Table 1.
| Authors | Year | ASD (N) | Control (N) | ASD Age in Years (Mean±SD) | Control Age in Years (Mean±SD) | ASD IQ (Mean±SD) | Control IQ (Mean±SD) | Type of Analyses | DTI Findings | DTI Correlates |
|---|---|---|---|---|---|---|---|---|---|---|
| Barnea-Goraly et al. | 2004 | 7 | 9 | 14.6±3.4 | 13.4±2.8 | 101±12.2 | 107±8.5 | VBA | Reduced FA in ASD near venral prefrontal cortex, ACC, TPJ, STS, occipitotemporal tracts, and corpus callosum | -- |
| Alexander et al. | 2007 | 43 | 34 | 16.2±6.7 | 16.4±6.0 | 107.5±13.0 | 112.8±12.1/ | ROI | Reduced FA in ASD in the corpus callosum (with increased MD and RD) | FA and RD of corpus callosum correlated with age (in both groups) and with PIQ in ASD (not control). Corpus callosum MD and genu FA correlated with processing speed in ASD |
| Ben Bashat et al. | 2007 | 7 | 18 | Range: 1.8–3.3 | Range: 0.3–23.0 | -- | -- | ROI | Increased FA, probability, and displacement in young children with ASD | -- |
| Keller, Kana, & Just | 2007 | 34 | 31 | 18.9±7.3 | 18.9±6.2 | 102.0±14.8 | 109.5±9.0 | VBA | Reduced FA in ASD in 5 regions of white matter, including the corpus callosum, internal capsule, and forceps minor | FA positively correlated with age in ASD group in areas where group differences found |
| Lee et al. | 2007 | 43 | 34 | 16.2±6.7 | 16.4±6.0 | PIQ: 107.5±13.0 | PIQ: 112.8±12.0 | ROI | Reduced FA, increased MD, and increased RD in ASD in STG and temporal stem | Less age-related changes in FA of right STG in ASD group compared to TD group |
| Catani et al. | 2008 | 15 | 16 | 31±9 | 35±11 | 109±17 | 120±21 | ROI, Tractography | Reduced FA in cerebellum of Aspergers but no MD group differences | FA of left superior cerebellar peduncle negatively correlated with ADI-R social domain scores |
| Conturo et al. | 2008 | 17 | 17 | 26.46±2.73 | 26.08±2.69 | 104.41±2.08 | 105.24±2.34 | ROI, Tractography | Reduced RD in ASD in the right hippocampo-fusiform pathway. Increased RD and AD in ASD group in the left hippocampo-fusiform pathway and bilateral amygdalo-fusiform pathways | Decreased across-fiber diffusivity related to poorer Benton face interpretation and PIQ scores |
| Sundaram et al. | 2008 | 50 | 16 | 4.79±2.43 | 6.84±3.53 | -- | -- | ROI, Tractography | Increased MD in ASD in entire frontal lobe, and in long and short-range association fibers. Reduced FA in ASD for short-range but not long-range fibers | No relation between FA and GARS AQ after correcting for multiple comparisons |
| Thakkar et al. | 2008 | 12 | 12 | 30±11 | 27±8 | VIQ: 124±12 PIQ: 120±10 | estimated VIQ: 114±9 | VBA | Reduced FA in ASD in white matter near ACC, as well as DLPFC, VPFC, intraparietal sulcus. Increased FA in the right insula. | Greater ADI repetitive behavior scores related with decreased FA in white matter near the left subgenual rostral ACC and related with greater fMRI activation during correct trials in the right rostral ACC |
| Adluru et al. | 2009 | 41 | 32 | 16.23±6.70 | 16.44±5.97 | -- | -- | VBA, T-SPOON, Classification | ~72% specificity when classifying ASD from controls using the shapes of white matter tracts passing through the splenium of the corpus callosum | -- |
| Brito et al. | 2009 | 8 | 8 | median 9.53±1.83 | median 9.57±1.36 | -- | -- | ROI | Reduced FA in ASD in aspects of the corpus callosum, corticospinal tract, internal capsule, and cerebellum. Increased MD in ASD in aspect of the corpus callosum. Increased FA in aspect of putamen | -- |
