Article

Angelman syndrome is a neurogenetic disorder characterized by severe
intellectual disability, absent speech, seizures, and outbursts of laughter. The
aim of this study was to utilize diffusion tensor imaging (DTI) to examine
alterations in white matter pathways in Angelman syndrome, with an emphasis on
correlations with clinical severity. METHOD: DTI was used to examine the arcuate
fasciculus (AF), uncinate fasciculus (UF), inferior longitudinal fasciculus
(ILF), inferior fronto-occipital fasciculus (IFOF), and the corpus callosum (CC).
We enrolled 14 children aged 8 to 17 years (mean age 10y 8mo; SD 2y 7mo) with
Angelman syndrome (seven male; seven female) and 13 typically developing
children, aged 8 to 17 years, for comparison (five male; eight female; mean age
12y; SD 2y 9mo). Individuals with Angelman syndrome were assessed using
standardized measures of development, language, and behaviour. RESULTS: The
children with Angelman syndrome exhibited lower fractional anisotropy and
increased radial diffusivity values than the comparison group for the AF, UF,
ILF, and CC (p < 0.006 corrected for multiple comparisons). They also had lower
fractional anisotropy values for the IFOF and higher radial diffusivity values
for the left IFOF (p < 0.006). Additionally, children with Angelman syndrome had
significantly higher apparent diffusion coefficient values in the AF, CC, ILF,
and the left IFOF (p < 0.006). Significant correlations were noted between DTI
parameters and some of the clinical assessment outcomes (e.g. language,
socialization, cognition) for three of the temporal pathways (AF, UF, ILF; p <
0.05). Interpretation: Changes in DTI parameters in individuals with Angelman
syndrome suggest decreased/delayed myelination, decreased axonal density or
diameter, or aberrant axonal organization. Our findings suggest a generalized
white matter alteration throughout the brain in those with Angelman syndrome;
however, only the alterations in temporal white matter pathways were associated
with language and cognitive and social functioning.
CI - (c) The Authors. Journal compilation (c) Mac Keith Press 2010.

Langue : ANGLAIS