Chronic parkinsonism associated with cirrhosis: a distinct subset of acquired hepatocerebral degeneration

Fate of manganese associated with the inhalation of welding fumes: Potential neurological effects

Welding fumes are a complex mixture composed of different metals. Most welding fumes contain a small percentage of manganese. There is an emerging concern among occupational health officials about the potential neurological effects associated with the exposure to manganese in welding fumes. Little is known about the fate of manganese that is complexed with other metals in the welding particles after inhalation. Depending on the welding process and the composition of the welding electrode, manganese may be present in different oxidation states and have different solubility properties. These differences may affect the biological responses to manganese after the inhalation of welding fumes. Manganese intoxication and the associated neurological symptoms have been reported in individual cases of welders who have been exposed to high concentrations of manganese-containing welding fumes due to work in poorly ventilated areas. However, the question remains as to whether welders who are exposed to low levels of welding fumes over long periods of time are at risk for the development of neurological diseases. For the most part, questions remain unanswered. There is still paucity of adequate scientific reports on welders who suffered significant neurotoxicity, hence there is a need for well-designed epidemiology studies that combine complete information on the occupational exposure of welders with both behavioral and biochemical endpoints of neurotoxicity.

The diagnosis of manganese-induced parkinsonism

Parkinsonism is a clinical syndrome consisting of tremor, bradykinesia, rigidity, gait, balance problems, in addition to various non-motor symptoms. There are many causes of parkinsonism such as neurodegenerative disease, drugs, vascular causes, structural lesions, infections, and toxicants. Parkinson's disease, or idiopathic parkinsonism, is the most common form of parkinsonism observed in the clinic. There is degeneration of the substantia nigra, pars compacta, which results in loss of striatal dopamine. Parkinson's disease is a slowly progressive condition in which there is a dramatic and sustained responsiveness to levodopa therapy. Manganese is an essential trace element that can be associated with neurotoxicity. Hypermanganism can occur in a variety of clinical settings. The clinical symptoms of manganese intoxication include non-specific complaints, neurobehavioral changes, parkinsonism, and dystonia. Although the globus pallidus is the main structure of damage, other basal ganglia areas can also be involved. MRI scans may show globus pallidus changes during (and for a short period after) exposure. Fluorodopa PET scans that assess the integrity of the substantia nigra dopaminergic system are abnormal in Parkinson's disease. However, these scans re-reported to be normal in a few cases studied with manganese-induced parkinsonism. The parkinsonism due to manganese may have some clinical features that occur less commonly in Parkinson's disease, such as kinetic tremor, dystonia, specific gait disturbances, and early mental, balance and speech changes. The clinical signs tend to be bilateral whereas Parkinson's disease begins on one side of the body. Patients with manganese-induced parkinsonism may be younger at the onset of the disease than with Parkinson's disease. Lastly, there appears to be a lack of response to levodopa therapy in manganese-induced parkinsonism. In summary it may be possible to differentiate manganese-induced parkinsonism from Parkinson's disease using clinical and imaging studies.

The use of magnetic resonance imaging (MRI) in the study of manganese neurotoxicity

Manganese (Mn), an element found in many foods, is an important and essential nutrient for proper health and maintenance. It is toxic in high doses, however, and exposure to excessive levels can result in the onset of a neurological disorder similar to, but distinct from, Parkinson's disease. Historically, Mn neurotoxicity was most commonly associated with various occupations, such as Mn mining, welding and steel production. More recently, increases in both blood and brain Mn levels have been observed in persons with liver disease or those receiving prolonged parenteral nutrition. Additionally, rodent data suggest that iron deficiency and anemia may be risk factors for Mn neurotoxicity. Clinically, brain Mn accumulation can be monitored in vivo using non-invasive magnetic resonance imaging (MRI) due to the paramagnetic nature of this element. Indeed, MRI has been used in a variety of settings to evaluate the brain Mn deposition in various populations. This review focuses on the use of MRI technology in studies related specifically to Mn neurotoxicity. Thus, we will examine reports using MRI to confirm brain Mn accumulation in human populations, and conclude with data from non-human primate and rodent models of Mn neurotoxicity.

