The Effects of SARS-CoV-2 Infection on the Cognitive Functioning of Patients with Pre-Existing Dementia.

Background: Cognitive postscripts of COVID-19, codenamed as 'cognitive COVID' or 'brain fog,' characterized by multidomain cognitive impairments, are now being reckoned as the most devastating sequelae of COVID-19. However, the impact on the already demented brain has not been studied. Objective: We aimed to assess the cognitive functioning and neuroimaging following SARS-CoV-2 infection in patients with pre-existing dementia. Methods: Fourteen COVID-19 survivors with pre-existing dementia (four with Alzheimer's disease, five with vascular dementia, three with Parkinson's disease dementia, and two with the behavioral variant of frontotemporal dementia) were recruited. All these patients had detailed cognitive and neuroimaging evaluations within three months before suffering from COVID-19 and one year later. Results: Of the 14 patients, ten required hospitalization. All developed or increased white matter hyperintensities that mimicked multiple sclerosis and small vessel disease. There was a significant increase in fatigue (p = 0.001) and depression (p = 0.016) scores following COVID-19. The mean Frontal Assessment Battery (p < 0.001) and Addenbrooke's Cognitive Examination (p = 0.001) scores also significantly worsened. Conclusion: The rapid progression of dementia, the addition of further impairments/deterioration of cognitive abilities, and the increase or new appearance of white matter lesion burden suggest that previously compromised brains have little defense to withstand a new insult (i.e., 'second hit' like infection/dysregulated immune response, and inflammation). 'Brain fog' is an ambiguous terminology without specific attribution to the spectrum of post-COVID-19 cognitive sequelae. We propose a new codename, i.e. 'FADE-IN MEMORY' (i.e., Fatigue, decreased Fluency, Attention deficit, Depression, Executive dysfunction, slowed INformation processing speed, and subcortical MEMORY impairment).

Transcortical sensory aphasia heralding SARS-Cov-2-induced autoimmune encephalitis with gyral restricted diffusion hyperintensities: a novel case report.

Background: Coronavirus disease 2019 (CoVID-19), primarily thought of as a respiratory system disease is actually a multi-system disease with immunological implications. CNS involvement in COVID has been explained in recent literature mainly for stroke, encephalopathy, encephalitis, acute disseminated encephalomyelitis and myelopathy. There are few studies characterizing clinical spectrum of COVID autoimmune encephalitis. We present a unique case of post-COVID autoimmune encephalitis in a diabetic male presenting with language dysfunction and novel radiologic findings. Case presentation: Patient admitted to inpatient department of a tertiary care hospital of India was evaluated by bedside clinical examination, routine blood tests, CSF study with intrathecal SARS-Cov-2 antibody detection, commercially available tests for autoimmune encephalitis, neuroviral panel with HSV PCR, EEG, 3-Tesla MRI and PET scan. Patient was found to have personality change and transcortical sensory aphasia in the outset of COVID encephalitis. MRI findings like temporal involvement and insular ribboning are also being reported. The patient was treated with IV immunoglobulin and is on an improving course. Conclusions: This case reports dysphasia due to COVID-mediated injury to the language networks, with novel radiologic findings. Role of parainfectious versus immune etiology is also discussed. Further studies are needed to elucidate the mechanism and clinical spectrum of post-COVID autoimmune encephalitis.

The cognitive basis of psychosocial impact in COVID-19 pandemic. Does it encircle the default mode network of the brain? A pragmatic proposal.

Epigenetics, hypothalamic-pituitary axes, environmental and metabolic influences, and transgenerational plasticity govern social behavior. Cognitive research considers the brain's default mode network (DMN) as a central hub that integrates various cognitive and social processing domains responsible for emotion perception, empathy, theory of mind, and morality. Hence, DMN is regarded as the "social brain." Upsurge in social turmoil, social anxiety, panic, depression, post-traumatic stress, hoarding, herd behavior, substance and behavioral addictions, sexual abuse, and violence in the time of the COVID-19 pandemic are intricately related to personality traits resulting in disruptive social cognition and social behavior, conceptualized as the result of unsettling and disruption of the functional nexus of the DMN. Considering overt and conspicuous display of neuroticism during the current pandemic, its impact upon modulation of the DMN functional nexus and the DMN itself, and the potential to presage cognitive impairment in the future, the authors caution that an increase in the global burden of dementia may be one of the long-term ramifications of COVID-19. Social behavior, a functional derivative of the DMN, can strikingly affect the functional nexus of DMN and the DMN itself, in a centripetal way via the phenomenon called "Experience-Dependent Plasticity," with long-term consequences. In this review, we intend to 1) decipher the association between social cognition and social behavior with the DMN, in time of COVID-19; and to 2) discuss the prospective aftermath of disrupted social behavior during the pandemic on modulation/alteration of functional connectomes of DMN or the DMN itself in the time ahead.

