B-waves in healthy persons

Mautner, D.; Dirnagl, Ulrich; Haberl, R.; Schmiedek, Peter; Garner, C.; Villringer, Arno; Einhaeupl, K. M.

doi:10.1080/01616412.1989.11739891

Cited by 52 publications

(33 citation statements)

References 14 publications

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“…Originally, Lundberg (32) proposed that B-waves persisting for a long period probably always could be regarded as a sign of cerebral dysfunction, even though some of the recorded patients had a ICP Ͻ11 mmHg. B-waves have been reported to be frequent in hydrocephalus (3,7,10) but have also been reported in nonhydrocephalic patients with normal ICP (14,34) and in healthy individuals through study of middle cerebral artery oscillations by transcranial Doppler sonography (13,36,38). To our knowledge, this is the first study to report on B-waves measured directly in CSF in healthy young adults, indicating that B-waves should be regarded as a physiological phenomenon.…”

Section: Discussionmentioning

confidence: 89%

Spinal CSF absorption in healthy individuals

Edsbagge

Tisell

Jacobsson

et al. 2004

American Journal of Physiology-Regulatory, Integrative and Comp

143

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The present study examines the extent of spinal cerebrospinal fluid (CSF) absorption in healthy individuals in relation to physical activity, CSF production, intracranial pressure (ICP), and spinal CSF movement. Thirty-four healthy individuals aged 21-35 yr were examined by lumbar puncture and radionuclide cisternography with repeated imaging. ICP was registered before and after CSF drainage, and CSF production was calculated. Spinal CSF absorption was calculated as reduction in spinal radionuclide activity. The radionuclide activity in the spinal subarachnoidal space was gradually decreased by 20 Ϯ 13% (mean Ϯ SD) during 1 h. The reduction was higher in active than in resting individuals (27 Ϯ 12% vs. 13 Ϯ 9%). The mean ICP in 19 of the individuals was 13.6 Ϯ 3.1 cmH 2O. B-waves were found in 79% of the individuals, with a mean frequency of 0.6 Ϯ 0.3 min Ϫ1 . The mean CSF production rate was 0.34 Ϯ 0.13 ml/min. There were no correlations between radionuclide reduction, spinal movement of the radionuclide, and CSF production rate. The spinal radionuclide reduction found in this study indicates a spinal CSF absorption of 0.11-0.23 ml/min, more pronounced in active than in resting individuals. arachnoid villi; cerebrospinal fluid spinal flow; cerebrospinal fluid production; cerebrospinal fluid pressure; radionuclide imaging CEREBROSPINAL FLUID (CSF) is mainly produced in the choroid plexus in the lateral, third, and fourth ventricles, and a minor part is derived from the extracellular space of the brain (37). The CSF flows in a to-and-fro movement with a caudaldirected net flow through the aqueduct of Sylvius and foramina of Luschka and Magendie into the spinal subarachnoidal space (SAS) (39). The pulsative brain movements create a "mixing" of CSF in the fourth ventricle, basal cisterns, and upper spinal SAS (17, 23). Older radionuclide cisternographic (RC) studies have shown that radioactively labeled substances move upward when injected in the lumbar region (11) and downward when injected in the ventricles (12). Within the spinal SAS, a pulsatile to-and-fro flow with a caudal-directed net flow in the ventral and a cranial-directed net flow in the lateral cervical SAS has been reported (25, 42). However, the existence of a CSF bulk flow in any direction within the spinal SAS has been questioned, and RC and MRI observations could be explained by mere diffusion (22). The arachnoid villi in the superior sagittal sinus have generally been thought to be the main site for CSF absorption in humans (2, 40). However, lymphatic drainage pathways have been shown in animal studies to play an important role for CSF clearance (5,27,46). The existence of this pathway in humans remains unclear. Spinal CSF absorption through arachnoid granulations located along the nerve roots, morphologically similar to cranial villi, was suggested by Kido et al. (28), and CSF clearance from the spinal SAS has been demonstrated in sheep and cats (6, 31). The extent and importance of the spinal absorption pathway in humans remain unclear and, to ...

