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P Busek

Publications and source records attributed to P Busek.

7 recordsLinked to original sources
PubMed2005

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.

Adult↗
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↗
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↗
PubMed2000

The influence of traumatic brain lesion on sleep architecture.

The authors deal with sleep changes in patients after brain injury. Ten patients were examined with the use of daytime routine EEG and night polysomnography. The amount of REM sleep is most sensitive to brain damage and is reduced in all patients with nonspecific epileptiform changes in the EEG. Changes in deep synchronous sleep are less frequent and are not in correlation with the prevalence of epileptiform changes. Thus the reduction of REM sleep seems to be a sensitive marker of development of epileptiform EEG-changes and perhaps could play a predictive role of development of post-traumatic epilepsy.

Adolescent↗
PubMed1999

[Sleep apnea syndrome in acromegaly. Treatment and development-- retrospective analysis].

In total 56 subjects with acromegaly (37 men and 19 females) were examined in attempt to find sleep apnoea syndrome (SAS). The examination consisted of clinical examination and of all-night monitoring MESAM4 or polyMESAM. The diagnosis of SAS was established in 76.4% of subjects: 31 men and 11 females, average age 51.8 (SD +/- 9.6) years. The average ODI (oxygen desaturation index--number of oxygen saturation drops per 1 hour of sleep) of SAS patients was 29.2 (+/- 20.7). The therapy of SAS was recommended to 27 patients: sleeping position on the side (3 patients), reduction of the weight (8 patients), change of hypnotic drug (1 patient) and CPAP--continuous positive airway pressure (24 patients). CPAP titration was performed in 18 patients (in one subject the titration was repeated 4 years later). CPAP was titrated within all-night polysomnography in 10 subjects and in 9 subjects using self adjusting CPAP. Primary acceptance of CPAP was 94.4%. The average CPAP pressure was 7.8 (+/- 2.1) mbar. The theoretical duration of CPAP use was 546.6 (+/- 533.7) days. Long term compliance was considered as sufficient (weekly 25 hours or more) in 66.7% of patients. Ten patients underwent important acromegaly therapy or its change during the follow up and the improvement or the disappearance of SAS symptoms occurred in 6 of them.

Acromegaly↗
PubMedDate not supplied

[Spectral analysis of the variations in heart rate and cardiac activation on waking up in sleepwalking].

INTRODUCTION: In sleepwalking, a disorder that is characterised by partial waking, the subject experiences an alteration of the microstructure of sleep that can affect autonomous activity during sleep and the waking state. AIMS: In order to evaluate any possible upset in the regulation of autonomous functioning in sleepwalkers during sleep and the waking state, we conducted a spectral analysis of their heart rate variability (HRV) during both sleep and the waking state. SUBJECTS AND METHODS: Spectral analysis of HRV was conducted in the group of 10 sleepwalkers and 10 normal controls during sleep and during the waking state in both the horizontal and vertical positions. Their pattern of cardiac activation was also analysed during different types of arousal. RESULTS: There were no differences between the group of sleepwalkers and the control group in the parameters used in the spectral analysis of HRV during sleep and in the horizontal position during the waking state. Sleepwalkers showed a greater shift in the sympathovagal balance in favour of sympathetic activity, as a response to standing. During the 5-minute sequences immediately before the start of pathological arousal in sleepwalkers, the total energy in the spectral analysis of HRV was seen to increase. No differences were found between the patterns of cardiac activation displayed by the groups of patients and normal subjects during several different types of arousal. CONCLUSIONS: Autonomous reactivity was seen to be altered as a response to the orthostatic load in sleepwalkers, which could be the consequence of the instability of these patients' sleep. The increase in the total energy in the spectral analysis of HRV immediately before pathological arousal during NREM 4 sleep in sleepwalkers suggests that autonomous activation precedes cortical arousal.

Adolescent↗