Table 1.
Longitudinal neuroimaging studies of idiopathic autism
| Reference | Samples, mean age at time 1 | Age range across all time points | Number of scans analyzed/participant | Average interscan interval | Imaging | Longitudinal analysis |
|---|---|---|---|---|---|---|
| Barnea-Goraly et al., 2014 [28] | 23 ASD, 23 TDC, age: 10.6 yrs., 100% male | 8–14 yrs. | 2 (73%) | 2.0 yrs. | Volumetric, amygdala and hippocampus | Mixed-effects regression |
| Frazier et al., 2012 [29] | 23 ASD, 23 TDC, age: 10.5 yrs., 100% male | 8–16 yrs. | 2 (80%) | 2.3 yrs. | Volumetric, corpus callosum | Mixed-effects regression |
| Hardan et al., 2009 [30] | 18 ASD, 16 TDC, age: 10.9 yrs., 100% male | 8–15 yrs. | 2 (82%) | 2.1 yrs. | Volumetric, lobar cortical thickness | Volumetric change over time; MANCOVA |
| Hazlett et al., 2011 [31] | 59 ASD, 38 TDC, age: 2.7 yrs., 81% male | 2–5 yrs. | 2 (59%) | 2.0 yrs. | Volumetric, total brain, cerebrospinal fluid, and so on | Linear-mixed models with repeated measures |
| Hua et al., 2013 [32] | 13 ASD, 7 TDC, age: 10.5 yrs., 100% male | 7–16 yrs. | 2 | 2.9 yrs. | Tensor-based morphometry, whole brain | Annual tissue growth rate maps, permutation tests |
| Jou et al., 2013 [33] | 23 ASD, 23 TDC, age: 10.6 yrs., 100% male | 8–17 yrs. | 2 (41%) | 2.0 yrs. | Volumetric, brainstem | Mixed-effects regression |
| Lange et al., 2014 [27▪▪] | 100 ASD, 56 TDC, age: 17.0 yrs., 100% male | 3–35 yrs. | 3 (47%) ≥ 2 (76%) | 2.6 yrs. | Volumetric, global, regional | Longitudinal mixed-effects, ANCOVA |
| Langen et al., 2014 [34] | 49 ASD, 37 TDC, age: 17.0 yrs., 100% male | 7–17 years | 2 | 2.3 yrs. | Volumetric; global brain, striatum | Volumetric growth per years; MANCOVA |
| Mosconi et al., 2009 [35] | 52 ASD, 33 TDC, age: 2.64 yrs., 81% male | 18–59 mos. | 2 | 2.0 yrs. | Volumetric, amygdala, total tissue | Mixed model repeated measures |
| Nordahl et al., 2012 [36] | 45 ASD, 25 TDC, age: 37 mos., 100% male | 2–4 yrs. | 2 (53%) | 13 mos. | Volumetric, amygdala, total cranial volume | Volume change over time, ANCOVA |
| Schumann et al., 2010 [37] | 41 ASD, 44 TDC, age: 12–67 mos., 75% male | 12–59 mos. | 2 (67%) ≥ 3 (33%) | 0–25 mos. | Volumetric, cerebral gray, white matter, lobar | Volume change over time, ANCOVA |
| Shen et al., 2013 [38] | 55 total, age: 6–9 mos., 67% male | 6–33 mos. | 3 (76%) | 6.5 mos. | Volumetric, total cerebral, extra-axial fluid, lateral ventricle | Linear mixed model for repeated measures |
| Zielinski et al., 2014 [39▪] | 97 ASD, 60 TDC, age: 16.8 yrs., 100% male | 3–43 yrs. | 3 (48%) ≥ 2 (76%) | 2.8 years | Cortical thickness | Longitudinal mixed-effects, ANCOVA |
ANCOVA, analysis of co-variance; ASD, autism spectrum disorder; MANCOVA, multivariate analysis of co-variance; mos., months; TDC, typically developing controls; yrs., years.