Publications by authors named "Petr Ridzon"

17 Publications

  • Page 1 of 1

Peripheral polyneuropathy after acute methanol poisoning: Six-year prospective cohort study.

Neurotoxicology 2020 07 5;79:67-74. Epub 2020 May 5.

Toxicological Information Centre, General University Hospital, Prague, Czech Republic; Department of Occupational Medicine, 1st Faculty of Medicine, Charles University, Prague, Czech Republic.

Background: Methanol is a widely used industrial short-chain aliphatic alcohol with known neurotoxic properties. Mass poisoning outbreaks due to the consumption of methanol-adulterated alcoholic drinks present a challenge to healthcare providers due to the high mortality and serious central nervous system (CNS) damage in survivors. However, the impact of methanol exposure on the peripheral nervous system is unknown.

Objectives: To investigate the role of acute methanol exposure in the development of peripheral polyneuropathy (PNP) during the years following discharge from the hospital.

Methods: A total of 55 patients with confirmed methanol poisoning (mean age of 47.9 ± 3.6 years; 9 females) were examined 4 times within a 6-year prospective longitudinal cohort study. The program included neurological and electromyographic examinations, visual evoked potentials, ocular examinations with retinal nerve fibre layer thickness measurements, brain magnetic resonance imaging, and a series of biochemical and toxicological tests.

Results: PNP was observed in 20/55 (36 %) patients, which, in most of the cases, was mild axonal sensorimotor neuropathy. In 8/55 (15 %) patients, worsening of electromyographic findings was registered during the follow-up period, including 5 cases with newly diagnosed PNP and 3 cases of PNP progression. In one subject, complete reversal of PNP was registered after cessation of alcohol intake. The patients with PNP were significantly older (57.3 ± 5.3 versus 42.5 ± 3.9 years; p < 0.001), with higher blood glucose (5.93 ± 0.97 versus 4.81 ± 0.32 mmol/L; p = 0.035) and lower vitamin B (45.5 ± 7.4 versus 57.5 ± 5.2 ug/L; p = 0.015) concentrations. The number of chronic alcohol abusers was significantly higher in the PNP group (17/20 versus 20/35; p = 0.034). No associations between PNP prevalence/ dynamics and acute parameters of poisoning severity, arterial blood pH (7.26 ± 0.07 with PNP versus 7.18 ± 0.09 without PNP; p = 0.150), or serum methanol (1320.0 ± 700.0 with PNP versus 1430.0 ± 510.0 mg/L without PNP; p = 0.813) and ethanol (460.0 ± 560.0 with PNP versus 340.0 ± 230.0 mg/L without PNP; p = 0.675) concentrations at admission were found. No difference in the number of patients with visual (9/20 with PNP versus 12/35 patients without PNP; p = 0.431) and CNS sequelae (9/20 with PNP versus 15/35 patients without PNP; p = 0.877) of poisoning was present.

Discussion: Despite the relatively high number of PNP cases, no association was found between the severity of acute methanol poisoning and the prevalence of PNP and its dynamics during six years of observation. We did not find an association between methanol-induced visual/ brain damage and the prevalence of PNP in survivors of poisoning. A high prevalence of PNP and its progression might be attributed to other causes, mainly a history of chronic alcohol abuse and insufficiently treated diabetes mellitus. Our results highlight the importance of complete cessation of alcohol consumption and better control of glycaemia in diabetic patients in the prevention and treatment of peripheral PNP.
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http://dx.doi.org/10.1016/j.neuro.2020.04.010DOI Listing
July 2020

Desminopathy: Novel Desmin Variants, a New Cardiac Phenotype, and Further Evidence for Secondary Mitochondrial Dysfunction.

J Clin Med 2020 Mar 29;9(4). Epub 2020 Mar 29.

Research Unit for Rare Diseases, Department of Pediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University, 11636 Prague, Czech Republic.

