COVID-19-associated encephalopathy
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For COVID-19 patient information, click here.
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Muhammad Adnan Haider, M.B.B.S.[2] Wajeeha Aiman, M.D.[3]
Synonyms and keywords:Encephalopathy in COVID-19, COVID-19 encephalopathy
Overview
Encephalopathy is an alteration of the level or contents of consciousness due to brain dysfunction and can result from global or focal brain lesions. SARS-CoV-2 which is the member of coronavirus family has caused many neurological complications including encephalopathy. Acute toxic encephalopathy is caused by toxemia, hypoxia and metabolic disorders due the systemic viral infection (viral sepsis).
Historical Perspective
COVID-19, a disease caused by SARS-CoV-2 first emerged in Wuhan, China in December 2019. It then spread so rapidly that it was declared as pandemic in Feb, 2020. It mostly presents with respiratory symptoms like flue, dry cough, fever, fatigue, dyspnea. Although rare but neurological manifestations have been reported throughout the spectrum of COVID-19 pandemic. These neurological symptoms range from headache, anosmia, meningitis, encephalitis, Guillain Berre Syndrome,and stroke. Encephalopathy is rare and few case has been reported with acute encephalopathy during the severe systemic SARS-CoV-2 infection.
Classification
- There is no established system for the classification of COVID-19-associated encephalopathy.
- On the basis of presentation, COVID-19-associated encephalopathy can be classified as acute.
Pathophysiology
- Severe COVID-19 infection can lead to dysfunction of multiple organs of the body that can lead to hypoxic or metabolic insults to brain and cause encephalopathy.
- Encephalitis/meningitis are caused by neurotropism of SARS-CoV-2 to brain and meninges through ACE2 receptors.[1]
- Encephalopathy is caused by hyper inflammation of brain by following three mechanisms;
- cytokine storm
- Hypoxic brain injury
- molecular mimicry
Cytokine storm
- SARS-CoV-2 causes several neurological complications through production of inflammatory cytokines (mainly IL-6) from glial cells called cytokine storm syndrome.[2]
- SARS-CoV-2 activates CD4 cells of the immune system and CD4 cells activate macrophages by producing granulocyte-macrophage colony stimulating factors. Actiavted macrophages now produce IL-6.
- IL-6 is a major cytokine of cytokine storm syndrome and leads to multiple organ failure. This severe organ damage leads to metabolic and toxic changes in the body which causes brain dysfunction and leads to SARS-CoV-2 related encephalopathy.[3]
- This fact can be supported by the evidence that tocilizumab which is IL-6 antagonist is used in severe COVID-19 infections.[4]
Hypoxic Brain Injury
- The hall mark of severe COVID-19 infection is dyspnea and hypoxemia due Acute Respiratory distress syndrome (ARDS).
- This hypoxia and hypoxemia is sometimes enough to cause diffuse brain injury and cause encephalopathy.[5]
Molecular Mimicry
- Post-infectious encephalomyelitis, an autoimmune demyelinating disease of the brain, can be triggered by the SARS‐CoV‐2 virus.[6]
- SARS-CoV-2 is considered to have similar antigenic determinants as that of some antigens present on human neuronal cells.
- Immunological response to the SARS‐CoV‐2 virus cross-react with the myelin autoantigens, resulting in post-infectious encephalomyelitis.
- Neuropathological findings confirmed vascular and demyelinating pathology in a patient who died from COVID-19.[7]
Causes
- COVID-19-associated encephalopathy may be caused by SARS-CoV-2.
- To read more about this virus, click here.
Differentiating COVID-19-associated encephalopathy from other Diseases
- For further information about the differential diagnosis, click here.
- To view the differential diagnosis of COVID-19, click here.
Epidemiology and Demographics
- The incidence of COVID-19-associated encephalopathy is approximately 93 patients worldwide.
- In July 2020, the incidence of COVID-19-associated encephalopathy is approximately 93 cases with 69% of the patients in intensive care unit.