Non-Aneurysmal Subarachnoid Hemorrhage in COVID-19: A Case Report and Review of Literature.

BACKGROUND: Hemorrhagic cerebrovascular events, either due to aneurysmal rupture or spontaneous subarachnoid hemorrhage (SAH), are not rare in COVID-19. Several mechanisms such as coagulopathy, cytokine storm, viral endotheliopathy, hypertension, and immune modulation might play a role in the pathogenesis of SAH in COVID-19. This study aimed to report the first case of spontaneous non-aneurysmal SAH associated with SARS-CoV-2 from India. We briefly discussed the possible pathogenetic mechanisms underlying this process and succinctly reviewed the relevant literature. CASE REPORT: We herein report a case of a non-comorbid young woman infected with SARS-CoV-2 presenting with thunderclap headache and eventually non-aneurysmal SAH, who recovered with conservative management. CONCLUSION: Headache, although a very common clinical feature of COVID-19 itself, must be investigated in detail to identify alternate causes that may be life-threatening. This case also incites further enquiry into the possible pathogenic mechanisms of neurovascular complications in COVID-19.

Impact of COVID-19 pandemic in natural course of Moyamoya Angiopathy: an experience from tertiary-care-center in India.

BACKGROUND: COVID-19 mediated immune dysregulation and cytokine storm can precipitate and aggravate Moyamoya angiopathy (MMA), influencing its disease course. This index study was undertaken to prospectively evaluate the status of neurological symptoms of MMA in relation to COVID-19 affection. METHODOLOGY AND RESULTS: Follow-up MMA patients of institute's Stroke-clinic were telephonically interview from 24th March to 30th September, 2020. The first call familiarized them with COVID-19 symptoms and neurological manifestations of MMA, followed by monthly-calls with predesigned questionnaire. Patients with suggestion of COVID-19 underwent nasopharyngeal-swab-testing for COVID-19 Reverse transcription-polymerase chain reaction (RT-PCR) positive cases were subjected to antibody levels for COVID-19 Enzyme-linked immunoassay (ELISA) 8-12 weeks after recovery. During symptomatic phase till 14 days of asymptomatic, they were contacted daily/alternate day. Any new onset/worsening of neurological symptoms were noted. The baseline clinico-radiological details were obtained from stroke-clinic registery. Subsequently, all data were analyzed and compared using descriptive statistics. Seventy four of 104 MMA patients could be contacted and enrolled. The mean age, time since last follow-up and compliance to previously prescribed medication were 23.5 ± 16.1 years, 9.2 ± 1.7 months and 90.5% (n = 67), respectively. Aggravation/new onset neurological symptom were seen in 64.3% (n = 9) of COVID-19 positive MMA (n = 14), of which 8 were seen among the 11 pediatric COVID-19 positive MMA [(Transient ischemic attacks) TIA-4, TIA with headache-1, seizure-2, stroke causing mortality-1]. CONCLUSION: COVID-19 infection can potentiate MMA causing significant morbidity and mortality, especially in children. Providing optimal care for severe diseases (such as MMA) in developing countries during pandemic remains a challenge.

MRI-negative myeloradiculoneuropathy following Covid-19 infection: An index case.

Covid-19 associated several neurological manifestation in the form of Post-infectious transverse myelitis(TM) and para-infectious TM has been reported. A 54 years old female patient presented to us with acute retention of urine and upper motor neuron type of bilateral lower limb weakness in shock stage, after 12 days of covid-19 infection. MRI (3T) brain and spine showed no abnormality and Nerve conduction study showed acquired motor axonal polyradiculoneuropathy in bilateral lower limbs. We herein present an index case of MRI-negative myeloradiculoneuropathy following covid-19 infection.