Resting-state EEG rhythms are abnormal in post COVID-19 patients with brain fog without cognitive and affective disorders.

OBJECTIVES: Several persons experiencing post-covid-19 (post-COVID) with "brain fog" (e.g., fatigue, cognitive and psychiatric disorders, etc.) show abnormal resting-state electroencephalographic (rsEEG) rhythms reflecting a vigilance dysfunction. Here, we tested the hypothesis that in those post-COVID persons, abnormal rsEEG rhythms may occur even when cognitive and psychiatric disorders are absent. METHODS: The experiments were performed on post-COVID participants about one year after hospitalization for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Inclusion criteria included a "brain fog" claim, no pre-infection, and actual organic chronic disease. Matched controls (no COVID) were also enrolled. All participants underwent clinical/neuropsychological assessment (including fatigue assessment) and rsEEG recordings. The eLORETA freeware estimated regional rsEEG cortical sources at individual delta (<4 Hz), theta (4-7 Hz), and alpha (8-13 Hz) bands. Beta (14-30 Hz) and gamma (30-40 Hz) bands were pre-fixed. RESULTS: More than 90% of all post-COVID participants showed no cognitive or psychiatric disorders, and 75% showed ≥ 2 fatigue symptoms. The post-COVID group globally presented lower posterior rsEEG alpha source activities than the Control group. This effect was more significant in the long COVID-19 patients with ≥ 2 fatigue symptoms. CONCLUSIONS: In post-COVID patients with no chronic diseases and cognitive/psychiatric disorders, "brain fog" can be associated with abnormal posterior rsEEG alpha rhythms and subjective fatigue. SIGNIFICANCE: These abnormalities may be related to vigilance and allostatic dysfunctions.

Role of the Vitreous in Retinal Pathology: A Narrative Review.

The vitreous body is an anatomically and biochemically complex structure. Because of its proximity and firm adherence to the retina, researchers have examined the link between these two structures and how their individual pathologies might be connected. Several experimental and clinical studies have already demonstrated the important role of vitreous in the pathogenesis of retinal disorders. This narrative review highlights the role of the vitreous in retinal diseases and the improvements that have been made since the introduction of optical coherence tomography. This leads to a better understanding of vitreoretinal diseases and demonstrates its determinant role in other retinal pathologies, such as diabetic retinopathy or age-related macular degeneration. As we deepen our knowledge of the vitreous's structure, function, and abnormal conditions, we can better link the changes in diseases and identify effective treatments.

Oculo-orbital complications of odontogenic sinusitis.

Introduction: Odontogenic sinusitis is a well-known, but under-studied bacterial infection of the maxillary sinus that can extend to other sinuses, the orbit, or even the endocranium. Material and methods: We performed an observational retrospective study on the patients with odontogenic sinusitis treated in our hospital over a five-year period. We included patients over 18 years old diagnosed with odontogenic sinusitis and ocular complications and we excluded patients with ocular complications nonrelated to dental-originated sinusitis or patients with odontogenic sinusitis without orbital-ocular complications. Results: We examined the charts of 46 patients. From the total number of patients with oculo-orbital complications generated by odontogenic sinusitis, only 7 were women. The mean age was 33,7 with a standard deviation of 15,7 years. The oculo-orbital complications were assessed according to the Chandler classification. The most frequent orbital complication was preseptal cellulitis followed by orbital cellulitis. All the patients were treated with antibiotic covering both anaerobic and aerobic bacteria and 40 of the patients in our study received surgical treatment. The outcomes were favorable for all the patients in our study with clinical resolution. Conclusion: The oculo-orbital complications of odontogenic sinusitis are severe because they can result in vision loss or other ocular sequelae. The bacteriological features of this sinusitis explain the special characteristics of this infection and can facilitate the extent of the infection to the orbit. Prompt intervention with antibiotics covering anaerobic and aerobic bacteria and surgery addressed to the affected sinus/ sinuses, the dental disease and the orbital pathology ensures a big success rate in the therapy of these complications.

What a single electroencephalographic (EEG) channel can tell us about patients with dementia due to Alzheimer's disease.

Abnormalities in cortical sources of resting-state eyes-closed electroencephalographic (rsEEG) rhythms recorded by hospital settings (10-20 electrode montage) with 19 scalp electrodes provide useful markers of neurophysiological dysfunctions in the vigilance regulation in patients with Alzheimer's disease dementia (ADD). Here we tested whether these markers may be effective from a few scalp electrodes towards the use of low-cost recording devices. Clinical and rsEEG data acquired in hospital settings (10-20 electrode montage) from 88 ADD participants and 68 age-, education-, and sex-matched normal elderly controls (Nold) were available in an international Eurasian database. Standard spectral FFT analysis of rsEEG data for individual delta, theta, and alpha frequency bands was from C3-P3, C4-P4, P3-O1, and P4-O2 bipolar channels. As compared to the Nold group, the ADD group showed increased delta, theta, low-frequency alpha power density and decreased high-frequency alpha power density at all those bipolar channels. The highest classification accuracy between the ADD and Nold individuals reached 90 % (area under the receiver operating characteristic curve) using Alpha2/Theta power density computed at the C3-P3 bipolar channel. Standard rsEEG power density computed from a few posterior bipolar channels successfully classified Nold and ADD individuals, thus encouraging a massive prescreening of neurophysiological mechanisms underpinning the vigilance dysregulation in underserved old seniors.

Multiple Sclerosis Presenting as an Anterior Semicircular Canal Benign Paroxysmal Positional Vertigo: Case Report.

We present the case of a 31-year-old woman with isolated symptomatology accusing positional vertigo. The videonystagmography (VNG) including Dix-Hallpike testing we have performed, highlighted atypical eye movements. We have observed a positional downbeating nystagmus with characteristics that could be accounted for anterior semicircular canal benign paroxysmal positional vertigo. Furthermore, examining the atypical nystagmus at the measurements performed during VNG recordings, we suspicioned a central positional vertigo. The abnormalities observed at the positional nystagmus were the lack of latency period, the downbeating component not limited in time, and the atypical torsional component. The magnetic resonance imaging examination recommended showed multiple white matter lesions characteristic for multiple sclerosis. The patient was referred to the neurology department for further evaluation and treatment. The diagnosis was unexpected because the patient did not have any other symptom that could have been linked to multiple sclerosis.