SCA3 and 18 controls matched for age, education as well as mental status. Cognitive assessments were carefully carried out to measure verbal fluency, memory, attention, executive function, visuospatial and visuoconstructive functions. RESULTS: The most common impairments of cognition in native Chinese with SCA3 were disruption of phonemic verbal fluency and frontal executive dysfunction. Deficits in semantic fluency were detected in about 31.8% patients. Impaired visuospatial function and verbal memory were also found in native Chinese with SCA3. The degree of ataxia, CAG repeat length and education were found to correlate with cognitive performance. Multivariate binary logistic regression suggested that an oculomotor disorder and depression are predictors of cognitive impairment. CONCLUSION: Native Chinese with SCA3 had cognitive impairment of frontal executive function, temporal and parietal functions. An oculomotor disorder might be an index of cognitive dysfunction.

Penicillamine increases free copper and enhances oxidative stress in the brain of toxic milk mice.

Wilson disease (WD) is characterized by the accumulation of copper arising from a mutation in the ATP7B gene. Penicillamine (PA) makes 10-50% of the patients with neurologic symptoms neurologically worse at the early stage of administration. The aim of this study was to determine how the copper metabolism changes and whether the change impairs the brain of toxic milk (tx) mice, an animal model of WD, during the PA administration. The free copper and protein-bound copper concentrations in the serum, cortex and basal ganglia of tx mice with PA administration for 3 days, 10 days and 14 days, respectively, were investigated. The expression of copper transporters, ATP7A and CTR1,was analyzed by real-time quantitative PCR, immunofluorescence and Western blot. Then SOD, MDA and GSH/GSSG were detected to determine whether the oxidative stress changed correspondingly. The results revealed the elevated free copper concentrations in the serum and brain, and declined protein-bound copper concentrations in the brain of tx mice during PA administration. Meanwhile, transiently increased expression of ATP7A and CTR1 was observed generally in the brain parenchyma by immunofluorescence, real-time quantitative PCR and Western blot. Additionally, ATP7A and CTR1 were observed to locate mainly at Golgi apparatus and cellular membrane respectively. Intense staining of ATP7A in the choroid plexus was found in tx mice on the 3rd and 10th day of PA treatment, but rare staining of ATP7A and CTR1 in the blood-brain barrier (BBB). Decreased GSH/GSSG and increased MDA concentrations were also viewed in the cortex and basal ganglia. Our results suggested the elevated free copper concentrations in the brain might lead to the enhanced oxidative stress during PA administration. The increased free copper in the brain might come from the copper mobilized from brain parenchyma cells but not from the serum according to the ATP7A and CTR1 expression analysis.