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The effect of raised intracranial pressure (ICP), due to infantile hydrocephalus, on the process of myelination has been suggested in the literature. In this study 19 hydrocephalic infants were followed-up with anterior fontanelle pressure (AFP) measurement (assessment of ICP), MRI (assessment of the myelination process and the CSF volume), and neurodevelopmental testing (NDT). There was a high correlation (r = 0.80) between the myelination and NDT scores. The size of the CSF volume showed a poor correlation with the mean AFP, the degree of myelination and the NDT scores. There was, however, a significant correlation between the mean AFP and the degree of myelination (r = 0.67) and also between the mean AFP and the NDT scores (r = 0.70). Longer-term follow-up (mean = 27 months) showed a significant correlation between the early progress of myelination and later developmental level (r = 0.78). Most of the children with a severely delayed myelination, preoperatively, showed a recovery of myelination following CSF drainage. It was concluded that: (1) raised ICP is related to developmental outcome, through the process of myelination; (2) the delay in myelination can be (partially) reversible; and (3) CSF volume is of minor importance regarding neurodevelopment.

A prospective cross-sectional study was performed on hydrocephalic infants and children. MRI was used to assess the state of myelination and to quantify the intracranial cerebrospinal fluid (CSF) volume repeatedly in all children. At the same time, neurodevelopmental testing was performed. A positive correlation was found between the progress of myelination and psychomotor development, but there were no significant correlations between CSF volume and myelination or between CSF volume and psychomotor development. This study provides strong evidence in favour of Flechsig's thesis that myelination expresses the functional maturity of the brain. The interdependency of neuronal maturation and progress of myelination are discussed.

CT scanning was done to calculate the volume of intracranial spaces in children with the purpose of developing a reliable method of differentiating the various causes of macrocephaly. The technique has been applied to the CT scans of 60 apparently normal children, and the resulting graphs show the normal relationship between intracranial volumes and age from birth to 15 years. The measurements for 25 children with macrocephaly and normal rate of growth of head circumference were then compared with the reference values. It was possible to make accurate differentiations between megalencephaly, extraventricular hydrocephalus and communicating hydrocephalus. The advantage of this technique in relation to length measurements on CT scans is discussed. The authors advocate the estimation of the product of head circumference and head height as a much more reliable indication of normal and deviant head-size than head circumference alone.