Table 4.
Electroencephalography in patients with COVID-19
| Author/country | Methods | Results | Major limitations | Level of evidence |
|---|---|---|---|---|
| Helms/France [53] | 42 COVID-19 patients with EEG recording due to change in mental status | EEG showed nonspecific abnormalities or diffuse, especially bifrontal, slow activity. CSF analysis revealed inflammatory disturbances in 18/28 patients, including oligoclonal bands with mirror pattern and elevated IL-6. The CSF RT-PCR SARS-CoV-2 was positive in one patient. | Small sample size | III |
| Pilato/USA [54] | 8 COVID-19 patients with EEG monitoring | Generalized background slowing in all and generalized epileptiform discharges with triphasic morphology in 3 patients. | A case series | IV |
| Galanopoulou/USA [55] | Retrospective study of 22 patients | New onset encephalopathy (68%) and seizure-like events (64%) were reasons for EEG study. Four patients had prior epilepsy. Epileptiform discharges were present in 41%. Many patients had organ failure. | Small sample size | III |
| Petrescu/France [56] | Retrospective study of 40 EEGs in 36 COVID-19 patients | Generalized periodic discharges, multifocal periodic discharges or rhythmic delta activity were found in 13 recordings (32.5%). | Small sample size | III |
| Assenza/Italy [57] | Survey of 206 centers on EEG management data | The number of EEGs performed was reduced by 76 ± 20%. Half of the centers performed inpatient EEGs only for urgencies. | – | IV |
| Vellieux/France [58] | 2 patients with COVID-19 and encephalopathy and a unique EEG pattern |
1. A 37-year-old man, EEG showed continuous, slightly asymmetric, monomorphic, diphasic, delta slow waves with greater amplitude over both frontal areas and with a periodic organization. Brain MRI showed hypoxic encephalopathy. CSF analysis was normal. At hospital discharge, he had a mild left sensorimotor deficit secondary infarction. 2. A 42-year-old man, EEG was similar to above. CSF analysis was not done. Brain imaging was not done. The patient died. |
– | IV |
| De Stefano/Switzerland [59] | A case with altered mental status (a 56-year-old woman) | EEG showed a focal monomorphic theta slowing in bilateral frontal-central regions. MRI showed microbleeds located in bilateral white matter junction, various regions of corpus callosum, and internal capsule. CSF analysis excluded the encephalitis. SARS-Cov2 RNA-PCR in CSF was negative. Outcome was not specified. | – | IV |
| Cecchetti/Italy[60] | A series of 18 patients | EEG showed generalized slowing in 88.9%; an anterior (bifrontal) prevalence of slow waves was noted in 55.6%. Two patients had epileptiform discharges (no seizures). One subject underwent lumbar puncture with normal results and negative PCR test for SARS-CoV-2. | A case series | IV |
| Pati/USA [61] | A series of 10 patients with continuous electroencephalography (cEEG) | Patients with good outcome had higher temporal-variance with greater diversity in frequency bands and spatial extents. QEEG features may prognosticate neurological outcome in critically ill patients with COVID-19. | A case series | IV |
| Pastor/Spain [62] | A series of 20 patients with QEEG | Temporal lobes showed different distribution for QEEG bands. | A case series | IV |
| Somani/UK [63] | 2 patients with COVID-19 and de novo status epilepticus |
1. A 49-year-old woman, EEG monitoring showed multiple seizures starting from the midline and left fronto-central regions. Brain MRI was normal. CSF analysis was not done. The patient was discharged home in a good condition. 2. A 73-year-old woman, EEG showed bilateral independent periodic discharges over the left and right hemisphere that evolved to form recurrent seizures starting from either right or left fronto-central-parietal regions. Brain CT scan was normal. CSF analysis was not done. The patient died. |
– | IV |
| Abdel-Mannan/UK [64] | 27 children with COVID-19 pediatric multisystem inflammatory syndrome | In all 3 patients who underwent EEG, a mild excess of slow activity was seen. In the 2 patients whose CSF was tested, samples were acellular, with negative SARS-CoV-2 PCR. | Small sample size | III |
| Vespignani/France [65] | 26 COVID-19 patients who underwent EEG to assess unexplained altered mental status | 5 patients had EEGs with periodic discharges consisting of high-amplitude frontal monomorphic delta waves with no epileptic activity. | Small sample size | III |
| Scullen/USA [66] | 27 critically ill patients with COVID-19 | 74% had encephalopathy, 7% acute necrotizing encephalopathy, and 19% vasculopathy. 44% had EEG abnormalities; most of them had generalized encephalopathy; one patient had nonconvulsive status epilepticus. | Small sample size | III |
| Passini/Italy [67] | EEG findings in 15 patients with COVID-19 and encephalopathy | The EEGs were abnormal (slow) in all cases. No epileptiform abnormalities or triphasic waves were observed. SARS-CoV-2 was not detected in the CSF in any case. | Small sample size | III |
| Abenza-Abildúa/Spain [68] | A case report (a 56-year-old woman with change in mental status) | EEG showed generalized slowing. CSF analysis was normal. Brain MRI was uneventful. The patient remained well. | – | IV |
| Roy-Gash/France [69] | A case report (a 63-year-old woman with status epilepticus) | EEG showed focal status epilepticus. CSF analysis was not done. Brain CT scan showed left temporal hemorrhage with venous thrombosis. The patient died. | – | IV |
| Pilotto/Italy [70] | A case report (a 60-year-old man with change in mental status) | EEG showed generalized slowing. CSF analysis showed lymphocytic pleocytosis (18/μL). CSF PCR for SARS-CoV-2 was negative. Brain MRI was normal. The patient was discharged home in a good condition. | – | IV |
CSF, cerebrospinal fluid; EEG, electroencephalography; CT, computerized tomography; MRI, magnetic resonance imaging; PCR, polymerase chain reaction; QEEG, quantitative EEG