Neonatal cranial sonography: ultrasound findings in neonatal meningitis—a pictorial review

Abstract

Neonatal bacterial meningitis is a common manifestation of late onset neonatal sepsis. Cranial sonography (CRS) has a crucial role in assessment of infants with clinical suspicion of bacterial meningitis as well as follows up of its complications. CRS is performed with high frequency transducer through anterior fontanelle in both coronal and sagittal planes. Various sonographic findings range from echogenic and widened sulci, ventriculomegaly, ventriculitis, hydrocephalus, extra-axial fluid collections, cerebritis and brain abscess. Sonography is extremely beneficial in evaluating intraventricular contents, especially debris and intraventricular septations. Linear high frequency probe along with color Doppler interrogation are of utmost importance in evaluating extra-axial fluid collection and helps differentiating it from benign subarachnoid space enlargement. Due to low cost, easy portability, speed of imaging, no need for sedation and above all lack of ionizing radiation make it superior to other cross sectional imaging, like CT and MRI, in evaluation of these sick neonates. Apart from textbooks, there is paucity of recently available literature on cranial sonographic findings in neonatal meningitis. This article is written with an educational intent to review the spectrum of findings in neonatal meningitis, with stress on findings that will be beneficial in the clinical practice.

Accuracy of cranial ultrasound in the diagnosis of hydrocephalus in children under 6 months of age keeping CT scan as a gold standard

“…Cranial sonography is also beneficial in the diagnosis of various neonatal pathologies other than hydrocephalus. 13 MRI is the best diagnostic and prognostic modality but availability and cost are the major concerns over it. CT scan exposes patients to a high dose of radiations, so a low dose protocol may be a suitable alternative.…”

Meningitis

“…12 Most of these deaths occurred in developing and under developed countries and leading cause of deaths include pneumonia, meningitis and sepsis. 13 Neonatal meningitis is inflammation of arachnoid and pia mater.…”

“…Meningitis is common presentation of LOS, 11 and it results in serious neurological sequale and 12 In a study conducted in India showed the prevalence of meningitis as 22.5% in neonates with LOS. 10 To the best of my knowledge, there is little information in Pakistan regarding the relation of meningitis with LOS in neonates.…”

Ring-enhancing lesions in neonatal meningitis: an analysis of neuroradiology pitfalls through exemplificative cases and a review of the literature

“…Neonatal meningitis (NM) represents an inflammatory response to many types of cerebrospinal fluid (CSF) and pia-arachnoid infections of the central nervous system (CNS). NM can be classified as early or late depending of their occurrence by vertical transmission during the first week of life, or by interpersonal/nosocomial transmission as a late onset presentation of neonatal sepsis (1,2). Grampositive NM represents the majority of cases, with Group B streptococcus (GBS) as the leading causative pathogen in this class (3).…”

“…Very often the clinical course of NM is characterized by sudden worsening, usually caused by convulsive states, but at times associated with cerebrovascular complications and cerebral strokes. Clinically it can be challenging to evaluate the severity, exact location, and degree of insult to the brain; for this reason, an immediate radiological recognition of these pathological patterns in patients admitted to Neurointensive Care Units (NICU) is pivotal in providing clinicians with useful information to guide the medical treatments (2).…”