The pleomorphic clinical presentation makes the diagnosis of desminopathy difficult. We aimed to describe the prevalence, phenotypic expression, and mitochondrial function of individuals with putative disease-causing desmin (DES) variants identified in patients with an unexplained etiology of cardiomyopathy. A total of 327 Czech patients underwent whole exome sequencing and detailed phenotyping in probands harboring DES variants. Rare, conserved, and possibly pathogenic DES variants were identified in six (1.8%) probands. Two DES variants previously classified as variants of uncertain significance (p.(K43E), p.(S57L)), one novel DES variant (p.(A210D)), and two known pathogenic DES variants (p.(R406W), p.(R454W)) were associated with characteristic desmin-immunoreactive aggregates in myocardial and/or skeletal biopsy samples. The individual with the novel DES variant p.(Q364H) had a decreased myocardial expression of desmin with absent desmin aggregates in myocardial/skeletal muscle biopsy and presented with familial left ventricular non-compaction cardiomyopathy (LVNC), a relatively novel phenotype associated with desminopathy. An assessment of the mitochondrial function in four probands heterozygous for a disease-causing DES variant confirmed a decreased metabolic capacity of mitochondrial respiratory chain complexes in myocardial/skeletal muscle specimens, which was in case of myocardial succinate respiration more profound than in other cardiomyopathies. The presence of desminopathy should also be considered in individuals with LVNC, and in the differential diagnosis of mitochondrial diseases.
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http://dx.doi.org/10.3390/jcm9040937DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7231262PMC
March 2020

Neurological and Neurophysiological Findings in Workers with Chronic 2,3,7,8-Tetrachlorodibenzo-p-Dioxin Intoxication 50 Years After Exposure.

Basic Clin Pharmacol Toxicol 2018 Feb 27;122(2):271-277. Epub 2017 Sep 27.

Department of Occupational Medicine, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic.

The last eight survivors of 80 workers accidentally exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) during production of herbicides based on trichlorophenoxyacetic acid in 1965-1967 in a chemical factory were followed. All were men, mean age 72.4 ± 1.3 years. Their current median TCDD blood level was 112 (46-390) pg/g lipids. Neurological examination revealed central nervous system impairment in all individuals and signs of polyneuropathy in 87.5%, which was confirmed by a nerve conduction study (NCS) in 75%. A Lanthony test demonstrated acquired dyschromatopsia in 87.5% of the patients, with deterioration of mean colour confusion index (CCI) from 1.52 ± 0.39 in 2010 to 1.73 ± 0.41 in 2016. Single-photon emission computer tomography (SPECT) of the brain showed focal reduction of perfusion in various brain locations in all patients and worsening in six patients. Visual-evoked potentials (VEP) was abnormal in 62.6% of individuals. Most patients complained of psychological problems. The neuropsychological test battery showed most positive impairments in the Trail Making Test evaluating processing speed (average level in the range of mild neurocognitive impairment), which correlated with mean CCI (p < 0.05).

Conclusion: Fifty years after exposure, blood levels of TCDD are still 10 times higher than the general population. NCS, VEP, Lanthony test and SPECT findings deteriorated from examination of these patients in 2004 and in 2010. The total of abnormal tests per patient in 2016 is very high. Minor differences among patients and their reduced count may explain why the number of impairments in 2016 does not correlate with TCDD blood level.
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http://dx.doi.org/10.1111/bcpt.12899DOI Listing
February 2018

Gait and Balance Impairment after Acute Methanol Poisoning.

Basic Clin Pharmacol Toxicol 2018 Jan 6;122(1):176-182. Epub 2017 Sep 6.

Department of Neurology, Charles University, First Faculty of Medicine and General University Hospital, Prague, Czech Republic.

Neurological sequelae including gait impairment were reported in survivors after methanol intoxication; however, no systematic study has been published so far. We aimed to analyse gait and balance impairment in a group of Czech methanol poisoning survivors. We examined 43 patients (age 46 ± 13 years) 2-8 months after methanol poisoning and 43 healthy controls. Investigations contained a shortened version of Falls Efficacy Scale (FES), clinical tests of gait and balance including Timed Up and Go test (TUG) and gait analysis using GaitRite system, neurological and neuropsychological examination, brain imaging, EMG and tests of alcohol consumption. Nineteen patients admitted balance and gait impairment according to FES. Mild to moderate parkinsonian signs showed seven patients. Patients were slower (8.8 versus 5.7 s, p < 0.001) and performed more steps (11.1 versus 7.9, p < 0.001) in TUG compared with the controls. Gait analysis revealed shorter step length (76.5 versus 88.7 cm, p < 0.001), increased double support phase (18.8 versus 15.5%, p < 0.001) and wider base of support (11.3 versus 9.6 cm, p = 0.006) in patients. Eleven patients had deficit of executive function and performed higher cadence compared to the patients with normal execution (122.7 versus 115.0 step/min., p = 0.025). Lower limb polyneuropathy was verified in nine patients, without relation with gait or balance parameters. Neuroimaging revealed lesions mainly in the basal ganglia. Methanol poisoning survivors presented slower wide-based gait with shortened steps corresponding with frontal gait disorder. Higher stepping cadence associated with executive deficit supported the evidence of frontal lobe dysfunction related to impairment of basal ganglia and connections in frontal cortico-basal ganglia loops.
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http://dx.doi.org/10.1111/bcpt.12853DOI Listing
January 2018

Gait and Balance Impairment after Acute Methanol Poisoning.

