A Bertrand1, D Leclercq2, L Martinez-Almoyna3, N Girard4, J-P Stahl5, T De-Broucker6. 1. Service de neuroradiologie diagnostique et fonctionnelle, groupe hospitalier Pitié-Salpêtrière, 47-83 boulevard de l'hôpital, 75651 Paris cedex 13, France; Sorbonne universités, UPMC université Paris 06, Inserm, CNRS, institut du cerveau et la moelle (ICM), Inria Paris, Aramis project-team, 75013 Paris, France. 2. Service de neuroradiologie diagnostique et fonctionnelle, groupe hospitalier Pitié-Salpêtrière, 47-83 boulevard de l'hôpital, 75651 Paris cedex 13, France. 3. Service de neurochirurgie, CHU Nord, AP-HM, 13015 Marseille, France. 4. Service de neuroradiologie, CHU La-Timone, AP-HM, 13015 Marseille, France. 5. Service d'infectiologie, CHU de Grenoble, « European study Group for the Infections of the Brain (ESGIB) », 38043 Grenoble, France. Electronic address: JPStahl@chu-grenoble.fr. 6. Service de neurologie, CH Saint-Denis, BP 279, 93205, France.
Abstract
BACKGROUND: Imaging is a key tool for the diagnosis of acute encephalitis. Brain CT scan must be urgently performed to rule out a brain lesion with mass effect that would contraindicate lumbar puncture. Brain MRI is less accessible than CT scan, but can provide crucial information with patients presenting with acute encephalitis. METHOD: We performed a literature review on PubMed on April 1, 2015 with the search terms "MRI" and "encephalitis". RESULTS: We first described the various brain MRI abnormalities associated with each pathogen of acute encephalitis (HSV, VZV, other viral agents targeting immunocompromised patients or travelers; tuberculosis, listeriosis, other less frequent bacterial agents). Then, we identified specific patterns of brain MRI abnomalies that may suggest a particular pathogen. Limbic encephalitis is highly suggestive of HSV; it also occurs less frequently in encephalitis due to HHV6, syphillis, Whipple's disease and HIV primary infection. Rhombencephalitis is suggestive of tuberculosis and listeriosis. Acute ischemic lesions can occur in patients presenting with severe bacterial encephalitis, tuberculosis, VZV encephalitis, syphilis, and fungal infections. CONCLUSION: Brain MRI plays a crucial role in the diagnosis of acute encephalitis. It detects brain signal changes that reinforce the clinical suspicion of encephalitis, especially when the causative agent is not identified by lumbar puncture; it can suggest a particular pathogen based on the pattern of brain abnormalities and it rules out important differential diagnosis (vascular, tumoral or inflammatory causes).
BACKGROUND: Imaging is a key tool for the diagnosis of acute encephalitis. Brain CT scan must be urgently performed to rule out a brain lesion with mass effect that would contraindicate lumbar puncture. Brain MRI is less accessible than CT scan, but can provide crucial information with patients presenting with acute encephalitis. METHOD: We performed a literature review on PubMed on April 1, 2015 with the search terms "MRI" and "encephalitis". RESULTS: We first described the various brain MRI abnormalities associated with each pathogen of acute encephalitis (HSV, VZV, other viral agents targeting immunocompromised patients or travelers; tuberculosis, listeriosis, other less frequent bacterial agents). Then, we identified specific patterns of brain MRI abnomalies that may suggest a particular pathogen. Limbic encephalitis is highly suggestive of HSV; it also occurs less frequently in encephalitis due to HHV6, syphillis, Whipple's disease and HIV primary infection. Rhombencephalitis is suggestive of tuberculosis and listeriosis. Acute ischemic lesions can occur in patients presenting with severe bacterial encephalitis, tuberculosis, VZV encephalitis, syphilis, and fungal infections. CONCLUSION: Brain MRI plays a crucial role in the diagnosis of acute encephalitis. It detects brain signal changes that reinforce the clinical suspicion of encephalitis, especially when the causative agent is not identified by lumbar puncture; it can suggest a particular pathogen based on the pattern of brain abnormalities and it rules out important differential diagnosis (vascular, tumoral or inflammatory causes).
Authors: V Pota; M B Passavanti; F Coppolino; F Di Zazzo; L De Nardis; R Esposito; M Fiore; G S R C Mangoni di Santostefano; C Aurilio; P Sansone; M C Pace Journal: J Med Case Rep Date: 2021-03-29
Authors: Elisabeth S Lindland; Anne Marit Solheim; Silje Andreassen; Else Quist-Paulsen; Randi Eikeland; Unn Ljøstad; Åse Mygland; Ahmed Elsais; Gro O Nygaard; Åslaug R Lorentzen; Hanne F Harbo; Mona K Beyer Journal: Insights Imaging Date: 2018-09-04