Biomedical subjects

A Wichniak

Publications and source records attributed to A Wichniak.

5 recordsLinked to original sources

PubMed2006

The incidence of sleep apnea in patients with stroke or transient ischemic attack.

Disorders of breathing during sleep are defined as cessation or reduction of air flow thorough the upper airway, accompanied by a decrease of oxygen saturation. The results of many studies underline the association between sleep-disordered breathing (SDB) and cerebrovascular disorders. SDB, mostly obstructive sleep apnea syndrome (OSAS), is believed to be an independent risk factor of stroke and is related to poor outcome and increased long-term stroke mortality. The present study evaluated the frequency of SDB in patients with stroke or transient ischemic attack transient ischemic attack. We studied 43 patients (mean age 68.5 +/-11.0), which included 35 males and 8 females, with acute stroke (n=37) and transient ischemic attack (n=6). The assessment included body mass index (BMI), age, cardiovascular risk factors, and localization of stroke. All patients underwent all-night screening for SDB with a portable 8-channel recorder. The apnea/hypopnea index (AHI) for the whole group was 13.3 +/-15.2. AHI <5 was found in 16 patients. Overall, SDB was present in 27 (62.8%) patients with stroke and transient ischemic attack, stratified into those with AHI 5-10, (10 patients), 10-20 (8 patients), and AHI>20 (9 patients). In 15 patients, there was an increase in AHI >or=5 on assuming the supine position. The patients' mean BMI was 27.8 +/-4.7. The analysis of BMI, age, and localization of stroke was not sufficient to identify patients with high risk for SDB. We submit that overnight screening for SDB should be routinely performed in every patient after stroke and transient ischemic attack and it should become a diagnostic tool in neurological departments.

Aged↗

PubMed2003

Spectral composition of NREM sleep in healthy subjects with moderately increased daytime sleepiness.

OBJECTIVE: This study addressed the relationship between daytime sleepiness and spectral composition of the preceding NREM sleep. METHODS: Nineteen healthy volunteers (mean age: 36.5 years; SD: 10.1) underwent polysomnography during two consecutive nights and the multiple sleep latency test (MSLT) on the following day. Daytime sleepiness was also assessed by the Epworth sleepiness scale (ESS). The sleep recordings were visually scored according to standard criteria. The quantitative sleep EEG analysis was performed using a fast Fourier transform routine. The sleep parameters were compared between subjects with short and long MSLT sleep latencies (cut-off=10 min) and between subjects with low and high ESS scores (cut-off=6 points). RESULTS: Subjects with short MSLT sleep latencies showed a reduced theta EEG activity. There was no evidence of reduced synchronization of sleep EEG in subjects with high ESS scores. CONCLUSIONS: Moderately increased daytime sleepiness as indicated by MSLT sleep latency less than 10 min is accompanied by decreased power of theta activity during NREM sleep indicating a deficit of sleep EEG synchronization.

Adult↗

PubMed2002

Ghrelin promotes slow-wave sleep in humans.

Ghrelin, an endogenous ligand of the growth hormone (GH) secretagogue (GHS) receptor, stimulates GH release, appetite, and weight gain in humans and rodents. Synthetic GHSs modulate sleep electroencephalogram (EEG) and nocturnal hormone secretion. We studied the effect of 4 x 50 microg of ghrelin administered hourly as intravenous boluses between 2200 and 0100 on sleep EEG and the secretion of plasma GH, ACTH, cortisol, prolactin, and leptin in humans (n = 7). After ghrelin administration, slow-wave sleep was increased during the total night and accumulated delta-wave activity was enhanced during the second half of the night. Rapid-eye-movement (REM) sleep was reduced during the second third of the night, whereas all other sleep EEG variables remained unchanged. Furthermore, GH and prolactin plasma levels were enhanced throughout the night, and cortisol levels increased during the first part of the night (2200-0300). The response of GH to ghrelin was most distinct after the first injection and lowest after the fourth injection. In contrast, cortisol showed an inverse pattern of response. Leptin levels did not differ between groups. Our data show a distinct action of exogenous ghrelin on sleep EEG and nocturnal hormone secretion. We suggest that ghrelin is an endogenous sleep-promoting factor. This role appears to be complementary to the already described effects of the peptide in the regulation of energy balance. Furthermore, ghrelin appears to be a common stimulus of the somatotropic and hypothalamo-pituitary-adrenocortical systems. It appears that ghrelin is a sleep-promoting factor in humans.

Adrenocorticotropic Hormone↗

PubMed2001

Rhythmic feet movements while falling asleep.

During the wake-sleep transition and sleep, diverse motor phenomena such as hypnagogic foot tremor may occur in the lower extremities. We investigated the relevance of this phenomenon in 375 consecutive subjects examined polysomnographically in a sleep disorders center. Rhythmic feet movements while falling asleep (RFM) were found in 28 subjects (7.5%). RFM occurred mostly as single, short series with a duration of between 10 and 15 seconds. They had a high night-to-night variability and were detected as rhythmic, oscillating movements of the whole foot or toes. Surface electromyographic (EMG) recordings displayed series of repetitive phasic bursts with a periodicity mostly between 1 and 2 per second. Single EMG burst duration varied between 300 and 700 msec. RFM at highest intensity occurred during presleep wakefulness, and usually persisted in sleep stages 1 and 2. RFM did not have a major sleep-disturbing effect in any of the affected subjects. Due to its high prevalence and the lack of a major sleep-disturbing effect, short series of RFM could be considered a quasiphysiological phenomenon. However, in more severe forms of RFM with evidence of a sleep-disturbing effect, RFM should be considered abnormal.

Adolescent↗

PubMed2000

Comparison between eye movement latency and REM sleep parameters in major depression.

Alterations of sleep can be observed polysomnographically in approximately 90 percent of depressed patients. Most of the registered sleep abnormalities in depression also occur in other psychiatric disorders. Only some types of REM sleep alterations-- short REM latency, increase of REM density and shortening of mean latency of eye movements--were reported as more specific for affective disorders. In the present study polysomnograms of 21 medication free patients with major depressive disorder (assessed with a structured interview for DSM-III-R and Hamilton Scale) and 21 healthy controls were analysed. REM latency (LREM), REM density (RD), latencies of eye movements (LEM) and mean latency of eye movements (M-LEM) were calculated for both groups. Depressed patients (compared with healthy controls) showed increased RD (38.2% vs. 28.2%, p < 0.0001), shortened M-LEM (35.7 s vs. 48.3 s, p < 0.04) and shortening of LEM in the 1st (28.9 s vs. 48.9 s, p < 0.007) and 4th (27.0 s vs. 59.1 s, p < 0.043) REM sleep periods. LREM was not shortened significantly in depressives (78.5 min vs. 91.3 min, ns). In healthy subjects a negative correlation between M-LEM and RD was found (rho = -0.47, p < 0.03). Since in the current study depressed patients differed from healthy controls, especially concerning phasic activity during REM sleep, presented data support the essential role of REM density for the assessment of sleep in depression. As a quick and easy manner to compute measurement, M-LEM is suggested as additional parameter for the assessment of phasic activity during REM sleep.

Adult↗