Low frequency pressure waves of possible autonomic origin in severely head-injured children

  • R. A. Minns
  • P. A. Jones
  • I. R. Chambers
Part of the Acta Neurochirurgica Supplementum book series (NEUROCHIRURGICA, volume 102)

Background Useful information (both clinical and patho-physiological) which may be extracted from intracranial pressure (ICP) recordings include: (1) the mean level of ICP (and CPP), (2) cerebrovascular autoregulation status, (3) the intracranial pulse pressure (the pulse wave index, ICPpp/ICPm) or the pressure-volume compensatory reserve index (RAP) and (4) the presence of any abnormal ICP waveform. This paper describes a slow frequency ICP waveform in children with TBI and postulates the patho-physiological basis and whether it contains clinically useful detail.

Methods Children admitted to the Regional Head Injury Service in Edinburgh with TBI have continuously monitored ICP, MAP, CPP, and other physiological data (stored at a 1-min resolution). Slow frequency waveforms were noted, prompting a review of the stored monitoring from all cases over a 10 year period.

Findings Episodic slow pressure waves were detected in 11 of 122 severely head-injured (HI) children The waveforms were detected in children of all ages (1.6–15 years) in the ICP signal, which were in phase with similar fluctuations in the MAP, CPP, and HR signals Their mean periodicity was 1 per 7 min (range 1 per 5–10 min), with a mean ICP pulse wave amplitude of 5.45 mmHg (range 4–7.5), and mean MAP pulse wave amplitude (pulse pressure) of 10.4 mmHg (range 4–15 mmHg). The duration was variable (range approx 2 h to 4.5 days). They were detected in the pre-terminal phase after serious HI, as well as in those children who made an independent recovery (GOS 4/5). The waves were not related to the mean levels of ICP, CPP, MAP, temperature or the state of cerebrovascular autoregulation.

Conclusions We postulate that these previously unreported slow waveforms may reflect the very low frequency (VLF) and ultra low frequency (ULF; ≤1 per 5 min) components of heart rate and arterial blood pressure variability.


Pressure waves ICP Ultra low frequency Head injury 


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  1. 1.
    Biswas AK, Scott WA, Sommerauer JF, Luckett PM (2000) Heart rate variability after acute traumatic brain injury in children. Crit Care Med 28(12):3907–3912PubMedCrossRefGoogle Scholar
  2. 2.
    Cunningham S, Deere S, McIntosh N (1993) Cyclical variation of blood pressure and heart rate in neonates. Arch Dis Child 69 (1 Spec No):64–7PubMedCrossRefGoogle Scholar
  3. 3.
    Di Rienzo M, Castiglioni P, Parati G, Frattola A, Mancia G, Pedotti A (1992) Role of arterial baroreflex in producing the 1/f shape of systolic blood pressure and heart rate spectra. 283– 286Google Scholar
  4. 4.
    Eckberg DL, Kuusela TA (15-9-2005) Human vagal baroreflex sensitivity fluctuates widely and rhythmically at very low frequencies. J Physiol 567(Pt 3):1011–1019Google Scholar
  5. 5.
    Howells TP (1994) Edinburgh monitor and browser. Computer Program (v1.4)Google Scholar
  6. 6.
    Kawahara E, Ikeda S, Miyahara Y, Kohno S (2003) Role of autonomic nervous dysfunction in electrocardio-graphic abnormalities and cardiac injury in patients with acute subarachnoid hemorrhage. Circ J 67(9):753–756PubMedCrossRefGoogle Scholar
  7. 7.
    Kitney RI (1974) The analysis and simulation of the human thermoregulatory control system. Med Biol Eng 12(1):57–65CrossRefGoogle Scholar
  8. 8.
    Kobayashi M, Musha T (1982) 1/f fluctuation of heartbeat period. IEEE Trans Biomed Eng 29(6):456–7PubMedCrossRefGoogle Scholar
  9. 9.
    Marsh DJ, Osborn JL, Cowley AW Jr. (1990) 1/f fluctuations in arterial pressure and regulation of renal blood flow in dogs. Am J Physiol 258(5 Pt 2):F1394–400PubMedGoogle Scholar
  10. 10.
    Rapenne T, Moreau D, Lenfant F, Vernet M, Boggio V, Cottin Y, Freysz M (2001) Could heart rate variability predict outcome in patients with severe head injury? A pilot study [see comment]. J Neurosurg Anesthesiol 13(3):260–268PubMedCrossRefGoogle Scholar
  11. 11.
    Togo F, Kiyono K, Struzik ZR, Yamamoto Y (2006) Unique very low-frequency heart rate variability during deep sleep in humans. IEEE Trans Biomed Eng 53(1):28–34PubMedCrossRefGoogle Scholar

Copyright information

© Springer-Verlag/Wien 2008

Authors and Affiliations

  • R. A. Minns
    • 1
    • 2
  • P. A. Jones
    • 1
  • I. R. Chambers
    • 3
  1. 1.Child Life and HealthUniversity of EdinburghEdinburghUK
  2. 2.Royal Hospital for Sick ChildrenEdinburghUK
  3. 3.Regional Medical Physics DepartmentThe James Cook University HospitalMiddlesbroughUK

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