Comparative study of the substantia nigra echogenicity and 123I-Ioflupane SPECT in patients with synucleinopathies with and without REM sleep behavior disorder.

OBJECTIVES: Hyperechogenicity of the substantia nigra (SN) and abnormal dopamine transporter-single-photon emission computed tomography (DAT-SPECT) are biomarkers commonly used in the assessment of prodromal synucleinopathy. Our goals were as follows: (1) to compare echogenicity of SN in idiopathic rapid eye movement (REM) behavior disorder (iRBD), Parkinson's disease (PD) without RBD (PD-noRBD), PD with RBD (PD + RBD), and control subjects; and (2) to examine association between SN degeneration assessed by DAT-SPECT and SN echogenicity. PATIENTS/METHODS: A total of 61 subjects with confirmed iRBD were examined using Movement Disorders Society-unified PD rating scale (MDS-UPDRS), TCS (transcranial sonography) and DAT-SPECT. The results were compared with 44 patients with PD (25% PD + RBD) and with 120 age-matched healthy subjects. RESULTS AND CONCLUSION: The abnormal SN area was found in 75.5% PD, 23% iRBD and 7.3% controls. Median SN echogenicity area in PD (0.27 ± 0.22 cm2) was higher compared to iRBD (0.07 ± 0.07 cm2; p < 0.0001) and controls (0.05 ± 0.03 cm2; p < 0.0001). SN echogenicity in PD + RBD was not significantly different from PD-noRBD (0.30 vs. 0.22, p = 0.15). Abnormal DAT-SPECT was found in 16 iRBD (25.4%) and 44 PD subjects (100%). No correlation between the larger SN area and corresponding putaminal binding index was found in iRBD (r = -0.13, p = 0.29), nor in PD (r = -0.19, p = 0.22). The results of our study showed that: (1) SN echogenicity area in iRBD was higher compared to controls, but the hyperechogenicity was present only in a minority of iRBD patients; (2) SN echogenicity and DAT-SPECT binding index did not correlate in either group; and (3) SN echogenicity does not differ between PD with/without RBD.

Diagnostic exome sequencing in early-onset Parkinson's disease confirms VPS13C as a rare cause of autosomal-recessive Parkinson's disease.

Parkinson's disease (PD) is a genetically heterogeneous disorder and new putative disease genes are discovered constantly. Therefore, whole-exome sequencing could be an efficient approach to genetic testing in PD. To evaluate its performance in early-onset sporadic PD, we performed diagnostic exome sequencing in 80 individuals with manifestation of PD symptoms at age 40 or earlier and a negative family history of PD. Variants in validated and candidate disease genes and risk factors for PD and atypical Parkinson syndromes were annotated, followed by further analysis for selected variants. We detected pathogenic variants in Mendelian genes in 6.25% of cases and high-impact risk factor variants in GBA in 5% of cases, resulting in overall maximum diagnostic yield of 11.25%. One individual was compound heterozygous for variants affecting canonical splice sites in VPS13C, confirming the causal role of protein-truncating variants in this gene linked to autosomal-recessive early-onset PD. Despite the low diagnostic yield of exome sequencing in sporadic early-onset PD, the confirmation of the recently discovered VPS13C gene highlights its advantage over using predefined gene panels.

Decreased perception of high frequency sound in severe obstructive sleep apnea.

Obstructive sleep apnea (OSA) is characterized by recurrent episodes of upper airway obstruction during sleep, which is manifested by apnea or hypopnea. Decreased blood oxygen saturation, changes in heart rate, fluctuations in brain perfusion, changes in intracranial pressure, snoring and vibration are factors that may potentially affect hearing in patients with OSA. The aim of the present study was to test the hypothesis that hearing is affected in OSA. 43 males aged 34-74 years (mean 48.2) with suspected sleep-disordered breathing without other comorbidity or medication that may affect sleep or hearing were included. Nocturnal polysomnography, pure tone audiometry (PTA), transient evoked otoacoustic emissions (TEOAE) and brainstem auditory evoked potentials (BAEP) were evaluated. The severity of OSA was indicated by the number of apneas and hypopneas per hour of sleep (apnoe/hypopnoe index - AHI). OSA (AHI>/=5) was detected in 28 patients by polysomnography. Mild OSA (AHI 5-15) was confirmed in 11 patients, severe OSA (AHI>/=30) in 17 patients. Simple snoring (AHI<5) was diagnosed in 15 males. In patients suffering from severe OSA, tone audiometry demonstrated higher auditory threshold at frequencies of 4000 and 8000 Hz than in patients with AHI<15 (p<0.005). Auditory threshold values correlated with age in all groups. At a frequency of 8000 Hz, auditory threshold additionally correlated with BMI, AHI, oxygen desaturation index and decreased oxygen saturation. No differences were detected in TEOAE and BAEP between subjects with OSA and snoring. PTA and TEOAE decreased with increasing age. The present results show decreased perception of high frequency sound in severe OSA.

