Colour-coded echographic flow imaging and spectral analysis of cerebrospinal fluid (CSF) in infants. Part II. CSF-dynamics.

41 comprehensive colour Doppler studies (including spectral analysis) of the ventricular system were performed in 6 infants with CSF-flow (age range: 2 to 27 days). Two premature infants showed no evidence of disease related to the central nervous system (CNS). Overt intraventricular hemorrhage or CNS-infection were present in the other infants. All children were examined several times until CSF-flow was no longer visible. The entire ventricular system, including the fourth ventricular outlet, was investigated for the presence of CSF-flow signals. Dynamic CSF-flow studies consisted of scanning during typical infant activity (crying, sucking, leg movement) and with external manoeuvres (abdominal or fontanellar palpation). CSF-flow was found to be: 1. synchronous with respiration 2. induced by rising intraabdominal (retrograde CSF-pulse) and transfontanellar pressure (orthograde CSF-pulse) 3. predominantly within the cerebral aqueduct, but also found at the foramina of Monro, within the third and fourth ventricles and at the foramen of Magendie. CSF-flow was not detected at the foramina of Luschka or within the lateral ventricles, except adjacent to the foramina of Monro. Dynamic CSF-flow as observed in infants may have important clinical and scientific implications. Examples of this are activity-related ventricular "reflux" of bacteria, erythrocytes, drugs, radionuclides or contrast; the importance of CSF-flow pulses for the development or progression of hydrocephalus; flow dynamics at the fourth ventricular outlet foramina and the study of CSF-pulse wave velocity and regional compliance. These issues are discussed and the new diagnostic approach is compared with other methods of CSF-investigation.