Ultrasound evaluation of brain infections and its complications in Nigerian infants

Abstract

Summary Infantile meningitis is a clinical diagnosis. However, suspicion of its complications may warrant further investigations; and transfrontanelle ultrasound is a reliable and cheap way to evaluate the usefulness of ultrasonography in diagnosing the complications of infantile meningitis. This is a retrospective study of the transfrontanelle ultrasound findings in 40 infants presenting with clinical indicators of complicated acute bacterial meningitis. There were 20 boys and 20 girls aged 5–115 days (mean, 42.6 ± 30.1 days). The complications of meningitis detectable on ultrasound were: hydrocephalus (21[52.5%]); cerebral abscess (2[5%]); subdural empyema (2 [5%]); and ventriculitis (3[7.5%]). Twelve babies (30%) had no abnormal findings. Hydrocephalus is the most common complication of meningitis in our setting. Transfontanelle ultrasound proved to be very reliable in the initial diagnosis and follow-up of complicated meningitis.

Brain sonography in African infants with complicated sporadic bacterial meningitis

“…From the age of 0-6 months, the anterior and posterior fontanels are patent and can be used as acoustic window to directly and clearly visualise the intracranial content and the brain for abnormalities 67. From the age of 6 months up to 2 years, the brain can be visualised through very thin temporal bones 8.…”

“…However, major disadvantages of both CT and MR imaging are the associated high cost and the fact that they are not readily available. Also, CT and MRI require high maintenance cost and high level of expert technical engineers for steady operation of the technical part of the machine 67811. For countries like Nigeria with lack of steady power supply, dedicated power generators are required to supply power to CT and MRI machines,11 which greatly increase the running cost.…”

“…The cost of MR imaging for children at the University College Hospital (UCH) Ibadan, located about 200 km from Irrua, the nearest centre with MR imaging scanner was ₦40,000:00 only. Radiation hazards to infants is also due to the use of CT for brain imaging in bacterial meningitis 67811…”

“…Ultrasound scan is cheap, readily available, lacks any form of radiation hazard and can be performed without sedation 78. When high frequency (7.5–15 MHz) transducer is used, it is possible to display excellent normal structure and any abnormality.…”

“…The cost of ultrasound scan in our centre at the time of this study was ₦700:00 (government hospital) and N1000.00 for Greenhill Radiological Centre, Ekhuokuala, Ekpoma, as compared to N15,000:00 for brain CT at UBTH, Benin City and about N40,000 for brain MR imaging at UCH, Ibadan. Therefore, when it is possible to assess the intracranial content using ultrasound, brain sonography is the most cost-effective, practical, radiation-free, readily available, and accessible method of imaging the brain of children in developing countries 678…”