Pre-Wallerian Degeneration in the Neonatal Brain Following Perinatal Cerebral Hypoxia–Ischemia Demonstrated with MRI

Aim

Pre-Wallerian degeneration was studied in term and near-term neonates with hypoxic–ischemic brain injury, and related to neurodevelopmental outcome.

Subjects

Thirty-nine surviving patients with hypoxic-ischemic encephalopathy or seizures and MRI-documented brain abnormalities were included. Patients were grouped according to the MRI findings: group 1 (n = 23), ischemic stroke or watershed infarcts; group 2 (n = 8), lesions of the basal ganglia; group 3 (n = 8), predominantly white matter lesions.

Methods

Cranial MRI, including diffusion-weighted MRI, was performed between 1 and 10 days after birth. ADC maps were created, and presence or absence of pre-Wallerian degeneration in the cerebral peduncles was assessed.

Results

Of the 15 neonates with pre-Wallerian degeneration, 14 had permanent abnormalities of motor development, whereas 1 had a transient asymmetry. Six neonates with a poor outcome had no pre-Wallerian degeneration, which may be contributed to the timing of the MRI in 2. Eighteen neonates had no pre-Wallerian degeneration and a normal motor development.

Conclusion

Pre-Wallerian degeneration of the cerebral peduncles in neonates with hypoxia–ischemia is almost invariably associated with a poor motor development. In neonates with abnormalities of the basal ganglia or white matter and a poor outcome, pre-Wallerian degeneration is less common than in neonates with stroke or watershed infarcts and a poor motor outcome.

Keywords:  hypoxia–ischemia , neonate , MRI , diffusion , neurodevelopment , Wallerian degeneration