Abstract: Objective To evaluate the alternations of degree centrality (DC) in the brain of a patient with alternating Horner’s
syndrome (AHS). Methods Conventional magnetic resonance imaging (MRI), 3D structure reconstruction and resting-state
functional MRI were performed in a patient with AHS and 8 healthy adults. The DC of brain functional connectivity was
calculated and statistically analyzed to evaluate the changes in the nodes in the brain default network of the patient. Results In
the AHS patient, the DC at onset of left eye involvement was located mainly in the bilateral anterior middle frontal gyri, frontal
operculum and opercula insulae; the brain regions with a DC greater than the mean DC of the whole brain were found mainly
in the bilateral occipital lobes, temporal lobes and cingulate gyri, and the brain regions with a significantly decreased DC
included mainly the left inferior temporal gyrus, postcentral gyrus, right superior temporal gyrus, lateral occipital gyri and
bilateral paracentral lobules (P<0.05). At the onset of right eye involvement, the DC was mainly located in the anterior part of
the bilateral superior and middle frontal gyri, parietal lobes, middle cingulate gyri and medial occipital gyri; the brain regions
with a DC greater than the mean DC of the whole brain included the bilateral occipital lobers, temporal lobes, cigulate, orbital
gyri and gyrus rectus, and the brain regions with a significantly decreased DC included the left supramarginal gyrus, right
lateral occipital gyrus, paracentral lobule and bilateral superior temporal gyrus. Conclusion The AHS patient exhibited a
decreased DC of functional connectivity in multiple brain regions.