Crossed Cerebellar Diaschisis Indicates Hemodynamic Compromise in Ischemic Stroke Patients

Abstract

Crossed cerebellar diaschisis (CCD) in internal carotid artery (ICA) stroke refers to attenuated blood flow and energy metabolism in the contralateral cerebellar hemisphere. CCD is associated with an interruption of cerebro-cerebellar tracts, but the precise mechanism is unknown. We hypothesized that in patients with ICA occlusions, CCD might indicate severe hemodynamic impairment in addition to tissue damage. Duplex sonography and clinical data from stroke patients with unilateral ICAO who underwent blood oxygen-level-dependent MRI cerebrovascular reserve (BOLD-CVR) assessment were analysed. The presence of CCD (either CCD+ or CCD−) was inferred from BOLD-CVR. We considered regions with negative BOLD-CVR signal as areas suffering from hemodynamic steal. Twenty-five patients were included (11 CCD+ and 14 CCD−). Stroke deficits on admission and at 3 months were more severe in the CCD+ group. While infarct volumes were similar, CCD+ patients had markedly larger BOLD steal volumes than CCD− patients (median [IQR] 122.2 [111] vs. 11.6 [50.6] ml; p < 0.001). Furthermore, duplex revealed higher peak-systolic flow velocities in the intracranial collateral pathways. Strikingly, posterior cerebral artery (PCA)-P2 velocities strongly correlated with the National Institute of Health Stroke Scale on admission and BOLD-CVR steal volume. In patients with strokes due to ICAO, the presence of CCD indicated hemodynamic impairment with larger BOLD-defined steal volume and higher flow in the ACA/PCA collateral system. Our data support the concept of a vascular component of CCD as an indicator of hemodynamic failure in patients with ICAO.

Crossed Cerebellar Diaschisis in Patients With Symptomatic Unilateral Anterior Circulation Stroke Is Associated With Hemodynamic Impairment in the IpsilateralMCATerritory

“…By using a standardized region of interest, that is, the MCA territory, we found impaired BOLD‐CVR, prolonged MTT, and TTP as well as increased CBV in the ipsilateral (=affected) MCA territory in the CCD(+) group. These findings further confirm the observation that a vascular component of CCD may be present in patients with steno‐occlusive disease 3,5 …”

“…This means that in those patients the initial hemodynamic impairment and not the stroke severity influences CCD, most likely through metabolic downregulation. In our previous study we found more severe supratentorial BOLD‐CVR impairment in CCD patients 3 as well as a larger brain tissue volume exhibiting steal physiology and increased collateral compensatory flow 5 …”

“…Traditionally, BOLD‐CVR has been used as a surrogate imaging marker for the remaining cerebrovascular reserve capacity 12 . Recently, however, we have also shown the capability of using BOLD‐CVR to detect diaschisis 3,5,13,14 . The principle of BOLD‐CVR to detect CCD arises out of the underlying physiology that BOLD‐fMRI signal primarily reflects changes in deoxyhemoglobin.…”

“…By using blood oxygenation‐level dependent cerebrovascular reactivity (BOLD‐CVR), the presence of impaired supratentorial CVR has been previously shown in steno‐occlusive patients with CCD with similar stroke volumes as patients without CCD 3–5 . This finding may indicate that hemodynamic impairment is more severe in patients with CCD; however, BOLD‐CVR only represents the relative difference of deoxyhemoglobin, while the BOLD signal is influenced by various parameters, such as cerebral blood flow (CBF) and oxygen extraction fraction (OEF) 6 .…”

“…Using multimodal MRI, the aim of the study was to study if hemodynamic alterations may also be involved for crossed cerebellar diaschisis rather than a functional disruption alone, that is, a vascular component of CCD, as recent findings suggest 3,5 …”