TABLE 3.
Summary of the case reports and case series findings
| Variables | No. of studies | n/N | % |
|---|---|---|---|
| Gender | |||
| Male | 29 | 32/53 | 60.38 |
| Female | 19 | 21/53 | 39.62 |
| Age | |||
| <30 (years old) | 6 | 6/53 | 11.32 |
| 31–50 (years old) | 16 | 18/53 | 33.96 |
| >51 (years old) | 25 | 29/53 | 54.72 |
| Age/sex | |||
| <30 (years old) | |||
| Male | 4 | 4/6 | 66.67 |
| Female | 2 | 2/6 | 33.33 |
| 31–50 (years old) | |||
| Male | 11 | 12/18 | 66.67 |
| Female | 6 | 6/18 | 33.33 |
| >51 (years old) | |||
| Male | 15 | 16/29 | 55.17 |
| Female | 12 | 13/29 | 44.83 |
| Clinical manifestation | |||
| Neurological manifestations | |||
| Decreased consciousness/unconsciousness | 17 | 18/54 | 33.33 |
| Behavioral changes | 6 | 6/54 | 11.11 |
| Altered mental status | 24 | 29/54 | 53.70 |
| Cerebellar signs | 4 | 5/54 | 9.25 |
| Seizure | 15 | 16/54 | 29.62 |
| Agitation | 5 | 6/54 | 11.11 |
| Headache | 11 | 11/54 | 20.37 |
| Memory deficits | 2 | 2/54 | 3.70 |
| Unresponsiveness | 4 | 4/54 | 7.40 |
| Convulsive status | 2 | 2/54 | 3.70 |
| Cognitive impairment | 2 | 5/54 | 9.26 |
| Language disturbance | 2 | 2/54 | 3.70 |
| Paraphasia | 1 | 1/54 | 1.85 |
| Tremors | 2 | 2/54 | 3.70 |
| Lower limbs paralysis | 2 | 2/54 | 3.70 |
| Gait disturbance | 3 | 3/54 | 5.55 |
| Unsteadiness | 1 | 1/54 | 1.85 |
| Hemi‐neglect | 1 | 1/54 | 1.85 |
| Impaired brain stem reflexes | 2 | 2/54 | 3.70 |
| Pain | 3 | 3/54 | 5.55 |
| Coma | 1 | 1/54 | 1.85 |
| Apraxia | 1 | 1/54 | 1.85 |
| Dysexecutive syndrome | 1 | 1/54 | 1.85 |
| Psychomotor slowing | 1 | 1/54 | 1.85 |
| Ideo‐motor slowing | 1 | 1/54 | 1.85 |
| Oral automatism | 1 | 1/54 | 1.85 |
| Neuropathy | 1 | 1/54 | 1.85 |
| Reduced tendon reflexes | 2 | 2/54 | 3.70 |
| Loss of sphincter control | 1 | 1/54 | 1.85 |
| Deep areflexia | 1 | 1/54 | 1.85 |
| Psychiatric symptoms | |||
| Psychiatric symptoms | 8 | 8/54 | 14.81 |
| General symptoms | |||
| Fever | 32 | 38/54 | 70.37 |
| Vomiting | 8 | 8/54 | 14.81 |
| Nausea | 3 | 3/54 | 5.55 |
| Diarrhea | 4 | 4/54 | 7.40 |
| Anosmia/hyposmia | 7 | 8/54 | 14.81 |
| Ageusia/dysgeusia | 8 | 8/54 | 14.81 |
| Dizziness | 2 | 2/54 | 3.70 |
| Malaise | 3 | 3/54 | 5.55 |
| Fatigue | 8 | 9/54 | 16.66 |
| Drowsiness | 9 | 9/54 | 16.66 |
| Weakness/asthenia | 10 | 10/54 | 18.51 |
| Lethargy | 3 | 3/54 | 5.55 |
| Chills | 2 | 3/54 | 5.55 |
| Anorexia | 3 | 3/54 | 5.55 |
| Food intolerance | 1 | 1/54 | 1.85 |
| Insomnia | 1 | 1/54 | 1.85 |
| Numbness | 1 | 1/54 | 1.85 |
| Neuromuscular symptoms | |||
| Myalgia | 4 | 4/54 | 7.40 |
| Hyperreflexia | 1 | 1/54 | 1.85 |
| Myoclonus | 3 | 3/54 | 5.55 |
| Neck stiffness | 1 | 1/54 | 1.85 |
| Flaccid muscles | 1 | 1/54 | 1.85 |
| Tetraplegia | 1 | 1/54 | 1.85 |
| Increased muscle tension | 1 | 1/54 | 1.85 |
| Other | |||
| Respiratory symptoms | 30 | 37/54 | 68.51 |
| Visual impairment | 4 | 4/54 | 7.40 |
| Renal dysfunction | 8 | 10/54 | 18.51 |
| Cardiac dysfunction | 2 | 4/54 | 7.40 |
| Rash | 2 | 2/54 | 3.70 |
| Viral sepsis | 1 | 1/54 | 1.85 |
| Delayed awakening after sedation | 1 | 2/54 | 3.70 |
