T2 hyperintense signal of the central tegmental tracts in children: disease or normal maturational process?

Cerebral central tegmental tract hyperintense signal on T2-weighted MRI (CTTH) is known from various clinical conditions, including children treated with vigabatrin (VGB) for West syndrome (WS), with hypoxic-ischemic brain injury, and metabolic diseases. Considering this clinical diversity, we hypothesized that CTTH might primarily mirror a physiologic process. We retrospectively analysed brain MRI data of the central tegmental tracts deriving from four different groups: (1) children with WS and VGB therapy (WS+VGB+), (2) children with WS but without VGB therapy (WS+VGB-), (3) children with different neurological diseases (WS-VGB-; maximum age 15 years), and (4) controls younger than 25 months of age (this age includes the peak age of WS). CTTH were detected in 4/17 WS+VGB+ children (24%), 4/34 WS+VGB- children (12%), 18/296 WS-VGB- children (6%), and 8/112 controls (7%). Independently from the underlying diagnosis, CTTH showed a peak age during early infancy and were not found before 4 months and after 7 years of life. The rate of CTTH among WS children +/- VGB therapy was similar so that VGB therapy seems of minor etiological impact. However, comparison of WS patients younger than 25 months of age (CTTH present in 7/40) with age-matched controls (CTTH present in 8/112) revealed that CTTH tend to be more frequent among WS patients in general. Our study suggests that CTTH represents a physiological maturation-related process. The high prevalence of CTTH among patients with WS indicates that this physiological process may be modified by additional endo- or exogeneous factors.