Neurological Manifestations in COVID-19 Infection: A Systematic Review and Meta-Analysis.

BACKGROUND: Growing evidence showed that coronavirus disease 2019 (COVID-19) infection may present with neurological manifestations. This review aimed to determine the neurological manifestations and complications in COVID-19. METHODS: We conducted a systematic review and meta-analysis that included cohort and case series/reports involving a population of patients confirmed with COVID-19 infection and their neurologic manifestations. We searched the following electronic databases until April 18, 2020: PubMed, Embase, Scopus, and World Health Organization database (PROSPERO registration number: CRD42020180658). RESULTS: From 403 articles identified, 49 studies involving a total of 6,335 confirmed COVID-19 cases were included. The random-effects modeling analysis for each neurological symptom showed the following proportional point estimates with 95% confidence intervals: "headache" (0.12; 0.10-0.14; I2 = 77%), "dizziness" (0.08; 0.05-0.12; I2 = 82%), "headache and dizziness" (0.09; 0.06-0.13; I2 = 0%), "nausea" (0.07; 0.04-0.11; I2 = 79%), "vomiting" (0.05; 0.03-0.08; I2 = 74%), "nausea and vomiting" (0.06; 0.03-0.11; I2 = 83%), "confusion" (0.05; 0.02-0.14; I2 = 86%), and "myalgia" (0.21; 0.18-0.25; I2 = 85%). The most common neurological complication associated with COVID-19 infection was vascular disorders (n = 23); other associated conditions were encephalopathy (n = 3), encephalitis (n = 1), oculomotor nerve palsy (n = 1), isolated sudden-onset anosmia (n = 1), Guillain-Barré syndrome (n = 1), and Miller-Fisher syndrome (n = 2). Most patients with neurological complications survived (n = 14); a considerable number of patients died (n = 7); and the rest had unclear outcomes (n = 12). CONCLUSION: This review revealed that neurologic involvement may manifest in COVID-19 infection. What has initially been thought of as a primarily respiratory illness has evolved into a wide-ranging multi-organ disease.

Encephalopathies Associated With Severe COVID-19 Present Neurovascular Unit Alterations Without Evidence for Strong Neuroinflammation.

OBJECTIVE: Coronavirus disease (COVID-19) has been associated with a large variety of neurologic disorders. However, the mechanisms underlying these neurologic complications remain elusive. In this study, we aimed at determining whether neurologic symptoms were caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) direct infection or by either systemic or local proinflammatory mediators. METHODS: In this cross-sectional study, we checked for SARS-CoV-2 RNA by quantitative reverse transcription PCR, SARS-CoV-2-specific antibodies, and 49 cytokines/chemokines/growth factors (by Luminex) in the CSF +/- sera of a cohort of 22 COVID-19 patients with neurologic presentation and 55 neurologic control patients (inflammatory neurologic disorder [IND], noninflammatory neurologic disorder, and MS). RESULTS: We detected anti-SARS-CoV-2 immunoglobulin G in patients with severe COVID-19 with signs of intrathecal synthesis for some of them. Of the 4 categories of tested patients, the CSF of IND exhibited the highest level of cytokines, chemokines, and growth factors. By contrast, patients with COVID-19 did not present overall upregulation of inflammatory mediators in the CSF. However, patients with severe COVID-19 (intensive care unit patients) exhibited higher concentrations of CCL2, CXCL8, and vascular endothelium growth factor A (VEGF-A) in the CSF than patients with a milder form of COVID-19. In addition, we could show that intrathecal CXCL8 synthesis was linked to an elevated albumin ratio and correlated with the increase of peripheral inflammation (serum hepatocyte growth factor [HGF] and CXCL10). CONCLUSIONS: Our results do not indicate active replication of SARS-CoV-2 in the CSF or signs of massive inflammation in the CSF compartment but highlight a specific impairment of the neurovascular unit linked to intrathecal production of CXCL8.

