A 10-month-old infant has an enlarging head circumference and delayed overall development. She has a bulging anterior fontanelle and her CSF pressure is elevated. Based on these findings, answer the following questions:
(a) What are the possible cause(s) of an enlarged head?
(b) Which tests might be helpful in obtaining information about this infant's problem?
(c) Assuming the tests conducted showed the cerebral aqueduct to be constricted, which ventricles or CSF-containing areas would you expect to be enlarged? Which would likely not be visible? Respond to the same questions based on a finding of obstructed arachnoid granulations.