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Biomedical subjects

S Nevsímalová

Publications and source records attributed to S Nevsímalová.

At least 19 recordsLinked to original sources
PubMed2005

[Heart rate variability during sleep].

BACKGROUND: Changes in the tone of the autonomic nervous system during sleep occur and characterize individual sleep stages and probably also sleep cycles. The spectral analysis of the heart rate variability (SA HRV) is a tool for exact assessment of autonomic nervous activity giving us precise information on the activity of the autonomic nervous system--on its sympathetic and parasympathetic component. METHODS AND RESULTS: All night polysomnographic recording was performed in 11 healthy subjects, during which the SA HRV was carried out. The total spectral power of the heart rate variability and relative values of its individual components were evaluated: the very low frequency component (VLF), the low frequency component (LF), and high frequency component (HF). The absolute value of the RR-interval duration was assessed. The LF spectral band in normalized units was significantly higher during REM sleep than in non-REM sleep. On the other hand, the HF spectral band in normalized units was significantly higher during non-REM sleep compared to REM sleep. The LF/HF ratio, which reflects the sympathovagal balance, had a maximal value during REM sleep and reached its minimum in non-REM sleep. A gradual lengthening of the RR-interval and lowering of the LF/HF ratio during night was observed. CONCLUSIONS: The SA HRV showed to be a sensitive method for detection of activity of the autonomic nervous system during sleep. The sympathovagal balance was shifted to prevailing sympathetic activity in REM sleep. On the contrary, during non-REM sleep this balance was shifted towards prevailing parasympathetic influence. A gradual increase of parasympathetic influence during night was also observed.

Adolescent↗
PubMed2005

[Periodic limb movements in sleep: polysomnographic and actigraphic methods for their detection].

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.

Electromyography↗
PubMed2005

[Alternating hemiplegia of childhood (AHC)].

BACKGROUND: Alternating hemiplegia of childhood (AHC) is a rare neurological disease of unknown aetiology characterized by recurrent paroxysmal attacks of side-alternating hemiplegias of variable duration associated with other paroxysmal dysfunctions. Paroxysmal attacks start in infants but neurological deficits become progressive with the age. METHODS AND RESULTS: During the last 20 years 8 patients (5 boys, 3 girls) with AHC were followed. Mean age at the time of diagnosis was 2.75 years, age range 2-5 years; mean follow up period 13.9 years (range 1 month-20 years) The diagnosis was based on clinical history and neurological findings, completed by neurophysiological and neuroimaging methods (SPECT, PET), and results of psychological and biochemical findings. Paroxysmal phenomena (occulo-motor, tonic, choreo-athetotic, autonomic) appearing at the age of 4.1 +/- 2.2 months and followed by repeated attacks of hemiplegia (age onset 16.3 +/- 13.0 months) were the first symptoms. Progressive neurological impairment covering spasticity, dyskinetic syndrome, cerebellar ataxia and intellectual deficit was present in all cases, epileptic seizures in 7 out of 8 patients. On ictal SPECT/PET examination hypoperfusion/glucose hypometabolism were demonstrated above affected hemispheres including basal ganglia, both thalami and cerebellar hemispheres. Improvement of hemiparesis was illustrated by nocturnal videomonitoring. CONCLUSIONS: AHC is a chronic disease with progressive neurological deficit. A flunarizine therapy has a favorable effect on frequency and severity of paroxysmal attacks, but does not prevent a progressive neurological impairment.

Child, Preschool↗
PubMed2004

Spectral analysis of the heart rate variability in sleep.

Spectral analysis of heart rate variability (HRV) during overnight polygraphic recording was performed in 11 healthy subjects. The total spectrum power, power of the VLF, LF and HF spectral bands and the mean R-R were evaluated. Compared to Stage 2 and Stage 4 non-REM sleep, the total spectrum power was significantly higher in REM sleep and its value gradually increased in the course of each REM cycle. The value of the VLF component (reflects slow regulatory mechanisms, e.g. the renin-angiotensin system, thermoregulation) was significantly higher in REM sleep than in Stage 2 and Stage 4 of non-REM sleep. The LF spectral component (linked to the sympathetic modulation) was significantly higher in REM sleep than in Stage 2 and Stage 4 non-REM sleep. On the contrary, a power of the HF spectral band (related to parasympathetic activity) was significantly higher in Stage 2 and Stage 4 non-REM than in REM sleep. The LF/HF ratio, which reflects the sympathovagal balance, had its maximal value during REM sleep and a minimal value in synchronous sleep. The LF/HF ratio significantly increased during 5-min segments of Stage 2 non-REM sleep immediately preceding REM sleep compared to 5-min segments of Stage 2 non-REM sleep preceding the slow-wave sleep. This expresses the sympathovagal shift to sympathetic predominance occurring before the onset of REM sleep. A significant lengthening of the R-R interval during subsequent cycles of Stage 2 non-REM sleep was documented, which is probably related to the shift of sympathovagal balance to a prevailing parasympathetic influence in the course of sleep. This finding corresponds to a trend of a gradual decrease of the LF/HF ratio in subsequent cycles of Stage 2 non-REM sleep.

