Evaluation of the Glymphatic System Using the DTI-ALPS Index in Patients with Spontaneous Intracerebral Haemorrhage

OBJECTIVE: To investigate the function of the human glymphatic system (GS) in patients with spontaneous intracerebral haemorrhage (sICH) using diffusion tensor imaging analysis along with the perivascular space (DTI-ALPS). METHODS: Twenty patients with sICH and 31 healthy controls (HCs) were recruited for DTI and susceptibility-weighted imaging scanning. The diffusivity along the perivascular spaces, as well as the projection fibres and association fibres, was evaluated separately. The DTI-ALPS index of each subject was also calculated. Two-sample t-tests and paired t-tests were performed to analyse the difference in ALPS scores between patients and HCs, as well as that between the lesion side and contralateral side. Pearson correlation analysis was used to observe the relationship between disease duration and GS function. RESULTS: The DTI-ALPS index on the lesion side was significantly lower than that of the contralateral side in patients with sICH (p < 0.01, t = −5.77), and it was also significantly lower than that of the ipsilateral side of HCs (p < 0.01, t = −9.50). No significant differences were found in the DTI-ALPS index on the nonlesion side between patients and HCs (p = 0.96, t = 0.05) or between the left and right cerebral hemispheres of HCs (p = 0.41, t = −0.83). The DTI-ALPS index of the lesion side in patients with sICH was significantly correlated with disease duration (p = 0.018, r = 0.537). CONCLUSIONS: The present study confirmed that GS dysfunction on the ipsilateral side of the lesion is impaired in patients with haemorrhagic stroke, indicating that the GS may be a separate system in the left and right cerebral hemispheres. The DTI-ALPS index can reflect disease duration. These findings have significant implications for understanding sICH from a new perspective.