| Cheung et al. | 2009 | 13 | 14 | 9.3±2.6 | 9.9±2.5 | 99.5±21.9 | 111.9±19.7 | VBA | Reduced FA in ASD in aspects of prefrontal lobes, ventral and middle temporal lobe, and cerebellum. Increased FA in ASD in superior longitudinal fasciculus and left occipital lobe | ADI-R social and communication scores negatively correlated with FA in fronto-striatal-temporal regions and posterior corpus callosum. ADI-R repetitive behavior scores negatively correlated with FA near basal ganglia, TPJ, splenium of corpus callosum, and cerebellum, but positively correlated with FA in left precentral gyrus |
| Ke et al. | 2009 | 12 | 10 | 8.75±2.26 | 9.40±2.07 | 100.60±18.79 | 99.83±17.93 | VBA, WM density | Reduced FA in ASD in aspects of inferior and middle frontal gyrus, and STG. Increased FA in ASD in aspects of frontal lobe, middle temporal gyrus, and sublobar extra nuclear area | FA of right frontal lobe (sub-gyral) positively correlated with CARS in children with ASD. No significant correlations with ADI-R |
| Knaus et al. | 2009 | 14 | 20 | 16.09 Range: 11–19 | 14.10 Range: 11–19 | VIQ mean: 103.29 PIQ mean: 102.57 | VIQ mean: 119.00 PIQ mean: 113.00 | ROI, Tractography | Atypical functional language laterality more common in ASD. No diagnostic group differences in FA, but those with more typical leftward lateralization had greater FA in the arcuate fasciculus across both ASD and control groups | -- |
| Lee et al. | 2009 | 43 | 34 | 16.23±6.70 | 16.44±5.97 | 107.5±13.0 | 112.8±12.1 | VBA, T-SPOON | Replicated results of Lee et al. (2007) and Alexander et al. (2007) using a T-SPOON voxel-based method. Diffuse MD and RD group differences observed | Found correlations between FA of corpus callosum and processing speed |
| Pardini et al. | 2009 | 10 | 10 | 19.7±2.83 | 19.9±2.64 | 49.20±6.94 | -- | VBA, Tractography | Reduced FA and WM volume in ASD in left OFC. Reduced FA in ASD in white matter near the ACC, the inferior and medial frontal gyri bilaterally, and the right superior frontal gyrus | In ASD group, IQ scores correlated positively with the mean FA values of the left orbitofrontal cortex network. |
| Pugliese et al. | 2009 | 24 | 42 | 23±12 | 25±10 | 104.7±12.05 | 121.2±16.1 | ROI, Tractography | No group differences in FA and MD. Higher number of streamlines in Aspergers in the cingulum and inferior longitudinal fasciculus. Lower number of streamlines in Aspergers in the right uncinate fasciculus | -- |
| Barnea-Goraly, Lotspeich, & Reiss | 2010 | 13 | 11 | 10.5±2.0 | 9.6±2.1 | 85.9±17.4 | 119.9±13.3 | VBA | No group differences in DTI measures between ASD and siblings. Reduced FA and reduced AD in ASD group and sibling group compared to control group in multiple regions across the frontal, temporal and parietal lobes | No significant correlations were found between the ADOS and ADI-R subscale scores and FA values |
| Bloemen et al. | 2010 | 13 | 13 | 39±9.8 | 37±9.6 | 110±15.7 | 115±14.4 | VBA | Reduced FA and increased RD in adults with Asperger syndrome over large areas of the brain. Reduced MD in brainstem in Asperger group | -- |
| Cheng et al. | 2010 | 25 | 25 | 13.71±2.54 | 13.51±2.20 | 101.60±18.91 | 109.04±9.45 | TBSS | Increased and decreased FA in ASD across multiple areas of the brain. Interaction effect of age by group, occurring mostly in the frontal lobe | -- |
| Fletcher et al. | 2010 | 10 | 10 | 14.25±1.92 | 13.36±1.34 | VIQ: 103.7±18.55 | VIQ: 102.7±9.52 | ROI | Increased MD and RD in left arcuate fasciculus in ASD. Lack of typical asymmetry between left and right AF in ASD | Both groups pooled demonstrated RD lateralization and CELF3 correlation |
