Table 1.
Summary of studies published between 2006–2012 investigating amygdala volumetry in patients with ASD compared with control subjects*
| Study | Subjects | Age in years (s.d.) | Full-scale IQ | Field strength (T) | Significant findings in ASD relative to controls |
|---|---|---|---|---|---|
| Dziobek et al. (2006) | 17 AS | 41.4 (9.9) | 113 (6) | n.r. | No differences in bilateral amygdala volume |
| 17 TD | 40.2 (13.0) | 115 (5) | |||
| Nacewicz et al. (2006) | 12 ASD | 16.8 (4.5) | n.r. | 3.0 | No differences in bilateral amygdala volume |
| 12 TD | 17.0 (2.9) | n.r. | |||
| Nacewicz et al. (2006) | 16 ASD | 14.3 (4.7) | 97 (26) | 3.0 | Reduction in bilateral amygdala volume, particularly in the older subgroup (>12.5 years) |
| 14 TD | 13.7 (3.9) | 122 (13) | |||
| Palmen et al. (2006) | 42 HFA | 15.6 (5.3) | 110.7 (16.9) | 1.5 | No differences in bilateral amygdala volume |
| 42 TD | 15.3 (5.4) | 107.6 (13.4) | |||
| Corbett et al. (2009) | 12 HFA | 9.0 (1.6) | 90.7 (13.8) | 1.5 | No differences in bilateral amygdala volume |
| 15 TD | 9.2 (1.4) | 115.7 (15.8) | |||
| Mosconi et al. (2009) | 50 ASD | 2.7 (0.3) | 53.8 (9.0) | 1.5 | Enlargement in bilateral amygdala volume |
| 11 DD | 2.8 (0.4) | 56.6 (16.9) | |||
| 22 TD | 2.5 (0.5) | 105.8 (16.0) | |||
| Mosconi et al. (2009)‡ | 31 ASD | 5.0 (0.4) | 56.6 (16.9) | 1.5 | Enlargement in bilateral amygdala volume |
| 6 DD | 5.0 (0.5) | 56.0 (6.8) | |||
| 14 TD | 4.6 (0.5) | 112.3 (12.3) | |||
| Schumann et al. (2009) | 32 (m)AD | 36 (7.2) months | 58 (20) | 1.5 | Enlargement in bilateral amygdala volume in AD, particularly evident in (f) |
| 9 (f)AD | 36 (4.7) months | 57 (23) | |||
| 6 (m)PDD-NOS | 36 (9.1) months | 93 (32) | |||
| 3 (f)PDD-NOS | 56 (6.1) months | 63 (19) | |||
| 28 (m)TD | 34 (7.1) months | 111 (17) | |||
| 11 (f)PDD-NOS | 37 (6.4) months | 115 (15) | |||
| Groen et al. (2010) | 23 AD | 15.1 (1.9) | 99.5 (20.1) | 1.5 | Enlargement in right amygdala volume |
| 29 TD | 15.6 (1.7) | 104.9 (9.6) | |||
| Kim et al. (2010) | 31 ASD | 6.5 (0.3) | 70.9 (23.2) | 1.5 | Enlargement in bilateral amygdala volume (laterobasal subregions) |
| 20 TD | 6.5 (0.4) | 115.6 (13.9) | |||
| Murphy et al. (2012) | 32 AS | 23 (11) | 108 (13) | 1.5 | Enlargement in bilateral amygdala volume |
| 32 TD | 23 (11) | 111 (15) | |||
| Nordahl et al. (2012) | 85 ASD | 36.8 (5.7) months | 63.4 (22.1) | 3.0 | Enlargement in bilateral amygdala volume |
| 47 TD | 36.9 (5.3) months | 103.8 (11.8) | |||
| Nordahl et al. (2012)‡ | 45 ASD | 49.0 (5.5) months | n.r. | 3.0 | Enlargement in bilateral amygdala volume |
| 25 TD | 51.2 (4.9) months | n.r. |
*Due to editorials guideline of limited number of references, only the most recent MRI studies on amygdala in ASD were considered, starting from year 2006.
‡Follow-up study; ASD, autism spectrum disorders; TD, typically developing control subjects; RD, subjects with reading disorders; HFA, high-functioning autism; LFA, low-functioning autism; AD, autistic disorder; AS, Asperger syndrome; ADM, autistic disorder with macrocephaly; TDM, typically developing control subjects with macrocephaly PAD, parents of children with autistic disorder; (m), males; (f), females; PDD-NOS, Pervasive developmental disorder not otherwise specified; PIQ, performance IQ; n.r., not reported; DD, developmental delay.