Translocator protein (TSPO)-PET as diagnostic and monitoring tool in COVID-19 related MRI-negative brainstem encephalitis: a case report.

BACKGROUND: Encephalitis and myelitis have been linked to both COVID-19 vaccination and infection, causing symptoms such as reduced consciousness, mental state alterations and seizures. Remarkably, most cases do not show significant structural alterations on MRI scans, which poses a diagnostic challenge. METHODS: We present the diagnostic workup and clinical course of a patient who developed a progressive brainstem syndrome two weeks after COVID-19 vaccination and subsequent infection. We used translocator protein (TSPO)-PET scans for the first time to investigate COVID-related neuroinflammation. RESULTS: The patient developed oculomotor disorder, dysarthria, paresthesia in all distal limbs and spastic-atactic gait. CSF analysis revealed mild lymphocytic pleocytosis with normal protein levels. Brain and spinal cord MRI scans were negative, but TSPO/PET scans showed increased microglia activity in the brainstem, which correlated with the clinical course. Steroid treatment led to clinical improvement, but relapse occurred during prednisone taper after four weeks. Plasmapheresis had no significant effect; however, complete remission was achieved with cyclophosphamide and methotrexate, with normal TSPO signal ten months after onset. CONCLUSIONS: TSPO-PET can be a valuable tool in the diagnostic and therapeutic monitoring of COVID-19-related encephalitis, particularly in cases where MRI scans are negative. Aggressive immunosuppressive therapy can lead to sustained remission.

Can diffusion tensor imaging (DTI) outperform standard magnetic resonance imaging (MRI) investigations in post-COVID-19 autoimmune encephalitis?

Background: Neurological and psychiatric manifestations related to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection are widely recognised. Standard magnetic resonance imaging (MRI) investigations are normal in 40-80% of symptomatic patients, eventually delaying appropriate treatment when MRI is unrevealing any structural changes. The aim of this study is to investigate white matter abnormalities during an early stage of post-COVID-19 (coronavirus disease 2019) encephalitis while conventional MRI was normal. Methods: A patient with post-COVID-19 autoimmune encephalitis was investigated by serial MRIs and diffusion tensor imaging (DTI). Ten healthy control individuals (HC) were utilised as a control group for the DTI analysis. Major projection, commissural and association white matter pathways were reconstructed, and multiple diffusion parameters were analysed and then compared to the HC average using a z-test for serial examinations. Results: Eleven days after the onset of neurological symptoms, DTI revealed early white matter changes, compared with HC, when standard MRI was normal. On day 68, DTI showed multiple white matter lesions compared with HC, visible at this time also by the MRI images, indicating inflammatory changes in different association and projection white matter pathways. Conclusion: We confirm a limitation in the sensitivity of conventional MRI at the acute setting of post-COVID-19 autoimmune encephalitis. A complementary DTI investigation could be a valuable diagnostic tool in early therapeutic decisions concerning COVID-19-related neurological symptoms.

Olfactory impairment in autoimmune encephalitis: another piece of the puzzle.

BACKGROUND: Despite being long neglected, olfaction has recently become a focus of intense research in neuroscience, as smell impairment has been consistently documented in both neurodegenerative and neuroinflammatory diseases. Considering the close anatomo-functional correlations between the limbic system and the central olfactory structures, we investigated olfaction in a population of patients with autoimmune encephalitis (AE). METHODS: Nineteen adult subjects (14 males, median age 64 years) diagnosed with definite (14/19) or possible (5/19) AE and followed for ≥ 6 months were enrolled. The Brief Smell Identification Test (B-SIT), a 12-item, forced-choice, scratch-and-sniff measure, was used to assess the patients' olfactory function in comparison with a group of sex- and age-matched healthy controls (HC). According to the B-SIT score, subjects were classified as anosmic (< 6), hyposmic (6-8) and normal (≥ 9). Electro-clinical, laboratory and neuroimaging findings were reviewed. RESULTS: Smell impairment was revealed in 15/19 patients (9 hyposmic, 6 anosmic), compared with 5/19 HC (p = 0.0029). Age, gender and smoking habits did not affect the participants' performance at B-SIT. Olfactory dysfunction appeared more common among patients with definite AE (p = 0.0374), regardless of autoantibody status. Subjects with higher modified Rankin Scale (mRS) scores at AE onset more likely presented hyposmia/anosmia (p = 0.033), and so did those with bilateral ictal/interictal EEG abnormalities (p = 0.006). CONCLUSIONS: We found olfaction to be impaired in a significantly large proportion of AE cases. Smell deficits appeared more common in subjects with severe AE (as indicated by both definite diagnosis and higher mRS score), and might represent an additional feature of immune-mediated encephalitis.

MOG-associated encephalitis following SARS-COV-2 infection.

A variety of neurologic manifestations of COVID-19 infections have been reported. Here, we present a case of steroid-responsive MOG-antibody associated encephalitis, characterized by cognitive decline, headaches, fever, unilateral FLAIR-hyperintensities, and leptomeningeal enhancement, that occurred in the setting of recent COVID-19 infection.

Neuroimaging findings in COVID-19: A narrative review.