Altered modulation of motor activity by group I metabotropic glutamate receptors in the nucleus accumbens in hyperammonemic rats

One of the neurological complications in hepatic encephalopathy is the impairment of motor coordination and function. Clinical signs of basal ganglia, cortico-spinal and cerebellar dysfunction have been commonly detected in these patients. We are studying the molecular bases of the alterations in motor coordination and function in hepatic encephalopathy. Hyperammonemia is considered the main factor responsible for the neurological alterations in patients with hepatic encephalopathy. Activation of metabotropic glutamate receptors (mGluRs) in the nucleus accumbens (NAcc) induces locomotion in rats. Asa first step in our studies on the alterations in motor co-ordination and function in hyperammonemia and hepatic encephalopathy we studied whether the control of motor function by mGluRs in the NAcc is altered in hyperammonemic rats. The locomotor activity induced by injection into the nucleus accumbens (NAcc) of DHPG, an agonist of group I mGluRs was significantly increased in hyperammonemic rats. Injection of DHPG increased extracellular dopamine but not glutamate in the NAcc of control rats. In hyperammonemic rats DHPG-induced increase in dopamine was significantly reduced, and extracellular glutamate increased 6-fold. The content of mGluR 1 but not mGluR 5, is increased in the NAcc of hyperammonemic rats. Blockade of mGluR 1 completely prevented motor and neurochemical effects induced by DHPG. These results show that modulation of both motor function and extracellular concentration of neurotransmitters by mGluRs in the NAcc is altered in hyperammonemia. This may contribute to the alterations in motor function in hepatic encephalopathy.

Motor dysfunction in patients with liver cirrhosis: impairment of handwriting

Motor dysfunction is an important clinical finding in patients with liver cirrhosis and mild forms of hepatic encephalopathy. The mechanisms and clinical appearance of motor impairment in patients with liver cirrhosis are not completely understood. We studied fine motor control in forty four patients with advanced liver cirrhosis (excluding those with hepatic encephalopathy grade II) and 48 healthy controls using a kinematic analysis of standardized handwriting tests. We analysed parameters of velocity, the ability to coordinate and the level of automatisation of handwriting movements. Furthermore, we studied the association between impairment of handwriting and clinical neuro-psychiatric symptoms. As compared with control subjects, patients showed a statistically significant reduction of movement peak velocity in all handwriting tasks as well as a substantial increase of number of velocity inversions per stroke. Using a z-score based assessment we found impairment of handwriting in fourteen out of forty four patients (31.8 %). The deterioration of handwriting was associated with clinical symptoms of motor dysfunction, such as bradykinesia, adiadochokinesia, dysmetria of upper extremities and gait ataxia. This is the first study that quantitatively investigates impairment of handwriting in patients with liver cirrhosis. Our findings suggest the application of kinematic analysis of handwriting for diagnostics of motor dysfunction in patients with mild forms of hepatic encephalopathy.

Multidimensional assessment of neuro-psychiatric symptoms in patients with low-grade hepatic encephalopathy: A clinical rating scale

AIM: To evaluate the feasibility of a new clinical rating scale for a standardized assessment of cirrhosis-associated neuro-psychiatric symptoms.

METHODS: Forty patients with liver cirrhosis (LC, with or without low-grade hepatic encephalopathy) were invest-igated using a clinical neuro-psychiatric rating scale based on a comprehensive list of neurological, psychomotor, cognitive, affective, behavioral symptoms, and symptoms of disturbed bioregulation.

RESULTS: The analysis revealed that the majority of cirrhotic patients showed, besides characteristic neurological symptoms of hepatic encephalopathy, various psychomotor, affective and bioregulatory symptoms (disturbed sleep and sexual dysfunction). Patients were impaired in the following subscales: sleep and biorhythm disorder (75.0% of patients), Parkinsonoid symptoms (25.0%), affective symptoms (17.5%), and psychomotor retardation (12.5%). The increase of total neuro-psychiatric clinical score was significantly associated with the degree of hepatic enceph-alopathy.

CONCLUSION: This study suggests that a substantial number of patients with LC and low-grade hepatic encephalopathy manifest various clinical neuro-psychiatric symptoms. The use of a rating scale, which explores clinical dimensions of hepatic encephalopathy, would improve the management of patients with LC.

Effects of hepatic function and hepatitis C virus on the nervous system assessment of advanced-stage HIV-infected individuals

OBJECTIVES

To examine the effects of liver function and hepatitis C virus (HCV) serostatus on neurological, neuropsychological, and psychiatric abnormalities in an advanced-stage HIV-infected cohort.

DESIGN

A correlational analysis of baseline data accumulated on 137 participants in the Manhattan HIV Brain Bank, a longitudinal study of HIV-infected individuals.

METHODS

Patients underwent a battery of neuropsychological tests, a semi-structured psychiatric interview, and a neurological examination. The resulting diagnostic data were correlated with biochemical indices of hepatic function and HCV serostatus.

