Diffusion‐weighted imaging changes in cerebral watershed distribution following neonatal encephalopathy are not invariably associated with an adverse outcome

Abstract

ABBREVIATIONS aEEGAmplitude integrated electroencephalography DNV Discontinuous normal voltage DWI Diffusion-weighted imaging AIM Patterns of injury in term-born infants with neonatal encephalopathy following hypoxiaischaemia are seen earlier and are more conspicuous on diffusion-weighted magnetic resonance imaging (DW-MRI) than on conventional imaging. Although the prognostic value of DW-MRI in infants with basal ganglia and thalamic damage has been established, data in infants in whom there is extensive injury in a watershed distribution are limited. The aim of this study was to assess cognitive and functional motor outcome in a cohort of infants with changes in a predominantly watershed distribution injury on neonatal cerebral MRI, including DWI.METHOD DW-MRI findings in infants with neonatal encephalopathy following hypoxiaischaemia were evaluated retrospectively. Twenty-two infants in whom DWI changes exhibited a predominantly watershed distribution were enrolled in the study (10 males, 12 females; mean birthweight 3337g, 2830-3900g; mean gestational age 40.5wks, 37.9-42.1wks). Follow-up MRI data at the age of 3 months (n=15) and over the age of 18 months (n=7) were analysed. In survivors, neurodevelopmental outcome was assessed with the Griffiths Mental Development Scales at the age of at least 18 months. Amplitude-integrated electroencephalography was used to score background patterns and the occurrence of epileptiform activity.RESULTS DW-MRI revealed abnormalities that were bilateral in all infants and symmetrical in 10. The posterior regions were more severely affected in five infants and the anterior regions in three. Watershed injury occurred in isolation in 10 out of 22 infants and was associated with involvement of the basal ganglia and thalami in the other 12, of whom seven died. Cystic evolution, seen on MRI at age 3 months, occurred in three of the 15 surviving infants. Neurodevelopmental assessment of the surviving infants was performed at a median age of 35 months (range 18-48mo). Of the five survivors with basal ganglia and thalamic involvement, two developed cerebral palsy, one had a developmental quotient of less than 85, and two had a normal outcome. Of the 10 infants with isolated watershed injury, nine had an early normal motor and cognitive outcome. In all infants with a favourable outcome, background recovery was seen on amplitude integrated EEG within 48 hours after birth.CONCLUSION Extensive DWI changes in a watershed distribution in term-born neonates are not invariably associated with adverse sequelae, even in the presence of cystic evolution. Associated lesions of the basal ganglia and thalami are a better predictor of adverse sequelae than the extent and severity of the watershed abnormalities seen on DW-MRI.

Severe Neonatal Anaemia, MRI Findings and Neurodevelopmental Outcome

“…It is of interest that early neurodevelopmental and motor outcomes in the first 2 years of life in the survivors is favourable. In the absence of damage in the thalamus and basal ganglia, neonatal anaemia itself does not have a significant effect on outcome at 2 years of age [12]. However, the children are still young and their outcome should be re-assessed at school age.…”

Serial 1- and 2-Dimensional Cerebral MRI Measurements in Full-Term Infants after Perinatal Asphyxia

“…However, we were able to analyze and compare infants with normal MRI or with different patterns of injury on their first MRI, such as WS pattern of injury, BGT pattern of injury, and perinatal arterial ischemic stroke without involvement of the BGT [10]. …”

“…Cystic evolution in the BGT or the white matter is almost invariably associated with severe adverse neurological sequelae [9,10]. In the absence of cystic evolution, but with visually apparent volume loss, outcome is more variable and more difficult to predict.…”

Comparison of early and late MRI in neonatal hypoxic–ischemic encephalopathy using three assessment methods

“…It distinguished normal/subnormal MR images (normal MRI, punctate periventricular white matter injury pattern, and watershed pattern with a W score ≤2) and abnormal MR images (watershed pattern with W score >2, central or diffuse pattern). Punctate periventricular white matter injuries and watershed injuries limited to anterior or posterior white matter are known to be associated with a favorable outcome -no or mild to moderate neurodevelopmental disabilities in childhood -in studies performed before the introduction of hypothermia [4,22,[24][25][26][27]. More extensive watershed injuries and central and diffuse patterns are associated with a poor outcome [1,24].…”

“…The overall BG score was 4, whereas the conventional imaging BG score was 2 Results are expressed as number of neonates with abnormal posterior limb of internal capsule signal intensity/ total number of neonates most watershed zone injuries were associated with central lesions or involved diffuse white matter and were classified as diffuse patterns according to our criteria. In some studies watershed injuries have been classified as watershedpredominant patterns of injury, involving lesions of more heterogeneous severity [15,16,25,27,[34][35][36]. The use of a diffuse pattern in our classification was interesting because it enabled more severe injuries to be classified in a separate group.…”