Brain dysfunction in COVID-19 and CAR-T therapy: cytokine storm-associated encephalopathy.

OBJECTIVE: Many neurological manifestations are associated with COVID-19, including a distinct form of encephalopathy related to cytokine storm, the acute systemic inflammatory syndrome present in a subgroup of COVID-19 patients. Cytokine storm is also associated with immune effector cell-associated neurotoxicity syndrome (ICANS), a complication of chimeric antigen receptor T-cell (CAR-T) therapy, a highly effective treatment for refractory hematological malignancies. We investigated whether COVID-19-related encephalopathy, ICANS, and other encephalopathies associated with cytokine storm, share clinical and investigative findings. METHODS: Narrative literature review. RESULTS: Comparisons between COVID-19-related encephalopathy and ICANS revealed several overlapping features. Clinically, these included dysexecutive syndrome, language disturbances, akinetic mutism and delirium. EEG showed a prevalence of frontal abnormalities. Brain MRI was often unrevealing. CSF elevated cytokine levels have been reported. A direct correlation between cytokine storm intensity and severity of neurological manifestations has been shown for both conditions. Clinical recovery occurred spontaneously or following immunotherapies in most of the patients. Similar clinical and investigative features were also reported in other encephalopathies associated with cytokine storm, such as hemophagocytic lymphohistiocytosis, sepsis, and febrile infection-associated encephalopathies. INTERPRETATION: COVID-19-related encephalopathy and ICANS are characterized by a predominant electro-clinical frontal lobe dysfunction and share several features with other encephalopathies associated with cytokine storm, which may represent the common denominator of a clinical spectrum of neurological disorders. Therefore, we propose a unifying definition of cytokine storm-associated encephalopathy (CySE), and its diagnostic criteria.

Treatment of unexplained coma and hypokinetic-rigid syndrome in a patient with COVID-19.

The COVID-19 pandemic has dealt a devastating blow to healthcare systems globally. Approximately 3.2% of patients infected with COVID-19 require invasive ventilation during the course of the illness. Within this population, 25% of patients are affected with neurological manifestations. Among those who are affected by severe neurological manifestations, some may have acute cerebrovascular complications (5%), impaired consciousness (15%) or exhibit skeletal muscle hypokinesis (20%). The cause of the severe cognitive impairment and hypokinesis is unknown at this time. Potential causes include COVID-19 viral encephalopathy, toxic metabolic encephalopathy, post-intensive care unit syndrome and cerebrovascular pathology. We present a case of a 60 year old patient who sustained a prolonged hospitalization with COVID-19, had a cerebrovascular event and developed a persistent unexplained encephalopathy along with a hypokinetic state. He was treated successfully with modafinil and carbidopa/levodopa showing clinical improvement within 3-7 days and ultimately was able to successfully discharge home.

The Brain on COVID-19.

In March 2020 -still the early days of the U.K.'s COVID-19 crisis-Rhys Thomas, a neurologist at Newcastle University, got a call at home from a concerned colleague. The colleague's cousin was hospitalized, critically ill with COVID-19, and had developed brainstem encephalitis, a severe inflammatory condition of the brain causing a suite of symptoms, from eye problems to balance problems and drowsiness. He wanted to know if Thomas knew anything about these conditions. At the time, the research coming out of Wuhan, China, only suggested a mild whiff of neurological symptoms-headache, dizziness, and the loss of taste and smell. Clearly the virus could affect the brain in some ways, but it wasn't, Thomas thought then, anything serious. But this report sounded much more concerning. Symptoms like this patient's would mean the virus was accessing more of the nervous system than scientists originally thought.

Persistent Brainstem Dysfunction in Long-COVID: A Hypothesis.

