Asymmetrical myelination of the posterior limb of the internal capsule in infants with periventricular haemorrhagic infarction: An early predictor ofhemiplegia

Aim: To prospectively assess the predictive value of asymmetrical myelinati on on MRI of the posterior limb of the internal capsule (PLIC) in newborn i nfants with an intraventricular haemorrhage (IVH) associated with unilatera l haemorrhagic parenchymal involvement (PI), for subsequent development of a hemiplegia. Methods: 12 preterm infants (GA 25 -36 wks) and 4 full-term infants were st udied, Using cranial ultrasound (US), the preterm infants were diagnosed to have an IVH with unilateral PI. The term infants presented with a porencep halic cyst (PC) on the first postnatal US, following an antenatal IVH with Pi. MRI was performed at 40 wks postmenstrual age in the preterm infants an d during the first 2 weeks of life in the full-term infants, using a 1.5T m agnet. Using an inversion recovery sequence, the myelination of the interna l capsule was recorded as normal, abnormal or equivocal, Neurological asses sment greater than or equal to 12 months disclosed the presence of a hemipl egia or asymmetry in tone pattern. Results: All 4 cases with a normal internal capsule had a normal outcome in spite of the development of a PC. All 9 cases with an abnormal PLIC develo ped a hemiplegia, while 1 of the 3 cases with an equivocal PLIC Is normal o n neurological assessment, one developed a mild asymmetry in tone and la mi ld hemiplegia. Conclusion: While a symmetrical signal intensity within the internal capsul e on MRI, performed at 40 weeks PMA, in infants with an IVH and unilateral PI appears to be strongly related to a normal outcome, an asymmetrical PLIC is an early predictor of future hemiplegia.