Restless legs syndrome in Czech patients with multiple sclerosis: an epidemiological and genetic study.

BACKGROUND: Restless legs syndrome (RLS) is a frequent neurological disorder which is presented in idiopathic and secondary form. Idiopathic RLS is associated with common genetic variants in four chromosomal regions. Recently, multiple sclerosis (MS) was identified as a common cause for secondary RLS. The aim of our study was to evaluate the prevalence of RLS among Czech patients with MS and to further analyze the impact of known genetic risk factors for RLS in patients with MS. METHODS: Each patient underwent a semi-structured interview. A patient was considered to be affected by RLS if all four standard criteria had ever been met in their lifetime. The sample was genotyped using 12 single nucleotide polymorphisms within the four genomic regions, which were selected according to the results of previous genome-wide association studies. RESULTS: A total of 765 subjects with MS were included in the study and the diagnosis of RLS was confirmed in 245 subjects (32.1%, 95%CI 28.7-35.4%). The genetic association study included 642 subjects; 203 MS patients with RLS were compared to 438 MS patients without RLS. No significant association with MEIS 1, BTBD9, and PTPRD gene variants was found despite sufficient statistical power for the first two loci. There was a trend for association with the MAP2K5/SCOR1 gene - the best model for the risk allele was the recessive one (p nominal=0.0029, p corrected for four loci and two models=0.023, odds ratio=1.60). CONCLUSION: We confirmed that RLS prevalence was high in patients with multiple sclerosis, but this form did not share all genetic risk variants with idiopathic RLS.

Sleep microstructure is not altered in children with attention-deficit/hyperactivity disorder (ADHD).

The high rate of occurrence of sleep disturbances in children with attention-deficit/hyperactivity disorder (ADHD) prompted the idea that structural and neurotransmitter changes might give rise to specific sleep pattern abnormalities. The aim of this study was to evaluate the microstructure of sleep in children with ADHD who had no polysomnographically diagnosed sleep disorder, had never been treated for ADHD, and were free from any psychiatric comorbidity. Participants were 14 patients with ADHD (12 boys and 2 girls aged 7-12 years, mean age 9.6+/-1.6). ADHD was diagnosed according to DSM-IV criteria (Diagnostic and statistical manual of mental disorders). Psychiatric comorbidities were ruled out by detailed psychiatric examination. The patients underwent two consecutive overnight video-polysomnographic (PSG) recordings, with the sleep microstructure (cyclic alternating pattern - CAP) scoring during the second night. The data were compared with age- and sex-matched controls. Sleep microstructure analysis using CAP revealed no significant differences between the ADHD group and the controls in any of the parameters under study. In conclusions, no ADHD-specific alterations were found in the sleep microstructure.

Sleep disorders in Wilson's disease.

