SV2A and delirium: While the absence of a correlation with these biomarkers in our study does not dismiss the role of synaptic dysfunction in delirium, it indicates the need to explore other biomarkers such as presynaptic proteins involved in vesicle release and postsynaptic receptors, such as neurogranin, synaptotagmin, synaptobrevin, syntaxin, growth-associated protein 43, α-synuclein, synaptic vesicle glycoprotein 2A, and other neuronal pentraxins (21, 32).