Brain : a journal of neurology
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Multicenter Study
Cortical spreading ischaemia is a novel process involved in ischaemic damage in patients with aneurysmal subarachnoid haemorrhage.
The term cortical spreading depolarization (CSD) describes a wave of mass neuronal depolarization associated with net influx of cations and water. Clusters of prolonged CSDs were measured time-locked to progressive ischaemic damage in human cortex. CSD induces tone alterations in resistance vessels, causing either transient hyperperfusion (physiological haemodynamic response) in healthy tissue; or hypoperfusion [inverse haemodynamic response = cortical spreading ischaemia (CSI)] in tissue at risk for progressive damage, which has so far only been shown experimentally. ⋯ Accordingly, we observed a spreading suppression of LF-VF, which accompanied spreading depression of high-frequency-electrocorticography activity, independently of whether CSD was associated with a physiological, absent or inverse haemodynamic response. Spreading suppressions of LF-VF thus allow the differentiation of progressive ischaemia and repair phases in a fashion similar to that shown previously for spreading depressions of high-frequency-electrocorticography activity. In conclusion, it is suggested that (i) CSI is a novel human disease mechanism associated with lesion development and a potential target for therapeutic intervention in stroke; and that (ii) prolonged spreading suppressions of LF-VF are a novel 'functional marker' for progressive ischaemia.