Basic Clin Pharmacol Toxicol 2018 Jan 6;122(1):176-182. Epub 2017 Sep 6.

Department of Neurology, Charles University, First Faculty of Medicine and General University Hospital, Prague, Czech Republic.

Neurological sequelae including gait impairment were reported in survivors after methanol intoxication; however, no systematic study has been published so far. We aimed to analyse gait and balance impairment in a group of Czech methanol poisoning survivors. We examined 43 patients (age 46 ± 13 years) 2-8 months after methanol poisoning and 43 healthy controls. Investigations contained a shortened version of Falls Efficacy Scale (FES), clinical tests of gait and balance including Timed Up and Go test (TUG) and gait analysis using GaitRite system, neurological and neuropsychological examination, brain imaging, EMG and tests of alcohol consumption. Nineteen patients admitted balance and gait impairment according to FES. Mild to moderate parkinsonian signs showed seven patients. Patients were slower (8.8 versus 5.7 s, p < 0.001) and performed more steps (11.1 versus 7.9, p < 0.001) in TUG compared with the controls. Gait analysis revealed shorter step length (76.5 versus 88.7 cm, p < 0.001), increased double support phase (18.8 versus 15.5%, p < 0.001) and wider base of support (11.3 versus 9.6 cm, p = 0.006) in patients. Eleven patients had deficit of executive function and performed higher cadence compared to the patients with normal execution (122.7 versus 115.0 step/min., p = 0.025). Lower limb polyneuropathy was verified in nine patients, without relation with gait or balance parameters. Neuroimaging revealed lesions mainly in the basal ganglia. Methanol poisoning survivors presented slower wide-based gait with shortened steps corresponding with frontal gait disorder. Higher stepping cadence associated with executive deficit supported the evidence of frontal lobe dysfunction related to impairment of basal ganglia and connections in frontal cortico-basal ganglia loops.
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http://dx.doi.org/10.1111/bcpt.12853DOI Listing
January 2018

Evaluation of Lumbar Spine Load by Computational Method in Order to Acknowledge Low-back Disorders as Occupational Diseases.

Cent Eur J Public Health 2016 Mar;24(1):58-67

Department of Occupational Medicine, First Medical Faculty, Charles University and General University Hospital, Prague, Czech Republic.

Aim: The aim of the study was to develop a computational module for the prediction of compressive force on the L4/L5 disc suitable for use in field settings.

Method: The value of compressive force is intended to be used as a proxy measure of the mechanical burden of low-back when performing work activities. The compressive force predicted by the module in a particular worker should be compared with the NIOSH limit value of 3,400 N for the assessment of lumbar spine load during manual lifting tasks. Exceeding the limit will be considered as the fulfilment of "hygienic criterion" that should be met to acknowledge low-back disorder as an occupational disease. To develop the computational module we used the ergonomic software TECNOMATIX Classic Jack taking into account the anthropometric parameters of a worker and ergonomic parameters of his/her work activity.

Results: We calculated compressive forces on the L4/L5 disc in about 1,300 simulated combinations of various factors influencing compressive force. Parameters which turned out to be crucial for the compression of L4/L5 disc were included in the computational algorithm.

Conclusion: Our study was primarily aimed at the assessment of lumbar disorders as occupational diseases. Moreover, the study can contribute to the recommendation of preventive measures to decrease health risks in occupations associated with the overload of low-back region. The graphic maps generated by the computational module enable a fast and exact analysis of particular job.
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http://dx.doi.org/10.21101/cejph.a4332DOI Listing
March 2016

Visual evoked potentials in patients after methanol poisoning.

Int J Occup Med Environ Health 2016 ;29(3):471-8

Charles University in Prague and General University Hospital in Prague, Prague, Czech Republic (Department of Occupational Medicine, 1st Faculty of Medicine).

Objectives: We report the results of the visual evoked potentials (VEP) examination in patients after severe poisoning by methanol.

