A 74‐year‐old man was transferred in a comatose state with fever and shock. Computed tomography (CT) of the brain showed no abnormal findings, and cerebrospinal fluid (CSF) showed a normal protein concentration with pleocytosis. Influenza type A antigen was isolated from a throat swab. After admission, a magnetic resonance imaging (MRI) scan of the brain showed symmetrically diffusion‐restricted lesions in the cerebellum, medulla, pons, bilateral thalami, and bilateral periventricular white matter (Figure 1). Based on these images, the diagnosis was influenza‐associated acute necrotizing encephalopathy (ANE). The patient had no prior or familial history of episodes of encephalopathy. The patient died 4 days after admission. ANE is a rare and fatal disease in adults, sometimes complicated by multiple organ failure. 1 , 2
FIGURE 1.
Diffusion‐weighted magnetic resonance imaging shows diffusion‐limited lesions in the cerebellar medulla, pons (right arrow), bilateral thalamus (left arrow), and bilateral periventricular white matter.
Testing for RAN‐binding protein 2 mutation is considered because it can cause genetic ANE. 3 Its typical imaging features are multiple symmetric lesions of the thalamus, brainstem, and cerebellum, with necrosis and hemorrhage. 4 However, CT findings are sometimes normal during the acute phase. 5 Patients with influenza with shock and impaired consciousness may be diagnosed with ANE using MRI based on typical imaging findings, regardless of age, even if head CT and CSF are normal.
CONFLICT OF INTEREST STATEMENT
The authors have no conflicts of interest directly relevant to the content of this article.
ETHICS STATEMENT
Approval of the research protocol: N/A.
Informed consent: N/A.
Registry and the registration no. of the study/trial: N/A.
Animal studies: N/A.
ACKNOWLEDGMENTS
We would like to thank Editage for assistance with editing the manuscript.
Hata N, Iwai Y, Ihara T. Acute necrotizing encephalopathy. Acute Med Surg. 2023;10:e888. 10.1002/ams2.888
DATA AVAILABILITY STATEMENT
The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.
REFERENCES
- 1. Morishima T, Togashi T, Yokota S, Okuno Y, Miyazaki C, Tashiro M, et al. Encephalitis and encephalopathy associated with an influenza epidemic in Japan. Clin Infect Dis. 2002;35:512–517. [DOI] [PubMed] [Google Scholar]
- 2. Kasai T, Togashi T, Morishima T. Encephalopathy associated with influenza epidemics. Lancet. 2000;355:1558–1559. [DOI] [PubMed] [Google Scholar]
- 3. Levine JM, Ahsan N, Ho E, Santoro JD. Genetic acute necrotizing encephalopathy associated with RANBP2: clinical and therapeutic implications in pediatrics. Mult Scler Relat Disord. 2020;43:102194. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4. Mizuguchi M, Abe J, Mikkaichi K, Noma S, Yoshida K, Yamanaka T, et al. Acute necrotising encephalopathy of childhood: a new syndrome presenting with multifocal, symmetric brain lesions. J Neurol Neurosurg Psychiatry. 1995;58:555–561. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5. Iizuka K, Suzuki K, Shiina T, Nakamura T, Funakoshi K, Hirata K. Two adult patients with acute necrotizing encephalopathy following influenza virus infection. [in Japanese] Rinsho Shinkeigaku. 2020;60:157–161. [DOI] [PubMed] [Google Scholar]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Data Availability Statement
The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.