Adolescent↗
PubMed2002

[Excessive daytime somnolence and its psychosocial sequelae].

Excessive daytime sleepiness arises frequently as a consequence of insufficient or shortened nocturnal sleep, or as a result of poor sleeps hygiene. One of the most common dyssomnias with imperative sleepiness is narcolepsy. Narcolepsy is a chronic disease that greatly affects quality of life. The present study of 57 patients shows that the negative assessment is partly due to the subjective views exhibited by the narcoleptic personality prone to underestimation, negative self-image and depressive disposition. The personality traits may be due to an adaptation reaction to the disease but also to the biological predisposition. Comparison with population data for our Republic brought no evidence of progress at education or family life being adversely affected by narcolepsy, however, decreased assertion in employment and limitation in self-realization in free time was an explicit consequence of the disease. All 57 patients reported excessive daytime sleepiness as the most discomforting symptom that in 40% of them was responsible for career curtailment in a productive age and for living on partial or full disability.

Adolescent↗
PubMed2001

Increased REM density in narcolepsy-cataplexy and the polysymptomatic form of idiopathic hypersomnia.

The present work is focused on REM sleep density in patients with primary hypersomnia in comparison with non-hypersomnia subjects. 28 unmedicated patients with narcolepsy-cataplexy (NC) and 10 unmedicated patients suffering from the polysymptomatic form of idiopathic hypersomnia (IH) and their age- and sex-matched controls were included in the study. The clinical diagnosis was confirmed by MSLT and nocturnal PSG, HLA typing was performed in a respective group of narcoleptic patients. Polygraphical recordings were visually scored with particular regard to the two most characteristic phasic features of REM sleep: the number of rapid eye movements (REMs) and chin muscle twitches (Tws) per minute. These events were evaluated according to recognized criteria; a closer look was taken at both their frequency and their distribution across all the nocturnal REM periods (REMPs). The following main differences between hypersomniac patients (of both groups examined) and healthy controls were found in terms of phasic activity: (I) REM density (expressed in REMs/min and Tws/min in each REM period) was significantly increased in the hypersomniac patients in comparison with the controls. (p>0.05).(II) The intra-night phasic activity distribution was found rising more conspicuously in the hypersomniacs than in the controls.

Adult↗
PubMed2001

[Analysis of the most frequent mutations in girls with Rett syndrome].

BACKGROUND: Rett syndrome is an X-linked dominant neurodevelopmental disorder affecting 1 from 10,000 to 15,000 females worldwide. The responsible gene, encoding methyl-CpG binding protein 2 was recently identified. Methyl-CpG binding protein 2 is thought to act as a global transcriptional repressor. In the methyl-CpG binding protein 2 gene are known 5 prevalent mutations that cause Rett syndrome. Four of them are detectable by restriction analysis. In this study we present the results of the molecular study of four prevalent mutations in the gene for methyl-CpG binding protein 2 in Czech and Slovak patients with Rett syndrome. METHODS AND RESULTS: 22 females with Rett syndrome were investigated by methods of molecular biology. Restriction analysis and direct sequencing of PCR products revealed in methyl-CpG binding protein 2 gene 3 different mutations (T158M, R168X, R270X) in six unrelated patients with Rett syndrome. Mutation R306C, frequent in Great Britain and Sweden, was not detected in our group of patients with Rett syndrome. CONCLUSIONS: The diagnosis of Rett syndrome and genetic counselling in affected families should go out from the close cooperation of the pediatric, neurologic, and genetic departments with the specialized laboratories dealing with the molecular biological diagnosis.

Adolescent↗
PubMed2001

Electromagnetic field of mobile phones affects visual event related potential in patients with narcolepsy.

