Guillain-Barré syndrome as only manifestation of COVID-19 infection.

Post-infectious/immune mediated effects of COVID-19 infection include descriptions of Guillain-Barré syndrome (GBS) in patients usually with respiratory failure and after 1-2 weeks from the onset of viral illness. Asymptomatic cases for COVID-19 infection were rarely described. Herein, we studied a 62-year-old patient with progressive weakness of lower extremities, rapidly evolving to a severe, flaccid tetraplegia and dysphagia. Neurological symptoms weren't preceded by fever or pulmonary symptoms. Because of laboratory test abnormalities (thrombocytopenia, lymphocytopenia, high inflammation indexes), the patient underwent to nasopharyngeal swab, resulted positive for SARS-CoV-2 on RT-PCR assay; cerebrospinal fluid (CSF) was negative for SARS-CoV-2. The clinical (severe symmetric distal upper and lower limbs weakness, grade 0/5; decreased proprioceptive sensitivity and hypoesthesia involving the four limbs; loss of deep tendon reflexes), electrophysiological (prevailing axonal polyradiculoneuritis) and CSF features (albumino-cytological dissociation) disclosed the GBS diagnosis (level 1 of diagnostic certainty according to the Brighton criteria). The patient received plasma exchange and immunoglobulin, and, at 4 weeks after treatment and physical therapy, the patient had moderate improvement (weakness at lower and upper extremities was grade 2/5 and 3/5, respectively). Neurologists and clinicians should be aware of the possible link between neurological symptoms and COVID-19 infection, not only after viral prodrome and pulmonary symptoms, but also without COVID-19 symptoms.

Poor desynchronisation of resting-state eyes-open cortical alpha rhythms in obese subjects without eating disorders.

OBJECTIVE: Obese subjects without eating disorders were characterised by poor electroencephalographic (EEG) alpha rhythms during resting-state eye-closed condition (Babiloni et al., 2011b). Is this true also for the desynchronisation of alpha rhythms during resting-state eyes opening? METHODS: EEG data were recorded in 15 underweight, 20 normal-weight, and 18 overweight/obese subjects during resting-state eyes-closed and -open conditions. EEG sources were estimated by LORETA for alpha 1 (8-10.5 Hz) and alpha 2 (10.5-13 Hz). The alpha desynchronisation was calculated as the difference eyes-open minus -closed condition. RESULTS: The occipital alpha 1 desynchronisation was lower in overweight/obese and underweight subjects compared with normal-weight subjects (p < 0.000005). The same was true for parietal, occipital and temporal alpha 2 (10.5-13 Hz) desynchronisation (p < 0.000002). The parietal and temporal alpha 1 desynchronisation was lower in overweight/obese than in normal-weight subjects (p < 0.00001). These effects spatially matched those observed in the resting-state eyes-closed condition. CONCLUSION: Subjects with abnormal weight and normal eating behaviour are characterised by poor alpha desynchronisation during resting-state eyes opening. SIGNIFICANCE: Obese subjects without eating disorders show abnormal mechanisms of cortical neural synchronisation and desynchronisation of alpha rhythms in the resting state condition.

Frontal-parietal responses to "oddball" stimuli depicting "fattened" faces are increased in successful dieters: an electroencephalographic study.

Here we tested the hypothesis that compared with normal weight non dieting (control) subjects, normal weight successful dieters submitted to a rigorous and continuous monitoring of body weight (i.e. karate athletes) are characterized by an increase of cortical responses to oddball visual stimuli depicting the enlargement of faces or foods, as neural underpinning of attention processes related to the control of weight and eating. Electroencephalographic (EEG) data were recorded in 18 successful dieters (5 females) and 24 non dieting subjects (9 females). The subjects were given frequent (70%) and rare (30%) stimuli depicting faces (FACE), food (FOOD), and landscapes (CONTROL). The task was to click the mouse after the rare stimuli. The rare stimuli depicted the frequent stimuli graphically dilated by 25% along the horizontal axis. Cortical responses accompanying attention processes were probed by the difference between positive event-related potentials peaking around 400-500ms post-stimulus for the rare minus frequent stimuli (P300). The popular freeware LORETA estimated P300 cortical sources. The results showed that in the FACE condition, the amplitude of left frontal (BA 6) and medial parietal (BA 5) P300 sources was higher in the successful dieters (karate athletes) than non dieting subjects. These results disclose that frontal-parietal responses to "oddball" stimuli depicting enlarged faces (i.e. representing face fattening) are enhanced in successful dieters (karate athletes). Future studies should evaluate this effect in other populations of successful dieters (i.e. boxers, top models etc.).

Resting state cortical electroencephalographic rhythms in subjects with normal and abnormal body weight.