| Kumar et al. | 2010 | 32 | 16 | 5.0 Range: 2.5–8.9 | 5.5 Range: 2.5–8.6 | -- | ≥85 | TBSS, ROI, WM volume | Reduced FA in ASD and DI groups across multiple areas, but no difference between ASD and DI groups. Longer uncinate and arcuate fibers in right hemisphere in ASD, whereas TD and DI children had longer UF and AF fibers in left hemisphere. | Fiber volume of the UF positively correlated with GARS stereotypic behavior, and fiber length and fiber density of the corpus callosum positively correlated with Vineland communication |
| Lange et al. | 2010 | 30 | 30 | 15.78±5.6 | 15.79±5.5 | 109.57±16.7 | 115.13±12.9 | ROI | Reversed hemispheric asymmetry in diffusion tensor skewness of the STG in ASD. Able to classify ASD from TD using the skew of the STG and temporal stem | FA of STG related to composite Vineland score. |
| Noriuchi et al. | 2010 | 7 | 7 | 13.96±2.68 | 13.36±2.74 | 92.71±6.68 | 116.43±9.50 | VBA | Reduced FA and AD in ASD in the left DLPFC, posterior STS/TPJ, right temporal pole, amygdala, SLF, and occipito-frontal fasciculus | FA of the left DLPFC was negatively correlated with total SRS scores in children with ASD |
| Sahyoun, Belliveau, & Mody | 2010 | 9 | 12 | 12.8±1.5 | 13.3±2.45 | 101.4±12.48 | 106.1±8.56 | TBSS | Reduced FA in ASD in multiple white matter tracts connecting with the frontal lobe. Increased FA in ASD in bilateral UF and right SLF | Group differences in the correlations between FA of different brain areas and task performance |
| Sahyoun, Belliveau, Soulieres, Schwartz, & Mody | 2010 | 9 | 12 | 12.8±1.5 | 13.3±2.45 | 101.4±12.48 | 106.1±8.6 | ROI, Tractography | Reduced FA in bilateral inferior frontal gyrus-fusiform gyrus and right inferior frontal gyrus-middle temporal gyrus tracts in ASD. No group differences in performance on a visuo-spatial task, but fMRI group differences in frontal and temporal activation | -- |
| Shukla, Keehn, Lincoln, & Müller | 2010 | 26 | 24 | 12.7±0.6(SEM) | 13.0±0.6(SEM) | VIQ: 105.6±3.6 (SEM) PIQ: 109.5 ± 3.3(SEM) | VIQ: 108.2 ± 2.6(SEM) PIQ: 110.3 ± 2.5(SEM) | VBA & ROI | Reduced FA, increased MD, and increased RD in ASD for whole-brain white matter and multiple regions across the brain. | Age negatively correlated with MD of the posterior limb of the internal capsule in both groups and with MD of the splenium in ASD. No correlations between DTI and ADOS/ADI-R scores |
| Sivaswamy et al. | 2010 | 27 | 16 | 5.0 Range: 2.6–9.0 | 5.9 Range: 2.6–8.9 | -- | -- | ROI | Increased MD in ASD in bilateral superior cerebellar peduncle, and increased FA in right middle cerebellar peduncle. Increased FA in ASD in left inferior cerebellar peduncle (but decreased FA in right) | -- |
| Thomas, Humphreys, Jung, Minshew, & Behrmann | 2010 | 12 | 18 | 28.5±9.7 | 22.4±4.1 | 106.92±10.47 | 111.6±9.91 | ROI | Decreased number of streamlines and voxels in ASD in the body and forceps minor of the corpus callosum. Leftward increase in volume in ASD in the inferior longitudinal fasciculus, the inferior fronto-occipital fasciculus, and the uncinate fasciculus. No group differences in FA | ADI-R repetitive behavior subscale negatively correlated with number of streamlines and voxels of the forceps minor. |
| Ameis et al. | 2011 | 19 | 16 | 12.4±3.1 | 12.3±3.6 | 98.5±20.4 | 100.7±14.5 | TBSS, post hoc ROI | Increased MD and RD in cortico-cortical and inter-hemispheric white matter tracts in ASD, especially in children and within the frontal lobe | -- |
