Increased iron deposition in the putamen, caudate, and nucleus accumbens (NAC) was found in patients with migraine compared with healthy individuals, suggesting iron deposition in the NAC may be a biomarker for migraine. These are the findings of a study published in the journal BMC Medicine.
Increasingly, evidence suggests that dysfunction of the subcortical structures may drive migraine pathophysiology, and an inverse relationship between iron accumulation and recurrent migraine attacks has been established. The novel technique, quantitative susceptibility mapping (QSM) may help improve understanding of any role of brain iron deposition in migraine.
For the study, researchers recruited patients (n=200) with confirmed episodic (n=144) or chronic (n=56) migraine and matched control individuals (n=41) between 2021 and 2023 at Zhejiang University School of Medicine in China. All participants underwent clinical evaluation and magnetic resonance imaging (MRI). Images were processed using a QSM approach and iron disposition was related with clinical characteristics.
The chronic migraine, episodic migraine, and control groups were mean age: 37.9, 47.5, and 43.9 years. And, 75.4%, 77.8%, and 65.9% were women, respectively. Among the migraine group, those with episodic migraine had a shorter disease duration (mean, 10.2 vs 18.5 mo; P <.001), fewer monthly migraine days (mean, 3.4 vs 21.0 d; P <.001), and a lower peak headache intensity on a visual analogue scale (mean, 6.4 vs 6.9; P <.05), compared with chronic migraine, respectively.
Compared with control individuals, patients with chronic migraine had higher QSM values in the NAC (P <.001), putamen (P = .001), and caudate (P = .002) and the patients with episodic migraine had higher QSM in the NAC (P <.001).
Among patients, chronic migraine was associated with higher QSM in the NAC (P <.001), putamen (P = .002), parabrachial pigmented nucleus (P = .003), habenular nuclei (P = .017), and substantianigra pars compacta (P = .018).
The QSM value in the NAC predicted migraine (area under the curve [AUC], 0.883; 95% CI, 0.826-0.939). The optimal cutoff was 22.91 parts per billion (ppb; sensitivity, 72.9%; specificity, 86.8%). Among patients, NAC QSM could also differentiate between episodic and chronic migraine (AUC, 0.797; 95% CI, 0.734-0.860) at a cutoff of 27.23 ppb (sensitivity, 85.45%; specificity, 71.53%).
Significant correlations between QSM in the NAC were observed with
- Migraine Disability Assessment scores (MIDAS; r, 0.605; P <.001),
- Pittsburgh Sleep Quality Index scores (PSQI; r, 0.428; P <.001),
- 6-item Headache Impact Test scores (HIT-6; r, 0.423; P <.001),
- frequency of attacks (r, 0.405; P <.001),
- migraine days per month (r, 0.403; P <.001), and
- longer disease duration (r, 0.160; P = .045).
This study may have been limited by including patients with wide age ranges. Additional studies with specific hypotheses about the effects of age on QSM values are needed.
These data indicated that iron deposition in the NAC may be a marker for migraine. The researchers concluded that “These findings provide evidence that iron deposition in NAC may be a biomarker for migraine chronicity and migraine-related dysfunctions, thus may help to understand the underlying vascular and neural mechanisms of migraine.”
Xu X, Zhou M, Wu X, et al. Increased iron deposition in nucleus accumbens associated with disease progression and chronicity in migraine. BMC Med. Published online April 7, 2023. doi:10.1186/s12916-023-02855-1