Increased intracranial pressure in infants with cystic fibrosis [letter].

Although the mechanism proposed by Dr Katznelson for the increased intracranial pressure 
observed in three infants with cystic fibrosis cannot be discounted, another 
explanation is possible. It has been reported previously that a deficiency 
of vitamin A may predispose to development of increased intracranial pressure 
and bulging fontanelles in cystic fibrosis. Finally, it is somewhat difficult 
to understand how such marked airway obstruction which produced increased intracranial 
pressure could occur with preservation of arterial blood gases. - Vitamin 
A and carotene blood levels were not determined in our cases 
and therefore obviously this possibility cannot be excluded, at least in 
two of the cases. Dr Taussig's suggestion that the improvement in 
the intracranial pressure in our cases was really the result of 
the "unknowing" associated administration of vitamin A and not to the 
improvements in the pulmonary status, as I proposed, fails to note 
the clinical observation that there had been a "rise and fall" 
in the bulge of the fontanel concomitantly with the increase and 
decrease of respiratory obstruction signs. As to the question of the 
severity of airway obstruction, the clinical reversible picture of severe tachypnea 
with poor air entry, clear lung fields on X-ray with overdistended 
lungs and small heart appear most suggestive of airway obstruction in 
C.F. 