Material And Methods: The group of 47 patients (38 males and 9 females) was assembled out of persons who survived an outbreak of poisoning by the methanol adulterated alcohol beverages, which happened in the Czech Republic in 2012-2013. The visual evoked potentials examination was performed using monocular checkerboard pattern-reversal stimulation. Two criteria of abnormality were chosen: missing evoked response, and wave P1 latency > 117 ms. Non-parametric statistical methods (median, range, and the median test) were used to analyze factors influencing the VEP abnormality.

Results: The visual evoked potential was abnormal in 20 patients (43%), 5 of them had normal visual acuity on the Snellen chart. The VEP abnormality did not correlate significantly with initial serum concentrations of methanol, formic acid or lactate; however, it showed statistically significant inverse relation to the initial serum pH: the subgroup with the abnormal VEP had significantly lower median pH in comparison with the subgroup with the normal VEP (7.16 vs. 7.34, p = 0.04). The abnormality was not related to chronic alcohol abuse.

Conclusions: The visual evoked potentials examination appeared sensitive enough to detected even subclinical impairment of the optic system. Metabolic acidosis is likely to be the key factor related to the development of visual damage induced by methanol. The examination performed with a delay of 1-9 months after the poisoning documented the situation relatively early after the event. It is considered as a baseline for the planned long-term follow-up of the patients, which will make it possible to assess the dynamics of the observed changes, their reversibility, and the occurrence of potential late sequelae.
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http://dx.doi.org/10.13075/ijomeh.1896.00452DOI Listing
January 2017

Imaging findings after methanol intoxication (cohort of 46 patients).

Neuro Endocrinol Lett 2015 ;36(8):737-44

MR Unit, Department of Diagnostic and Interventional Radiology, Institute for Clinical and Experimental Medicine, Prague, Czech Republic.

Objectives: Our goal is to demonstrate the variability of imaging findings, primarily in the MRI, in 46 patients who survived acute methanol poisoning. This cohort of patients is the largest such sample group examined by MRI.

Methods: Patients were examined by means of imaging methods (42 patients by MRI and 4 by CT). All had an identical protocol of MR examination (T2WI, FLAIR, T1WI with or without application of contrast medium and T2WI/FFE, DWI in the transversal plane of the scan, and with focus on the optic nerves in the coronal plane of the scan in T2WI-SPIR).

Results: Imaging methods revealed a positive finding associated with methanol intoxication in 21 patients (46%). These consisted of symmetrical lesions in the putamen--13 patients (28%), haemorrhage--13 cases (28%), deposits in white matter with localization primarily subcortically--4 cases (9%), lesions in the region of the globus pallidus--7 cases (15%) (in 6 cases without combination with the lesions in the putamen), lesions in the brainstem afflicted 6 patients (13%), and lesion in the cerebellum was found in one case. A pathological finding was found only in the patients examined by MRI.

Conclusion: Almost half of the patients who survived acute methanol poisoning had pathological findings by MRI. The most common finding concerned an affliction of the putamen, which is a predilection area. An interesting finding was the relatively frequent occurrence of selective lesion of the globus pallidus, which is more usually associated with other types of intoxication.
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July 2016

LOW-BACK PAIN DISORDERS AS OCCUPATIONAL DISEASES IN THE CZECH REPUBLIC AND 22 EUROPEAN COUNTRIES: COMPARISON OF NATIONAL SYSTEMS, RELATED DIAGNOSES AND EVALUATION CRITERIA.

Cent Eur J Public Health 2015 Sep;23(3):244-51

Aim: Low-back pain diseases (LBPD) belong to the most frequent diagnoses determined by general practitioners, and constitute one of the most common reasons for sick leave and permanent disability pension in the Czech Republic and other European countries. Epidemiological studies have shown a statistically significant association between LBPD and certain types of occupational burden. However, in the Czech Republic, LBPD caused by overload and/or whole-body vibrations have not yet been included in the list of occupational diseases. The aim of this study was to collect and compare the systems, criteria and diagnoses used to recognize LBPD as occupational diseases in other European countries.

Methods: A questionnaire focused on LBPD was distributed and answered by specialists in occupational diseases in European countries. It included items concerning LBPD in the national list of occupational diseases, and work-related and diagnostic criteria that need to be fulfilled for recognizing LBPD as occupational diseases and possible awarding compensations to the patients.

