COVID-19-associated encephalitis
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Wajeeha Aiman, M.D.[2]
Synonyms and keywords:
Overview
Encephalitis is inflammation of the brain parenchyma and it is commonly caused by viruses. COVID-19 is a virus related to the severe acute respiratory syndrome coronavirus (SARS-CoV) group and named as SARS-CoV-2.
Historical Perspective
- Covid-19 associated encephalitis was first discovered by Moriguchi T. et al. a Japanese critical care physician in late February 2020 during the pandemic of SARS-Coronavirus-2: SARS-CoV-2.[1]
- The association between COVID-19 and encephalitis was made during this pandemic started in December in Wuhan, China and named as Wuhan coronavirus.[2]
- In March 2020, Dr. Ali A. was the first to discover the association between COVID-19 and neurological diseases e.g. encephalitis. He made a clinical diagnosis along with his team and then MRI used to diagnose the disease.[3]
- In January 2020, Chinese doctors confirmed the first case of encephalitis due to COVID-19 in a 56 year old male and they conducted gene sequencing on cerebrospinal fluid (CSF) samples and confirmed the novel virus inside brain, but it was not published.
- There have been several outbreaks of SARS and MERS.
Classification
- There is no established system for the classification of COVID-19 associated encephalitis.
- Based on the duration of symptoms, this disease is classified as acute.
Pathophysiology
- The exact pathogenesis of COVID-19 encephalitis is not fully understood.
- It is thought that this viral encephalitis is the result of multiple pathologies.
| SARS-CoV-2 Entry via Nose | |||||||||||||||||||||||||||||||||||||||||
| Olfactory Epithelium | |||||||||||||||||||||||||||||||||||||||||
| Olfactory Bulb | |||||||||||||||||||||||||||||||||||||||||
| ACE2 | Direct Injury due to Infection | Immune Injury | Hypoxic Injury | Hypercoagulability | |||||||||||||||||||||||||||||||||||||
| Viral Encephalitis | |||||||||||||||||||||||||||||||||||||||||
- ACE2: Angiotensin converting enzyme receptor 2 is present in multiple organs e.g. lungs, brain, and kidney, etc.
- Hypercoagulability: With elevated D-dimer
- Immune injury: Cytokine activation and vascular involvement.
- Direct injury: Due to hematogenous and neuronal pathway involvement.
- Hypoxic injury: Due to anaerobic metabolism.[4]
Causes
COVID-19 associated encephalitis is caused by SARS-CoV-2.
To review risk factors for the development of [disease name], click here.
Differentiating COVID-19-associated encephalitis from other Diseases
[Disease name] must be differentiated from other diseases that cause [clinical feature 1], [clinical feature 2], and [clinical feature 3], such as [differential dx1], [differential dx2], and [differential dx3].
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[Disease name] must be differentiated from [[differential dx1], [differential dx2], and [differential dx3].
Epidemiology and Demographics
The incidence/prevalence of [disease name] is approximately [number range] per 100,000 individuals worldwide.
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In [year], the incidence/prevalence of [disease name] was estimated to be [number range] cases per 100,000 individuals worldwide.
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In [year], the incidence of [disease name] is approximately [number range] per 100,000 individuals with a case-fatality rate of [number range]%.
Patients of all age groups may develop [disease name].
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The incidence of [disease name] increases with age; the median age at diagnosis is [#] years.
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[Disease name] commonly affects individuals younger than/older than [number of years] years of age.
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[Chronic disease name] is usually first diagnosed among [age group].
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[Acute disease name] commonly affects [age group].
There is no racial predilection to [disease name].
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[Disease name] usually affects individuals of the [race 1] race. [Race 2] individuals are less likely to develop [disease name].
[Disease name] affects men and women equally.
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[Gender 1] are more commonly affected by [disease name] than [gender 2]. The [gender 1] to [gender 2] ratio is approximately [number > 1] to 1.
The majority of [disease name] cases are reported in [geographical region].
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[Disease name] is a common/rare disease that tends to affect [patient population 1] and [patient population 2].
Risk Factors
There are no established risk factors for [disease name].
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The most potent risk factor in the development of [disease name] is [risk factor 1]. Other risk factors include [risk factor 2], [risk factor 3], and [risk factor 4].