- Patients of all age groups may develop COVID-19-associated encephalopathy.
- The incidence of COVID-19-associated encephalopathy increases with age; the median age at diagnosis is 54 years.
- There is no racial predilection to COVID-19-associated encephalopathy but more cases were present in African Americans.
- COVID-19-associated encephalopathy affects men and women equally.
Risk Factors
- There are no established risk factors for COVID-19-associated encephalopathy.
- To view the risk factors of COVID-19, click here.
Screening
- There is insufficient evidence to recommend routine screening for COVID-19-associated encephalopathy.
- To view screening for COVID-19, click here.
Natural History, Complications, and Prognosis
- If left untreated, COVID-19-associated encephalopathy may cause long term neurological complications.
- To view Natural History for COVID-19, click here.
Complications
- Long term neurological complications can develop according to the involved brain parenchymal area.
Encephalopathy | |||||||||||||||||||||||||||||||||||||||||
Memory loss | Epilepsy | Personality changes | Hearing/vision loss | Coma/Death | |||||||||||||||||||||||||||||||||||||
Diagnosis
Diagnostic Study of Choice
- There are no established criteria for the diagnosis of COVID-19-associated encephalopathy.
- The diagnostic study of choice for COVID-19-associated encephalopathy is CSF analysis along with RT-PCR for SARS-CoV-2 positive on nasopharyngeal swab or on CSF.
Signs and symptoms
Common Symptoms
- These are the common presenting features:
- Fever,
- Shortness of breath
- Headache,
- Impaired consciousness
- Cough
- Fatigue
Less Common Symptoms
- There are few symptoms which are not present in all patients with COVID-19-associated encephalopathy:
- Transient generalized seizure,
- Absent brain reflexes,
- Myoclonus,
- Speech difficulty,
- Choreiform movements,
- Paralysis,
- Dizziness,
- Sedation,
- Coma.
The COVID-19-associated encephalopathy cases have been analyzed in the table below:
Patient No. | Early symptoms | Later presentation | Lab. Findings | Specific Tests | Imaging studies | |||
---|---|---|---|---|---|---|---|---|
CSF | bacterial panel | viral panel (VZV, CMV, HSV1, HSV2) | SARS-CoV-2 | MRI/CT scan | ||||
on nasopharyngeal sawab | on CSF | |||||||
1. Poyiadji et.al reported a case report of a female in her late fifties who presented with COVID-19 associated acute hemorrhagic necrotizing encephalopathy[8] | fever
cough |
altered mentation | Not possible due to traumatic rupture | Negative | Negative | RT-PCR for SARS-CoV-2 positive on nasopharyngeal swab | Negative |
|
2. A 74 year male who had traveled from Europe to USA was presented to emergency with COVID-19 related encephalopathy[9] | Fever
cough |
headache
altered mentationn |
|
Negative | Negative | positive | Negative | CT scan normal |
3. 59 year female with history of aplastic anemia presented with COVID-19 related acute necrotizing encephalopathy involving brain stem. She returned from trip to Afghanistan[10] | fever
cough headache |
|
|
Negative | Negative | RT-PCR positive | Negative | MRI showed diffuse swelling and hemorrhage in the brain stem and both amygdalae |
4. Benameur et. al reported a 31 year old african american presented with COVID-19 related encephalopathy.[11] | fever
dyspnea |
|
|
Negative | Negative | RT-PCR positive for SARS-CoV-2 | Negative | MRI howed nonenhancing cerebral edema and diffusion weighted imaging abnormalities predominantly involving the right cerebral hemisphere, as well as brain herniation |
5.Benameur et. al reported a 34 year old african american with hypertension presented with COVID-19 related encephalopathy.[11] | fever
cough dyspnea |
|
|
Negative | Negative | positive RT-PCR for SARS-CoV-2 | Negative | Brain MRI on day 15 showed a nonenhancing hyperintense lesion within the splenium of the corpus callosum |