In this mini-review, we aim to summarize some of the most common neuroimaging findings seen in patients with COVID-19.

Acute myelitis and SARS-CoV-2 infection. A new etiology of myelitis?

The etiological agent of coronavirus disease-19 (COVID-19), SARS-coronavirus-2 (SARS-CoV-2), emerged in Wuhan, China, and quickly spread worldwide leading the World Health Organization (WHO) to recognize it not only as a pandemic but also as an important thread to public health. Beyond respiratory symptoms, new neurological manifestations are being identified such as headache, ageusia, anosmia, encephalitis or acute cerebrovascular disease. Here we report the case of an acute transverse myelitis (TM) in a patient with SARS-CoV-2 infection detected by the nasopharyngeal swab technique but not in cerebrospinal fluid (CSF) analysis. Anti-herpes simplex virus (HSV) 1 and varicella-zoster IgM antibodies were not detected in serum samples and spinal and brain magnetic resonance imaging (MRI) showed no abnormal findings. This case remarks that COVID-19 nervous system damage could be caused by immune-mediated mechanisms.

SARS-CoV-2-Associated Acute Hemorrhagic, Necrotizing Encephalitis (AHNE) Presenting with Cognitive Impairment in a 44-Year-Old Woman without Comorbidities: A Case Report.

BACKGROUND Acute hemorrhagic necrotizing encephalitis (AHNE) is a rare manifestation of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. AHNE usually involves the subcortical white matter but not the cortical grey matter. This study describes the disruptive effects of AHNE associated with SARS-CoV-2 on cognitive function in a previously healthy and sound middle-aged woman resulting from alterations in cortical areas involved in the cognitive network. CASE REPORT A 44-year-old previously healthy woman with a history of inter-state travel developed a flu-like illness, followed by acute, steadily progressive cognitive impairment. She was admitted in a comatose state after a first tonic-clonic seizure. Blood tests were non-informative. Cerebral magnetic resonance imaging (MRI) was indicative of AHNE. Cerebrospinal fluid analysis showed mild lymphocytosis with normal protein and normal glucose but an elevated IgG index. After testing positive for SARS-CoV-2, she was administered steroids. Treatment was ineffective, and the patient died. CONCLUSIONS SARS-CoV-2 is a potential central nervous system (CNS) pathogen, which may manifest as AHNE. These patients may present with generalized tonic-clonic seizures and frontal dysexecutive syndrome, with cognitive impairment being the presenting feature of neuro-coronavirus disease-2019 (COVID-19). The patient described in this report is unique for acute-onset and isolated cognitive impairments due to SARS-CoV-2 infection in the absence of clinical or radiological respiratory manifestations. These findings may help in the early detection and diagnosis of neuro-COVID-19, especially among clinicians and neurologists working in areas of endemic SARS-CoV-2 infection.

Neurologic and neuroimaging findings in patients with COVID-19: A retrospective multicenter study.

OBJECTIVE: To describe neuroimaging findings and to report the epidemiologic and clinical characteristics of patients with coronavirus disease 2019 (COVID-19) with neurologic manifestations. METHODS: In this retrospective multicenter study (11 hospitals), we included 64 patients with confirmed COVID-19 with neurologic manifestations who underwent a brain MRI. RESULTS: The cohort included 43 men (67%) and 21 women (33%); their median age was 66 (range 20-92) years. Thirty-six (56%) brain MRIs were considered abnormal, possibly related to severe acute respiratory syndrome coronavirus. Ischemic strokes (27%), leptomeningeal enhancement (17%), and encephalitis (13%) were the most frequent neuroimaging findings. Confusion (53%) was the most common neurologic manifestation, followed by impaired consciousness (39%), presence of clinical signs of corticospinal tract involvement (31%), agitation (31%), and headache (16%). The profile of patients experiencing ischemic stroke was different from that of other patients with abnormal brain imaging: the former less frequently had acute respiratory distress syndrome (p = 0.006) and more frequently had corticospinal tract signs (p = 0.02). Patients with encephalitis were younger (p = 0.007), whereas agitation was more frequent for patients with leptomeningeal enhancement (p = 0.009). CONCLUSIONS: Patients with COVID-19 may develop a wide range of neurologic symptoms, which can be associated with severe and fatal complications such as ischemic stroke or encephalitis. In terms of meningoencephalitis involvement, even if a direct effect of the virus cannot be excluded, the pathophysiology seems to involve an immune or inflammatory process given the presence of signs of inflammation in both CSF and neuroimaging but the lack of virus in CSF. CLINICALTRIALSGOV IDENTIFIER: NCT04368390.

Evolution and resolution of brain involvement associated with SARS- CoV2 infection: A close Clinical - Paraclinical follow up study of a case.

The new severe acute respiratory syndrome- coronavirus 2 is reported to affect the nervous system. Among the reports of the various neurological manifestations, there are a few documented specific processes to explain the neurological signs. We report a para-infectious encephalitis patient with clinical, laboratory, and imaging findings during evolution and convalescence phase of coronavirus infection. This comprehensive overview can illuminate the natural history of similar cases. As the two previously reported cases of encephalitis associated with this virus were not widely discussed regarding the treatment, we share our successful approach and add some recommendations about this new and scarce entity.