Amyloid-β dynamics correlate with neurological status in the injured human brain

The amyloid-β peptide (Aβ) plays a central pathophysiological role in Alzheimer's disease, but virtually nothing is known about the concentration and dynamics of this secreted peptide in the extracellular space of the human brain. We used intracerebral microdialysis to obtain serial brain interstitial fluid (ISF) samples in 18 patients who were undergoing invasive intracranial monitoring after acute brain injury. We found a strong positive correlation between changes in brain ISF Aβ levels and neurological status, and correlations with other cerebral physiological and metabolic abnormalities reflecting depressed neuronal function. Such dynamics fit well with the hypothesis that neuronal activity regulates extracellular Aβ concentration. ©2009 IEEE.