BACKGROUND: Wilson's disease (WD) is an autosomal recessive inherited disease with copper accumulation; neurodegeneration is associated with dopaminergic deficit. The aim of the study is to verify sleep co-morbidity by questionnaire and objective sleep examinations (polysomnography, multiple sleep latency test). METHODS: fifty-five patients with WD (22 hepatic, 28 neurological, five asymptomatic form) and 55 age- and sex-matched control subjects completed a questionnaire concerning their sleep habits, sleep co-morbidity, Epworth sleepiness scale (ESS), and answered screening questions for rapid eye movement (REM) behaviour disorder (RBD-SQ). Twenty-four patients with WD and control subjects underwent polysomnographic examination. RESULTS: unlike the controls, patients with WD were more prone to daytime napping accompanied by tiredness and excessive daytime sleepiness, cataplexy-like episodes and poor nocturnal sleep. Their mean ESS as well as RBD-SQ was higher than that of the controls. Total sleep time was lower, accompanied by decreased sleep efficiency and increased wakefulness. Patients with WD had lower latency of stage 1 and stage 2 of non-rapid eye movement (NREM) sleep and less amount of NREM sleep stage 2. One-third of the patients with WD were found to have short or borderline multiple sleep latency test (MSLT) values independent of nocturnal pathology (sleep apnoea, periodic leg movements and/or restless leg syndrome). CONCLUSIONS: patients with WD often suffer from sleep disturbances (regardless of the clinical form). The spectrum of sleep/wake symptoms raises the suspicion that altered REM sleep function may also be involved.

Polymorphisms in serotonin-related genes in anorexia nervosa. The first study in Czech population and metaanalyses with previously performed studies.

Anorexia nervosa is a serious psychiatric disorder characterized by the inability to maintain normal body weight. The frequently studied polymorphisms in the serotonin 5-HT2A receptor gene (-1438A/G) and in serotonin transporter 5-HTT gene (LPR, VNTR) have led to controversial results in different populations. The aim of the study was to address association of the above-mentioned polymorphisms with anorexia nervosa in the Czech population. We genotyped a well-defined group of 75 patients with anorexia nervosa (average age of 25.39 years, SD 6.18; average BMI 14.65 (SD 1.38)). The control group consisted of 65 Caucasian healthy females (average age 25.76 years, SD 5.12; average BMI 20.69, SD 1.85). The 5-HT2A receptor -1438A/G polymorphism analysis showed a trend for the association with odds ratios for risk allele A being in the same direction. In combination with a previously published Polish cohort, the allelic test reached a suggestive borderline (P = 0.0362, chi2 statistics, 1 df). In meta-analysis which included all published results for allelic tests, the resulting P value was highly significant (0.0003, chi2 statistics, 1 df). Using quantitative association of 5-HTR2A polymorphism with BMI in the Czech sample, a borderline association (P = 0.055) was observed. In 5-HTT, LPR polymorphism analysis, unlike in 5-HT2A, neither allelic nor quantitative association with BMI for the bi-allelic 5-HTT marker was observed. Results of this study support previous reports of a significant role of the A allele (-1438A/G, 5-HT2A receptor) as a risk factor in anorexia nervosa.

Arousals in nocturnal groaning.

BACKGROUND AND OBJECTIVE: Nocturnal groaning (catathrenia) is a chronic sleep disorder classified as parasomnia with unclear effects on sleep and life quality. It is characterized by repeated episodes of monotonous vocalization in prolonged expiration (episodes of bradypnea) occurring mostly in REM sleep. We sought to assess its impact on sleep microstructure, i.e., the frequency of arousals relative to the groaning episodes. The frequency, duration and sleep-stage distribution of the groaning episodes were also studied. METHODS: Eight patients with nocturnal groaning (5 male, 3 female, age range 11-32 years, mean age 23+/-7.1) were evaluated. All underwent standard neurologic examination and nocturnal videopolysomnography for two consecutive nights. The second night polysomnography data were used to evaluate sleep parameters. The groaning episodes (bradypneic events) were counted separately, not as clusters. RESULTS: Sleep macrostructure revealed no specific changes. The number of groaning episodes/bradypneic events during the night varied from 40 to 182 (total number 725). The duration of bradypnea was from 2 to 46s (mean duration 12.5s). Groaning episodes prevailed in REM sleep (76.5%). The rate for NREM 2 was 21.5%, and only sporadic episodes were noted in delta sleep (1.9%); 63.3% of the events were associated with arousals, and in 94% of them an arousal occurred before or together with the onset of bradypnea. The arousal index was increased in 5 patients (mean 20.4). Bruxism was present in 4 cases, in 1 patient appearing in close association with groaning episodes. Ronchopathy was noted in 4 cases. CONCLUSION: Almost two-thirds of the groaning episodes were connected with arousals. Hypothetically, nocturnal groaning may well be a source of sleep disruption (mainly REM) in some cases. Because an arousal mostly preceded or coincided with groaning we believe that arousal mechanisms may be involved in the pathogenesis of nocturnal groaning.