6. Benameur et. al reported a 64 year old african american with hypertension presented with COVID-19 related encephalopathy.[11] | Fever
Cough Dyspnea |
|
Normal | Negative | Negative | RT-PCR positive for SARS-CoV-2 | Negative | MRI showed an equivocal nonenhancing area of fluid-attenuated inversion recovery abnormality in the right temporal lobe. |
7. Espinosa et. al presented a case report of COVID-19 related encephalopathy[12] | Fever |
|
WBCs =2 cells
proteins = 27 glucose = 68 |
Negative | Negative | Positive PCR for SARS-CoV-2 | Negative | on MRI diffusion-weighted imaging shows an area of restricted diffusion in the left parietocoritcal region |
8. Byrness et. al reported a case of 36 years old male who was suspected to have drug overdose but later was diagnosed with COVID-19 related encephalopathy [13] | Presented with suspected drug overdose. urine screen positive for cocaine, opiates and benzodiazepenes |
|
CSF findings negative for bacterial or viral meningitis/encephalitis | Negative | Negative | RT-PCR positive for SARS-CoV-2 | Negative | (MRI) was obtained which demonstrated multiple focal enhancing lesions primarily affecting the bilateral medial putamen and left cerebellum |
9. A 64 year old female presented with posterior reversible encephalopathy syndrome (PRES) and was reported by reported by Cariddi et. al[14] | fever
dyspnea |
On 25th day of admission when she was weaned off sedation she had:
|
CSF negative for bacterial or viral findings | Negative | negative | RT-PCR positive for SARS-CoV-2 | negative |
|
10. A 48 year old male, ail pilot presented with hemorrhagic posterior reversible encephalopathy syndrome[15] | fever
dyspnea |
|
NA | Negative | negative | RT-PCR positive for SARS-CoV-2 | negative | MRI showed vasogenic edema in the posterior parieto-occipital regions with subacute blood products suggestive of hemorrhagic posterior reversible encephalopathy syndrome (PRES) |
11. Hayashi et.al reported the first case of COVID-19-associated mild encephalitis/encephalopathy with a reversible splenial lesion in 75-year-old male[16] |
|
|
NA | negative | negative | RT-PCR on throat swab positive for SARS-CoV-2 | Negative | (MRI) of the brain revealed an abnormal hyperintensity in the splenium of corpus callosum (SCC), suspicious for clinically mild encephalitis/encephalopathy with a reversible splenial lesion (MERS) |
12. Cani et. al reported Frontal encephalopathy related to hyperinflammation in 77-year-old female with COVID-19[17] | fever
respiratory symptoms |
|
normal | negative | negative | SARS-CoV-2 positive on RT-PCR | Negative | MRI displayed diffuse white-matter lesions consistent with chronic small vessel disease without contrast enhancement |
13. Encephalopathy and seizure activity in a 41-year-old COVID-19 well-controlled HIV patient was reported by Haddad S et.al[18] | Fever
fatigue chills cough |
|
WBCs = 0
RBCs = 5 cells Proteins = 102 Glucose = 81 |
Negative | negative | SARS-CoV-2 positive on RT-PCR | neagtive | NA |
Physical Examination
- Patients with COVID-19-associated encephalopathy usually appear confused.
- Physical examination of patients with COVID-19-associated encephalopathy is usually remarkable for altered mentation, speech arrest, seizure, and neurological illness.
- The presence of seizures, confusion, and neurological illnesses on physical examination is highly suggestive of COVID-19-associated encephalopathy.
Laboratory Findings
- Laboratory findings consistent with the diagnosis of COVID-19-associated encephalopathy include CSF analysis, RT-PCR for SARS-CoV-2 on nasopharyngeal swab and on CSF.
- RT-PCR for SARS-CoV-2 on CSF is usually normal among patients with COVID-19-associated encephalopathy.
- Some patients with COVID-19-associated encephalopathy may have reduced activity of brain on EEG, whih is usually suggestive of progression.