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Common risk factors in the development of [disease name] include [risk factor 1], [risk factor 2], [risk factor 3], and [risk factor 4].
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Common risk factors in the development of [disease name] may be occupational, environmental, genetic, and viral.
Screening
There is insufficient evidence to recommend routine screening for [disease/malignancy].
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According to the [guideline name], screening for [disease name] is not recommended.
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According to the [guideline name], screening for [disease name] by [test 1] is recommended every [duration] among patients with [condition 1], [condition 2], and [condition 3].
Natural History, Complications, and Prognosis
If left untreated, [#]% of patients with [disease name] may progress to develop [manifestation 1], [manifestation 2], and [manifestation 3].
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Common complications of [disease name] include [complication 1], [complication 2], and [complication 3].
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Prognosis is generally excellent/good/poor, and the 1/5/10-year mortality/survival rate of patients with [disease name] is approximately [#]%.
Diagnosis
Diagnostic Study of Choice
The diagnosis of [disease name] is made when at least [number] of the following [number] diagnostic criteria are met: [criterion 1], [criterion 2], [criterion 3], and [criterion 4].
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The diagnosis of [disease name] is based on the [criteria name] criteria, which include [criterion 1], [criterion 2], and [criterion 3].
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The diagnosis of [disease name] is based on the [definition name] definition, which includes [criterion 1], [criterion 2], and [criterion 3].
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There are no established criteria for the diagnosis of [disease name].
History and Symptoms
The majority of patients with [disease name] are asymptomatic.
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The hallmark of [disease name] is [finding]. A positive history of [finding 1] and [finding 2] is suggestive of [disease name]. The most common symptoms of [disease name] include [symptom 1], [symptom 2], and [symptom 3]. Common symptoms of [disease] include [symptom 1], [symptom 2], and [symptom 3]. Less common symptoms of [disease name] include [symptom 1], [symptom 2], and [symptom 3].
Physical Examination
Patients with [disease name] usually appear [general appearance]. Physical examination of patients with [disease name] is usually remarkable for [finding 1], [finding 2], and [finding 3].
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Common physical examination findings of [disease name] include [finding 1], [finding 2], and [finding 3].
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The presence of [finding(s)] on physical examination is diagnostic of [disease name].
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The presence of [finding(s)] on physical examination is highly suggestive of [disease name].
Laboratory Findings
An elevated/reduced concentration of serum/blood/urinary/CSF/other [lab test] is diagnostic of [disease name].
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Laboratory findings consistent with the diagnosis of [disease name] include [abnormal test 1], [abnormal test 2], and [abnormal test 3].
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[Test] is usually normal among patients with [disease name].
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Some patients with [disease name] may have elevated/reduced concentration of [test], which is usually suggestive of [progression/complication].
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There are no diagnostic laboratory findings associated with [disease name].
Electrocardiogram
There are no ECG findings associated with [disease name].
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An ECG may be helpful in the diagnosis of [disease name]. Findings on an ECG suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].
X-ray
There are no x-ray findings associated with [disease name].
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An x-ray may be helpful in the diagnosis of [disease name]. Findings on an x-ray suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].
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There are no x-ray findings associated with [disease name]. However, an x-ray may be helpful in the diagnosis of complications of [disease name], which include [complication 1], [complication 2], and [complication 3].
Echocardiography or Ultrasound
There are no echocardiography/ultrasound findings associated with [disease name].
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Echocardiography/ultrasound may be helpful in the diagnosis of [disease name]. Findings on an echocardiography/ultrasound suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].
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There are no echocardiography/ultrasound findings associated with [disease name]. However, an echocardiography/ultrasound may be helpful in the diagnosis of complications of [disease name], which include [complication 1], [complication 2], and [complication 3].
CT scan
There are no CT scan findings associated with [disease name].
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[Location] CT scan may be helpful in the diagnosis of [disease name]. Findings on CT scan suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].
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There are no CT scan findings associated with [disease name]. However, a CT scan may be helpful in the diagnosis of complications of [disease name], which include [complication 1], [complication 2], and [complication 3].
MRI
There are no MRI findings associated with [disease name].
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[Location] MRI may be helpful in the diagnosis of [disease name]. Findings on MRI suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].
