Dynamic metabolic response to multiple spreading depolarizations in patients with acute brain injury: an online microdialysis study.
Spreading depolarizations (SDs) occur spontaneously with high incidence in patients with acute brain injury. They can be detected by subdural electrocorticographic recordings. We here characterize the dynamic metabolic response to these events. A microdialysis catheter was inserted into perilesional cortical tissue adjacent to a strip for electrocorticography following craniotomy in 10 patients. The microdialysis catheter was connected to an online microdialysis assay measuring glucose and lactate concentrations every 30 to 60 secs. Spontaneously occurring SDs systematically caused a reduction in dialysate glucose by -32.0 micromol/L (range: -92.3 to -18.4 micromol/L, n=90) and increase in lactate by +23.1 micromol/L (range: +5.5 to +93.6 micromol/L, n=49). The changes were sustained at 20 mins after the SD events and highly significant using an area under the curve analysis (P<0.0001). Multiple and frequent SDs led to a progressive stepwise depletion of brain glucose. Hence, SD events cause a massive energy imbalance and their frequent occurrence leads to a local insufficiency of glucose supply. Such a failure would compromise cellular repolarization and hence tissue viability. The findings offer a new mechanism to account for otherwise unexplained instances of depletion of brain microdialysate glucose.
Department of Bioengineering, Imperial College London, London, UK. delphine.feuerstein05@imperial.ac.uk
Delphine
D
Feuerstein
Andrew
A
Manning
Parastoo
P
Hashemi
Robin
R
Bhatia
Martin
M
Fabricius
Christos
C
Tolias
Clemens
C
Pahl
Max
M
Ervine
Anthony J
AJ
Strong
Martyn G
MG
Boutelle
D000328:Adult; D000368:Aged; D019540:Area Under Curve; D001921:Brain / Q000378:metabolism / Q000473:pathology; D001930:Brain Injuries / Q000378:metabolism / Q000473:pathology; D003399:Craniotomy; D004569:Electroencephalography; D005260:Female; D005947:Glucose / Q000378:metabolism; D006801:Humans; D019344:Lactic Acid / Q000378:metabolism; D008297:Male; D008564:Membrane Potentials / Q000502:physiology*; D017551:Microdialysis; D008875:Middle Aged; D055815:Young Adult
D019344:Lactic Acid; D005947:Glucose