Department of Neuroscience, Neurology, Uppsala University, Uppsala, Sweden.
Department of Surgical Sciences, Radiology, Uppsala University, Uppsala, Sweden.
J Neuroimaging. 2022 Jan;32(1):90-96. doi: 10.1111/jon.12932. Epub 2021 Sep 14.
The main radiological finding in progressive supranuclear palsy (PSP) is reduced midbrain volume. Both qualitative (e.g., hummingbird sign) and quantitative (e.g., area measurements) markers have been noted. Recent studies have shown a similar reduction also in idiopathic normal pressure hydrocephalus (iNPH). The purpose was to investigate the reliability and accuracy of these markers in discriminating PSP from iNPH and controls.
Eight neuroradiologists viewed sagittal MR images of the midbrain from 104 subjects: 26 PSP patients, 40 iNPH patients, and 38 healthy controls. They visually assessed whether the hummingbird sign was present or not, grading their confidence from 1 to 5. Assessments were translated into a score between +5 and -5: from maximum confidence of presence to maximum confidence of absence. A positive median score was considered to indicate hummingbird sign. Sagittal midbrain area was manually measured in each subject.
Seventy-seven percent of PSP patients, 65% of iNPH, and 3% of controls were visually assessed as having the hummingbird sign. Manually measured midbrain area also showed overlap between PSP and iNPH. Regarding discrimination of PSP patients, midbrain area measurements, using a cutoff of 90 mm , yielded a higher area under the curve (AUC = 0.86) than visual assessment scores (AUC = 0.83), and higher reliability.
Measuring sagittal midbrain area is more accurate and reliable than visual assessment. Due to significant overlap in appearance, a midbrain with a hummingbird sign or reduced sagittal area should raise the suspicion of PSP only after other signs of iNPH have been considered.
进行性核上性麻痹（PSP）的主要放射学发现是中脑体积缩小。已经注意到定性（例如，蜂鸟征）和定量（例如，面积测量）标志物。最近的研究表明，特发性正常压力脑积水（iNPH）也存在类似的减少。目的是研究这些标志物在鉴别 PSP 与 iNPH 和对照组中的可靠性和准确性。
8 名神经放射科医生观察了 104 名受试者的中脑矢状位 MRI：26 名 PSP 患者，40 名 iNPH 患者和 38 名健康对照者。他们对蜂鸟征是否存在进行了视觉评估，从 1 到 5 对其信心进行了分级。评估结果转换为+5 到-5 之间的分数：从存在的最大置信度到不存在的最大置信度。中位数评分阳性被认为表示存在蜂鸟征。手动测量了每位受试者的中脑矢状面积。
77%的 PSP 患者，65%的 iNPH 和 3%的对照组被评估为具有蜂鸟征。中脑面积的手动测量也显示 PSP 和 iNPH 之间存在重叠。关于 PSP 患者的鉴别，中脑面积测量，使用 90mm 的截止值，产生了更高的曲线下面积（AUC = 0.86），而视觉评估评分（AUC = 0.83），可靠性更高。
测量矢状中脑面积比视觉评估更准确和可靠。由于外观上存在明显重叠，只有在考虑了 iNPH 的其他迹象后，才应怀疑中脑出现蜂鸟征或矢状面积缩小与 PSP 有关。
