Does the brain regenerate after perinatal infarction?

We have used registered serial magnetic resonance scans to assess the growth of the brain after perinatal infarction in six infants. The initial scans were performed at ages of 4 days to 8 weeks and follow-up studies were performed from 4 days to 21 weeks later. A three-dimensional volume acquisition was performed on each occasion. Rigid body translations and rotations were used to match the images obtained on each occasion. Subtraction of the first image from the second then provided an assessment of the growth of the brain that had occurred between the two examinations. In the early phase of infarction (up to 2 months) low signal areas with clearly defined margins developed at the site of infarction. In the late phase (2 months onwards) growth was seen in the brain at the margins of the infarct in each case, and the size of the infarcted region showed a marked decrease in size. The rate of growth of the brain into the infarcted area exceeded that of the surrounding brain in some cases and was less in others. Growth of undamaged tissue may provide an important mechanism for recovery of the developing brain.