Table 4 Summary of EEG and MEG studies
From: Neuroimaging advances regarding subjective cognitive decline in preclinical Alzheimer’s disease
Authors | Definition of SCD | Modality | Design | Sample (mean age ± SD) | Main findings |
|---|---|---|---|---|---|
Alexander et al. (2006) [171] | Memory clinic consultation | EEG | Cross-sectional | NC: n = 79 (63.1 ± 7.9) SCD: n = 100 (64.9 ± 8.7) | SCD showed higher alpha power and changes in wave activity both related to decreased memory. |
Babiloni et al. (2010) [172] | Memory clinic consultation | EEG | Cross-sectional | NC: n = 79 (69.7 ± 0.9) SCD: n = 53 (69.0 ± 1.0) aMCI: n = 92 (72.0 ±) naMCI: n = 51 (73.0 ± 1.1) | SCD showed greater frontal delta sources and lower parietal and occipital theta sources in amplitude. |
Gouw et al. (2017) [173] | Criteria by SCD-I | EEG | Cross-sectional | SCD: n = 63 (66.2 ± 8.2) MCI: n = 142 (68.3 ± 7.4) | In SCD, higher delta and theta power and lower alpha power and peak frequency were associated with clinical progression |
Teipel et al. (2018) [178] | 2 binary questions | EEG and 18F-florbetapir-PET | Cross-sectional | SCD amyloid-: n = 255 (75.9 ± 3.5) SCD amyloid +: n = 63 (76.7 ± 3.5) | Amyloid accumulation does not impair cortical FC in SCD. |
Lopez-Sanz et al. (2016) [175] | Self-reported cognitive concerns, older than 60 | MEG and T1 MRI | Cross-sectional | NC: n = 39 (70.4 ± 3.7) SCD: n = 41 (71.6 ± 4.5) MCI: n = 51 (73 ± 3.7) | SCD and MCI exhibited a similar reduction in alpha band activity compared with NC. MCI showed a slowing in alpha peak frequency compared with both SCD and NC. |
Lopez-Sanz et al. (2017) [168] | Self-reported cognitive concerns, older than 60 | MEG and T1 MRI | Cross-sectional | NC: n = 39 (70.4 ± 3.7) SCD: n = 41 (71.6 ± 4.5) MCI: n = 51 (73 ± 3.7) | SCD and MCI showed lower FC in a hyper-synchronized anterior network and a posterior network. |
Lopez-Sanz et al. (2017) [168] | Self-reported cognitive concerns, older than 60 | MEG and T1 MRI | Cross-sectional | NC: n = 63 (70.7 ± 4.5) SCD: n = 55 (71.0 ± 5.0) MCI: n = 69 (71.9 ± 4.2) | SCD showed decreased clustering and transitivity in theta and beta bands but increased modularity and transitivity in alpha band. |
Maestu et al. (2011) [176] | Patient stating that their memory function has deteriorated compared to earlier stages in life | MEG | Cross-sectional | NC: n = 6 (72 ± 8) SCD: n = 12 (72 ± 6) MCI: n = 21 (75 ± 3) | The SCD showed higher activation than the control group in posterior ventral regions and in the dorsal pathway. MCI patients showed higher activation than the control group in the posterior part of the ventral pathway. |
Prichep et al., (2006) [174] | Memory clinic consultation | EEG | Cross-sectional | Nondecliners: n = 17 (70.0 ± 4.1) Decliners: n =27 (73.5 ± 4.9) | Decliners showed increase in theta power. |