| Beacher et al. | 2011 | 28 | 30 | Males: 32±10, Females: 32±7 | Males: 28±8, Females: 32±8 | -- | -- | ROI | Sex-by-diagnosis interactions in the corpus callosum, anterior cingulum, and corona radiata, with increased FA in TD males compared to females, but no sex difference in Aspergers | -- |
| Bode et al. | 2011 | 27 | 26 | 14.7±1.6 | 14.5±1.5 | -- | -- | TBSS | Increased FA and reduced RD in ASD in right inferior fronto-occipital fasciculus and right optic radiation | FA not correlated with age |
| Cheon et al. | 2011 | 17 | 17 | 11.0±2.1 | 10.2±2.0 | 112.1±12.0 | 113.8±11.0 | TBSS, ROI | Decreased FA and increased MD in right anterior thalamic radiation, corpus callosum, and left uncinate fasciculus in ASD | FA of right anterior thalamic radiation and right uncinate negatively correlated with SRS scores within ASD group |
| Groen, Buitelaar, van der Gaag, & Zwiers | 2011 | 17 | 25 | 14.4±1.6 | 15.5±1.8 | 98±18 | 105±9 | VBA, WM volume, GM volume | Increased overall MD in ASD. No difference in gray or white matter volume | -- |
| Hong et al. | 2011 | 18 | 16 | 8.7±2.18 | 9.8±1.9 | 105.2±21.1 | 106.1±20.1 | ROI, Tractography | Increased MD and decreased fiber number in ASD in anterior third of corpus callosum | No relations between DTI measures and CARS |
| Ingalhalikar, Parker, Bloy, Roberts, & Verma | 2011 | 45 | 30 | 10.5±2.5 | 10.3±2.5 | -- | -- | Classification, ROI | ~84% specificity in classifying ASD from controls, using MD of the left middle occipital gyrus, right STG, right superior occipital gyrus, right insula, right middle temporal, right internal capsule, right inferior temporal, and left caudate and using FA of the right inferior occipital white matter, the left fornix, the left SLF, the right inferior occipital gyrus, the right external capsule, the left caudate nucleus, the left hippocampus, the left posterior corona radiata, and left cuneus, and the right internal capsule | Classifier scores related to SRS and SCQ scores |
| Jeong, Kumar, Sundaram, Chugani, & Chugani | 2011 | 32 | 14 | 4.88±1.89 | 5.61±1.98 | -- | -- | Tractography, ROI | More curvature, higher bending, reduced FA, and increased RD in ASD in the bilateral arcuate, the bilateral uncinate, and genu of the corpus callosum (especially near the TPJ) | Negative correlations between curvature and FA in both groups in all three white matter ROIs. Positive correlations between curvature and RD in ASD in all three ROIs, but only in genu of the corpus callosum in the TD group |
| Langen et al. | 2011 | 21 | 22 | 25.57±6.08 | 28.45±6.39 | 107.45±15.08 | 109.82±13.71 | ROI | Reduced FA in ASD in left putamen tracts. Increased MD in ASD in right accumbens tract. ASD poorer accuracy on no-go portion of go/no-go task and smaller total brain white matter volume | No relation of FA and repetitive behaviors on ADI-R or ADOS. Possible relation between FA and go/no-go task performance, but not found within either group alone |
| Lo et al. | 2011 | 15 | 15 | 15.2±1.0 | 15.0±0.8 | 108.4±7.3 | 110.6±10.2 | ROI, Tractography | Reduced generalized FA in ASD in the three corpus callosum tracts under investigation. Leftward asymmetry pattern observed in controls but not in the ASD | -- |
| Pardini et al. | 2011 | 22 | -- | Age at post-therapy scan: 21.9±0.5 | -- | PIQ at therapy onset 48.9±1.6 | -- | VBA | Increased FA of the uncinate in those with ASD who highly adhered to the therapy versus those who moderately adhered to the therapy | FA of the uncinate positively correlated with both the difference between pre- and post-therapy autism symptom severity and the length of time in therapy but negatively correlated with the age of therapy onset |
