S100B and NSE in Cluster Headache - Evidence for Glial Cell Activation?

Biomarkers in cluster headache: A systematic review

OBJECTIVE

To systematically investigate previously examined biomarkers in blood, urine, cerebrospinal fluid, tear fluid, and saliva of patients with cluster headache.

BACKGROUND

Cluster headache is a condition with extensive clinical challenges in terms of diagnosis and treatment. Identification of a biomarker with diagnostic implications or as a potential treatment target is highly warranted.

METHODS

We conducted a systematic review including peer reviewed full text of studies that measured biochemical compounds in either blood, urine, cerebrospinal fluid, tear fluid, or saliva of patients with cluster headache diagnosed after the implementation of the International Classification of Headache Disorders (1988) written in English, Danish, Swedish, or Norwegian. Inclusion required a minimum of five participants. The search was conducted in PubMed and EMBASE, in September 2022, and extracted data were screened by two authors. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines for reporting systematic reviews were followed. The Newcastle-Ottawa Scale was used to assess the risk of bias in case-controlled studies.

RESULTS

We included 40 studies involving 832 patients with cluster headache and 872 controls, evaluating 80 potential biomarkers. The risk of bias for case-controlled studies was a median of 6 (range: 3-8) and 20 studies out of 40 (50%) were of fair or good quality. Most studies were identified within three groups: hypothalamic-regulated hormones, inflammatory markers, and neuropeptides. Among the hypothalamic hormones, cortisol was the most frequently investigated (N = 7) and was elevated in cluster headache in most of the studies. The most frequently examined inflammatory marker was interleukin 1 (N = 3), but findings were divergent. Calcitonin gene-related peptide was the most investigated neuropeptide (N = 9) and all studies found increased levels during attacks.

CONCLUSION

Biomarker findings have been inconsistent and widely non-specific for cluster headache, which explains why none of the previous studies succeeded in identifying a unique biomarker for cluster headache, but instead contributed to substantiating the underlying pathophysiologic mechanisms. Several of the examined biomarkers could hold promise as markers for disease activity but are unfit for a clear distinction from both controls and other headaches.

Increased Neuron-Specific Enolase Level Predicts Symptomatic Intracranial Hemorrhage in Patients with Ischemic Stroke Treated with Endovascular Treatment

BACKGROUND

Neuron-specific enolase (NSE), which is a highly specific marker for neurons, could be a predictor for prognosis in patients with symptomatic intracranial hemorrhage (sICH) with acute ischemic stroke who are receiving endovascular treatment (EVT). This study aimed to investigate the relationship between NSE and sICH in patients with acute anterior circulation stroke undergoing EVT.

METHODS

A total of 215 consecutive patients with acute stroke treated with EVT were included. Patients with stroke and acute anterior circulation occlusion, receiving EVT treated at our hospital, were enrolled between January 2017 and August 2021. NSE level was measured on arrival at the neurology intensive care unit after EVT. The patients were divided into 2 groups according to whether sICH was present. Univariate and multivariate analyses were performed. NSE level was also incorporated into the TAG score (modified Thrombolysis in Cerebral Infarction score, Alberta Stroke Program Early CT Score, and glucose level), which was developed as a scoring system to predict sICH, and the prediction capability was compared with the TAG score alone. Causal inference was performed using the package DoWhy in Python to evaluate the causal relationship between NSE and sICH.

RESULTS

The area under the curve (AUC) value of NSE showed moderate accuracy, with an AUC value of 0.729 (95% confidence interval, 0.655-0.795; P < 0.001). The NSE cutoff value was set at 23.88 ng/mL. When the NSE level ≥23.88 ng/mL, the sensitivity was 58.33% and the specificity was 78.72% (P < 0.001). The AUC for the TAG + NSE score was 0.801 compared with an AUC of 0.632 for the TAG score (Z = 2.034; P = 0.042). A causal inference model using the DoWhy library shows a proportional relationship between NSE and the diagnosis of sICH.

CONCLUSIONS

This study is the first to show that increased NSE level is an independent predictor of sICH in patients with acute anterior circulation stroke who are undergoing endovascular treatment.

Elevated Blood S100B Levels in Patients With Migraine: A Systematic Review and Meta-Analysis

Background:

In recent years, a growing number of researches indicate that S100B may act in migraine, but the relationship between S100B and migraine remains controversial. Therefore, the current study aimed to perform a meta-analysis to quantitatively summarize S100B levels in migraine patients.

Methods

We used Stata 12.0 software to summarize eligible studies from PubMed, EMBASE, Web of Science, Cochrane Library, China National Knowledge Infrastructure (CNKI), and Wanfang databases. We applied standardized mean differences (SMDs) with 95% confidence intervals (95%CIs) to appraise the association between S100B and migraine.

Results

The combined results of nine case-control studies indicated that compared with healthy controls, overall migraine patients had significantly increased S100B levels in peripheral blood (SMD = 0.688, 95%CI: 0.341–1.036, P < 0.001). The S100B levels in migraineurs during ictal periods (SMD =1.123, 95%CI: 0.409–1.836, P = 0.002) and interictal periods (SMD = 0.487, 95%CI: 0313–0.661, P < 0.001), aura (SMD = 0.999, 95%CI: 0.598–1.400, P < 0.001) and without aura (SMD = 0.534, 95%CI: 0.286–0.783, P < 0.001) were significantly higher than those in the controls. The subgroup analyses by age, country, migraine assessment, and assay method of S100B also illustrated a statistically obvious association between S100B levels and migraine, indicating that age may be the most important source of heterogeneity. Sensitivity analysis showed that no individual study has a significant influence on the overall association between S100B and migraine.

Conclusion

This meta-analysis demonstrates that the level of S100B in peripheral blood of patients with migraine was significantly increased. Migraine may be associated with pathological reactions involving S100B, which is instrumental for the clinical diagnosis of migraine and therapy that considers S100B as a potential target.