Electrocardiogram
- There are no ECG findings associated with COVID-19-associated encephalopathy.
X-ray
- There are no x-ray findings associated with COVID-19-associated encephalopathy.
Echocardiography or Ultrasound
- There are no echocardiography findings associated with COVID-19-associated encephalopathy.
- Echocardiography may be helpful in the diagnosis of COVID-19-associated cardiac disease.
CT scan
- Head CT scan may be helpful in the diagnosis of COVID-19-associated encephalopathy.
- Findings on head CT scan suggestive of COVID-19-associated encephalopathy include:
- Noncontrast head CT images demonstrated symmetric hypoattenuation within the bilateral medial thalami with a normal CT angiogram and CT venogram,
- Hemorrhagic Posterior Reversible Encephalopathy Syndrome.
MRI
- Brain MRI is helpful in the diagnosis of COVID-19-associated encephalopathy.
- Findings on brain MRI suggestive of COVID-19-associated encephalopathy include:
- Hemorrhagic rim enhancing lesions within the bilateral thalami, medial temporal lobes, and subinsular regions,
- Diffuse swelling and hemorrhage in the brain stem and both amygdalae,
- Nonenhancing cerebral edema and diffusion weighted imaging abnormalities,
- Brain herniation
- Nonenhancing hyperintense lesion.
Other Imaging Findings
Other imaging studies may be helpful in the diagnosis of COVID-19-associated encephalopathy include:
- MR spectroscopy,
- CT angiogram and
- CT venogram may be helpful in the diagnosis of COVID-19-associated encephalopathy.
Other Diagnostic Studies
Other diagnostic studies for COVID-19-associated encephalopathy include:
- Antibody IgM for acute infection, and
- Antibody IgG for resolved or chronic infection.
- RT-PCR of SARS-CoV-2 RNA positive in CSF or nasopharyngeal swab.
Treatment
Medical Therapy
The mainstay of medical therapy for viral encephalitis are:
Symptomatic Treatment
- There is no specific treatment for COVID-19-associated encephalopathy; the mainstay of therapy is supportive care.
- Supportive therapy for COVID-19-associated encephalopathy includes corticosteroids, anti-epileptic drugs, and treating underlying condition.
- COVID-19-associated encephalopathy can present in a medical emergency and requires prompt treatment.
- Severe disease require intubation and mechanical ventilation.
- Anti-inflammatory medicines like pulse steroids (methylprednisolone 1,000 mg/day)[19] are helpful in this disease, some patients improved even with a very low dose (60mg/day)[17].
- Anti-epileptic drugs like levetiracetam (50-60 mg/kg/day)[20] is necessary for seizure management in patients with refractory seizures.
- Tocilizumab (8mg/kg/dose)[21] is IL-6 anatgonist, that reduces cytokine storm syndrome responsible for neurological manifestations in a COVID-19 patient.[22]
- To see treatment protocol to manage the underlying cause i.e., COVID-19, click here
Surgery
- Surgical intervention is not recommended for the management of COVID-19-associated encephalopathy.
- Focal epileptic involvement of brain parenchyma can be treated with resection of the area.
Primary Prevention
- There are no established measures for the primary prevention of COVID-19-associated encephalopathy.
- To view primary prevention for COVID-19 click here.
Secondary Prevention
- There are no established measures for the secondary prevention of COVID-19-associated encephalopathy.
- To view secondary prevention for COVID-19 click here.