The effects of the mobile phone (MP) electromagnetic fields on electroencephalography (EEG) and event-related potentials (ERP) were examined. With regard to the reported effects of MP on sleep, 22 patients with narcolepsy-cataplexy were exposed or sham exposed for 45 min to the MP (900 MHz, specific absorption rate 0.06 W/kg) placed close to the right ear in a double blind study. There were no changes of the EEG recorded after the MP exposure. A subgroup of 17 patients was studied on visual ERP recorded during the MP exposure. Using an adapted "odd-ball" paradigm, each patient was instructed to strike a key whenever rare target stimuli were presented. There were three variants of target stimuli (horizontal stripes in (i) left, (ii) right hemifields or (iii) whole field of the screen). The exposure enhanced the positivity of the ERP endogenous complex solely in response to target stimuli in the right hemifield of the screen (P < 0.01). The reaction time was shortened by 20 ms in response to all target stimuli (P < 0.05). In conclusion, the electromagnetic field of MP may suppress the excessive sleepiness and improve performance while solving a monotonous cognitive task requiring sustained attention and vigilance.

Brain Mapping↗
PubMed2000

[Prevalence of obesity, hypertension and smoking in patients with the sleep apnea syndrome--comparison with the Czech population].

BACKGROUND: Sleep apnoea syndrome (SAS) is an serious disease increasing morbidity and mortality. SAS is often associated with cardiovascular diseases. This retrospective study is focused on the prevalence of selected risk factors of ischemic heart disease. METHODS AND RESULTS: The comparison of BMI, prevalence of obesity, hypertension and smoking was performed in 356 patients with SAS (287 men, 69 women, age 25-64 years) and 2353 persons--representing 1% of Czech population (WHO project MONICA). T-test was used for statistical analysis of BMI and chi-square test for obesity, hypertension and smoking prevalence. Groups of patients and the MONICA group were stratified by age into 4 subgroups. Statistical significant difference was found in BMI and obesity prevalence in men in all age subgroups. Men aged 35-64 years differed in systemic hypertension prevalence (p < 0.001) and in age subgroups of 45-64 years in smoking prevalence (p < 0.001). Females aged subgroups of 35-54 years differed significantly in BMI (p < 0.001) and in age subgroups of 45-54 years in hypertension (p < 0.01). CONCLUSIONS: Higher prevalence of obesity, hypertension, and smoking were found in patients with SAS compared to non-selected Czech population.

Adult↗
PubMed2000

Seizures in sleep apnea patients: occurrence and time distribution.

A retrospective survey of consecutive 480 adult patients (394 men, 96 women, mean age 50.3, SD +/- 10.4 years) with sleep apnea syndrome (SAS) was made in attempt to find out among them the patients with epilepsy. In total 19 subjects (17 men, 2 women, average age 55.8 +/- 8.7 years) representing 4.0% experienced at least two seizures in adult age. The average age at the first seizure was 48.4 +/- 16.1 years. Ten subjects suffered from primarily generalized tonic-clonic seizures, seven from secondarily generalized tonic-clonic seizures, one had complex partial seizures and one simple partial seizures. In 15 subjects (78.9%) the seizures occurred exclusively during sleep. Two patients (11.1%) had seizures exclusively during vigilance and in remaining two subjects the seizures occurred during sleep and vigilance. The findings of high proportion of subjects with epilepsy among SAS subjects, of late seizure onset and of predominantly sleep occurrence of seizures suggest that sleep apnea and hypopnea can facilitate epileptic seizures.

Epilepsy↗
PubMed2000

[Sleep disorders and the 24-hour profile of melatonin and cortisol].

The aim of our study was to assess the prevalence of the specific disorders of the circadian rhythm of cortisol and melatonin in the patients with sleep disorders. The group of our patients consisted of 93 persons (25 men, 68 women), from 4-72 years (mean age 38.3 years) with a sleep disorders. These patients were studied on Department of Neurology of 1st Medical Faculty of Charles University in Prague during years 1997-1999. Patients were divided by the clinical diagnosis into many subgroups: idiopathic hypersomnia (IH) 24 patients and other hypersomnias 8, narcolepsy 22, degenerative disorders 9, delay sleep phase syndrome (DSPS) 7, periodic leg movements syndrome (PLMS) 6, insomnia 7 and Parkinson's disease 10 patients. Twelve salivary samples were taken from each patient during a period of 24 hours in order to investigate the circadian secretion pattern of melatonin and cortisol. Salivary melatonin and cortisol levels were estimated by radioimmunoassay in the Department of Physiology of the Academy of Science, Czech Republic. Significant differences were found between our patients and the control group in idiopathic hypersomnia--acrophase of melatonin was delayed and secretion was prolonged. Patients suffered from narcolepsy often displayed multiple peak of melatonin secretion. The peak of the melatonin concentration occurred later in DSPS (non significantly). Low level of melatonin and prolonged signal of melatonin was in Parkinson's disease patients.

