Our objective was to find a mean flow velocity (MFV) cut-off point to differentiate between normal and cognitive impaired patients using Clinical Dementia Rating (CDR) as a comparison method. To evaluate MFV (in cm/s) and pulsatility index (PI) from the left middle cerebral artery (MCA) and basilar artery using transcranial Doppler in a pilot study from an outpatient cognition unit and compare with cognitively normal older adults (at the age of sixty or older) from the Geriatric Ambulatory of Fluminense Federal University. We hypothesized that there is a MFV and PI cut-off point to potentially distinguish between normal and impaired cognition. Sixty-one patients with cognitive decline, including 18 with amnestic mild cognitive impairment (aMCI), 31 with probable Alzheimer disease (AD), 12 with vascular dementia (VD), and 10 cognitively normal older adults were included in the study. Patients with dementia (both AD and VD, p < 0.01) and aMCI (p < 0.05) had lower MFV than the control group in the MCA (32.2 cm/s, 31.9 cm/s, and 36.6 cm/s, respectively) and dementia patients had higher PI compared to control (AD and VD, both p < 0.05). Basilar MFV showed to be no difference between the patients and the control group. A cut off value of 39.1 cm/s was found in a ROC curve (area under de curve value 0.85, 95% CI 0.75–0.95) for mean MCA MFV to be predictive of cognitive impairment (CDR ≥ 0.5). In this study, the values of MCA MFV below 39.1 cm/s were predictive of cognitive impairment according to CDR. TCD is an inexpensive method that could be used in a clinical scenario to help differentiate normal cognition from cognitive decline. Multicentric and longitudinal studies should be done to validate that.

我们的目标是找到一个平均流速 (MFV) 分界点，以使用临床痴呆评分 (CDR) 作为比较方法来区分正常和认知障碍患者。在门诊认知单元的一项试点研究中，使用经颅多普勒评估左大脑中动脉 (MCA) 和基底动脉的 MFV（以 cm/s 为单位）和搏动指数 (PI)，并与认知正常的老年人（在六十岁或以上）来自弗鲁米嫩塞联邦大学的老年门诊。我们假设有一个 MFV 和 PI 临界点可以潜在地区分正常和受损的认知。61 名认知能力下降患者，其中 18 名患有遗忘性轻度认知障碍 (aMCI)，31 名患有可能的阿尔茨海默病 (AD)，12 名患有血管性痴呆 (VD)，研究包括 10 名认知正常的老年人。痴呆症患者（AD 和 VD，p  < 0.01) 和 aMCI ( p  < 0.05) 的 MFV 低于 MCA 中的对照组（分别为 32.2 cm/s、31.9 cm/s 和 36.6 cm/s），痴呆患者的 PI 高于对照组（ AD 和 VD，均为p < 0.05)。基底 MFV 显示患者和对照组之间没有差异。在 ROC 曲线（曲线下面积值 0.85，95% CI 0.75–0.95）中发现 39.1 cm/s 的临界值，平均 MCA MFV 可预测认知障碍（CDR ≥ 0.5）。在本研究中，根据 CDR，低于 39.1 cm/s 的 MCA MFV 值可预测认知障碍。TCD 是一种廉价的方法，可用于临床场景，以帮助区分正常认知和认知衰退。应该进行多中心和纵向研究来验证这一点。