Diffusion along perivascular spaces index in patients after subarachnoid hemorrhage

Motivation: Following subarachnoid hemorrhage (SAH), toxic blood byproducts accumulate in the brain, impairing glymphatic system (GS) function. Diffusion tensor imaging (DTI) along perivascular spaces (ALPS) index could indirectly evaluate GS function in SAH patients. Goal(s): To investigate the ALPS index in SAH patients and healthy controls (HC). Approach: The bilateral mean ALPS index was used to compare patients and HC and investigate the relationship between SAH symptoms and the index. Results: The ALPS index was lower in SAH patients than HC. Additionally, in patients with severe symptoms the index was significantly lower than in the mild symptom group. No significant interhemispheric differences were found. Impact: We did not observe any interhemispheric differences in SAH patients and controls according the ALPS-index. Additionally, the ALPS index of SAH patients was lower than in controls, and there might be a negative correlation between the index and Hunt&Hess grading.