Naeglaeria infection of the central nervous system, CT scan findings: a case series

The imaging findings in four cases of a rare infection of the central nervous system caused by amoebae, Naeglaeria fowleri are presented. Naeglaeria fowleri are pathogenic free-living amoebae. They cause primary amoebic meningoencephalitis (PAM), a rapidly fatal disease of the central nervous system. The computed tomography brain findings in 3 (75%) of our cases of pan amoebic meningoencephalitis showed non-specific brain oedema; 2 (66%) of these cases also had moderate hydrocephalus and among that 1 (50%) case showed an old lacunar infarction in peri-ventricular region. In the remaining 1 (25%) case the scan was normal with no evidence of oedema or abnormal lesion. Out of three cases with diffuse brain oedema, post-contrast images showed abnormal meningeal enhancement throughout the brain parenchyma in 1 (33%) case. However, no definite focal enhancing lesion was noted. In the rest of the cases, no abnormal parenchymal or meningeal enhancement was seen on post-contrast images. The study was conducted in the Radiology Department of Aga Khan University Hospital, Karachi from July to December 2010