| Autonomic disturbances | 1 | 1/54 | 1.85 |
| Comorbidities | |||
| Hypertension | 13 | 14/48 | 29.16 |
| Diabetes mellitus | 7 | 7/48 | 14.58 |
| Obesity | 6 | 6/48 | 12.50 |
| Neurologic disorders | 5 | 5/48 | 10.41 |
| Cardiologic disorder | 4 | 4/48 | 8.33 |
| Dyslipidemia | 2 | 2/48 | 4.16 |
| Anemia | 1 | 1/48 | 2.08 |
| Psychiatric disorders | 2 | 2/48 | 4.16 |
| Renal dysfunction | 3 | 3/48 | 6.25 |
| Immunosuppressive state | 2 | 2/48 | 4.16 |
| Smoking | 2 | 2/48 | 4.16 |
| Hypercholesterolemia | 1 | 1/48 | 2.08 |
| Hypothyroidism | 1 | 1/48 | 2.08 |
| Vitiligo | 1 | 1/48 | 2.08 |
| Monoclonal gammopathy | 1 | 1/48 | 2.08 |
| Asthma | 1 | 1/48 | 2.08 |
| Colorectal cancer | 1 | 1/48 | 2.08 |
| Fatty liver disease | 1 | 1/48 | 2.08 |
| Gastroesophageal reflux disease | 1 | 1/48 | 2.08 |
| Hyperuricemia | 1 | 1/48 | 2.08 |
| Obstructive sleep apnea | 1 | 1/48 | 2.08 |
| Benign prostatic hypertrophy | 1 | 1/28 | 3.57 |
| Gestation | 1 | 1/20 | 5.00 |
| No comorbidities | 15 | 15/48 | 31.25 |
| Presence of SARS‐CoV‐2 RNA in the CSF sample | |||
| Positive | 7 | 7/34 | 20.58 |
| Negative | 21 | 27/34 | 79.41 |
| SARS‐CoV‐2 diagnosis method | |||
| RT‐PCR | 40 | 49/53 | 92.45 |
| Chest CT | 20 | 20/53 | 37.73 |
| Serological testing (anti‐SARS‐CoV‐2 antibody) | 5 | 6/53 | 11.32 |
| Simplexa SARS‐CoV‐2 assay | 1 | 1/53 | 1.88 |
| Encephalitis diagnosis method | |||
| Brain MRI | 36 | 44/54 | 81.48 |
| Head CT scan | 15 | 20/54 | 37.03 |
| CSF analysis | 21 | 25/54 | 46.29 |
| Electroencephalogram | 15 | 23/54 | 42.59 |
| Total body PET/TC | 1 | 1/54 | 1.85 |
| FDG‐PET/CT imaging | 1 | 4/54 | 7.40 |
| CT angiogram | 1 | 1/54 | 1.85 |
| Magnetic resonance angiography and venography | 1 | 1/54 | 1.85 |
| Biochemical blood tests | 3 | 3/54 | 5.55 |
| Post‐mortem biopsy | 1 | 1/54 | 1.85 |
| Physical and neurological examination | 2 | 2/54 | 3.70 |
| Immunoblot analysis | 1 | 1/54 | 1.85 |
| Brain tomography | 1 | 1/54 | 1.85 |
| Special encephalitis treatment | |||
| Dexamethasone | 2 | 3/36 | 8.33 |
| Plasma exchange | 3 | 3/36 | 8.33 |
| IV methylprednisolone/oral prednisone | 13 | 13/36 | 36.11 |
| IV immunoglobulin | 8 | 10/36 | 27.77 |
| Corticosteroids | 2 | 4/36 | 11.11 |
| Steroids | 1 | 1/36 | 2.77 |
| Propofol infusion | 1 | 1/36 | 2.77 |
| Mannitol | 2 | 2/36 | 5.55 |
| Acyclovir | 6 | 6/36 | 16.66 |
| Ceftriaxone | 3 | 3/36 | 8.33 |
| Vancomycin | 4 | 4/36 | 11.11 |
| Meropenem | 2 | 2/36 | 5.55 |
| Tocilizumab | 4 | 4/36 | 11.11 |
| Azithromycin | 1 | 1/36 | 2.77 |
| Rituximab | 1 | 1/36 | 2.77 |
| Anti‐edematous therapy | 1 | 1/36 | 2.77 |
| COVID‐19 treatment | |||
| Hydroxychloroquine | 15 | 15/30 | 50.00 |
| Chloroquine | 1 | 1/30 | 3.33 |
| Azithromycin | 4 | 4/30 | 13.33 |
| IV amoxicillin‐clavulanic acid | 1 | 1/30 | 3.33 |
| IV immunoglobulin | 2 | 2/30 | 6.66 |
| Ceftriaxone | 3 | 3/30 | 10.00 |
| Dexamethasone | 3 | 3/30 | 10.00 |
| Favipiravir | 2 | 2/30 | 6.66 |
| Ritonavir/lopinavir | 5 | 5/30 | 16.66 |
| Plasma exchange | 2 | 2/30 | 6.66 |
| Remdesevir | 1 | 1/30 | 3.33 |
| Clarithromycin | 1 | 1/30 | 3.33 |
| Corticosteroid pulse | 1 | 1/30 | 3.33 |
