Brain positron emission tomography (PET) and cognitive abnormalities one year after COVID-19.

Emerging evidence indicates that the etiologic agent responsible for coronavirus disease 2019 (COVID-19), can cause neurological complications. COVID-19 may induce cognitive impairment through multiple mechanisms. The aim of the present study was to describe the possible neuropsychological and metabolic neuroimaging consequences of COVID-19 12 months after patients' hospital discharge. We retrospectively recruited 7 patients (age [mean ± SD] = 56 years ± 12.39, 4 men) who had been hospitalized for COVID-19 with persistent neuropsychological deficits 12 months after hospital discharge. All patients underwent cognitive assessment and brain (18F-FDG) PET/CT, and one also underwent 18F-amyloid PET/CT. Of the seven patients studied, four had normal glucose metabolism in the brain. Three patients showed various brain hypometabolism patterns: (1) unilateral left temporal mesial area hypometabolism; (2) pontine involvement; and (3) bilateral prefrontal area abnormalities with asymmetric parietal impairment. The patient who showed the most widespread glucose hypometabolism in the brain underwent an 18F-amyloid PET/CT to assess the presence of Aß plaques. This examination showed significant Aß deposition in the superior and middle frontal cortex, and in the posterior cingulate cortex extending mildly in the rostral and caudal anterior cingulate areas. Although some other reports have already suggested that brain hypometabolism may be associated with cognitive impairment at shorter intervals from SarsCov-2 infection, our study is the first to assess cognitive functions, brain metabolic activity and in a patient also amyloid PET one year after COVID-19, demonstrating that cerebral effects of COVID-19 can largely outlast the acute phase of the disease and even be followed by amyloid deposition.

One-year cognitive follow-up of COVID-19 hospitalized patients.

BACKGROUND AND PURPOSE: Cognitive dysfunction has been observed following recovery from COVID-19. To the best of our knowledge, however, no study has assessed the progression of cognitive impairment after 1 year. The aim was to assess cognitive functioning at 1 year from hospital discharge, and eventual associations with specific clinical variables. METHODS: Seventy-six patients (aged 22-74 years) who had been hospitalized for COVID-19 were recruited. Patients received neuropsychological assessments at 5 (n = 76) and 12 months (n = 53) from hospital discharge. RESULTS: Over half (63.2%) of the patients had deficits in at least one test at 5 months. Compared to the assessment at 5 months, verbal memory, attention and processing speed improved significantly after 1 year (all p < 0.05), whereas visuospatial memory did not (all p > 0.500). The most affected domains after 1 year were processing speed (28.3%) and long-term visuospatial (18.1%) and verbal (15.1%) memory. Lower PaO2 /FiO2 ratios in the acute phase were associated with worse verbal long-term memory (p = 0.029) and visuospatial learning (p = 0.041) at 5 months. Worse visuospatial long-term memory at 5 months was associated with hyposmia (p = 0.020) and dysgeusia (p = 0.037). CONCLUSION: Our study expands the results from previous studies showing that cognitive impairment can still be observed after 1 year. Patients with severe COVID-19 should receive periodic cognitive follow-up evaluations, as cognitive deficits in recovered patients could have social and occupational implications.

Critical illness neuropathy in severe COVID-19: a case series.

INTRODUCTION: Neurological complications of SARS-CoV-2 disease have received growing attention, but only few studies have described to date clinical and neurophysiological findings in COVID patients during their stay in intensive care units (ICUs). Here, we neurophysiologically assessed the presence of either critical illness neuropathy (CIP) or myopathy (CIM) in ICU patients. MATERIALS AND METHODS: Patients underwent a neurophysiological assessment, including bilateral examination of the median, ulnar, deep peroneal and tibial motor nerves and of the median, ulnar, radial and sural sensory nerves. Needle electromyography (EMG) was performed for both distal and proximal muscles of the lower and upper limbs. In order to differentiate CIP from CIM, Direct Muscle Stimulation (DMS) was applied either to the deltoid or tibialis anterior muscles. Peak to peak amplitudes and onset latencies of the responses evoked by DMS (DMSamp, DMSlat) or by motor nerve stimulation (MNSamp, MNSlat) were compared. The ratio MNSamp to DMSamp (NMR) and the MNSlat to DMSlat difference (NMD: MNSlat - DMSlat) were also evaluated. RESULTS: Nerve conduction studies showed a sensory-motor polyneuropathy with axonal neurogenic pattern, as confirmed by needle EMG. Both MNSamp and NMR were significantly reduced when compared to controls (p < 0.0001), whereas MNSlat and NMD were markedly increased (p = 0.0049). CONCLUSIONS: We have described COVID patients in the ICU with critical illness neuropathy (CIP). COVID-related CIP could have implications for the functional recovery and rehabilitation strategies.

Long-Lasting Cognitive Abnormalities after COVID-19.

Considering the mechanisms capable of causing brain alterations in COVID-19, we aimed to study the occurrence of cognitive abnormalities in the months following hospital discharge. We recruited 38 (aged 22-74 years; 27 males) patients hospitalized for complications of SARS-CoV-2 infection in nonintensive COVID units. Participants underwent neuropsychological testing about 5 months after hospital discharge. Of all patients, 42.1% had processing speed deficits, while 26.3% showed delayed verbal recall deficits. Twenty-one percent presented with deficits in both processing speed and verbal memory. Bivariate analysis revealed a positive correlation between the lowest arterial oxygen partial pressure (PaO2) to fractional inspired oxygen (FiO2) (P/F) ratio during hospitalization and verbal memory consolidation performance (SRT-LTS score, r = 0.404, p = 0.027), as well as a positive correlation between SpO2 levels upon hospital arrival and delayed verbal recall performance (SRT-D score, rs = 0.373, p = 0.042). Acute respiratory distress syndrome (ARDS) during hospitalization was associated with worse verbal memory performance (ARDS vs. no ARDS: SRT-LTS mean score = 30.63 ± 13.33 vs. 44.50 ± 13.16, p = 0.007; SRT-D mean score = 5.95 ± 2.56 vs. 8.10 ± 2.62, p = 0.029). Cognitive abnormalities can frequently be found in COVID-19 patients 5 months after hospital discharge. Increased fatigability, deficits of concentration and memory, and overall decreased cognitive speed months after hospital discharge can interfere with work and daily activities.