It is well known that resting state regional cerebral blood flow is abnormal in obese when compared to normal-weight subjects but the underlying neurophysiological mechanisms are poorly known. To address this issue, we tested the hypothesis that amplitude of resting state cortical electroencephalographic (EEG) rhythms differ among underweight, normal-weight, and overweight/obese subjects as a reflection of the relationship between cortical neural synchronization and regulation of body weight. Eyes-closed resting state EEG data were recorded in 16 underweight subjects, 25 normal-weight subjects, and 18 overweight/obese subjects. All subjects were psychophysically healthy (no eating disorders or major psychopathologies). EEG rhythms of interest were delta (2-4Hz), theta (4-8Hz), alpha 1 (8-10.5Hz), alpha 2 (10.5-13Hz), beta 1 (13-20Hz), beta 2 (20-30Hz), and gamma (30-40Hz). EEG cortical sources were estimated by low-resolution brain electromagnetic tomography (LORETA). Statistical results showed that parietal and temporal alpha 1 sources fitted the pattern underweight>normal-weight>overweight/obese (p<0.004), whereas occipital alpha 1 sources fitted the pattern normal-weight>underweight>overweight/obese (p<0.00003). Furthermore, amplitude of the parietal, occipital, and temporal alpha 2 sources was stronger in the normal-weight subjects than in the underweight and overweight/obese subjects (p<0.0007). These results suggest that abnormal weight in healthy overweight/obese subjects is related to abnormal cortical neural synchronization at the basis of resting state alpha rhythms and fluctuation of global brain arousal.

Attention cortical responses to enlarged faces are reduced in underweight subjects: an electroencephalographic study.

OBJECTIVE: A previous electroencephalographic (EEG) study has shown that obese subjects are characterized by reduced attention frontal responses to food images, thus raising the hypothesis of attention deficits associated with abnormal body weight (Babiloni et al., 2009a,b). In this line, here we tested the hypothesis of reduced attention cortical responses in underweight subjects. METHODS: EEG data were recorded in 16 normal-weight and 16 underweight subjects during an "oddball" paradigm. The subjects were given frequent (70%) and rare (30%) stimuli depicting faces (FACE), food (FOOD), and landscapes (CONTROL), and clicked the mouse after the rare stimuli. These stimuli depicted the same frequent stimuli graphically dilated by 25% along the horizontal axis. Cortical attention responses were probed by the difference between positive event-related potentials peaking around 400-500 ms post-stimulus for the rare minus frequent stimuli (P300). Low resolution electromagnetic source tomography (LORETA) estimated P300 sources. RESULTS: In the FACE condition, the amplitude of prefrontal (Brodmann area: BA10 and BA11) and tempo-parietal (BA19, BA20, BA21, BA22, BA36, BA37, BA39, BA40) sources was lower in the underweight than normal-weight subjects. CONCLUSIONS: These results suggest that anterior-posterior cortical attention processes to face images declined in underweight subjects. SIGNIFICANCE: The present study motivates future research evaluating if this mechanism is related to a poor judgment about body shape.

Frontal attentional responses to food size are abnormal in obese subjects: an electroencephalographic study.

OBJECTIVE: Are obese subjects characterized by a reduction of attentional cortical responses to the enlargement of food or body images? METHODS: Electroencephalographic data were recorded in 19 obese and 15 normal-weight adults during an "oddball" paradigm. The subjects were given frequent (70%) and rare (30%) stimuli depicting faces (FACE), food (FOOD), and landscapes (CONTROL), and clicked the mouse after the rare stimuli. These stimuli depicted the same frequent stimuli graphically dilated by 25% along the horizontal axis. Bioelectrical impedance indexed subjects' body fat percentage. Cortical attentional responses were probed by the difference between positive event-related potentials peaking around 400-500ms post-stimulus for the rare minus frequent stimuli (P300). Low resolution electromagnetic source tomography (LORETA) estimated P300 sources. RESULTS: In the FOOD condition, the amplitude of medial prefrontal P300 sources (Brodmann area 9) was lower in the obese than normal-weight subjects, and there was a negative correlation between the body fat percentage and the amplitude of these sources in all subjects as a single group. CONCLUSIONS: These results disclose that prefrontal attentional processes to food size are abnormal in obese subjects. SIGNIFICANCE: The present study motivates future research evaluating the effects of cognitive rehabilitation in obese subjects.

Attentional cortical responses to enlarged faces are related to body fat in normal weight subjects: an electroencephalographic study.

OBJECTIVE: Here we tested the hypothesis that in normal weight subjects, attentional cortical responses to the enlargement of faces are related to features of body weight, as a basis for future studies on the role of neurocognitive mechanisms in eating and weight disorders. METHODS: Electroencephalographic data were recorded in 15 normal weight adults during a visual "oddball" paradigm. The subjects were given frequent (70%) and rare (30%) stimuli depicting faces (FACE), food (FOOD), and landscapes (CONTROL). The task was to click the mouse after the rare stimuli. These stimuli depicted the same frequent stimuli graphically dilated by 25% along the horizontal axis. Analysis of bioelectrical impedance indexed subjects' body fat percentage. Cortical attentional responses were probed by the difference between positive event-related potentials peaking around 200-600 ms post-stimulus for the frequent minus rare stimuli (P300). LORETA estimated P300 cortical sources. RESULTS: Main results showed that in the FACE condition, there was a negative correlation between the body fat percentage and the reaction time to the rare stimuli, and a positive correlation between the body fat percentage and the amplitude of prefrontal P300 sources (p<0.05). CONCLUSIONS: These results disclose a relationship between body fat and prefrontal attentional processes to body image in normal weight adults. SIGNIFICANCE: The present study motivates future research testing the hypothesis that this relationship might be altered in patients with eating and weight disorders.