B waves: a systematic review of terminology, characteristics, and analysis methods.

BACKGROUND: Although B waves were introduced as a concept in the analysis of intracranial pressure (ICP) recordings nearly 60 years ago, there is still a lack consensus on precise definitions, terminology, amplitude, frequency or origin. Several competing terms exist, addressing either their probable physiological origin or their physical characteristics. To better understand B wave characteristics and ease their detection, a literature review was carried out. METHODS: A systematic review protocol including search strategy and eligibility criteria was prepared in advance. A literature search was carried out using PubMed/MEDLINE, with the following search terms: B waves + review filter, slow waves + review filter, ICP B waves, slow ICP waves, slow vasogenic waves, Lundberg B waves, MOCAIP. RESULTS: In total, 19 different terms were found, B waves being the most common. These terminologies appear to be interchangeable and seem to be used indiscriminately, with some papers using more than five different terms. Definitions and etiologies are still unclear, which makes systematic and standardized detection difficult. CONCLUSIONS: Two future lines of action are available for automating macro-pattern identification in ICP signals: achieving strict agreement on morphological characteristics of "traditional" B waveforms, or starting a new with a fresh computerized approach for recognition of new clinically relevant patterns.

[A foreign object in the frontal lobe].

In this case report a 77-year-old male tumbled in his lavatory and hit his head against a toilet roll holder. The holder penetrated his eye and orbita and left a 0.5 × 1 cm cylindrical piece of plastic inside his frontal lobe. He was admitted at a neurosurgical department, where the foreign object was removed. In this report, we summarise some of the basic principles of handling patients with a penetrating brain trauma, including risk of infection, control of bleeding and technical considerations before surgically removing a foreign object.