gms | German Medical Science

Objective: Thyroid hormones are probably important for neurological recovery after acute brain injury but the dynamics of these hormones after subarachnoid hemorrhage (SAH) are actually not well understood. Objective of the present study was the evaluation of the dynamics of TSH and fT3 levels during the first days after SAH and the possible correlation to the severity of the SAH and the clinical outcome of these patients.

Methods: Since 2013 we prospectively included all patients with non-traumatic SAH admitted to our Department of Neurosurgery within the first 24h after onset of bleeding. All patients were evaluated with a computed tomography (CT) angiogram and a conventional invasive angiography within the first 24 hours. Aneurysms were secured by clipping or coiling. Exclusion criteria were age under 18 years and any endocrine disease (except diabetes mellitus). Serum concentrations of TSH, thyroxin (fT4) and T3 were measured once on day 1, 3, 5 and 10 after the onset of the bleeding. Values were correlated to the severity of SAH (according to Hunt and Hess, HH), location of the aneurysm, neurological condition on admission and outcome at hospital discharge using the Glasgow Outcome Sale (GOS).

Results: 83 patients could be included in the last 4years (60 female/ 23male) with an mean age of 56,6 years. In 78 cases an aneurysm was detected and adequately secured (Clip 18.07%, Coil 69,88%, Clip+Coil 2,41%). 5 (7,23%) patients had an SAH without detection of an aneurysm.51 patients (61,25%) showed a decrease of TSH between day 1 and day 3. Interestingly TSH values on day 10 were significantly higher compared to day 1 (p=0.001). The time course of T3 differed, showing a decrease between day 3 and 10 compared to day 1 (p=0,001). In addition 25 (80%) of the patients with a suppressed TSH on day 3 also had subthreshold values of T3 on that day. When we compared the TSH values to the outcome we found that the GOS values were significantly lower in patients with decreaing TSH compared to stable or increasing TSH values between day 1 and 3 (p <0.03).

Conclusion: In general there was a decrease in mean TSH and fT3 values between day 3 and 10 after SAH. In addition a suppressed TSH on day 3 was often combined with subthreshold levels of T3. That possibly indicates a central dysregulation and argues against reflex testing and contrast agent induced relative hyperthyroidism. Patients with poor clinical course showed a more significant decrease of TSH and fT3. Due to this TSH and fT3 could be used as an additional factor to predict outcome.