Replication of restless legs syndrome loci in three European populations.

BACKGROUND: Restless legs syndrome (RLS) is associated with common variants in three intronic and intergenic regions in MEIS1, BTBD9, and MAP2K5/LBXCOR1 on chromosomes 2p, 6p and 15q. METHODS: Our study investigated these variants in 649 RLS patients and 1230 controls from the Czech Republic (290 cases and 450 controls), Austria (269 cases and 611 controls) and Finland (90 cases and 169 controls). Ten single nucleotide polymorphisms (SNPs) within the three genomic regions were selected according to the results of previous genome-wide scans. Samples were genotyped using Sequenom platforms. RESULTS: We replicated associations for all loci in the combined samples set (rs2300478 in MEIS1, p = 1.26 x 10(-5), odds ratio (OR) = 1.47, rs3923809 in BTBD9, p = 4.11 x 10(-5), OR = 1.58 and rs6494696 in MAP2K5/LBXCOR1, p = 0.04764, OR = 1.27). Analysing only familial cases against all controls, all three loci were significantly associated. Using sporadic cases only, we could confirm the association only with BTBD9. CONCLUSION: Our study shows that variants in these three loci confer consistent disease risks in patients of European descent. Among the known loci, BTBD9 seems to be the most consistent in its effect on RLS across populations and is also most independent of familial clustering.

Does bilirubin level correspond to interaction of c.-3279T>G and A(TA)7TAA variants in UGT1A1 gene?

Promoter variants c.-3279T>G and A(TA)7TAA show decreased level of expression of UDP-glucuronosyl transferase 1A1 (UGT1A1) and consequently reduced activity of the enzyme catalyzing glucuronidation of bilirubin in hepatocytes. Thus, coincidental occurence of both variants should lead to increase of hyperbilirubinemia or contribute to its manifestation. In this study, investigation of both variants in 101 patients and 84 controls in a Caucasian population was performed and the results were compared with serum bilirubin levels. Despite high linkage disequilibrium between the loci (D' = 0.91, r(2) = 0.69), we have proven an interaction between the variants increasing the odds ratio for [(TA)7]+c.[-3279T>G] homozygotes to 54.2.

Advanced oxidation protein products in obstructive sleep apnea.

Obstructive sleep apnea (OSA) is a risk factor of hypertension, coronary artery disease and stroke. OSA is also considered a cause of accelerated atherogenesis. Advanced oxidation protein products (AOPP) are among the biochemical indicators of higher risk of atherogenesis as an independent risk factor for coronary artery disease. 20 men suffering from OSA were examined using night polygraphy, the AOPP were determined from their morning blood samples. The mean AOPP concentration in the patients group was 91.8 (SD=42.3) micromol/l, in the control group 76.2 (SD=35.3) pmol/l, the difference was not significant. The AOPP were found correlated with the AHI (apnoe/hypopnoe index) (R=0.485, P=0.030). The results support the hypothesis that OSA increases the oxidative stress and atherogenesis.

Cervical meningioma in childhood. A case report.

We report on a meningioma of the cervical spine in a 12-year-old boy with atypical clinical presentation. Meningiomas are relatively rare neoplasms in childhood, representing only 1 to 2% of all pediatric intracranial tumors. The distinction between the meningioma and another extramedullary, intradural tumors like schwannoma might pose difficulties. This case report points out that although a very rare tumor in children, it must be taken into account in differential diagnostics.

[Periodic limb movements in sleep: polysomnographic and actigraphic methods for their detection]. / Periodické pohyby koncetinami ve spáinku a jejich vysetrování pomocí polygrafie a aktigrafie.