Long-COVID is a postviral illness that can affect survivors of COVID-19, regardless of initial disease severity or age. Symptoms of long-COVID include fatigue, dyspnea, gastrointestinal and cardiac problems, cognitive impairments, myalgia, and others. While the possible causes of long-COVID include long-term tissue damage, viral persistence, and chronic inflammation, the review proposes, perhaps for the first time, that persistent brainstem dysfunction may also be involved. This hypothesis can be split into two parts. The first is the brainstem tropism and damage in COVID-19. As the brainstem has a relatively high expression of ACE2 receptor compared with other brain regions, SARS-CoV-2 may exhibit tropism therein. Evidence also exists that neuropilin-1, a co-receptor of SARS-CoV-2, may be expressed in the brainstem. Indeed, autopsy studies have found SARS-CoV-2 RNA and proteins in the brainstem. The brainstem is also highly prone to damage from pathological immune or vascular activation, which has also been observed in autopsy of COVID-19 cases. The second part concerns functions of the brainstem that overlap with symptoms of long-COVID. The brainstem contains numerous distinct nuclei and subparts that regulate the respiratory, cardiovascular, gastrointestinal, and neurological processes, which can be linked to long-COVID. As neurons do not readily regenerate, brainstem dysfunction may be long-lasting and, thus, is long-COVID. Indeed, brainstem dysfunction has been implicated in other similar disorders, such as chronic pain and migraine and myalgic encephalomyelitis or chronic fatigue syndrome.

Severe cortical damage associated with COVID-19 case report.

Symptoms of COVID-19, as reported during the SARS-CoV-2 pandemic in 2019-2020, are primarily respiratory and gastrointestinal, with sparse reports on neurological manifestations. We describe the case of a 17-year old female with Cornelia de Lange syndrome and well controlled epilepsy, who sustained significant cortical injury during a COVID-19 associated multi-inflammatory syndrome.

Neuroimaging manifestations in children with SARS-CoV-2 infection: a multinational, multicentre collaborative study.

BACKGROUND: The CNS manifestations of COVID-19 in children have primarily been described in case reports, which limit the ability to appreciate the full spectrum of the disease in paediatric patients. We aimed to identify enough cases that could be evaluated in aggregate to better understand the neuroimaging manifestations of COVID-19 in the paediatric population. METHODS: An international call for cases of children with encephalopathy related to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and abnormal neuroimaging findings was made. Clinical history and associated plasma and cerebrospinal fluid data were requested. These data were reviewed by a central neuroradiology panel, a child neurologist, and a paediatric infectious diseases expert. The children were categorised on the basis of their time of probable exposure to SARS-CoV-2. In addition, cases were excluded when a direct link to SARS-CoV-2 infection could not be established or an established alternate diagnostic cause could be hypothesised. The accepted referral centre imaging data, from ten countries, were remotely reviewed by a central panel of five paediatric neuroradiologists and a consensus opinion obtained on the imaging findings. FINDINGS: 38 children with neurological disease related to SARS-CoV-2 infection were identified from France (n=13), the UK (n=8), the USA (n=5), Brazil (n=4), Argentina (n=4), India (n=2), Peru (n=1), and Saudi Arabia (n=1). Recurring patterns of disease were identified, with neuroimaging abnormalities ranging from mild to severe. The most common imaging patterns were postinfectious immune-mediated acute disseminated encephalomyelitis-like changes of the brain (16 patients), myelitis (eight patients), and neural enhancement (13 patients). Cranial nerve enhancement could occur in the absence of corresponding neurological symptoms. Splenial lesions (seven patients) and myositis (four patients) were predominantly observed in children with multisystem inflammatory syndrome. Cerebrovascular complications in children were less common than in adults. Significant pre-existing conditions were absent and most children had favourable outcomes. However, fatal atypical CNS co-infections developed in four previously healthy children infected with SARS-CoV-2. INTERPRETATION: Acute-phase and delayed-phase SARS-CoV-2-related CNS abnormalities are seen in children. Recurring patterns of disease and atypical neuroimaging manifestations can be found and should be recognised being as potentially due to SARS-CoV-2 infection as an underlying aetiological factor. Studies of paediatric specific cohorts are needed to better understand the effects of SARS-CoV-2 infection on the CNS at presentation and on long-term follow-up in children. FUNDING: American Society of Pediatric Neuroradiology, University of Manchester (Manchester, UK). VIDEO ABSTRACT.

