Axonal damage and outcome in subarachnoid haemorrhage

Background: On the basis of preliminary evidence from patients with subarachnoid haemorrhage (SAH), axonal degeneration is thought to be an underestimated pathological feature. Methods: A longitudinal study in 17 patients with aneurysmal SAH. Ventricular CSF was collected daily for up to 14 days. The neurofilament heavy chain SMI35 (NfH SMI35 , a biomarker for axonal damage) was quantified using a standard ELISA (upper limit of normal 0.73 ng/ml). The primary outcome measure was the Glasgow Outcome Score (GOS) at 3 months. Results: Of 148 samples from patients with SAH, pathologically high NfH levels in the CSF were found in 78 (52.7%) samples, compared with 20 (5%) of 416 samples from the reference population (p v 0.37 ng/ml, p SMI35 levels in the CSF (World Federation of Neurological Surgeons, r = 0.63, p Conclusion: Patients with SAH thus have secondary axonal degeneration, which may adversely affect their outcome.