Intellectual and visuo-spatial assessment in long-term pediatric liver transplantation for biliary atresia.

Biliary atresia affects children in the first few months after birth. Therefore, the need for liver transplantation (LT) is early. Studies examining the cognitive and neuropsychological outcomes of patients who underwent LT identified deficits in global intellectual assessment (1), language performance (2), attention, and memory (3). In contrast, visuo-motor tests were normal after the LT (4). In these studies, a variety of pretransplant diagnoses and ages at transplantation were included. Thus, we assessed intellectual and visuo-spatial status in the late postoperative phase (average 9.2 years postoperatively) of children who had undergone LT with a diagnosis of biliary atresia. The sample consisted of 13 children (nine females and four males) who obtained postoperative follow-up for at least 4 years. The mean age at testing time was 10.5 years. Intellectual performances were assessed with the five subscales of Wechsler Intellectual Scale for Children, fourth edition (WISC-IV) (5): total intellectual quotient and the four composite indices: verbal comprehension index (VCI), perceptual reasoning index (PRI), processing speed index (PSI), and working memory index. The visuospatial status was assessed by the REY figure copy test (6). The children scored in the normal range on the total intellectual quotient, VCI, PRI, and PSI, see Table 1. The Wilcoxon rank sum test shows that the children scored significantly below the norm in the working memory index (P 0.003) and the REY figure copy test (P 0.001). In contrast to Adebäck et al. (1), the current study shows no difference between LT children performances and normal values in total intelligence score, verbal and nonverbal (i.e., performance reasoning) parts. Furthermore, no difference is observed between LT children performances and normal values in PSI. The difference between the two studies can be explained by the two versions of the WISC test. First, the WISC-IV is composed of four composite scores instead of two in the WISC-III. Second, the verbal part of the WISC-III was composed of arithmetic subtest, which is considered as a sensitive task to the working memory and attention components. Third, the performance part was made of object assembly and image completion very sensitive subtests to the visuo-spatial performances. In the visuo-spatial domain, contrary to LT adults who performed normally 2 years postoperatively (4), LT children demonstrate weak performances several years after the transplantation. The current study cannot provide definitive evidence concerning effects of LT on intellectual functions because of the lack of baseline testing before the LT attributed to the age limits of the tests and the relatively small group size. Nevertheless, it seems that the early age at LT and the long period after the LT are positive factors, which allow the children who underwent LT to perform normally in total intellectual, VCI, PRI, and PSI scores. However, the domains of working memory and visuo-spatial functions are deficient even after a 9.2 year average postoperative period in LT children. Thus, we suggest that the liver failure these children experienced caused cerebral dysfunction, which led to the longterm damage in these two cognitive components.