RESULTS

Biochemical indices of liver function correlated with motor dysfunction determined by neurological evaluation, but not with neuropsychological or psychiatric disorders. Discrete neurological diagnostic entities showed no relationship with biochemical indices, with one exception: patients with cryptococcal leptomeningitis had worse liver function than those without. HCV had no relationship with any neurological disorder or symptom complex. In contrast, HCV serostatus was related to neuropsychological and psychiatric abnormalities, and indices of liver function were not. HCV-seropositive patients were more likely to have histories of opiate, cocaine or stimulant dependency, to have greater impairment in executive functioning, and to meet diagnostic criteria for AIDS dementia, compared with HCV-negative individuals of similar immunological and virological status.

CONCLUSIONS

HCV and biochemical indices of liver function associate differentially with nervous system abnormalities in this HIV-infected population. Neurological abnormalities correlate with biochemical indices of liver function, whereas neuropsychological and psychiatric dysfunction are linked to HCV infection. We postulate that multifactorial impacts of HCV and liver disease on HIV-related nervous system disorders may originate in different anatomical and cellular compartments.

Hepatic encephalopathy: a dynamic or static condition

Hepatic encephalopathy (HE) is a neuropsychiatric disorder associated with portal hypertension. The mechanism of this disorder is still being characterized and the management has relied primarily on lowering the amount of ammonia present in the gastrointestinal tract or reversing liver disease by replacing the diseased liver. It is, however, not established that all the effects of hepatic encephalopathy are reversed by liver transplantation. In this review, we have outlined the mechanisms underlying HE and the pros and cons of reversibility of HE.

[18F]FDOPA PET and clinical features in parkinsonism due to manganism

Manganese exposure reportedly causes a clinically and pathophysiologically distinct syndrome from idiopathic Parkinson's disease (PD). We describe the clinical features and results of positron emission tomography with 6-[18F]fluorodopa ([18F]FDOPA PET) of a patient with parkinsonism occurring in the setting of elevated blood manganese. The patient developed parkinsonism associated with elevated serum manganese from hepatic dysfunction. [18F]FDOPA PET demonstrated relatively symmetric and severely reduced [18F]FDOPA levels in the posterior putamen compared to controls. The globus pallidum interna had increased signal on T1-weighted magnetic resonance imaging (MRI) images. We conclude that elevated manganese exposure may be associated with reduced striatal [18F]FDOPA uptake, and MRI may reveal selective abnormality within the internal segment of the pallidum. This case suggests that the clinical and pathophysiological features of manganese-associated parkinsonism may overlap with that of PD.

Searching for a relationship between manganese and welding and Parkinson's disease

Research into the causes of Parkinson disease (PD) has accelerated recently with the discovery of novel gene mutations. The majority of PD cases, however, remain idiopathic and in those cases environmental causes should be considered. Several recent reports have focused on welding and manganese toxicity as potential risk factors for parkinsonism and some have even proposed that welding is a risk factor for PD. The controversy has stimulated this review, the primary aim of which is to critically and objectively examine the evidence or lack of evidence for a relationship among welding, manganese, parkinsonism, and PD.

Clinical significance of extrapyramidal signs in patients with cirrhosis

BACKGROUND/AIMS

Extrapyramidal signs have been described in cirrhosis and there is little information about their clinical significance. The aims of this study have been to investigate the relationship between extrapyramidal signs and cognitive impairment, and what is their influence on quality of life.

METHODS

46 patients with cirrhosis were evaluated for cognitive impairment with psychometric tests (Trail-Making Test part A, Grooved-Pegboard, Block-Design, Oral Symbol Digit and Stroop Test) and cognitive evoked potentials (P300). Extrapyramidal signs were evaluated using the UPDRS scale. Health-related quality of life (HRQL) was measured using SF-36 scale and the Chronic Liver Disease Questionnaire (CLDQ).

RESULTS

Twenty-two patients had extrapyramidal signs, and these patients scored worse in all psychometric tests, except Block-Design. Patients with extrapyramidal signs also showed a longer P300 latency. Moreover, patients with extrapyramidal signs had the worst score in all the HRQL scales used. A multivariate analysis disclosed that the only variable showing an independent relationship to the mental component summary of SF-36 and with CLDQ was UPDRS score.

CONCLUSIONS

We have found a clear relationship between the presence of extrapyramidal signs and cognitive impairment. Moreover, patients with extrapyramidal signs have worse scores in quality of life scales.