BACKGROUND: The aim of our study was to compare the results obtained by simultaneous polysomnographic and actigraphic recording and thus to estimate the specificity and sensitivity of actigraphic evaluation of periodic leg movements in sleep (PLMS). As a standard method, PLMS are detected by means of polysomnography, including superficial EMG of anterior tibial muscles. Since 1995, there have been efforts to detect PLMS by means of actigraphy, which is more convenient for both patient and investigator. METHODS AND RESULTS: Recordings were done during 44 nights in 42 patients (10 women, mean age 49.2, SD 13.1 years) in our sleep laboratory. The same criteria for periodic leg movements and the cut-off periodic leg movements index (PLMI > 5) were used in both methods. For the actigraphic way of PLMS detection, we found a specificity of 90%, sensitivity 60%, positive predictive value 88.2%, negative predictive value 64.3 % and total diagnostic accuracy of 73.3%. A close correlation (Spearman's coefficient rho > 0.64, p < 0.0001) between PLMI resulting from either method of recording was observed, though the PLMI actigraph proved to be significantly lower (Sign test--p < 0.01). CONCLUSIONS: Our study has proven good specificity a negative predictive value of the actigraphic recording. To improve its sensitivity, we suggest to reduce the threshold of significant presence PLMS, as expressed by PLMI, from 5 to 3. Actigraphy seems to be a suitable method from PLMS screening in the general population for both clinical and research purposes.

The influence of the respiratory cycle on the EEG.

In order to evaluate the influence of the respiratory cycle on the EEG, we compared the power spectral analysis of the EEG performed by fast Fourier transformation during inspirium and exspirium in 10 healthy subjects. The measurement was performed during spontaneous breathing and then during eupnoe (0.25 Hz), bradypnoe (0.1 Hz) and tachypnoe (0.5 Hz) paced by a metronome. In the course of spontaneous breathing and bradypnoe, there was an increase in the delta power and in the total power in the anterior temporal region during inspirium in comparison with exspirium. The eupnoe was characterized by an inspiratory decrease in the delta power in the parietal region and in the total power in the frontal region. The tachypnoe resulted in a decrease of the beta power in the central region and a decrease of the theta power in the posterior temporal and in the occipital region during inspirium. In comparison of the EEG in eupnoe, bradypnoe and tachypnoe, a decrease of spectral power of all spectral bands was found except for delta during faster breathing frequencies and vice versa with a significant difference which was found mostly between bradypnoe and tachypnoe, less frequently between eupnoe and tachypnoe.

Restless legs syndrome in 2004.

The restless legs syndrome (RLS) is a sensorimotor disorder characterised by an intense urge to move the legs and sometimes also other parts of the body, and accompanied by a marked sense of discomfort or pain in the affected body parts. This urge has a circadian pattern - it is most pronounced in the evening or during the night. RLS symptoms are relieved by movement. The pathophysiology of RLS is related to dopamine transmission insufficiency, low iron storage in substantia nigra neurons, and spinal cord dysfunction. RLS is idiopathic or secondary (usually associated with iron deficiency, end-stage renal failure, pregnancy and spinal lesions). One half of the patients with idiopathic RLS have positive family history of RLS. RLS is curable, though the choice of therapy and proper dosage titration may take a long time, and though the therapy may sometimes have to be changed owing to augmentation. The most important pharmacologic treatment used in RLS includes L-DOPA, dopamine agonists, opiates, anticonvulsants and benzodiazepines. Therapy improves significantly the condition in long-term at least in 80% of RLS patients.

PXO set of recombinant inbred strains of the rat: a new strain distribution pattern containing 448 markers.

A new PXO set of RIS represents a fixed F2 population derived from polydactylous (P) congenic strain SHR.Lx and oligodactylous (O) RI strain BXH2. The PXO strains were derived as a complementary set to current RIS (HXB, BXH) of the laboratory rat. All PXO strains are homozygous in the Lx allele and express different morphological phenotypes of the polydactyly-luxate syndrome (PLS) due to variable combinations of Lx modifying genes of either SHR or BN origin. The SDP is being built up by genotyping polymorphic microsatellite markers and several gene polymorphisms. The markers were ordered according to data from public mapping resources such as the Rat Genome Database (rgd.mcw.edu) and current SDP of the other RI strain sets (HXB, BXH). The resulting map corresponding to the common SDP of HXB, BXH RIS sets consists of 448 markers, from which 261 were proven to be polymorphic in the PXO set. The SDP of PXO strains with polymorphic markers arranged in approximately 5 cM intervals is ready for the association analysis and interval mapping in interconnection with the SDP of HXB/BXH strains.