References
- ↑ Turner AJ, Hiscox JA, Hooper NM (2004). "ACE2: from vasopeptidase to SARS virus receptor". Trends Pharmacol Sci. 25 (6): 291–4. doi:10.1016/j.tips.2004.04.001. PMC 7119032 Check
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value (help). PMID 15165741. - ↑ Chen C, Zhang XR, Ju ZY, He WF (2020) [Advances in the research of mechanism and related immunotherapy on the cytokine storm induced by coronavirus disease 2019.] Zhonghua Shao Shang Za Zhi 36 (6):471-475. DOI:10.3760/cma.j.cn501120-20200224-00088 PMID: 32114747
- ↑ Bohmwald K, Gálvez NMS, Ríos M, Kalergis AM (2018). "Neurologic Alterations Due to Respiratory Virus Infections". Front Cell Neurosci. 12: 386. doi:10.3389/fncel.2018.00386. PMC 6212673. PMID 30416428.
- ↑ Zhang C, Wu Z, Li JW, Zhao H, Wang GQ (2020). "Cytokine release syndrome in severe COVID-19: interleukin-6 receptor antagonist tocilizumab may be the key to reduce mortality". Int J Antimicrob Agents. 55 (5): 105954. doi:10.1016/j.ijantimicag.2020.105954. PMC 7118634 Check
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value (help). PMID 32234467 Check|pmid=
value (help). - ↑ Vashisht R, Duggal A (2020). "Respiratory failure in patients infected with SARS-CoV-2". Cleve Clin J Med. doi:10.3949/ccjm.87a.ccc025. PMID 32409443 Check
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value (help). - ↑ Parsons T, Banks S, Bae C, Gelber J, Alahmadi H, Tichauer M (2020). "COVID-19-associated acute disseminated encephalomyelitis (ADEM)". J Neurol. doi:10.1007/s00415-020-09951-9. PMC 7260459 Check
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value (help). PMID 32474657 Check|pmid=
value (help). - ↑ Reichard RR, Kashani KB, Boire NA, Constantopoulos E, Guo Y, Lucchinetti CF (2020). "Neuropathology of COVID-19: a spectrum of vascular and acute disseminated encephalomyelitis (ADEM)-like pathology". Acta Neuropathol. 140 (1): 1–6. doi:10.1007/s00401-020-02166-2. PMC 7245994 Check
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value (help). PMID 32449057 Check|pmid=
value (help). - ↑ Poyiadji N, Shahin G, Noujaim D, Stone M, Patel S, Griffith B (2020). "COVID-19-associated Acute Hemorrhagic Necrotizing Encephalopathy: CT and MRI Features". Radiology: 201187. doi:10.1148/radiol.2020201187. PMC 7233386 Check
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value (help). PMID 32228363 Check|pmid=
value (help). - ↑ Filatov A, Sharma P, Hindi F, Espinosa PS (2020). "Neurological Complications of Coronavirus Disease (COVID-19): Encephalopathy". Cureus. 12 (3): e7352. doi:10.7759/cureus.7352. PMC 7170017 Check
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value (help). PMID 32328364 Check|pmid=
value (help). - ↑ Dixon L, Varley J, Gontsarova A, Mallon D, Tona F, Muir D; et al. (2020). "COVID-19-related acute necrotizing encephalopathy with brain stem involvement in a patient with aplastic anemia". Neurol Neuroimmunol Neuroinflamm. 7 (5). doi:10.1212/NXI.0000000000000789. PMC 7286661 Check
|pmc=
value (help). PMID 32457227 Check|pmid=
value (help). - ↑ 11.0 11.1 11.2 Benameur K, Agarwal A, Auld SC, Butters MP, Webster AS, Ozturk T; et al. (2020). "Encephalopathy and Encephalitis Associated with Cerebrospinal Fluid Cytokine Alterations and Coronavirus Disease, Atlanta, Georgia, USA, 2020". Emerg Infect Dis. 26 (9). doi:10.3201/eid2609.202122. PMID 32487282 Check
