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Background: Subarachnoid haemorrhage (SAH) is one of the most severe forms of stroke in which delayed cerebral ischemia is one of the major complications. Neurointensive care aims at preventing and treating such complications and identification of biomarkers of early signs of ischemia might therefore be helpful., Methods: We aimed at describing proteome profile in cerebral microdialysate in four patients with aneurysmal SAH using two dimensional gel electrophoresis in combination with mass spectrometry in search for new biomarkers for delayed cerebral ischemia and to investigate if there were temporal fluctuations in those biomarkers over time after aneurysmal bleed., Results: The results showed transthyretin in nine different proteoforms (1001, 1102, 2101, 3101, 4101, 4102, 5001, 5101, 6101) in cerebral microdialysate samples from four patients having sustained SAH. Several proteoforms show highly differing levels and pooled analysis of all samples showed varying optical density related to time from aneurysmal bleed, indicating a temporal evolution., Conclusions: Transthyretin proteoforms have not earlier been shown in cerebral microdialysate after SAH and we describe differing levels based on proteoform as well as time from subarachnoid bleed. Transthyretin is well known to be synthetized in choroid plexus, whilst intraparenchymal synthesis remains controversial. The results need to be confirmed in larger studies in order to further describe transthyretin., (© 2023. The Author(s).)

Traumatic brain injury (TBI) is the leading cause of death among the young, and has an increasing incidence among the elderly. In Sweden there are 20 000 new TBI cases each year, of which most are mild. The primary impact can lead to different types of brain hemorrhages, fractures and diffuse axonal injuries. The level of consciousness is used to define injury severity. Of all TBIs,  4-5 percent require surgical intervention. The primary impact initiates injury processes exacerbating the initial brain injury, and the goal of the acute management and neurointensive care treatment is to prevent these secondary insults. Among unconscious TBI patients, monitoring of intracranial pressure and cerebral perfusion pressure (CPP, defined as the difference between the mean arterial pressure and intracranial pressure) is routine. In this article we present an overview on different types of TBI, and describe the treatment of patients in the acute setting.

Cerebral blood flow is monitored in the neurointensive care unit (NICU) to avoid further brain damage caused by secondary insults following subarachnoid hemorrhage and brain trauma. Current techniques are mainly snap-shot based and focus on larger vessels. However, continuous monitoring of the smaller vessels may help detect the onset of secondary insults at an earlier stage. In this study, long-term measurements of brain microcirculation with laser Doppler flowmetry (LDF) were performed and evaluated. The aim was to identify and describe physiological signal variations and separate these from movement artifacts. Fiberoptic probes for subcortical LDF recordings of perfusion and total light intensity (TLI) were implanted in three patients with subarachnoid hemorrhage. Data were successfully collected and visualized in real-time over 4 days, resulting in 34, 12, and 8.5 h per patient. Visual observation, wavelet transforms, moving medians, and peak envelopes were used to identify and describe movement artifacts and physiological changes. Artifacts occurred in <5% of the total recording time and could be identified through signal processing. Identified physiological signal patterns included a slowly increasing perfusion trend over hours, vasomotion mainly at 2 cycles/min both in the perfusion and the TLI, and rapid, synchronized changes in the TLI and the perfusion on 38 occasions. Continuous LDF recordings indicating changes in the microvascular blood flow can increase the understanding of the microcirculation in the injured brain. In the long run, this may become a complement for the detection of secondary insults at an earlier stage than possible with today's techniques., Competing Interests: Author KW has shares in FluoLink AB. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Mauritzon, Ginstman, Hillman and Wårdell.)