Cerebral malaria is a rare intracranial complication of a malarial infection.
Cerebral malaria is mainly encountered in young children and adults living or travelling in malaria-endemic areas. It is estimated to occur in ~2% of patients with acute Plasmodium falciparum infection, the most common species of Plasmodium that causes malaria.
Cerebral malaria should be suspected when there are neurological symptoms on a background of malarial infection. Clinical presentations include: headache, altered state of consciousness, seizures, backache, vomiting, nausea, etc.
It can at times be characterised by diffuse petechial haemorrhages on postmortem pathological specimens which are often difficult to identify retrospectively on imaging 1-2.
The haemorrhages are thought to occur when cerebral capillaries and small veins are occluded by sequestered Plasmodium-infected erythrocytes. Hence, this pathological process may lead to areas of infarction.
Imaging features on its own are often nonspecific correlation with travel history or exposure in an endemic area is mandatory 7. Most published articles are based on case reports and small case series.
The most common findings are related to ischemia involving: deep white matter, cortex, basal ganglia, thalami and cerebellum. These areas of ischemia can be haemorrhagic 6.
CT findings do not appear to not correlate with the degree of parasitaemia and can sometimes be normal 1. However, reported features include 1:
- cerebral oedema
- thalamic hypoattenuation from infarcts
- cerebellar white matter hypoattenuation from infarcts
Described features include:
- T2/FLAIR: nonspecific hyperintensities located in the bilateral periventricular white matter, corpus callosum, occipital subcortex, and/or bilateral thalamic regions 3,8
- DWI: high diffusion signal if cortical infarcts are present
- SWI: regions of hypointensity representing either petechial microbleeds or regions of haemorrhage in infarcted tissue 6
It is often associated with a high mortality rate (20-50%). However, those patients who survive often have a full recovery with minimal or no long-term sequelae.
- 1. Patankar TF, Karnad DR, Shetty PG et-al. Adult cerebral malaria: prognostic importance of imaging findings and correlation with postmortem findings. Radiology. 2002;224 (3): 811-6. doi:10.1148/radiol.2243010588 - Pubmed citation
- 2. Nickerson JP, Tong KA, Raghavan R. Imaging cerebral malaria with a susceptibility-weighted MR sequence. AJNR Am J Neuroradiol. 2009;30 (6): e85-6. doi:10.3174/ajnr.A1568 - Pubmed citation
- 3. Cordoliani YS, Sarrazin JL, Felten D et-al. MR of cerebral malaria. AJNR Am J Neuroradiol. 1998;19 (5): 871-4. AJNR Am J Neuroradiol (abstract) - Pubmed citation
- 4. Gupta S, Patel K. Case series: MRI features in cerebral malaria. Indian J Radiol Imaging. 2008;18 (3): 224-6. doi:10.4103/0971-3026.41832 - Free text at pubmed - Pubmed citation
- 5. Looareesuwan S, Laothamatas J, Brown TR et-al. Cerebral malaria: a new way forward with magnetic resonance imaging (MRI). Am. J. Trop. Med. Hyg. 2009;81 (4): 545-7. doi:10.4269/ajtmh.2009.07-0411 - Pubmed citation
- 6. Millan JM, San millan JM, Muñoz M et-al. CNS complications in acute malaria: MR findings. AJNR Am J Neuroradiol. 14 (2): 493-4. AJNR Am J Neuroradiol (abstract) - Pubmed citation
- 7. Sakai O, Barest GD. Diffusion-weighted imaging of cerebral malaria. J Neuroimaging. 2005;15 (3): 278-80. doi:10.1177/1051228405277341 - Pubmed citation
- 8. Yadav P, Sharma R, Kumar S et-al. Magnetic resonance features of cerebral malaria. Acta Radiol. 2008;49 (5): 566-9. doi:10.1080/02841850802020476 - Pubmed citation