Table 1 Summary of C9ORF72 neuroimaging studies

Boxer et al. [12] (2011)

n = 5(4 bvFTD and 1 ALS)

C9⁺ patients showed atrophy in bilateral frontal, temporal, and parietal and right occipital regions.

Simón-Sánchez et al. [9] (2012)

n = 32(bvFTD, ALS, and PPA)

C9⁺ patients showed 'predominantly' frontotemporal atrophy in 23% and temporal atrophy in 42%. Thirteen percent showed generalized atrophy, and 9% showed no visible atrophy. Atrophy extended to the parietal region in 31% and included the cerebellum in 25%.

C9⁺ patients, compared with MAPT and GRN carriers, more often showed temporally predominant atrophy. MAPT and GRN were more often associated with frontally predominant atrophy.

Mahoney et al. [10] (2012)

n = 16(12 bvFTD, 3 FTD-MND, and 1 nfvPPA)

C9⁺ patients showed atrophy in the left orbitofrontal cortex, left frontal operculum, bilateral cerebellum, and bilateral thalamus.

C9⁺ patients showed more atrophy in the PFC and cerebellum compared with MAPT carriers and more atrophy in the left PFC compared with GRN carriers. MAPT showed more atrophy in temporal lobe, including hippocampus and amygdala, than C9⁺ patients. GRN showed more atrophy in the left temporal lobe, postcentral gyri, and inferior frontal gyri than C9⁺ patients.

Boeve et al. [8] (2012)

n = 18(14 bvFTD, 3 FTD-ALS, and 1 ALS)

Fourteen of eighteen C9⁺ patients showed frontal atrophy. Eight showed temporal atrophy. Five showed parietal atrophy. Three C9⁺ patients had no detectable atrophy.

Whitwell et al. [11] (2012)

n = 19

C9⁺ patients showed diffuse atrophy involving the frontal, temporal, parietal, and occipital lobes.

C9⁺ patients showed more atrophy in parietal, occipital, lateral, frontal, and cerebellar regions compared with sporadic FTD. Sporadic FTD showed more atrophy in the medial frontal lobe.

C9⁺ patients showed more atrophy in parietal, occipital, lateral, frontal, and cerebellar regions compared with MAPT. MAPT showed more atrophy in the anterior temporal regions.

Sha et al. [13] (2012)

bvFTD: n = 13FTD-MND: n = 8(Each diagnosis was analyzed separately.)

C9⁺ patients showed di3 use frontal anterior temporal, parietal, and cerebellar and thalamic atrophy compared with controls.

C9⁺ patients without MND showed more parietal and thalamic atrophy than sporadic bvFTD. Sporadic FTD showed more medial frontal atrophy. C9⁺ patients with MND showed more dorsal frontal, posterior, and cerebellar atrophy compared with sporadic FTD-MND.