|pmid=
value (help). - ↑ Espinosa PS, Rizvi Z, Sharma P, Hindi F, Filatov A (2020). "Neurological Complications of Coronavirus Disease (COVID-19): Encephalopathy, MRI Brain and Cerebrospinal Fluid Findings: Case 2". Cureus. 12 (5): e7930. doi:10.7759/cureus.7930. PMC 7266087 Check
|pmc=
value (help). PMID 32499974 Check|pmid=
value (help). - ↑ Byrnes S, Bisen M, Syed B, Huda S, Siddique Z, Sampat P; et al. (2020). "COVID-19 encephalopathy masquerading as substance withdrawal". J Med Virol. doi:10.1002/jmv.26065. PMC 7283690 Check
|pmc=
value (help). PMID 32458578 Check|pmid=
value (help). - ↑ Princiotta Cariddi L, Tabaee Damavandi P, Carimati F, Banfi P, Clemenzi A, Marelli M; et al. (2020). "Reversible Encephalopathy Syndrome (PRES) in a COVID-19 patient". J Neurol. doi:10.1007/s00415-020-10001-7. PMC 7312113 Check
|pmc=
value (help). PMID 32583053 Check|pmid=
value (help). - ↑ Franceschi AM, Ahmed O, Giliberto L, Castillo M (2020). "Hemorrhagic Posterior Reversible Encephalopathy Syndrome as a Manifestation of COVID-19 Infection". AJNR Am J Neuroradiol. 41 (7): 1173–1176. doi:10.3174/ajnr.A6595. PMC 7357664 Check
|pmc=
value (help). PMID 32439646 Check|pmid=
value (help). - ↑ Hayashi M, Sahashi Y, Baba Y, Okura H, Shimohata T (2020). "COVID-19-associated mild encephalitis/encephalopathy with a reversible splenial lesion". J Neurol Sci. 415: 116941. doi:10.1016/j.jns.2020.116941. PMC 7251406 Check
|pmc=
value (help). PMID 32474220 Check|pmid=
value (help). - ↑ 17.0 17.1 Cani I, Barone V, D'Angelo R, Pisani L, Allegri V, Spinardi L; et al. (2020). "Frontal encephalopathy related to hyperinflammation in COVID-19". J Neurol. doi:10.1007/s00415-020-10057-5. PMC 7353824 Check
|pmc=
value (help). PMID 32654063 Check|pmid=
value (help). - ↑ Haddad S, Tayyar R, Risch L, Churchill G, Fares E, Choe M; et al. (2020). "Encephalopathy and seizure activity in a COVID-19 well controlled HIV patient". IDCases: e00814. doi:10.1016/j.idcr.2020.e00814. PMC 7228895 Check
|pmc=
value (help). PMID 32426230 Check|pmid=
value (help). - ↑ Nakano A, Yamasaki R, Miyazaki S, Horiuchi N, Kunishige M, Mitsui T (2003). "Beneficial effect of steroid pulse therapy on acute viral encephalitis". Eur. Neurol. 50 (4): 225–9. doi:10.1159/000073864. PMID 14634267.
- ↑ Ueda R, Saito Y, Ohno K, Maruta K, Matsunami K, Saiki Y, Sokota T, Sugihara S, Nishimura Y, Tamasaki A, Narita A, Imamura A, Maegaki Y (May 2015). "Effect of levetiracetam in acute encephalitis with refractory, repetitive partial seizures during acute and chronic phase". Brain Dev. 37 (5): 471–7. doi:10.1016/j.braindev.2014.08.003. PMID 25174548.
- ↑ [+https://clinicaltrials.gov/ct2/show/NCT04372186 "A Study to Evaluate the Efficacy and Safety of Tocilizumab in Hospitalized Participants With COVID-19 Pneumonia - Full Text View - ClinicalTrials.gov"] Check
|url=
value (help). - ↑ Zhang C, Wu Z, Li JW, Zhao H, Wang GQ (2020). "Cytokine release syndrome in severe COVID-19: interleukin-6 receptor antagonist tocilizumab may be the key to reduce mortality". Int J Antimicrob Agents. 55 (5): 105954. doi:10.1016/j.ijantimicag.2020.105954. PMC 7118634 Check
|pmc=
value (help). PMID 32234467 Check|pmid=
value (help).