Two computerized methods used to analyze intracranial pressure B waves: comparison with traditional visual interpretation
2001 (English)In: Journal of Neurosurgery, ISSN 0022-3085, Vol. 94, no 3, 392-396 p.Article in journal (Refereed) Published
OBJECT: Slow and rhythmic oscillations in intracranial pressure (ICP), also known as B waves, have been claimed to be one of the best preoperative predictive factors in idiopathic adult hydrocephalus syndrome (IAHS). Definitions of B waves vary widely, and previously reported results must be treated with caution. The aims of the present study were to develop a definition of B waves, to develop a method to estimate the B-wave content in an ICP recording by using computer algorithms, and to validate these procedures by comparison with the traditional visual interpretation. METHODS: In eight patients with IAHS, ICP was continuously monitored for approximately 20 hours. The ICP B-wave activity as a percentage of total monitoring time (B%) was estimated by using visual estimation according to the definition given by Lundberg, and also by using two computer algorithms (Methods I and II). In Method I each individual wave was classified as a B wave or not, whereas Method II was used to estimate the B-wave content by evaluating the B-wave power in 10-minute blocks of ICP recordings. CONCLUSIONS: The two computerized algorithms produced similar results. However, with the amplitude set to 1 mm Hg, Method I yielded the highest correlation with the visual analysis (r = 0.74). At least 5 hours of monitoring time was needed for an acceptable approximation of the B% in an overnight ICP recording. The advantages of using modern technology in the analysis of B-wave content of ICP are obvious and these methods should be used in future studies.
Place, publisher, year, edition, pages
2001. Vol. 94, no 3, 392-396 p.
IdentifiersURN: urn:nbn:se:umu:diva-4544DOI: 10.3171/jns.2001.94.3.0392PubMedID: 11235941OAI: oai:DiVA.org:umu-4544DiVA: diva2:143687