AUTHOR=Carteron Laurent , Patet Camille , Solari Daria , Messerer Mahmoud , Daniel Roy T. , Eckert Philippe , Meuli Reto , Oddo Mauro 

TITLE=Non-Ischemic Cerebral Energy Dysfunction at the Early Brain Injury Phase following Aneurysmal Subarachnoid Hemorrhage

JOURNAL=Frontiers in Neurology

VOLUME=8

YEAR=2017

URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2017.00325

DOI=10.3389/fneur.2017.00325

ISSN=1664-2295

ABSTRACT=<sec id="ST1"><title>Background</title><p>The pathophysiology of early brain injury following aneurysmal subarachnoid hemorrhage (SAH) is still not completely understood.</p></sec><sec id="ST2"><title>Objective</title><p>Using brain perfusion CT (PCT) and cerebral microdialysis (CMD), we examined whether non-ischemic cerebral energy dysfunction may be a pathogenic determinant of EBI.</p></sec><sec id="ST3"><title>Methods</title><p>A total of 21 PCTs were performed (a median of 41 h from ictus onset) among a cohort of 18 comatose mechanically ventilated SAH patients (mean age 58 years, median admission WFNS score 4) who underwent CMD and brain tissue PO<sub>2</sub> (PbtO<sub>2</sub>) monitoring. Cerebral energy dysfunction was defined as CMD episodes with lactate/pyruvate ratio (LPR) &gt;40 and/or lactate &gt;4 mmol/L. PCT-derived global CBF was categorized as oligemic (CBF &lt; 28 mL/100 g/min), normal (CBF 28–65 mL/100 g/min), or hyperemic (CBF 69–85 mL/100 g/min), and was matched to CMD/PbtO<sub>2</sub> data.</p></sec><sec id="ST4"><title>Results</title><p>Global CBF (57 ± 14 mL/100 g/min) and PbtO<sub>2</sub> (25 ± 9 mm Hg) were within normal ranges. Episodes with cerebral energy dysfunction (<italic>n</italic> = 103 h of CMD samples, average duration 7.4 h) were frequent (66% of CMD samples) and were associated with normal or hyperemic CBF. CMD abnormalities were more pronounced in conditions of hyperemic vs. normal CBF (LPR 54 ± 12 vs. 42 ± 7, glycerol 157 ± 76 vs. 95 ± 41 µmol/L; both <italic>p</italic> &lt; 0.01). Elevated brain LPR correlated with higher CBF (<italic>r</italic> = 0.47, <italic>p</italic> &lt; 0.0001).</p></sec><sec id="ST5"><title>Conclusion</title><p>Cerebral energy dysfunction is frequent at the early phase following poor-grade SAH and is associated with normal or hyperemic brain perfusion. Our data support the notion that mechanisms alternative to ischemia/hypoxia are implicated in the pathogenesis of early brain injury after SAH.</p></sec>