| Poustka et al. | 2011 | 18 | 18 | 9.7±2.1 | 9.7±1.9 | 111.0±14.4 | 112.8±14.9 | VBA, Tractography | Reduced FA in ASD in right SLF and bilateral uncinate fasciculus | FA of left SLF and left uncinate negatively correlated with ADI-R communication & interaction scores. FA of right SLF negatively correlated with ADOS Communication. FA of left fornix negatively correlated with ADOS communication and interaction. FA of right fornix negatively correlated with ADI-R communication |
| Shukla, Keehn, & Müller | 2011 | 26 | 24 | 12.8±.6(SEM) | 13.0±0.6(SEM) | VIQ: 104.3±3.4(SEM) PIQ: 108.8±3.3(SEM) | VIQ: 108.2±2.6(SEM) PIQ: 110.3±2.5(SEM ) | TBSS | Reduced FA and increased MD for ASD in the anterior and posterior limbs of the internal capsule, the corpus callosum, inferior and superior longitudinal fasciculi, inferior fronto-occipital fasciculus, corticospinal tract, cingulum, and anterior thalamic radiation | FA of whole-brain white matter positively correlated with age in TD group but only marginally in ASD. MD and RD of whole-brain white matter negatively correlated with age in TD, but not in ASD |
| Shukla, Keehn, Smylie, & Müller | 2011 | 26 | 24 | 12.6±3.06(SEM ) | 13.0±2.94(SEM ) | VIQ: 106 ± 3.6(SEM) PIQ: 109.1 ±3.3(SEM) | VIQ: 108.2±2.6(SEM) PIQ: 110.3±2.5(SEM) | TBSS | Reduced FA in ASD in the short-distance tracts of the frontal lobes. Increased MD and RD in ASD in the short-distance tracts of the frontal, temporal, and parietal lobes | Positive correlation between age and FA and negative correlation between age and MD and RD for short-distance tracts in each lobe for the TD group. However, for the ASD group, correlations only significant in the frontal lobe |
| Verhoeven et al. | 2011 | 19 | 21 (+13 SLI) | 13.8±1.6 | 10.1±0.4 | -- | -- | ROI, Tractography | FA of SLF similar in ASD-language impairment and controls | FA of SLF not correlated with language scores in ASD |
| Weinstein et al. | 2011 | 21 | 26 | 3.2±1.1 | 3.4±1.3 | -- | -- | TBSS, Tractography | Increased FA and decreased RD in ASD in genu and body of corpus callosum, left SLF, and bilateral cingulum | -- |
| Jou et al. … Pelphrey | 2011 a | 15 | 8 | 10.9±3.8 | 11.5±2.6 | -- | -- | TBSS | Decreased FA in ASD in multiple tracts with the largest group differences occurring in the forceps minor, fronto-occipital fasciculus, and superior longitudinal fasciculus | No relation between FA and SRS after correcting for multiple comparisons |
| Jou et al. … Volkmar | 2011 b | 10 | 10 | 13.06±3.85 | 13.94±4.23 | 91.0±24.79 | 105.0±17.83 | VBA, Tractography | Reduced FA in the arcuate and inferior longitudinal fasciculi, SLF, corpus callosum/cingulum, and inferior fronto-occipital fasciculus | -- |
| Wolff et al. | 2012 | 92 high-risk infants: 28 met ADOS criteria for ASD at 24 month s | 64 did not meet criteria for ASD at 24 months | Time 1: 0.57±0.07 Time 2: 1.06±0.06 Time 3: 2.04±0.05 | Time 1: 0.56±0.07 Time 2: 1.06±0.05 Time 3: 2.06±0.07 | Time 1: 90.4±23.7 Time 2: 89.8±20.3 Time 3: 86.6±22.0 | Time 1: 102.1±15.7 Time 2: 101.3±14.5 Time 3: 99.0±18.0 | Tractography, ROI | Increased FA in ASD-positive high-risk siblings at 6 months of age, similar FA at 12 months, but decreased FA at 24 months compared to ASD-negative high-risk siblings | -- |
*
Reported asADC, assume equivalent to MD,
**
Reported as eigenvalues.
Notation changedin table to AD and RD: AD = l1, RD ~ either l2 or l3,
***
number of b0 not reported