Table 4.
Brain functional connectivity in patients who have cluster headache.
| Study | Subject cohorts | Analysis | Main finding |
|---|---|---|---|
| Chou et al.59 | Episodic CH (n = 17) HC (n = 18) | ICA | CH in-bout vs. HC and CH out-of-bout vs. HC: Connectivity differences in temporal, frontal, salience, default mode, somatosensory, dorsal attention, and visual networks. CH in-bout vs. out-of-bout: Connectivity differences in frontal and dorsal attention networks |
| Farago et al.45 | Episodic CH (n = 17) HC (n = 26) | ICA | CH out-of-bout vs. HC: Connectivity differences in attention network and cerebellar network |
| Qiu et al.60 | Episodic CH (n = 21) HC (n = 21) | ICA | CH in-bout, inter-ictal vs. HC: Decreased resting-state hypothalamus to salience network co-activation |
| Yang et al.64 | Episodic CH (n = 18) HC (n = 19) | ROI (hypothalamus) | CH in-bout vs. out-of-bout: Decreased hypothalamic connectivity with medial frontal gyrus, middle frontal gyrus, inferior temporal gyrus, precuneus, and cerebellum. CH in-bout vs. HC and CH out-of-bout vs. HC: Altered hypothalamic connectivity with medial frontal gyrus, middle frontal gyrus, cuneus, inferior semilunar lobule, and inferior temporal gyrus. |
| Qiu et al.61 | Episodic CH (n = 12) HC (n = 12) | ROI (hypothalamus) | CH ictal vs. CH in-bout, inter-ictal: Increased connectivity hypothalamus with numerous pain matrix regions including anterior cingulate cortex, posterior cingulate cortex, superior frontal gyrus, middle frontal gyrus, inferior frontal gyrus, superior temporal gyrus, inferior parietal lobule, parahippocampal gyrus, and amygdala. CH in-bout, inter-ictal vs. HC: Stronger connectivity hypothalamus with inferior frontal gyrus, superior and middle temporal gyri, temporal pole, insula, parahippocampal gyrus, and uncus. Weaker connectivity hypothalamus with precuneus, inferior parietal lobule, and occipital lobe. |
| Qiu et al.62 | Episodic CH (n = 12) HC (n = 12) | Regional homogeneity | CH ictal vs. CH in-bout, inter-ictal: Increased regional homogeneity in posterior cingulate cortex and ventromedial prefrontal cortex. Decreased regional homogeneity in middle frontal gyrus, and parahippocampal gyrus. CH in-bout, inter-ictal vs. HC: Stronger regional homogeneity in anterior cingulate cortex, gyrus rectus, and orbital gyrus. Weaker regional homogeneity in middle prefrontal cortex, posterior cingulate cortex, insula, and dorsolateral prefrontal cortex. |
| Rocca et al.63 | Episodic CH (n = 13) HC (n = 15) | ICA ROI (hypothalamus, thalamus) | CH out-of-bout vs. HC: Connectivity differences in sensorimotor network and primary visual network. Increased connectivity of hypothalamus with anterior cingulate cortex, secondary sensorimotor cortex, primary visual cortex, middle occipital gyrus, thalamus, and insula. Increased connectivity of thalamus with primary sensorimotor cortex, supplementary motor area, and anterior cingulate cortex. |
Note: This table summarizes the methods and findings from published studies that have investigated brain functional connectivity in individuals with cluster headache.
CH: cluster headache; HC: healthy control; ICA: independent components analysis; ROI: region of interest.