Results: In 13 countries out of the 23 countries studied, LBPD caused by overload can be recognized as occupational, providing that the diagnosis is sufficiently proven and exposure criteria and/or listed occupation are met and duration of exposure is confirmed (Belgium, Denmark, France, Germany, Hungary, Italy, Lithuania, Macedonia, Netherlands, Romania, Slovakia, Sweden, and Switzerland). LBPD due to vibrations can be also recognized as occupational in 14 countries. In 8 countries LBPD are not accepted as occupational unless they are caused by an injury at work. Specific criteria to evaluate occupational exposure of patients with LBPD were set in Belgium, Denmark, France, Germany, Lithuania, Macedonia, Netherlands, and Slovakia. In other countries, the evaluation is done at an individual basis.

Conclusions: In practice, the assessment of occupational overload and its contribution to the development of LBPD as well as its inclusion in the compensation system are important for several reasons. Firstly, it may be considered essentially preventable. Secondly, cases with a significant contribution of occupational aetiology may be viewed as occupational diseases for which compensation may be claimed, as it is the case in many European countries. Importantly, inclusion of LBPD in the list of occupational diseases or another system of compensation may be viewed as a preventive measure as it increases the visibility of this problem not only for the workers, but especially for the employers.
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http://dx.doi.org/10.21101/cejph.a4185DOI Listing
September 2015

Czech mass methanol outbreak 2012: epidemiology, challenges and clinical features.

Clin Toxicol (Phila) 2014 Dec 25;52(10):1013-24. Epub 2014 Oct 25.

Department of Occupational Medicine,Toxicological Information Center, First Faculty of Medicine, Charles University in Prague and General University Hospital , Prague , Czech Republic.

Objectives: Methanol poisonings occur frequently globally, but reports of larger outbreaks where complete clinical and laboratory data are reported remain scarce. The objective of the present study was to report the data from the mass methanol poisoning in the Czech Republic in 2012 addressing the general epidemiology, treatment, and outcomes, and to present a protocol for the use of fomepizole ensuring that the antidote was provided to the most severely poisoned patients in the critical phase.

Methods: A combined prospective and retrospective case series study of 121 patients with confirmed methanol poisoning.

Results: From a total of 121 intoxicated subjects, 20 died outside the hospital and 101 were hospitalized. Among them, 60 survived without, and 20 with visual/CNS sequelae, whereas 21 patients died. The total and hospital mortality rates were 34% and 21%, respectively. Multivariate regression analysis found pH < 7.0 (OR 0.04 (0.01-0.16), p < 0.001), negative serum ethanol (OR 0.08 (0.02-0.37), p < 0.001), and coma on admission (OR 29.4 (10.2-84.6), p < 0.001) to be the only independent parameters predicting death. Continuous hemodialysis was used more often than intermittent hemodialysis, but there was no significant difference in mortality rate between the two [29% (n = 45) vs 17% (n = 30), p = 0.23]. Due to limited stockpiles of fomepizole, ethanol was administered more often; no difference in mortality rate was found between the two [16% (n = 70) vs. 24% (n = 21), p = 0.39]. The effect of folate administration both on the mortality rate and on the probability of visual sequelae was not significant (both p > 0.05).

Conclusions: Severity of metabolic acidosis, state of consciousness, and serum ethanol on admission were the only significant parameters associated with mortality. The type of dialysis or antidote did not appear to affect mortality. Recommendations that were issued for hospital triage of fomepizole administration allowed conservation of valuable antidote in this massive poisoning outbreak for those patients most in need.
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http://dx.doi.org/10.3109/15563650.2014.974106DOI Listing
December 2014

Rare alleles within the CYP2E1 (MEOS system) could be associated with better short-term health outcome after acute methanol poisoning.

Basic Clin Pharmacol Toxicol 2015 Feb 19;116(2):168-72. Epub 2014 Sep 19.

Centre for Experimental Medicine, Institute for Clinical and Experimental Medicine, Prague, Czech Republic.

