# Impact of thyroid hormone replacement therapy on the course and functional outcome of aneurysmal subarachnoid hemorrhage

## TL;DR

Thyroid hormone replacement therapy may improve outcomes in patients with aneurysmal subarachnoid hemorrhage by reducing cerebrovascular events and improving recovery.

## Contribution

This study is the first to investigate the impact of thyroid hormone replacement therapy on aneurysmal subarachnoid hemorrhage outcomes.

## Key findings

- THRT was associated with a lower risk of cerebral infarction and unfavorable outcomes.
- Patients on THRT had a reduced risk of intracranial pressure- or vasospasm-related events.
- THRT did not significantly affect in-hospital mortality.

## Abstract

Thyroid hormones were reported to exert neuroprotective effects after ischemic stroke by reducing the burden of brain injury and promoting post-ischemic brain remodeling.

We aimed to analyze the value of thyroid hormone replacement therapy (THRT) due to pre-existing hypothyroidism on the clinical course and outcome of aneurysmal subarachnoid hemorrhage (SAH).

SAH individuals treated between January 2003 and June 2016 were included. Data on baseline characteristics of patients and SAH, adverse events and functional outcome of SAH were recorded. Study endpoints were cerebral infarction, in-hospital mortality and unfavorable outcome at 6 months. Associations were adjusted for outcome-relevant confounders.

109 (11%) of 995 individuals had THRT before SAH. Risk of intracranial pressure- or vasospasm-related cerebrovascular events was inversely associated with presence of THRT (p = 0.047). In multivariate analysis, THRT was independently associated with lower risk of cerebral infarction (adjusted odds ratio [aOR] = 0.64, 95% confidence interval [CI] = 0.41–0.99, p = 0.045) and unfavorable outcome (aOR = 0.50, 95% CI = 0.28–0.89, p = 0.018), but not with in-hospital mortality (aOR = 0.69, 95% CI = 0.38–1.26, p = 0.227).

SAH patients with THRT show lower burden of ischemia-relevant cerebrovascular events and more favorable outcome. Further experimental and clinical studies are required to confirm our results and elaborate the mechanistic background of the effect of THRT on course and outcome of SAH.

The online version contains supplementary material available at 10.1007/s00701-024-06118-7.