Manganese-induced Parkinsonism in a patient undergoing maintenance hemodialysis

Estimated glomerular filtration rate is a biomarker of cognitive impairment in Parkinson's disease

Backgrounds

The relationship between kidney function and cognitive impairment in Parkinson's disease (PD) is poorly understood and underexplored. This study aims to explore whether renal indices can serve as indicators to monitor the cognitive impairment of PD.

Methods

A total of 508 PD patients and 168 healthy controls from the Parkinson's Progression Markers Initiative (PPMI) were recruited, and 486 (95.7%) PD patients underwent longitudinal measurements. The renal indicators including serum creatinine (Scr), uric acid (UA), and urea nitrogen, as well as UA/Scr ratio and estimated glomerular filtration rate (eGFR), were measured. Cross-sectional and longitudinal associations between kidney function and cognitive impairment were evaluated using multivariable-adjusted models.

Results

eGFR was associated with lower levels of cerebrospinal fluid (CSF) Aβ_1-42 (p = 0.0156) and α-synuclein (p = 0.0151) and higher serum NfL (p = 0.0215) in PD patients at baseline. Longitudinal results showed that decreased eGFR predicted a higher risk of cognitive impairment (HR = 0.7382, 95% CI = 0.6329-0.8610). Additionally, eGFR decline was significantly associated with higher rates of increase in CSF T-tau (p = 0.0096), P-tau (p = 0.0250), and serum NfL (p = 0.0189), as well as global cognition and various cognitive domains (p < 0.0500). The reduced UA/Scr ratio was also linked to higher NfL levels (p = 0.0282) and greater accumulation of T-tau (p = 0.0282) and P-tau (p = 0.0317). However, no significant associations were found between other renal indices and cognition.

Conclusion

eGFR is altered in PD subjects with cognitive impairment, and predict larger progression of cognitive decline. It may assist identifying patients with PD at risk of rapid cognitive decline and have the potential to monitoring responses to therapy in future clinical practice.

Movement Disorders Due to Selective Basal Ganglia Lesions with Uremia

BACKGROUND

Basal ganglia (BG) lesions are rarely reported in patients with uremia and may manifest by movement disorders. However, their exact incidence and pathogenesis have not been extensively studied. This study aimed to determine the frequency, types, risk variables (clinical, laboratory, and imaging), and manifestations of BG lesions with uremia and patients' neurologic outcomes.

METHODS

This observational study included 70 adults (mean age: 45.87 ± 3.36 years; duration of uremia: 5.5 ± 1.5 years). They underwent extensive evaluations (clinical, laboratory, and neuroimaging) and had prospectively evaluated clinically every 3 months for 2 years. Repeated magnetic resonance imaging (MRI) brains were done to patients with movement disorders and correlated with their neurologic outcomes.

RESULTS

BG lesions were found in 15 patients (21.4%) and 6 (8.6%) had movement disorders [Parkinsonism (n = 4), choreo-dystonia (n = 1) and dystonia (n = 1)] after the onset of uremia (mean = 10 months). There were no characteristic risk variables that distinguished patients with movement disorders from those without. Five developed movement disorders prior to the period of the study and one was de novo. The majority was females and had diabetes and higher frequencies of abnormal renal dysfunction, metabolic derangements, and white matter hyperintensities in MRIs. Movement disorders persisted in all patients despite the resolution of neuroimaging in three patients.

CONCLUSIONS

There is no clear threshold for renal failure to result in movement disorders due to BG lesions. The clinical outcome is variables depending on each patient's comorbidities and complications. Persistent neuronal damage (due to uremic toxins/metabolic/nutritional and ischemic/microvascular factors) has been suggested as the cause of poor neurologic outcomes.

Brain manganese and the balance between essential roles and neurotoxicity

Manganese (Mn) is an essential micronutrient required for the normal development of many organs, including the brain. Although its roles as a cofactor in several enzymes and in maintaining optimal physiology are well-known, the overall biological functions of Mn are rather poorly understood. Alterations in body Mn status are associated with altered neuronal physiology and cognition in humans, and either overexposure or (more rarely) insufficiency can cause neurological dysfunction. The resultant balancing act can be viewed as a hormetic U-shaped relationship for biological Mn status and optimal brain health, with changes in the brain leading to physiological effects throughout the body and vice versa. This review discusses Mn homeostasis, biomarkers, molecular mechanisms of cellular transport, and neuropathological changes associated with disruptions of Mn homeostasis, especially in its excess, and identifies gaps in our understanding of the molecular and biochemical mechanisms underlying Mn homeostasis and neurotoxicity.

