ObjectiveMost neurodegenerative dementias present with substantial overlap in clinical features. Therefore, differential diagnosis is often a challenging task necessitating costly and sometimes invasive diagnostic procedures. A promising, non-invasive and cost-effective method is the widely available electroencephalography (EEG).MethodsTwenty-three subjects with Alzheimer’s disease (AD), 28 subjects with dementia with Lewy bodies (DLB), 15 subjects with frontotemporal dementias (FTDs), and 22 healthy controls (HC) were enrolled. Nineteen channel computerized EEG recordings were acquired. Mean relative powers were calculated using the standard frequency bands. Theta/alpha ratio (TAR), theta/beta ratio (TBR), a spectral index of (alpha + beta)/(theta + delta) and an alpha reactivity index (alpha in eyes-open condition/alpha in eyes-closed condition) were also calculated. Receiver operating characteristic (ROC) analyses were performed to assess diagnostic accuracy.ResultsFor the comparison of EEG measures across groups, we performed a multivariate ANOVA followed by univariate ANOVAs controlling for the effects of age, with post hoc tests. Theta power and TBR were increased in DLB compared to other groups. Alpha power was decreased in DLB compared to HC and FTD; and in AD compared to FTD. Beta power was decreased in DLB compared to AD and HC. Furthermore, regional analyses demonstrated a unique pattern of theta power increase in DLB; affecting frontal, central, parietal, occipital, and temporal regions. In AD, theta power increased compared to HC in parietal, occipital, and right temporal regions. TAR was increased in DLB compared to other groups; and in AD compared to HC. Finally, alpha reactivity index was higher in DLB compared to HC and FTD. In AD, EEG slowing was associated with cognitive impairment, while in DLB, this was associated with higher DLB characteristics. In the ROC analyses to distinguish DLB from FTD and AD, measures of EEG slowing yielded high area under curve values, with good specificities. Also, decreased alpha reactivity could distinguish DLB from FTD with good specificity. EEG slowing in DLB showed a diffuse pattern compared to AD, where a posterior and temporal slowing predominated.ConclusionWe showed that EEG slowing was satisfactory in distinguishing DLB patients from AD and FTD patients. Notably, this slowing was a characteristic finding in DLB patients, even at early stages, while it paralleled disease progression in AD. Furthermore, EEG slowing in DLB showed a diffuse pattern compared to AD, where a posterior and temporal slowing predominated. These findings align with the previous evidence of the diencephalic dysfunction in DLB.

中文翻译：

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定量脑电图在痴呆亚型鉴别诊断中的应用

目的大多数神经退行性痴呆的临床特征有很大的重叠。因此，鉴别诊断通常是一项具有挑战性的任务，需要昂贵且有时是侵入性的诊断程序。广泛使用的脑电图 (EEG) 是一种有前途、非侵入性且经济有效的方法。方法 23 名阿尔茨海默病 (AD) 受试者、28 名路易体痴呆 (DLB) 受试者、15 名额颞叶痴呆 (FTD) 受试者，并招募了 22 名健康对照 (HC)。获取了十九通道计算机脑电图记录。使用标准频带计算平均相对功率。Theta/alpha 比率 (TAR)、theta/beta 比率 (TBR)、(alpha + beta)/(theta + delta) 光谱指数和 alpha 反应性指数（睁眼条件下的 alpha/闭眼条件下的 alpha） ）也进行了计算。进行受试者操作特征（ROC）分析以评估诊断准确性。结果为了比较各组脑电图测量值，我们进行了多变量方差分析，然后进行单变量方差分析，通过事后检验控制了年龄的影响。与其他组相比，DLB 组的 Theta 功率和 TBR 有所增加。与 HC 和 FTD 相比，DLB 的 Alpha 功率降低；AD 与 FTD 相比。与 AD 和 HC 相比，DLB 的 Beta 功率降低。此外，区域分析证明了 DLB 中 θ 功率增加的独特模式；影响额叶、中央、顶叶、枕叶和颞叶区域。在 AD 中，与 HC 相比，顶叶、枕叶和右颞叶区域的 theta 功率有所增加。与其他组相比，DLB 组的 TAR 增加；AD 与 HC 相比。最后，与 HC 和 FTD 相比，DLB 中的 α 反应指数更高。在 AD 中，脑电图减慢与认知障碍相关，而在 DLB 中，这与较高的 DLB 特征相关。在区分 DLB 与 FTD 和 AD 的 ROC 分析中，EEG 减慢的测量产生了高曲线下面积值，具有良好的特异性。此外，降低的 α 反应性可以以良好的特异性区分 DLB 和 FTD。与 AD 相比，DLB 患者的脑电图减慢表现出弥漫性模式，其中后部和颞部减慢占主导地位。结论我们表明，脑电图减慢在区分 DLB 患者与 AD 和 FTD 患者方面是令人满意的。值得注意的是，这种减慢是 DLB 患者的一个特征性发现，即使在早期阶段也是如此，同时它与 AD 的疾病进展平行。此外，与 AD 相比，DLB 中的脑电图减慢表现出弥漫性模式，其中后部和颞部减慢占主导地位。这些发现与 DLB 间脑功能障碍的先前证据一致。