Page 52 - PIECES OF THE PUZZLE Eline Vissia

CHAPTER 3
RESULTS
Hippocampal global and subfield volumes
We found a significant main effect of PTSD on global hippocampal volumes (F(2,54)=6.65, p=0.003) which was independent of hemisphere (group x side) (Wilks’ Lambda=0.97, F(1,57)=1.69, p=0.20). We also found a significant main effect of PTSD diagnosis on hippocampal subfield volumes (F(12,44)=3.19, p=0.002), also independent of hemisphere (group x side: Wilks’ Lambda=0.99, F(1,55)=0.052, p=0.82).
Bilateral global hippocampal volumes were significantly smaller (left: 6.75%; right 8.33%) in All-PTSD compared with HC (Table 3.2). Further pairwise t-tests (Table 3.2) showed that PTSD-DID had significantly smaller bilateral hippocampal volumes as compared with PTSD-only (left: 7.25%; right: 6.58%) and to HC groups (left: 10.19%; right: 11.37%). We also found a trend for a smaller right hippocampal volume in PTSD-only as compared with HC (right: 5.13%; p=0.067). Post hoc analyses (see supplementary material S3.3) revealed that bilateral hippocampal volumes were only significantly smaller in those PTSD-only patients with childhood onset traumatizing events (left: 7.11%; right: 7.31%) (see Figure 3.2).
Compared with HC, the All-PTSD group had significantly smaller volume in the bilateral CA2-3, right CA4-DG, and left presubiculum, and, at trend level, also in the right CA1, left CA4-DG and bilateral subiculum. Pairwise t-tests revealed that PTSD-DID patients had significantly smaller right CA1, bilateral CA2-3, CA4-DG and subiculum, and left presubiculum volumes than HC. Furthermore, the PTSD-DID group showed significantly smaller left CA4-DG and subiculum volumes than the PTSD-only group. In contrast, hippocampal subfield volumes of the PTSD-only group were not different from those of HC.
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