Chronic renal dysfunction, proteinuria, and risk of Parkinson's disease in the elderly

BACKGROUND

The roles of chronic kidney disease and proteinuria in the development of Parkinson's disease have not been widely studied. The objective of this study was to examine the associations of chronic renal dysfunction and proteinuria with the risk of PD in older adults using cohort data of the whole South Korean population.

METHODS

We included 3,580,435 individuals aged ≥65 years who had undergone health checkups provided by the National Health Insurance Service of South Korea between 2009 and 2012 and were followed until 2015. Multivariable Cox proportional hazards regression models were performed.

RESULTS

During a mean follow-up of 5.2 ± 1.3 years, 30,813 individuals (0.86% of the total population) developed PD. Lower estimated glomerular filtration rate and a higher degree of proteinuria on a dipstick test were associated with higher incidence probability of PD (log-rank P < 0.001). In Cox regression models, chronic renal dysfunction graded by estimated glomerular filtration rate (mL/min/1.73 m² ) was associated with increased risk of PD after adjusting for potential confounding variables; hazard ratio (95% confidence interval) was 1.13 (1.10-1.17) for estimated glomerular filtration rate 60-90, 1.36 (1.31-1.42) for estimated glomerular filtration rate 30-60, and 1.47 (1.32-1.63) for estimated glomerular filtration rate <30 (P for trend <0.001). Proteinuria ≥1+ was also associated with increased risk of PD development (hazard ratio, 1.12; 95% confidence interval, 1.06-1.18). Coexistence of chronic kidney disease and proteinuria showed an increased hazard ratio of 1.33 (95% confidence interval, 1.23-1.45) for PD occurrence.

CONCLUSIONS

Our findings suggest that chronic renal dysfunction and dipstick-positive proteinuria may be independent risk factors for the development of PD in older adults. © 2019 International Parkinson and Movement Disorder Society.

Association between urine protein/creatinine ratio and cognitive dysfunction in Lewy body disorders

BACKGROUND

Impaired renal function and proteinuria have been associated with cognitive impairment and dementia. Chronic kidney disease is considered to be an independent risk factor for Lewy body spectrum disorders (LBD). However, few studies have mentioned an association between proteinuria and cognition in LBD. We investigated the relationship between proteinuria and cognitive dysfunction in patients with Parkinson's disease (PD) and dementia with Lewy bodies (DLB).

METHODS

Among 186 patients with LBD, 53 had PD-normal cognition (PD-NC), 76 had PD-mild cognitive impairment (PD-MCI), 43 had PD-dementia (PDD) and 14 had DLB. The urine protein/creatinine ratio was calculated using the spot urine test and brain magnetic resonance scans was obtained in all patients.

RESULTS

The urine protein/creatinine ratio was significantly higher in patients with PDD and DLB than in those with PD-MCI, PD-NC patients and healthy controls, and was correlated with white matter hyperintensities on magnetic resonance imaging. All abnormal neuropsychological test results were associated with increased urine protein/creatinine ratio. After controlling for age, education, symptom duration, diabetes mellitus, hypertension, and parkinsonian motor severity, the urine protein/creatinine ratio was significantly associated with decreased cognition.

CONCLUSION

The urine protein/creatinine ratio was associated with cognitive status in LBD. These finding suggests that increased protein excretion is associated with cognitive dysfunction in patients with LBD.

Association of plasma manganese levels with chronic renal failure

Manganese (Mn) is an essential trace element involved in the formation of bone and in amino acid, lipid and carbohydrate metabolism. Mn excess may be neurotoxic to humans, affecting specific areas of the central nervous system. However, relatively little is known about its physiological and/or toxicological effects, and very few data are available concerning the role of Mn in chronic renal failure (CRF). This paper describes a 12-month study of the evolution of plasma Mn levels in predialysis patients with CRF and the relationship with energy and macronutrient intake. The participants in this trial were 64 patients with CRF in predialysis and 62 healthy controls. Plasma levels of creatinine, urea, uric acid, total protein and Mn were measured. The glomerular filtration rate (GFR) was calculated using the Cockcroft-Gault index. The CRF patients had higher plasma levels of creatinine, urea, uric acid and Mn and a lower GFR than the controls. Plasma Mn was positively correlated with creatinine, plasma urea and plasma uric acid and was negatively correlated with the GFR and the intake of energy and macronutrients. In conclusion, CRF in predialysis patients is associated with increases in circulating levels of Mn.

Increased risk of Parkinson's disease in patients with end-stage renal disease: a retrospective cohort study

BACKGROUND

Studies on dyskinesia and Parkinson's syndrome associated with chronic kidney disease or end-stage renal disease (ESRD) have been mainly limited to case reports or case series studies. This population-based study investigated the risk of Parkinson's disease in patients with ESRD.