The case of a 69-year-old man with COVID-19 and encephalopathy.

A 69-year-old man with uncontrolled type 2 diabetes presented to an outside hospital with altered mental status. He progressed from being argumentative to encephalopathic and agitated by the evening with urinary frequency, urinary urgency, nausea, and vomiting. His vital signs were normal, and he had no focal neurological deficits on presentation. He was generally encephalopathic, only groaning with no ability to follow commands. He was found to have diabetic ketoacidosis on initial labs. A left parietal hypodensity on CT Head was found, and he was positive for Sars-COV-2.

Reversible splenial lesion syndrome associated with SARS-CoV-2 infection in two children.

BACKGROUND: Reversible splenial lesion syndrome (RESLES) is characterized by a temporary lesion in the splenium of the corpus callosum, emerging related to encephalitis, seizures, antiepileptic drug withdrawal, or metabolic disturbances. Among RESLES, mild encephalitis/encephalopathy with reversible splenial lesion (MERS) has been defined as a distinct clinicoradiologic syndrome associated with viral infections. CASE PRESENTATION: We report two children with multisystem inflammatory syndrome-children related to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) who developed RESLES during the disease course. Encephalopathy was the main central nervous system symptom. Both of the children showed a rapid recovery, and brain magnetic resonance imaging revealed complete resolution of the splenial lesion within 1 week. CONCLUSION: The complete resolution of the splenial lesion and rapid recovery from encephalopathy in RESLES associated with SARS CoV-2 were similar to observed in MERS.

Frequent neurologic manifestations and encephalopathy-associated morbidity in Covid-19 patients.

OBJECTIVE: Covid-19 can involve multiple organs including the nervous system. We sought to characterize the neurologic manifestations, their risk factors, and associated outcomes in hospitalized patients with Covid-19. METHODS: We examined neurologic manifestations in 509 consecutive patients admitted with confirmed Covid-19 within a hospital network in Chicago, Illinois. We compared the severity of Covid-19 and outcomes in patients with and without neurologic manifestations. We also identified independent predictors of any neurologic manifestations, encephalopathy, and functional outcome using binary logistic regression. RESULTS: Neurologic manifestations were present at Covid-19 onset in 215 (42.2%), at hospitalization in 319 (62.7%), and at any time during the disease course in 419 patients (82.3%). The most frequent neurologic manifestations were myalgias (44.8%), headaches (37.7%), encephalopathy (31.8%), dizziness (29.7%), dysgeusia (15.9%), and anosmia (11.4%). Strokes, movement disorders, motor and sensory deficits, ataxia, and seizures were uncommon (0.2 to 1.4% of patients each). Severe respiratory disease requiring mechanical ventilation occurred in 134 patients (26.3%). Independent risk factors for developing any neurologic manifestation were severe Covid-19 (OR 4.02; 95% CI 2.04-8.89; P < 0.001) and younger age (OR 0.982; 95% CI 0.968-0.996; P = 0.014). Of all patients, 362 (71.1%) had a favorable functional outcome at discharge (modified Rankin Scale 0-2). However, encephalopathy was independently associated with worse functional outcome (OR 0.22; 95% CI 0.11-0.42; P < 0.001) and higher mortality within 30 days of hospitalization (35 [21.7%] vs. 11 [3.2%] patients; P < 0.001). INTERPRETATION: Neurologic manifestations occur in most hospitalized Covid-19 patients. Encephalopathy was associated with increased morbidity and mortality, independent of respiratory disease severity.

Alpha coma EEG pattern in patients with severe COVID-19 related encephalopathy.

