Background & Aims

Patients with atraumatic subarachnoid hemorrhage (SAH) face high mortality and brain function impairment. Vasospasms in 70% of survivors lead to delayed cerebral ischemia (DCI) and poor prognosis. Long-term, 30-40% develop chronic headaches, potentially due to vascular hyperreactivity. The brain’s glymphatic system, important in neurodegenerative and traumatic conditions, involves glymphatic transport along perivascular spaces and Aquaporin-4 (Aqp-4) mediated transport for macromolecule removal. This study explores the link between SAH-related changes in glymphatic flow, vascular hyperresponsiveness, vasospasm, and chronic headaches post-hemorrhage.

Methods

30 patients who have suffered SAH in the past will be compared with 30 healthy control subjects. Glymphatic flow will be visualized using different MR imaging techniques, including diffusion tensor imaging along the perivascular spaces (DTI-ALPS) and T2 sequences to assess the width of the perivascular spaces. Furthermore, various questionnaires are performed to evaluate headache, possible cognitive impairment, and potential quality of life limitations (MOCA, PSQI, DSF, Kiel Headache Questionnaire). In addition, information on the occurrence/non-occurrence of posthemorrhagic vasospasms will be collected retrospectively from the medical history of SAH patients.

Results

The DTI-ALPS for calculation of the glymphatic flow has been established using 30 healthy controls and was checked for reproducibility. There will be a comparison between the individual width of the perivascular spaces and the DTI-ALPS and an analysis of a potential correlation between a lowered glymphatic flow and posthemorrhagic complications. To date, 20 healthy volunteers and 10 SAH patient have already been enrolled in the study. In August 2024 the results, comparing the glymphatic flow of healthy individuals with that of patients who suffered from a SAH will be available.

Conclusions

The glymphatic system is of great importance for the proper function of the brain. Impairment of this fluid system can have far-reaching consequences, which has already been shown especially in neurodegenerative diseases, but also in traumatic, inflammatory, and ischemic events. If impairment of the glymphatic system by SAH is confirmed, this could contribute to a better understanding of the pathophysiology of posthemorrhagic complications and open the way for new therapeutic approaches of chronic headache and vasospasms in SAH patients.

References

Rümenapp JE, Sendel M, Kersebaum D, Larsen N, Jansen O, Baron R. Impaired glymphatic flow as a potential driver of pain chronification. Pain. 2023 Oct 1;164(10):2191-2195. doi: 10.1097/j.pain.0000000000002979. Epub 2023 Jul 7. PMID: 37433183.

Presenting Author

Johanna Rümenapp

Poster Authors

Johanna Rümenapp

Dr. med.

UKSH Kiel, Germany

Lead Author

E-mail

Nele Wallem

UKSH Kiel

Lead Author

E-mail

Oliver Granert

UKSH Kiel

Lead Author

E-mail

Naomi Larsen

UKSH Kiel

Lead Author

E-mail

Olav Jansen

UKSH Kiel

Lead Author

E-mail

Charlotte Flüh

UKSH Kiel

Lead Author

E-mail

Ralf Baron

UKSH Kiel

Lead Author

E-mail

Topics

  • Pain Imaging