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There are no MRI findings associated with [disease name]. However, a MRI may be helpful in the diagnosis of complications of [disease name], which include [complication 1], [complication 2], and [complication 3].
Other Imaging Findings
There are no other imaging findings associated with [disease name].
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[Imaging modality] may be helpful in the diagnosis of [disease name]. Findings on an [imaging modality] suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].
Other Diagnostic Studies
There are no other diagnostic studies associated with [disease name].
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[Diagnostic study] may be helpful in the diagnosis of [disease name]. Findings suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].
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Other diagnostic studies for [disease name] include [diagnostic study 1], which demonstrates [finding 1], [finding 2], and [finding 3], and [diagnostic study 2], which demonstrates [finding 1], [finding 2], and [finding 3].
Treatment
Medical Therapy
There is no treatment for [disease name]; the mainstay of therapy is supportive care.
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Supportive therapy for [disease name] includes [therapy 1], [therapy 2], and [therapy 3].
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The majority of cases of [disease name] are self-limited and require only supportive care.
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[Disease name] is a medical emergency and requires prompt treatment.
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The mainstay of treatment for [disease name] is [therapy].
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The optimal therapy for [malignancy name] depends on the stage at diagnosis.
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[Therapy] is recommended among all patients who develop [disease name].
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Pharmacologic medical therapy is recommended among patients with [disease subclass 1], [disease subclass 2], and [disease subclass 3].
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Pharmacologic medical therapies for [disease name] include (either) [therapy 1], [therapy 2], and/or [therapy 3].
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Empiric therapy for [disease name] depends on [disease factor 1] and [disease factor 2].
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Patients with [disease subclass 1] are treated with [therapy 1], whereas patients with [disease subclass 2] are treated with [therapy 2].
Surgery
Surgical intervention is not recommended for the management of [disease name].
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Surgery is not the first-line treatment option for patients with [disease name]. Surgery is usually reserved for patients with either [indication 1], [indication 2], and [indication 3]
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The mainstay of treatment for [disease name] is medical therapy. Surgery is usually reserved for patients with either [indication 1], [indication 2], and/or [indication 3].
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The feasibility of surgery depends on the stage of [malignancy] at diagnosis.
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Surgery is the mainstay of treatment for [disease or malignancy].
Primary Prevention
There are no established measures for the primary prevention of [disease name].
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There are no available vaccines against [disease name].
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Effective measures for the primary prevention of [disease name] include [measure1], [measure2], and [measure3].
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[Vaccine name] vaccine is recommended for [patient population] to prevent [disease name]. Other primary prevention strategies include [strategy 1], [strategy 2], and [strategy 3].
Secondary Prevention
There are no established measures for the secondary prevention of [disease name].
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Effective measures for the secondary prevention of [disease name] include [strategy 1], [strategy 2], and [strategy 3].
References
- ↑ Moriguchi T, Harii N, Goto J, Harada D, Sugawara H, Takamino J; et al. (2020). "A first case of meningitis/encephalitis associated with SARS-Coronavirus-2". Int J Infect Dis. 94: 55–58. doi:10.1016/j.ijid.2020.03.062. PMC 7195378 Check
|pmc=value (help). PMID 32251791 Check|pmid=value (help). - ↑ Riou J, Althaus CL (2020). "Pattern of early human-to-human transmission of Wuhan 2019 novel coronavirus (2019-nCoV), December 2019 to January 2020". Euro Surveill. 25 (4). doi:10.2807/1560-7917.ES.2020.25.4.2000058. PMC 7001239 Check
|pmc=value (help). PMID 32019669 Check|pmid=value (help). - ↑ Asadi-Pooya AA, Simani L (2020). "Central nervous system manifestations of COVID-19: A systematic review". J Neurol Sci. 413: 116832. doi:10.1016/j.jns.2020.116832. PMC 7151535 Check
|pmc=value (help). PMID 32299017 Check|pmid=value (help). - ↑ Baig AM (2020). "Neurological manifestations in COVID-19 caused by SARS-CoV-2". CNS Neurosci Ther. 26 (5): 499–501. doi:10.1111/cns.13372. PMC 7163592 Check
|pmc=value (help). PMID 32266761 Check|pmid=value (help).