Table 4.
Studies investigating multiple different mutations in FTLD.
| No. | Author | Year | Study design | No. of subjects | Techniques | Findings |
|---|---|---|---|---|---|---|
| 1 | Benussi et al. (70) | 2019 | Longitudinal | (48 aGRN+, 4 aC9+) vs. 73 NC | sMRI | GM volume loss in the insula |
| 2 | Jiskoot et al. (21) | 2019 | Longitudinal | 35 non-converter (27 aGRN+, 8 aMAPT+) vs. 30 NC | sMRI | Non-converter: no difference at any time point |
| 8 converter (3 GRN+, 5 MAPT+) vs. 30 NC | Converter: GM volume loss (the prefrontal, temporal, cingulate, and insular cortex) from 2 years before symptom onset | |||||
| DTI | Non-converter: no difference at any time point | |||||
| Converter: extensive lower FA (the genu corpus callosum, forceps minor, uncinate fasciculus, and superior longitudinal fasciculus) from 2 years before symptom onset | ||||||
| 3 | Dopper et al. (7) | 2014 | Cross-sectional | 39 carriers (28 aGRN+, 11 aMAPT+) vs. 36 NC | sMRI | No difference |
| DTI | Reduced FA in the right uncinate fasciculus | |||||
| rfMRI | Reduced functional connectivity in the SN | |||||
| 4 | Cash et al. (6) | 2018 | Cross-sectional | 23 aMAPT+, 65 aGRN+, 40 aC9+ vs. 144 NC | sMRI | Atrophy in the anterior insula |
| 5 | Panman et al. (22) | 2019 | Longitudinal | 14 aMAPT+ vs. 33 aGRN+ | sMRI | Baseline: no differenceFollow-up: Cortical thinning in the right temporal pole in aMAPT+Longitudinal: no difference |
| 14 aMAPT+ vs. 28 aGRN+ | DTI | No difference | ||||
| 6 | Panman et al. (22) | 2019 | Longitudinal | 11 aC9+ vs. 14 aMAPT+ (sMRI) | sMRI | Baseline and follow-up: lower GM volume in the cerebellum, thalamus, and insula in aC9+ Longitudinal: no difference |
| 12 aC9+ vs. 14 aMAPT+ | DTI | No difference | ||||
| 7 | Panman et al. (22) | 2019 | Longitudinal | 11 aC9+ vs. 33 aGRN+ | sMRI | Baseline and follow-up: lower GM volume in the cerebellum, thalamus, insula, and frontal cortical regions; and thinning cortical thickness in the precentral and postcentral gyrus in aC9+ |
| Longitudinal: no difference | ||||||
| 12 aC9+ vs. 28 aGRN+ | DTI | No difference |
aMAPT+, asymptomatic MAPT mutation carriers; HC, healthy controls; PET, positron emission tomography; AChE, acetylcholinesterase; MRS, magnetic resonance spectroscopy; mI, myo-inositol; Cr, creatine; NAA, N-acetylaspartate; PCC, posterior cingulate cortex; NC, non-carriers; sMRI, structural MRI; rfMRI, resting state functional MRI; DMN =default mode network; DTI, diffusion tensor imaging; FA, fractional anisotropy; DR, radial diffusivity; ASL, arterial spin labeling; GM, gray matter; MD, mean diffusivity; WM, white matter; FDG, fluorodeoxyglucose; aGRN+, asymptomatic GRN mutation carriers; sym, symptomatic; EO, expected onset; aC9+, asymptomatic C9orf72 mutation carriers; SN, salience network.