Genetic polymorphisms influence the metabolism of ethanol and methanol, but the potential effects of genetic predisposition on the clinical course, outcome and short-term health sequelae of acute methanol poisoning are unknown. To evaluate the role of the MEOS system in methanol poisoning, we analysed the effect of three polymorphisms (RsaI - rs2031920; PstI - rs3813867; insertion/deletion I/D) within the CYP2E1 enzyme (MEOS system) in 50 adult survivors of methanol poisoning and compared their genotype frequencies with 460 controls. The minor allele frequencies of all three polymorphisms were below 5% in both groups. We did not detect significant differences in the genotype frequencies between survivors of methanol poisoning and controls (p = 0.34 for the RsaI variant; p = 0.59 for the PstI variant and p = 0.21 for the I/D polymorphism). The carriers of at least one minor allele in the CYP2E1 gene had less severe clinical symptoms and better short-term outcome after acute poisoning. Variants within the CYP2E1 gene are likely not significant genetic determinants of acute methanol poisoning (if survivors are analysed), but they may influence the severity of methanol poisoning and its visual/central nervous system (CNS) outcome.
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http://dx.doi.org/10.1111/bcpt.12310DOI Listing
February 2015

Isolated X-linked hypertrophic cardiomyopathy caused by a novel mutation of the four-and-a-half LIM domain 1 gene.

Circ Cardiovasc Genet 2013 Dec 10;6(6):543-51. Epub 2013 Oct 10.

Institute of Inherited Metabolic Disorders, First Faculty of Medicine, Charles University in Prague, Prague, Czech Republic.

Background: Hypertrophic cardiomyopathy with severe left ventricular diastolic dysfunction has been associated with marked exercise intolerance and poor prognosis. However, molecular pathogenesis of this phenotype remains unexplained in a large proportion of cases.

Methods And Results: We performed whole exome sequencing as an initial genetic test in a large Czech family with 3 males affected by nonobstructive hypertrophic cardiomyopathy with severe left ventricular diastolic dysfunction in end-stage disease. A novel frameshift mutation of four-and-a-half LIM domain 1 gene (FHL1) (c.599_600insT; p.F200fs32X) was detected in these individuals. The mutation does not affect transcription, splicing, and stability of FHL1 mRNA and results in production of truncated FHL1 protein, which is contrary to heart tissue homogenate not detectable in frozen tissue sections of myocardial biopsy of affected males. The identified mutation cosegregated also with abnormal ECG and with 1 case of apical hypertrophic cardiomyopathy in heterozygous females. Although skeletal muscle involvement is a common finding in FHL1-related diseases, we could exclude myopathy in all mutation carriers.

Conclusions: We identified a novel FHL1 mutation causing isolated hypertrophic cardiomyopathy with X-chromosomal inheritance.
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http://dx.doi.org/10.1161/CIRCGENETICS.113.000245DOI Listing
December 2013

Ulnar nerve at the elbow - normative nerve conduction study.

J Brachial Plex Peripher Nerve Inj 2013 Feb 11;8(1). Epub 2013 Feb 11.

Department of Neurology, Regional Hospital and Faculty of Health Studies, University of Pardubice, 44 Kyjevská, 532 03, Pardubice, Czech Republic.

Introduction: A goal of our work was to perform nerve conduction studies (NCSs) of the ulnar nerve focused on the nerve conduction across the elbow on a sufficiently large cohort of healthy subjects in order to generate reliable reference data.

Methods: We examined the ulnar nerve in a position with the elbow flexion of 90o from horizontal. Motor response was recorded from the abductor digiti minimi muscle (ADM) and the first dorsal interosseous muscle (FDI).

Results: In our sample of 227 healthy volunteers we have examined 380 upper arms with the following results: amplitude (Amp)-CMAP(wrist) for ADM 9.6 ± 2.3 mV, MNCV at the forearm 60.4 ± 5.2 m/s, MNCV across the elbow 57.1 ± 5.9 m/s.

Discussion: Our study showed that motor NCSs of the ulnar nerve above elbow (AE) and below elbow (BE) in a sufficiently large cohort using methodology recommended by AANEM gave results well comparable for registration from FDI and ADM.
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http://dx.doi.org/10.1186/1749-7221-8-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3653784PMC
February 2013

Increased oxidative/nitrosative stress markers measured non- invasively in patients with high 2,3,7,8-tetrachloro-dibenzo-p-dioxin plasma level.

Neuro Endocrinol Lett 2011 ;32 Suppl 1:71-6

Department of Occupational Medicine of the First Faculty of Medicine and General University Hospital, Charles University Prague, Czech Republic.

