A 5 day old full term male infant admitted with a two day history of fever, irritability, and convulsions was diagnosed as having Enterobacter cloacae septicaemia and meningitis. A computed tomography (CT) brain scan on admission showed cerebral oedema and areas of low density signals near the occipital horns of the lateral ventricles. A repeat CT scan five days after admission (fig 1) revealed the presence of diffuse pneumocephalus. T₁ weighted magnetic resonance images of the brain three days later (fig 2), as well as a CT scan two weeks after admission, showed a pronounced interval increase in the collection of intracranial air. The baby died from multiorgan failure 18 days after admission.

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Figure 1

 Computed tomography scan of the brain of a 10 day old male infant showing diffuse pneumocephalus.

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Figure 2

 Magnetic resonance image of the brain three days later showing a pronounced interval increase in intracranial air.

Pneumocephalus, defined as the presence of air or gas in the cranial cavity, is a known complication of head trauma, neurosurgical procedures, and cranial irradiation. It has been reported associated with meningitis caused by mixed aerobic-anaerobic infection as well as Clostridium perfringens, Streptococcus pneumoniae, and Clostridium septicum, mostly in adult patients.

To our knowledge, this is the first reported case of diffuse pneumocephalus associated with Enterobacter cloacae meningitis in a neonate. The presence of focal areas of pneumocephalus in the CT scan on admission before lumbar puncture and its subsequent interval increase in the following days exclude other causes of pneumocephalus in our patient.