METHODS

From a universal insurance claims database of Taiwan, we established a cohort of 8,325 adults with newly diagnosed ESRD from 1997 to 2010 without a history of Parkinson's disease. A control cohort of 33,382 insured subjects without a history of kidney disease or Parkinson's disease was also selected, with frequency matched for age, sex and index date of the patients with ESRD. Both cohorts were followed up until the end of 2010.

RESULTS

The Parkinson's disease incidence was 1.55-fold higher in the cohort with ESRD than in the comparison cohort (48.8 vs. 31.7 per 10,000 person-years) with an adjusted hazard ratio of 1.73 (95% confidence interval, 1.39-2.15). Sex-specific and age-specific analysis showed a higher relative risk for women and younger patients with ESRD compared to the control cohort.

CONCLUSIONS

ESRD is significantly associated with an increased risk of Parkinson's disease. Close surveillance for Parkinson's disease should be considered for patients with ESRD.

Reversible acute chorea in a patient with diabetes treated with hemodialysis

Chorea is an abnormal hyperkinetic movement disorder. The reasons for chorea are diverse and include hereditary, endocrine, toxic, vascular, infectious, autoimmune, and metabolic etiologies. We present a 64-year-old woman with acute chorea who suffered from diabetes with recurrent hypoglycemia, and chronic renal failure treated by hemodialysis. The full clinical recovery, negative work-up and disappearance of basal ganglia lesions on the follow-up imaging emphasize the transient character of encephalopathy expressed by acute chorea in patients with diabetes treated with hemodialysis.

General and electrophysiological toxic effects of manganese in rats following subacute administration in dissolved and nanoparticle form

In an attempt to model occupational and environmental Mn exposures and their possible interaction, young male Wistar rats were exposed to Mn by oral administration in dissolved form (MnCl(2)·4H(2)O, 14.84 and 59.36 mg/kg b.w.) and by intratracheal application of MnO(2) nanoparticles (2.63 mg/kg b.w.). After 3 and 6 weeks oral, or 3 weeks oral plus 3 weeks intratracheal, exposure, general toxicological, and electrophysiological tests were done. Body weight gain was significantly reduced after 6 and 3 plus 3 weeks exposure, but the effect of the latter on the pace of weight gain was stronger. Organ weights signalized systemic stress and effect on lungs. Changes in evoked electrophysiological responses (cortical sensory evoked potential and nerve action potential) indicated that the 3 plus 3 weeks combined exposure caused equal or higher changes in the latency of these responses than 6 weeks of exposure, although the calculated summed Mn dose in the former case was lower. The results showed the importance of the physicochemical form of Mn in determining the toxic outcome, and suggested that neurofunctional markers of Mn action may indicate the human health effect better than conventional blood Mn measurement.

A pilot study with simultaneous recording of changes in motility and cortical electrical activity of rats during four weeks of oral manganese exposure

Manganese as an environmental neurotoxicant can cause oral exposure. Six rats were equipped with a connector "crown", allowing repeated recording of electrocorticogram (ECoG) with simultaneous recording of motor activity in an open field box. Weekly one 30-min recording session was held, and after two control sessions, four of the six rats had 2.5 mg/ml manganese chloride in their drinking water. The treated rats showed higher motility during the exposure period than the untreated ones; and substantially decreased total ECoG power without marked change the spectrum. The changes of both motility and ECoG were correlated to the individual brain Mn levels, and the activity decrease during a session was correlated to the total ECoG power. These effects can be likened to early adult manganism and to symptoms of children exposed to Mn via drinking water. Repeated simultaneous recording of open field motility and spontaneous cortical activity seems suitable to detect early electrophysiological and behavioral effects of an oral neurotoxic exposure.

Altered striatal dopamine release following a sub-acute exposure to manganese

Certain metals that are necessary for regulating biological function at trace levels hold the potential to become neurotoxic when in excess. Specifically, chronic exposure to high levels of manganese leads to manganism, a neurological disorder that exhibits both motor and learning deficits similar to Parkinson's disease. Since Parkinson's disease symptomatology is primarily attributed to dopamine neurodegeneration in the striatum, dopamine system dysfunction has been implicated in the onset of manganism. In this study, dopamine system function in the dorsal striatum was evaluated in C57Bl/6 mice, 1, 7, and 21 days following repeated injections of manganese(II) chloride (50 mg/kg, subcutaneous) intermittently for 7 days. Tissue content analysis confirmed the presence of persistent accumulation of manganese in the striatum up to 21 days after cessation of treatment. In vitro fast scan cyclic voltammetry examined the effect of sub-acute manganese on electrically stimulated dopamine release and uptake in the striatum. While no difference was observed in uptake rates following manganese treatment, dopamine release was attenuated on days 7 and 21, compared to control levels. Basal levels of extracellular dopamine determined by the zero net flux microdialysis method were significantly lower in manganese-treated mice at 7 days post-treatment. On the other hand, potassium stimulated increases in extracellular dopamine were attenuated at all three time points. Together, these findings indicate that repeated manganese exposure has long-term effects on the regulation of exocytotic dopamine release in the striatum, which may be involved in the mechanism underlying manganese toxicity.