OBJECTIVE: Encephalopathy is a major neurological complication of severe Coronavirus Disease 2019 (COVID-19), but has not been fully defined yet. Further, it remains unclear whether neurological manifestations are primarily due to neurotropism of the virus, or indirect effects, like cerebral hypoxia. METHODS: We analysed the electroencephalograms (EEGs) of 19 consecutive patients with laboratory-confirmed COVID-19, performed at peak disease severity as part of their clinical management. Disease severity, respiratory failure, immune and metabolic dysfunction, sedation status, and neurological examination on the day of the EEG were noted. RESULTS: Severe encephalopathy was confirmed in 13 patients, all with severe COVID-19; 10 remained comatose off sedation, and five of them had alpha coma (AC). Disease severity, sedation, immune and metabolic dysfunction were not different between those with AC and those without. CONCLUSIONS: Severe COVID-19 encephalopathy is a principal cause of persisting coma after sedation withdrawal. The relatively high incidence of the rare AC pattern may reflect direct SARS-CoV-2 neurotropism with a predilection for the brainstem ascending reticular system. SIGNIFICANCE: Systematic early EEG detection of encephalopathy related to severe COVID-19 is important for the acute care and the management of long-term neurological and cognitive sequelae, and may help our better understanding of its pathophysiology.

Report on Electroencephalographic Findings in Critically Ill Patients with COVID-19.

In March 2020, we treated a cohort of 26 critically ill hospitalized SARS-CoV-2-infected patients who underwent electroencephalography to assess unexplained altered mental status, loss of consciousness, or poor arousal and responsiveness. Of the 26 patients studied, 5 patients had electroencephalograms that showed periodic discharges consisting of high-amplitude frontal monomorphic delta waves with absence of epileptic activity. These findings may suggest central nervous system injury potentially related to COVID-19 in these patients. ANN NEUROL 2020;88:626-630.

Continuous EEG findings in patients with COVID-19 infection admitted to a New York academic hospital system.

OBJECTIVE: There is evidence for central nervous system complications of coronavirus disease 2019 (COVID-19) infection, including encephalopathy. Encephalopathy caused by or arising from seizures, especially nonconvulsive seizures (NCS), often requires electroencephalography (EEG) monitoring for diagnosis. The prevalence of seizures and other EEG abnormalities among COVID-19-infected patients is unknown. METHODS: Medical records and EEG studies of patients hospitalized with confirmed COVID-19 infections over a 2-month period at a single US academic health system (four hospitals) were reviewed to describe the distribution of EEG findings including epileptiform abnormalities (seizures, periodic discharges, or nonperiodic epileptiform discharges). Factors including demographics, remote and acute brain injury, prior history of epilepsy, preceding seizures, critical illness severity scores, and interleukin 6 (IL-6) levels were compared to EEG findings to identify predictors of epileptiform EEG abnormalities. RESULTS: Of 111 patients monitored, most were male (71%), middle-aged or older (median age 64 years), admitted to an intensive care unit (ICU; 77%), and comatose (70%). Excluding 11 patients monitored after cardiac arrest, the most frequent EEG finding was moderate generalized slowing (57%), but epileptiform findings were observed in 30% and seizures in 7% (4% with NCS). Three patients with EEG seizures did not have epilepsy or evidence of acute or remote brain injury, although all had clinical seizures prior to EEG. Only having epilepsy (odds ratio [OR] 5.4, 95% confidence interval [CI] 1.4-21) or seizure(s) prior to EEG (OR 4.8, 95% CI 1.7-13) was independently associated with epileptiform EEG findings. SIGNIFICANCE: Our study supports growing evidence that COVID-19 can affect the central nervous system, although seizures are unlikely a common cause of encephalopathy. Seizures and epileptiform activity on EEG occurred infrequently, and having a history of epilepsy or seizure(s) prior to EEG testing was predictive of epileptiform findings. This has important implications for triaging EEG testing in this population.