A newly described imaging finding for idiopathic normal pressure hydrocephalus: Can hummingbird sign contribute to the diagnosis?

ATALAY B., Soylemez U. P. O. , Yildiz H.

TURKISH JOURNAL OF MEDICAL SCIENCES, vol.51, no.6, pp.3053-3060, 2021 (Peer-Reviewed Journal) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 51 Issue: 6
  • Publication Date: 2021
  • Doi Number: 10.3906/sag-2107-86
  • Journal Indexes: Science Citation Index Expanded, Scopus, Academic Search Premier, CAB Abstracts, EMBASE, MEDLINE, Veterinary Science Database, TR DİZİN (ULAKBİM)
  • Page Numbers: pp.3053-3060
  • Keywords: Idiopathic normal pressure hydrocephalus, hummingbird sign, progressive supranuclear palsy, magnetic resonance imaging, mesencephalon, PROGRESSIVE SUPRANUCLEAR PALSY, CEREBELLAR PEDUNCLE, MRI


Background/aim: In this study, we aimed to evaluate whether morphological changes in the mesencephalon, which were previously described as a diagnostic tool for progressive supranuclear palsy, could be associated also with idiopathic normal pressure hydrocephalus. Materials and methods: Consecutive 52 patients with a possible diagnosis of idiopathic normal pressure hydrocephalus (32 female, mean age 73.6 years) and 40 controls (23 female, mean age 72.7 years) with similar demographic characteristics were included the study. The morphologic changes in mesencephalon, hummingbird sign, and the vascular compression to mesencephalon were noted. Besides, three independent observers evaluated the imaging parameters for idiopathic normal pressure hydrocephalus in magnetic resonance imaging. Inter-observer reliabilities for qualitative and quantitative data were assessed using the Cronbach's alpha and intra class correlation coefficient. The correlation of the imaging parameters with each other was evaluated with Pearson correlation. Results: Hummingbird sign was found to be significantly more common among patients with idiopathic normal pressure hydrocephalus (p < 0.0001). A statistically significant correlation was found between hummingbird sign and vascular compression of patients in the study group (p < 0.0001). A substantial, good, and perfect agreement was found between observers at all levels except callosal angle (fair agreement). Conclusion: Hummingbird sign can be used to support the diagnosis of idiopathic normal pressure hydrocephalus in addition to other radiological findings. A significant correlation between vascular compression and hummingbird sign in the patient group may explain the morphological changes in the mesencephalon that resemble the Hummingbird sign, which was previously described for progressive supranuclear palsy.