| Clindamycin | 1 | 1/30 | 3.33 |
| Interferon beta‐1b | 1 | 1/30 | 3.33 |
| Darunavir/cobicistat | 1 | 1/30 | 3.33 |
| Cephalosporin | 2 | 2/30 | 6.66 |
| Aminoglycoside | 1 | 1/30 | 3.33 |
| Vancomycin | 1 | 1/30 | 3.33 |
| Linezolide | 2 | 2/30 | 6.66 |
| Acyclovir | 6 | 6/30 | 20.00 |
| Acetaminophen | 1 | 1/30 | 3.33 |
| Gamma globulin | 1 | 1/30 | 3.33 |
| Levofloxacin | 2 | 2/30 | 6.66 |
| Meropene | 1 | 1/30 | 3.33 |
| Atazanavir | 1 | 1/30 | 3.33 |
| Trimethoprime‐sulfamethoxazole | 1 | 1/30 | 3.33 |
| Meropenem aminosid | 1 | 1/30 | 3.33 |
| Outcome | |||
| Death | 13 | 13/46 | 28.26 |
| Discharged | 20 | 23/46 | 50.00 |
| Discharged to rehabilitation/partial recovery | 4 | 4/46 | 8.69 |
| Still hospitalized | 4 | 4/46 | 8.69 |
| Transferred to another hospital | 2 | 2/46 | 4.34 |
| Brain MRI pattern | |||
| Unremarkable | 6 | 6/47 | 12.76 |
| Hyperintensity in the white matter | 15 | 21/47 | 44.68 |
| Hyperintensity in the corpus callosum | 5 | 6/47 | 12.76 |
| Hyperintensity in the cerebellum | 3 | 3/47 | 6.38 |
| Hyperintensity of the thalamus | 6 | 6/47 | 12.76 |
| Hyperintensity in the temporal lobe | 8 | 8/47 | 17.02 |
| Hyperintensity in the frontal lobe | 5 | 5/47 | 10.63 |
| Hyperintensity in the brainstem | 3 | 3/47 | 6.38 |
| Hyperintensity in the parietal lobe | 2 | 2/47 | 4.25 |
| Hyperintensity along the wall of lateral ventricle | 1 | 1/47 | 2.12 |
| Hemorrhagic/microhemrorrhagic areas | 4 | 5/47 | 10.63 |
| Signs of brain edema | 4 | 4/47 | 8.51 |
| Confluent diffusion restriction in the white matter | 2 | 4/47 | 8.51 |
| Compression and displacement of the brainstem and fourth ventricle | 1 | 1/47 | 2.12 |
| Downward cerebellar tonsilar herniation | 2 | 2/47 | 4.25 |
| Mild gyral expansion | 2 | 2/47 | 4.25 |
| Involvement of cortical and deep gray matter and midbrain | 1 | 1/47 | 2.12 |
| Diffuse hemosiderin staining throughout the white matter and corpus callosum | 1 | 1/47 | 2.12 |
| Linear meningeal enhancement | 1 | 1/47 | 2.12 |
| Contrast enhancement on the floor of the fourth ventricle | 1 | 1/47 | 2.12 |
| Bilateral optic nerve enhancement | 1 | 1/47 | 2.12 |
| Slight hippocampus atrophy | 1 | 1/47 | 2.12 |
| Mild hippocampal thickening | 1 | 1/47 | 2.12 |
| Generalized brain atrophy | 1 | 1/47 | 2.12 |
| Head CT scan pattern | |||
| Unremarkable | 15 | 20/35 | 57.14 |
| Hypodensity of the white matter | 6 | 6/35 | 17.14 |
| Hypodensity of the thalamus | 3 | 3/35 | 8.57 |
| Hypodensity of the corpus callosum | 2 | 2/35 | 5.71 |
| Hypodensity in the cerebellum | 2 | 3/35 | 8.57 |
| Cerebral hemorrhages/hemorrhagic foci | 4 | 4/35 | 11.42 |
| Brain swelling and edema | 2 | 2/35 | 5.71 |
| Brain herniation | 1 | 1/35 | 2.85 |
| Opacification of paranasal sinuses | 1 | 1/35 | 2.85 |
| Internal hydrocephalus | 1 | 1/35 | 2.85 |
| Parenchymal hematoma with surrounding edema | 1 | 1/35 | 2.85 |
| Cerebral parenchymal volume loss with sulcal enlargement | 1 | 1/35 | 2.85 |
| Enlargement of the lateral ventricles with intraventricular masses | 1 | 1/35 | 2.85 |
| Increased supratentorial leptomeningeal enhancement | 1 | 1/35 | 2.85 |