Trace minerals in patients with end-stage renal disease

The kidneys are famously responsible for maintaining external balance of prevalent minerals, such as sodium, chloride, and potassium. The kidney's role in handling trace minerals is more obscure to most nephrologists. Similarly, the impact of kidney failure on trace mineral metabolism is difficult to anticipate. The associated dietary modifications and dialysis create the potential for trace mineral deficiencies and intoxications. Indeed, there are numerous reports of dialysis-associated mishaps causing mineral intoxication, notable for the challenge of assigning causation. Equally challenging has been the recognition of mineral deficiency syndromes, amid what is often a cacophony of multiple comorbidities that vie for the attention of clinicians who care for patients with chronic kidney disease. In this paper, I review a variety of minerals, some of which are required for maintenance of normal human physiology (the U.S. Food and Drug Administration's list of essential minerals), and some that have attracted attention in the care of dialysis patients. For each mineral, I will discuss its role in normal physiology and will review reported deficiency and toxicity states. I will point out the interesting inter-relationships between several of the elements. Finally, I will address the special concerns of aluminum and magnesium as they pertain to the dialysis population.

Manganese and its role in Parkinson's disease: from transport to neuropathology

The purpose of this review is to highlight recent advances in the neuropathology associated with Mn exposures. We commence with a discussion on occupational manganism and clinical aspects of the disorder. This is followed by novel considerations on Mn transport (see also chapter by Yokel, this volume), advancing new hypotheses on the involvement of several transporters in Mn entry into the brain. This is followed by a brief description of the effects of Mn on neurotransmitter systems that are putative modulators of dopamine (DA) biology (the primary target of Mn neurotoxicity), as well as its effects on mitochondrial dysfunction and disruption of cellular energy metabolism. Next, we discuss inflammatory activation of glia in neuronal injury and how disruption of synaptic transmission and glial-neuronal communication may serve as underlying mechanisms of Mn-induced neurodegeneration commensurate with the cross-talk between glia and neurons. We conclude with a discussion on therapeutic aspects of Mn exposure. Emphasis is directed at treatment modalities and the utility of chelators in attenuating the neurodegenerative sequelae of exposure to Mn. For additional reading on several topics inherent to this review as well as others, the reader may wish to consult Aschner and Dorman (Toxicological Review 25:147-154, 2007) and Bowman et al. (Metals and neurodegeneration, 2009).

A preliminary study revealing a new association in patients undergoing maintenance hemodialysis: manganism symptoms and T1 hyperintense changes in the basal ganglia

BACKGROUND AND PURPOSE

Patients undergoing parenteral nutrition and those with portosystemic encephalopathy secondary to chronic liver disease and acquired and congenital portosystemic venous shunts frequently present manganese deposition in the basal ganglia, detected by MR imaging as hyperintense areas on T1-weighted sequences. We also observed similar abnormalities in the basal ganglia of patients with chronic renal failure undergoing maintenance hemodialysis. Our aim was to evaluate the pallidal signal intensity on T1-weighted images in a series of patients undergoing hemodialysis, with further evaluation of serum manganese levels and neurologic correlation, comparing them with patients with chronic renal failure without dialytic treatment.

MATERIALS AND METHODS

We performed MR imaging examinations in 9 patients with chronic renal failure, 5 of whom were undergoing hemodialysis. An experienced neuroradiologist scrutinized the presence of symmetric hyperintensities in the basal ganglia on T1-weighted sequences. We also determined the serum manganese levels and performed the neurologic evaluations in all patients.

RESULTS

All patients undergoing hemodialysis presented elevated serum manganese levels and symmetric hyperintensities within the globus pallidus. In this group, 4 patients presented with parkinsonian symptoms, myoclonus, and syndromes with vestibular and vestibular-auditory symptoms. The patients without dialytic treatment presented with neither bilaterally increased T1 MR imaging signal intensity within the globus pallidus nor symptoms of manganism.

CONCLUSION

Our preliminary results demonstrated the occurrence of bilateral pallidal hyperintensity on T1-weighted images in all patients undergoing hemodialysis associated with high serum manganese levels, revealing a new association.