Multimodality Imaging of a Retrocerebellar Abscess in Early Infancy Complicated by Acute Hydrocephalus and Ipsilateral Thalamic Infarction
Multimodality imaging of infant abscess
DOI:
https://doi.org/10.66288/actamedi.2026.86Keywords:
Brain abscess, posterior fossa, diffusion-weighted imaging, hydrocephalus, thalamic infarction, Staphylococcus aureusAbstract
Background: Brain abscesses are uncommon in early infancy, and posterior fossa abscesses are particularly rare. In this age group, clinical findings may be nonspecific, and imaging plays a central role in establishing the diagnosis and characterizing complications such as obstructive hydrocephalus and secondary ischemic injury. We report the imaging features of a Staphylococcus aureus retrocerebellar abscess presenting with acute hydrocephalus and ipsilateral thalamic infarction in a 6-week-old infant.
Case presentation: A 6-week-old female infant presented with fever, vomiting, irritability, and a tense anterior fontanel. Transfontanel ultrasonography demonstrated marked hydrocephalus, a hyperechoic lesion in the left thalamus, and a retrocerebellar loculated collection. CT and contrast-enhanced MRI confirmed a retrocerebellar abscess compressing the fourth ventricle, with marked diffusion restriction with low ADC values and peripheral rim enhancement. Diffusion-weighted MRI also demonstrated an acute ipsilateral thalamic infarction, attributed to acute obstructive hydrocephalus. Due to ventricular obstruction, urgent external ventricular drainage was performed for CSF diversion, followed by surgical abscess drainage via an occipital approach. Culture of the abscess material grew Staphylococcus aureus. The patient improved clinically with targeted antimicrobial therapy, and follow-up imaging showed regression of hydrocephalus.
Conclusion: In infants presenting with nonspecific symptoms and signs of raised intracranial pressure, early neuroimaging is essential. Multimodality imaging provides key diagnostic clues for posterior fossa abscess. Diffusion-weighted MRI is particularly valuable for confirming abscess and detecting associated ischemic injury, thereby influencing the urgency and scope of management planning.
References
1. Muzumdar D, Jhawar S, Goel A. Brain abscess: an overview. Int J Surg. 2011;9(2):136-44. doi: 10.1016/j.ijsu.2010.11.005. DOI: https://doi.org/10.1016/j.ijsu.2010.11.005
2. El-Khashab M, Zonouzi TH, Naghani IM, Nejat F. Cerebellar staphylococcal abscess accompanied with high alfa-fetoprotein in a young infant. Iran J Pediatr. 2012 Dec;22(4):539-42. PMID: 23431058; PMCID: PMC3533158.
3. Vartzelis G, Theodoridou M, Daikos GL, Dellagrammaticas H, Syriopoulou VP. Brain abscesses complicating Staphylococcus aureus sepsis in a premature infant. Infection. 2005 Feb;33(1):36-8. doi: 10.1007/s15010-005-4062-z. DOI: https://doi.org/10.1007/s15010-005-4062-z
4. Gilard V, Beccaria K, Hartley JC, Blanot S, Marqué S, Bourgeois M, Puget S, Thompson D, Zerah M, Tisdall M. Brain abscess in children, a two-centre audit: outcomes and controversies. Arch Dis Child. 2020 Mar;105(3):288-291. doi: 10.1136/archdischild-2018-316730. DOI: https://doi.org/10.1136/archdischild-2018-316730
5. Licht-van der Stap RG, de Vries LS, Alarcon A, Govaert P, Steggerda SJ; EurUS.Brain group. Cranial ultrasound in neonatal brain infections. Dev Med Child Neurol. 2025;67(8):986-1003. doi:10.1111/dmcn.16279 DOI: https://doi.org/10.1111/dmcn.16279
6. Bodilsen J, D'Alessandris QG, Humphreys H, Iro MA, Klein M, Last K et. al. ESCMID Study Group for Infections of the Brain (ESGIB). European society of Clinical Microbiology and Infectious Diseases guidelines on diagnosis and treatment of brain abscess in children and adults. Clin Microbiol Infect. 2024 Jan;30(1):66-89. doi: 10.1016/j.cmi.2023.08.016. DOI: https://doi.org/10.1016/j.cmi.2024.01.026
7. Agrawal D, Suri A, Mahapatra AK. Primary excision of pediatric posterior fossa abscesses--towards zero mortality? A series of nine cases and review. Pediatr Neurosurg. 2003 Feb;38(2):63-7. doi: 10.1159/000068051. DOI: https://doi.org/10.1159/000068051
8. Chetty M, Rakhi B, Rachana K, Sujatha S, Srinivasan GM. An Eight Year Clinico-Microbiological Retrospective Study on Brain Abscesses in India. Microbiol Insights. 2022 Jun 28;15:11786361221106111. doi: 10.1177/11786361221106111. DOI: https://doi.org/10.1177/11786361221106111
9. Laulajainen-Hongisto A, Lempinen L, Färkkilä E, Saat R, Markkola A, Leskinen K et. al. Intracranial abscesses over the last four decades; changes in aetiology, diagnostics, treatment and outcome. Infect Dis (Lond). 2016 Apr;48(4):310-316. doi: 10.3109/23744235.2015.1113557. DOI: https://doi.org/10.3109/23744235.2015.1113557
10. Bodilsen J, Dalager-Pedersen M, van de Beek D, Brouwer MC, Nielsen H. Incidence and mortality of brain abscess in Denmark: a nationwide population-based study. Clin Microbiol Infect. 2020 Jan;26(1):95-100. doi: 10.1016/j.cmi.2019.05.016. DOI: https://doi.org/10.1016/j.cmi.2019.05.016
11. Helweg-Larsen J, Astradsson A, Richhall H, Erdal J, Laursen A, Brennum J. Pyogenic brain abscess, a 15 year survey. BMC Infect Dis. 2012 Nov 30;12:332. doi: 10.1186/1471-2334-12-332. DOI: https://doi.org/10.1186/1471-2334-12-332
12. Tsutsumi S, Arai H, Hishii M, Suzuki K, Sato K. A case of neonatal cerebellar abscess. Childs Nerv Syst. 2003 Sep;19(9):683-5. doi: 10.1007/s00381-003-0741-1. DOI: https://doi.org/10.1007/s00381-003-0741-1
Downloads
Published
How to Cite
Issue
Section
License
Copyright (c) 2026 Mehmet Salih Karaca, Ali Oğuz, Tarık Sağlam, Sadullah Şimşek
This work is licensed under a Creative Commons Attribution 4.0 International License.