A Novel Isoform of the Secretory Pathway Ca2+,Mn2+-ATPase, hSPCA2, Has Unusual Properties and Is Expressed in the Brain

Unlike lower eukaryotes, mammalian genomes have a second gene, ATP2C2, encoding a putative member of the family of secretory pathway Ca2+,Mn(2+)-ATPases, SPCA2. Human SPCA2 shares 64% amino acid identity with the protein defective in Hailey Hailey disease, hSPCA1. We show that human SPCA2 (hSPCA2) has a more limited tissue distribution than hSPCA1, with prominent protein expression in brain and testis. In primary neuronal cells, endogenous SPCA2 has a highly punctate distribution that overlaps with vesicles derived from the trans-Golgi network and is thus different from the compact perinuclear distribution of hSPCA1 seen in keratinocytes and nonpolarized cells. Heterologous expression in a yeast strain lacking endogenous Ca2+ pumps reveals further functional differences from hSPCA1. Although the Mn(2+)-specific phenotype of hSPCA2 is similar to that of hSPCA1, Ca2+ ions are transported with much poorer affinity, resulting in only weak complementation of Ca(2+)-specific yeast phenotypes. These observations suggest that SPCA2 may have a more specialized role in mammalian cells, possibly in cellular detoxification of Mn2+ ions, similar to that in yeast. We point to the close links between manganese neurotoxicity and Parkinsonism that would predict an important physiological role for SPCA2 in the brain.

Recovery from parkinson syndrome and prolonged visually evoked potentials in hepatic encephalopathy

The combination of Parkinson syndrome (PS) and prolonged visually evoked potentials (VEPs) in a single patient with hepatic encephalopathy (HE) has not been reported. A 52-year-old male with chronic HE developed PS in early 2001. Treatment with L-DOPA was only of minimal effect. In August 2001 he was admitted because of worsening PS and HE. There was anemia, hyperlipidaemia, markedly elevated liver-function-parameters, hyperammonemia, elevated resting-lactate, steatosis hepatis and hepatomegalia. VEPs showed markedly prolonged P100-latencies. Under L-DOPA, pramipexol, L-ornithin-L-aspartate, paromomycin-sulfate, and lactulose liver-function-parameters normalized and PS markedly improved. In February 2003, VEPs were normal. L-DOPA was discontinued by the patient in April 2003 and pramipexol in December 2003. Since then PS did not recur. This case shows that HE may go along with reversible PS and prolonged VEPs. Under adequate therapy liver-function-parameters and VEPs normalize and PS disappears.

Acquired hepatocerebral degeneration: A case report

AIM: Acquired hepatocerebral degeneration (AHD) is an exceptional type of hepatic encephalopathies (HE). It is characterized by neuropsychiatric and extrapyramidal symptomathology similar to that seen in hepatolenticular degeneration (Wilson’s disease). In this paper, we report a case of AHD with unusual presenting features.

METHODS: A 28-year-old man with AHD was described and the literature was reviewed.

RESULTS: The man had a history of HBV-related liver cirrhosis. He was admitted to our hospital with apathy, dysarthria, mild consciousness impairment and extrapyramidal symptoms after hematemesis. By review of the literature, cases with AHD often did not present consciousness impairment. So our case was once diagnosed incorrectly as Wilson’s disease.

CONCLUSION: AHD is a rare syndrome and its variable clinical manifestations make it difficult to be diagnosed. But we believe that extensive examination and thorough understanding of the disease are beneficial to a correct diagnosis. Moreover, biocoene is effective in treating the case.

Systemic diseases that cause movement disorders

The present review is aimed at providing practical assistance to the clinical neurologist in reaching a diagnosis, understanding the pathogenic mechanisms of movement disorders associated with systemic diseases, and determining appropriate therapy. Infectious disease by direct effect or as an acquired autoimmune neurological disease, stroke, hypoxia-ischemia, paraneoplastic syndromes, collagen disorders, endocrine, liver and kidney diseases that may cause hypokinetic or hyperkinetic abnormal movement are considered separately. The type and evolution of abnormal movement caused by systemic disease vary with age and underlying pathology. Therapy for abnormal movements should include a primary treatment for the systemic disease.

Manganese-induced parkinsonism and Parkinson's disease

It has long been appreciated that manganese exposure can cause neurotoxicity and a neurologic syndrome that resembles Parkinson's disease (PD). Current evidence indicates that manganese-induced parkinsonism can be differentiated from PD because of its predilection to accumulate in and damage the pallidum and striatum rather than the SNc. The clinical syndrome, response to levodopa, imaging studies with MRI and PET, and pathologic features all help to distinguish these two conditions and permit the correct diagnosis to be established. This is of particular relevance in differentiating patients with parkinsonism due to manganese intoxication from patients with idiopathic PD who have incidental manganese exposure.