Objectives: 2,3,7,8-tetrachloro-dibenzo-p-dioxin (TCDD) is a highly toxic persistent environmental contaminant, classified as a human carcinogen affecting any target organ. The mechanism of carcinogenesis by TCDD is unclear as TCDD shows a lack of direct genotoxicity. Experimental studies also support the role of oxidative stress in TCDD neurotoxicity and vascular dysfunction. The aim was to investigate markers of oxidative/nitrosative stress and inflammation using non-invasive methods in subjects who got ill due to severe occupational exposure to TCDD in the years 1965-1968.

Methods: In 11 TCDD-exposed patients, and 16 controls, the analysis of following oxidative products of lipids, proteins and nucleic acids in plasma, urine and exhaled breath condensate (EBC) was performed: 8-iso-prostaglandin F2α (8-isoprostane), 4-hydroxy-trans-2-nonenale (HNE), malondialdehyde (MDA), o-tyrosine (o-Tyr), 8-hydroxyguanosine (8-OHG), 8-hydroxy-2´-deoxy-guanosine (8-OHdG), 5-hydroxymethyluracil (5-OHMeU). In addition, nitric-oxide-tyrosine (NO-Tyr) and leukotriene (LT) B4, C4, D4, and E4 were detected by liquid chromatography-mass spectrometry/mass spectrometry (LC-ESI-MS/MS). TCDD was measured by HRGC/HRMS, body lipid content by densitometry. Single-photon emission spectrometry (SPECT) of the brain was performed and compared with the findings of the patients in 2008.

Results: Mean TCDD plasma level in 2010 was 175 ± 162 pg/g lipids (population level about 2 pg/g), total TCDD content in the body 5.16 ± 4.62 mg. Reduction of cerebral blood flow in SPECT progressed in 8 patients, finding was stable in 2 subjects, and improvement occurred in 1 patient. In the EBC, 10 from 12 markers (all except LT D4 and LT E4), were significantly increased in the patients (p<0.05). In the urine, 7 markers were significantly higher than in the controls (p<0.05): 8-isoprostane, MDA, HNE, LT C4, LT E4, o-Tyr and NO-Tyr. In plasma, only NO-Tyr and 8-OHG were elevated (p<0.05).

Conclusion: NO-Tyr was increased in all matrices in dioxin-exposed patients. EBC is not limited to lung disorders as the markers of oxidative stress and inflammation were elevated in EBC of patients with normal lung functions. TCDD-induced oxidative stress and inflammation markers can be detected non-invasively in the EBC and urine in the follow-up of the highly-exposed patients. Their prognostic value, however, needs to be elucidated.
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April 2012

FTLD-TDP with motor neuron disease, visuospatial impairment and a progressive supranuclear palsy-like syndrome: broadening the clinical phenotype of TDP-43 proteinopathies. A report of three cases.

BMC Neurol 2011 May 10;11:50. Epub 2011 May 10.

Department of Neurology, Thomayer Teaching Hospital and Institute for Postgraduate Education in Medicine, Prague, Czech Republic.

Background: Frontotemporal lobar degeneration with ubiquitin and TDP-43 positive neuronal inclusions represents a novel entity (FTLD-TDP) that may be associated with motor neuron disease (FTLD-MND); involvement of extrapyramidal and other systems has also been reported.

Case Presentation: We present three cases with similar clinical symptoms, including Parkinsonism, supranuclear gaze palsy, visuospatial impairment and a behavioral variant of frontotemporal dementia, associated with either clinically possible or definite MND. Neuropathological examination revealed hallmarks of FTLD-TDP with major involvement of subcortical and, in particular, mesencephalic structures. These cases differed in onset and progression of clinical manifestations as well as distribution of histopathological changes in the brain and spinal cord. Two cases were sporadic, whereas the third case had a pathological variation in the progranulin gene 102 delC.

Conclusions: Association of a "progressive supranuclear palsy-like" syndrome with marked visuospatial impairment, motor neuron disease and early behavioral disturbances may represent a clinically distinct phenotype of FTLD-TDP. Our observations further support the concept that TDP-43 proteinopathies represent a spectrum of disorders, where preferential localization of pathogenetic inclusions and neuronal cell loss defines clinical phenotypes ranging from frontotemporal dementia with or without motor neuron disease, to corticobasal syndrome and to a progressive supranuclear palsy-like syndrome.
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http://dx.doi.org/10.1186/1471-2377-11-50DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3112085PMC
May 2011

Quantitative brain MR imaging in amyotrophic lateral sclerosis.

MAGMA 2011 Apr 15;24(2):67-76. Epub 2011 Mar 15.

