Serial ultrasonographic observation of bilateral thalami in low birth weight infants with periventricular leukomalacia

Periventricular leukomalacia is a major form of neuropathology in preterm infants that is associated with adverse motor and cognitive outcomes. The volume of periventricular white matter and corpus callosum has been reported to be diminished in infants with PVL, and the degree of the volume loss is correlated with the severity of neurological impairment. The thalamic index was calculated from the length, height, width of the thalamus, and thalamic volume was calculated using the formula for an ovoid in 62 low birth weight infants with gestational ages of 24–35 weeks, 51 control infants (cerebral palsy, 1 case), and 11 infants diagnosed with PVL (cerebral palsy, 7 cases) at postnatal days 0–70. The indices of the right thalamus were lower in infants with PVL than in control infants from day 0 to day 70, and there were significant differences on days 21, 28, 35, 42, 49, 56, 63, and 70. The indices of the left thalamus were lower in infants with PVL than in control infants from day 0 to day 70, and there were significant differences on days 21, 28, 35, 42, 49, 56, 63, and 70. The results of the present study suggest that the volume of the thalami is reduced and that thalamic injury is associated with white matter lesions in infants with PVL.