Adolescent↗
PubMed2000

[Hypocretin (orexin) deficiency in narcolepsy-cataplexy].

A mutation in the HCRT locus was proved in 18-yrs old male suffering from narcolepsy-cataplexy. He has demonstrated cataplectic attacks (brief spells of head dropping provoked by laughter) as well as imperative sleep in spells of several minutes up to one hour since the age of six months. He has suffered from severe bulimia since five years; later hypnagogic hallucinations, sleep paralysis and unquiet nocturnal sleep accompanied by periodic limb movements appeared. Symptoms are partially controlled with methylphenidate and either imipramine, clomipramine or fluoxetine. Periodic leg movements poorly responded to L-DOPA and clonazepam treatment. He is HLA-DQB1*0602 negative. Repeated MSLT (over 16 years followed-up period) showed extremely short latency with predominant SOREMPs and also nocturnal PSG recordings revealed fragmented sleep with SOREMPs. This case report demonstrates that hypocretin (orexin) mutations in human can produce the full narcolepsy phenotype and validates data recently reported in dog and mouse models suggesting a role for hypocretin (orexin) in the pathophysiology of narcolepsy and the regulation of REM sleep.

Adolescent↗
PubMed1997

Neuronal ceroid lipofuscinosis in the Czech Republic: analysis of 57 cases. Report of the 'Prague NCL group'.

A series of 57 patients (from 51 families) with neuronal ceroid lipofuscinosis (NCL) has been diagnosed during the last 25 years. Using clinical and electrophysiological criteria together with results of ultrastructural, histochemical, immunohistochemical and neuropathological analyses it has been possible to classify the following NCL types. Two cases were of the infantile type (CLN1), one case of the juvenile (CLN3) type and one case of the adult (CLN4) type. The bulk of the series was represented by 26 cases of the late infantile (CLN2) type and by 27 cases of the early juvenile (CLN6) type (also called non-Finnish variant late infantile, or Lake-Cavanagh). Besides the infantile form, microcephaly was a relatively frequent finding (nine cases) in the late infantile and early juvenile NCLs. In more than half of the late infantile and early juvenile cases there was a significant reduction of the nerve conduction velocity. The early juvenile CLN6 type was found to have a relatively high incidence in the Romany population (12 cases in nine families). Incidence of NCL in the Czech republic is estimated to be 1.3:100,000.

Adolescent↗
PubMed1997

Familial aspects of narcolepsy-cataplexy in the Czech Republic.

A group of 153 probands with narcolepsy included 38 subjects (24.8%) with a familial incidence of excessive daytime sleepiness (EDS). In 15 cases (9.8%), at least one additional family member suffered from narcolepsy-cataplexy; only EDS was present in the remaining 23 cases (15.0%). One thousand eighty-two relatives were evaluated. The percentage of first degree relatives affected with narcolepsy-cataplexy was 2.28% (1.20% if only clinically confirmed cases were accounted); the adequate value for second degree relatives was 1.49%. The occurrence of EDS exceeded these values several times (4.28% in first degree relatives, 6.57% in second degree relatives). The vertical mode of transmission was found in most families. Human leukocyte antigen (HLA) typing was performed in six families with multiple-case incidence of narcolepsy. Forty-one blood samples were analyzed (12 patients with narcolepsy, 7 with only EDS, 2 with sleep apnea syndrome, and 20 healthy relatives). HLA DR2+ and DQB1*0602+ were found in only 8 out of 12 narcoleptic patients with cataplexy and in six out of seven patients with isolated attacks of sleepiness. These findings support the hypothesis that there is a common genetic basis for narcolepsy associated with cataplexy and "monosymptomatic" forms of narcolepsy and suggest the existence of non-major histocompatibility complex (MHC) susceptibility factors for narcolepsy.

Adolescent↗