Third Faculty of Medicine, Charles University in Prague, Prague, Czech Republic.

Object: To evaluate the potential of quantitative MR techniques [voxel-based morphometry (VBM), T2-relaxometry, mean diffusivity (MD), fractional anisotropy (FA)] in the diagnostics of amyotrophic lateral sclerosis (ALS).

Materials And Methods: Thirty-three ALS patients and thirty age- and sex-matched healthy volunteers were included in the cross-sectional study. T1WI, T2WI and T2 relaxometry sequences were performed at 1.5T. DWI was performed in a subgroup of 12 patients. Disease severity was estimated with the ALS Functional Rating Scale (ALS-FRS).

Results: We detected decreased T2 relaxation rate (R2) in the frontal white matter (FWM) (left and right P < 0.005) and caudate nucleus (left P < 0.005) in ALS patients. R2 in the FWM correlated with age in patients and controls. A correlation (P < 0.01, cluster-level corrected) between atrophy in the corona radiata and the limb ALS-FRS subset was found, as well as a difference between patients and controls in this area. No correlation between FA/MD and ALS-FRS was observed in the T2 hyperintense region of the posterior limb of the internal capsule (PLIC), or in the site of atrophy detected by VBM. No R2 or PD changes in the PLIC were detected. TBSS revealed decreased FA in the corona radiata and callosal body.

Conclusions: Decreased R2 in the left caudate and bilateral FWM may help in the diagnostic process and disqualifies these regions as internal controls in ALS studies. The PLIC is not a reliable diagnostic marker of ALS.
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http://dx.doi.org/10.1007/s10334-010-0237-4DOI Listing
April 2011

Chronic health impairment due to 2,3,7,8-tetrachloro-dibenzo-p-dioxin exposure.

Neuro Endocrinol Lett 2009 ;30 Suppl 1:219-24

Department of Occupational Medicine, Charles University Prague, Czech Republic.

Objectives: The aim of this study, performed in 2008, was to evaluate the consequences of severe occupational intoxication with 2,3,7,8-tetrachloro-dibenzo-p-dioxin (TCDD) that occurred during production of the herbicide trichlorophenoxyacetic acid in the period 1965-1968.

Design: Examination of 11 men, mean age 64.4+/-1.5 years, included: internal and neurological examination, eye fundus examination, TCDD in plasma, thyroid-stimulating hormone (TSH), testosterone and serum lipids, ultrasonography of the carotid artery, nerve conduction study (NCS), electroencephalography (EEG), visual evoked potential (VEP), Lanthony test of acquired visual impairment, single photon emission computer tomography (SPECT) of the brain, neuropsychological examination and carbohydrate-deficient transferrin (CDT), a marker of chronic ethanol intake.

Results: Mean TCDD level in 2008 was still 274.0+/-181.2 pg/g blood lipids (reference level is 2-3 pg/g). All (100%) patients had residues of chloracne/chloracne consequences, atherosclerotic changes on the eye fundus and plaques in the carotid arteries. Progression of intima-media thickness (IMT) from a mean of 0.84+/-0.14 mm in 2003 to 1.09+/-0.18 mm in 2008 was observed. Ninety-one per cents of patients had impairment in SPECT of the brain; and 55% of patients had hyperfixation of the perfusion indicator as a measure of increased neuronal activity. Additionally, 91 % of patients were treated for hyperlipidaemia, 73 % for hypertension, 55 % for diabetes type 2, 45 % for ischemic heart disease, and 36 % for psychological disorders. The Lanthony test demonstrated acquired dyschromatopsia in 80 % of patients. Mean colour confusion index (CCI) was 1.438, which indicates impairment since 2003, when the index was 1.302. CDT was in the normal range and did not correlate with CCI. Neuropsychological status appeared stabilized in all 8 patients examined, with impairment in one or more parameter (memory, attention, verbal fluency, psychomotor speed, motorics) in comparison to the norm.

Conclusion: Forty years after intoxication, the blood level of TCDD is still 100 times higher than in the general population. Other PCDD/Fs were not elevated. A high percentage of subjects suffer from neurological and vascular disorders. No association of alcohol consumption with neurological impairment was seen, and the highly significant correlation between CCI and TCDD blood concentration suggests that acquired colour impairment was associated with TCDD but not with alcohol consumption. IMT significantly increased during past 5 years. The patients obviously need complex treatment, including intense hypolipidaemic and antidepressant therapy.
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May 2010
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