scholarly journals Non-invasive brain microcurrent stimulation therapy of long-COVID-19 reduces vascular dysregulation and improves visual and cognitive impairment

2021 ◽  
pp. 1-16
Author(s):  
Bernhard A. Sabel ◽  
Wanshu Zhou ◽  
Frank Huber ◽  
Florentina Schmidt ◽  
Kornelia Sabel ◽  
...  
Keyword(s):  
Blood Flow ◽  
Visual Field ◽  
Cognitive Deficits ◽  
Recovery Of Function ◽  
Surrogate Marker ◽  
Visual Field Loss ◽  
Cognitive Test ◽  
Non Invasive ◽  
Vascular Dysregulation ◽  
Impaired Attention

Background: An effective treatment is needed for long-COVID patients which suffer from symptoms of vision and/or cognition impairment such as impaired attention, memory, language comprehension, or fatigue. Objective: Because COVID-19infection causes reduced blood flow which may cause neuronal inactivation, we explored if neuromodulation with non-invasive brain stimulation with microcurrent (NIBS), known to enhance blood flow and neuronal synchronization, can reduce these symptoms. Methods: Two female long-COVID patients were treated for 10–13 days with alternating current stimulation of the eyes and brain. While one patient (age 40) was infected with the SARS CoV-2 virus, the other (age 72) developed symptoms following AstraZeneca vaccination. Before and after therapy, cognition was assessed subjectively by interview and visual field using perimetry. One patient was also tested with a cognitive test battery and with a retinal dynamic vascular analyser (DVA), a surrogate marker of vascular dysregulation in the brain. Results: In both patients NIBS markedly improved cognition and partially reversed visual field loss within 3–4 days. Cognitive tests in one patient confirmed recovery of up to 40–60% in cognitive subfunctions with perimetry results showing stable and visual field recovery even during follow-up. DVA showed that NIBS reduced vascular dysregulation by normalizing vessel dynamics (dilation/constriction), with particularly noticeable changes in the peripheral veins and arteries. Conclusions: NIBS was effective in improving visual and cognitive deficits in two confirmed SARS-COV-2 patients. Because recovery of function was associated with restoration of vascular autoregulation, we propose that (i) hypometabolic, “silent” neurons are the likely biological cause of long-COVID associated visual and cognitive deficits, and (ii) reoxygenation of these “silent” neurons provides the basis of neurological recovery. Controlled trials are now needed to confirm these observations.

scholarly journals Transcranial Doppler

2015 ◽  
Vol 02 (03) ◽  
pp. 215-220
Author(s):  
Manish Marda ◽  
Hemanshu Prabhakar
Keyword(s):  
Decision Making ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Transcranial Doppler ◽  
Surrogate Marker ◽  
Vessel Diameter ◽  
Limiting Factor ◽  
Clinical Scenario ◽  
Non Invasive ◽  
Clinical Scenarios

AbstractTranscranial Doppler (TCD) is a bedside, non-invasive, reproducible, non-expensive neuromonitoring device which can be used in many clinical scenarios. Based on the principle of the Doppler shift, blood flow velocity (FV) in the cerebral vessels can be measured. It should be noted that TCD measures blood FV and not the cerebral blood flow (CBF). However, in a given condition, FV can be used as a surrogate marker for vessel diameter or CBF. Indirectly, it can also measure the CBF and the intracranial pressure. This review describes briefly the method of using the equipment and the various indices that can be measured. The applications of TCD are varied. The review also gives an account of the various clinical situations where TCD can be used. An inter-operator variability is an important limiting factor with the use of the TCD. However, in many of clinical scenario, the TCD can still be used to guide for decision-making.

Integration Between Computed Tomography and Nuclear Medicine for Non-invasive Assessment of Coronary Anatomy and Myocardial Perfusion

2009 ◽  
Vol 5 (2) ◽  
pp. 15
Author(s):  
Wanda Acampa ◽  
Mario Petretta ◽  
Carmela Nappi ◽  
Alberto Cuocolo ◽  
◽  
...  
Keyword(s):  
Computed Tomography ◽  
Coronary Heart Disease ◽  
Blood Flow ◽  
Heart Disease ◽  
Myocardial Perfusion ◽  
Myocardial Blood Flow ◽  
Imaging Techniques ◽  
Emission Computed Tomography ◽  
Coronary Anatomy ◽  
Non Invasive