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Section: Discussionmentioning

confidence: 89%

Spinal CSF absorption in healthy individuals

Edsbagge

Tisell

Jacobsson

et al. 2004

American Journal of Physiology-Regulatory, Integrative and Comp

143

View full text Add to dashboard Cite

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“…It has also been proposed that B-waves may be physiological, since they were found in apparently healthy persons [27]. Furthermore, spontaneous rhythmic oscillations of cerebral blood flow velocity resembling B-waves were detected in healthy young persons [11, 13,28]. There is also disagreement about the diagnostic value of amplitude and morphology [6,7,19,36,38].…”

Section: Introductionmentioning

confidence: 97%

The relation of intracranial pressure B-waves to different sleep stages in patients with suspected normal pressure hydrocephalus

et al. 1995

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The interpretation of data from continuous monitoring of intracranial pressure (ICP) in patients with suspected normal pressure hydrocephalus (NPH) is the subject of controversy. Despite the fact that overnight ICP monitoring is widely used for the diagnosis of NPH, normative criteria are poorly defined. The present study demonstrates that there is a relationship between the relative frequency, the absolute amplitude, the wavelength and the morphology of B-waves and different sleep stages. Intraventricular intracranial pressure was recorded continuously overnight in 16 patients with suspected normal pressure hydrocephalus. Simultaneous polysomnography was performed to investigate the relation of spontaneous ICP oscillations to different sleep stages. A correlative analysis was done with the data of 13 patients. Three patients were excluded, one who was awake throughout the night and two in whom polysomnography was incomplete due to technical reasons. The mean resting cerebrospinal fluid (CSF) pressure was 12.87 cm CSF. B-waves were observed in the ICP recordings of all patients. They were present for a mean of 72% of the total recording time. The relative frequency of B-waves was higher during REM sleep and sleep stage 2 as compared to wakefulness (87.8% and 83.2% vs. 56. p < 0.05). The absolute amplitude was higher during REM sleep than in wakefulness (9.56 vs. 3.44 cm CSF, p < 0.05). Wavelengths were longer in REM sleep than in wakefulness and stages 1 and 2 (62.4 vs. 42, 40.7 and 44.8 sec, p < 0.05). The morphology of B-waves was also related to different sleep stages. Ramp-type B-waves were associated with REM sleep in six patients, however, were also present in sleep stage 2 in three of them. Knowledge of the relation of spontaneous ICP oscillations to different sleep stages may help to establish physiological foundations and alterations. Furthermore, polysomnography may be useful to avoid erroneous interpretation of ICP recordings due to sleep stage related variability.

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“…Our results of a missing decline in LF CBFV-O with increasing age as evidenced in this paper fit well into nonlinear control theory. In respect to adults, why then do especially older studies report missing LF CBFV-O except in REM sleep [7,8,13] while recent papers disagree [15,21]? The simple explanation is that former studies showing absent LF oscillations have been performed using suboptimal methodology as there is an inadequately short observation period of only 1 min [1] thus missing very low frequency components such as 1/min, and subjective visual evaluation instead of objective mathematical data analysis of the tracings [1,7,8] which are more or less superimposed by slow trends and artifacts resulting from hand-holding the probes and hence unstable probe fixation [7,8].…”

Section: Discussionmentioning

confidence: 99%

“…It was reported to decrease with increasing gestational age (GA) and postconceptional age (PCA) [6]. In adults it was not constantly found, and its occurrence rate was linked to sleep state, being highest during REM sleep [7,8,13,15,21]. The phenomenon of LF oscillating CBFV was interpreted as reflecting an underdamped immature AR [1], implicitly assuming a linear type control system for AR.…”

Section: Introductionmentioning

confidence: 97%

Cyclic variation pattern of cerebral blood flow velocity and postconceptional age

et al. 1994

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In preterm neonates, the risk for intracerebral haemorrhage is linked to immaturity of cerebral autoregulation. The preterm's 2-5/min cyclic variation pattern of cerebral blood flow velocity is thought to reflect the degree of immaturity of autoregulation--a speculation to be tested. In a cross-sectional study 15 infants (gestational age 26-40 weeks, postconceptional age (PCA) 26-42 weeks, age 1-99 days were investigated. We performed a 10 min pulsed Doppler tracing on an internal carotid artery by means of a computer controlled 5 MHz Duplex device. Systolic velocity (Vs) was recorded pulse by pulse. After appropriate data transformation, in all infants the Fast Fourier Transform of the time course of Vs revealed the presence of a 2-5/min cyclic variation pattern (one sample z-test, P < 0.0001). There was no significant correlation between proportionate spectral power of the 2-5/min frequency band and either PCA (r = 0.23, P = 0.42) or age (r = 0.41, P = 0.13). Between 26 and 42 weeks PCA, the cycling phenomenon is constant thus not reflecting cerebral maturation, and its presence does not mean immaturity of cerebral autoregulation.

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B-waves in healthy persons

Cited by 52 publications

References 14 publications

Spinal CSF absorption in healthy individuals

Spinal CSF absorption in healthy individuals

The relation of intracranial pressure B-waves to different sleep stages in patients with suspected normal pressure hydrocephalus

Cyclic variation pattern of cerebral blood flow velocity and postconceptional age

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