Recurrent bacterial meningitis: the need for sensitive imaging

Sensitive imaging is needed in children with recurrent bacterial meningitis to detect cranial anatomical defects

Recurrent bacterial meningitis in childhood is unusual and should prompt a search for immune deficiency. A variety of immunological defects may predispose to recurrent meningitis, including antibody or complement deficiency and hyposplenism. It is equally important to consider cranial anatomical defects such as skull fractures, particularly those affecting the base of the brain and extending to the sinuses and petrous pyramids.1 Craniospinal dermal sinuses, neurenteric or dermoid cysts, occult intranasal encephaloceles, or transethmoidmeningoceles are also potential portals of entry for pathogens into the subarachnoid space. 2 3

Encephaloceles may occur anywhere in the midline and arise from failure of closure of the embryonic neuraxis, creating a defect in the dura and cranium with or without protrusion of brain and meningeal tissue. Basal ethmoidal encephaloceles may extend into the nose and be mistaken for nasal polyps2 or into ethmoid sinuses or orbits.

Sometimes there may be a delay in establishing a diagnosis owing to a failure to consider anatomical defects or the use of insufficiently sensitive imaging procedures. We describe two children with recurrent bacterial meningitis due to cranial anatomical defects in whom diagnosis was delayed.