Many non-invasive imaging techniques are available for the evaluation of patients with known or suspected coronary heart disease. Among these, computed-tomography-based techniques allow the quantification of coronary atherosclerotic calcium and non-invasive imaging of coronary arteries, whereas nuclear cardiology is the most widely used non-invasive approach for the assessment of myocardial perfusion. The available single-photon-emission computed tomography flow agents are characterised by a cardiac uptake proportional to myocardial blood flow. In addition, different positron emission tomography tracers may be used for the quantitative measurement of myocardial blood flow and coronary flow reserve. Extensive research is being performed in the development of non-invasive coronary angiography and myocardial perfusion imaging using cardiac magnetic resonance. Finally, new multimodality imaging systems have recently been developed bringing together anatomical and functional information. This article provides a description of the available non-invasive imaging techniques in the assessment of coronary anatomy and myocardial perfusion in patients with known or suspected coronary heart disease.

scholarly journals What do patients with glaucoma see: a novel iPad app to improve glaucoma patient awareness of visual field loss

2020 ◽  
pp. bjophthalmol-2020-317034
Author(s):  
Meghal Gagrani ◽  
Jideofor Ndulue ◽  
David Anderson ◽  
Sachin Kedar ◽  
Vikas Gulati ◽  
...  
Keyword(s):  
Visual Field ◽  
Vision Loss ◽  
Peripheral Vision ◽  
Glaucoma Patient ◽  
Visual Field Loss ◽  
Sensitivity Threshold ◽  
Roc Curve Analysis ◽  
The Mean ◽  
Ipad App ◽  
Field Defects

PurposeGlaucoma patients with peripheral vision loss have in the past subjectively described their field loss as ‘blurred’ or ‘no vision compromise’. We developed an iPad app for patients to self-characterise perception within areas of glaucomatous visual field loss.MethodsTwelve glaucoma patients with visual acuity ≥20/40 in each eye, stable and reliable Humphrey Visual Field (HVF) over 2 years were enrolled. An iPad app (held at 33 cm) allowed subjects to modify ‘blur’ or ‘dimness’ to match their perception of a 2×2 m wall-mounted poster at 1 m distance. Subjects fixated at the centre of the poster (spanning 45° of field from centre). The output was degree of blur/dim: normal, mild and severe noted on the iPad image at the 54 retinal loci tested by the HVF 24-2 and was compared to threshold sensitivity values at these loci. Monocular (Right eye (OD), left eye (OS)) HVF responses were used to calculate an integrated binocular (OU) visual field index (VFI). All three data sets were analysed separately.Results36 HVF and iPad responses from 12 subjects (mean age 71±8.2y) were analysed. The mean VFI was 77% OD, 76% OS, 83% OU. The most common iPad response reported was normal followed by blur. No subject reported dim response. The mean HVF sensitivity threshold was significantly associated with the iPad response at the corresponding retinal loci (For OD, OS and OU, respectively (dB): normal: 23, 25, 27; mild blur: 18, 16, 22; severe blur: 9, 9, 11). On receiver operative characteristic (ROC) curve analysis, the HVF retinal sensitivity cut-off at which subjects reported blur was 23.4 OD, 23 OS and 23.3 OU (dB).ConclusionsGlaucoma subjects self-pictorialised their field defects as blur; never dim or black. Our innovation allows translation of HVF data to quantitatively characterise visual perception in patients with glaucomatous field defects.

scholarly journals Association of ocular blood flow and contrast sensitivity in normal tension glaucoma

2021 ◽  
Author(s):  
David Kuerten ◽  
Matthias Fuest ◽  
Peter Walter ◽  
Babac Mazinani ◽  
Niklas Plange
Keyword(s):  
Blood Flow ◽  
Visual Field ◽  
Contrast Sensitivity ◽  
Visual Field Defect ◽  
Prospective Trial ◽  
Normal Tension Glaucoma ◽  
Ocular Blood Flow ◽  
Retinal Blood Flow ◽  
Control Group ◽  
Field Defect

Abstract Purpose To investigate the relationship of ocular blood flow (via arteriovenous passage time, AVP) and contrast sensitivity (CS) in healthy as well as normal tension glaucoma (NTG) subjects. Design Mono-center comparative prospective trial Methods Twenty-five NTG patients without medication and 25 healthy test participants were recruited. AVP as a measure of retinal blood flow was recorded via fluorescein angiography after CS measurement using digital image analysis. Association of AVP and CS at 4 spatial frequencies (3, 6, 12, and 18 cycles per degree, cpd) was explored with correlation analysis. Results Significant differences regarding AVP, visual field defect, intraocular pressure, and CS measurement were recorded in-between the control group and NTG patients. In NTG patients, AVP was significantly correlated to CS at all investigated cpd (3 cpd: r =  − 0.432, p< 0.03; 6 cpd: r =  − 0.629, p< 0.0005; 12 cpd: r =  − 0.535, p< 0.005; and 18 cpd: r =  − 0.58, p< 0.001), whereas no significant correlations were found in the control group. Visual acuity was significantly correlated to CS at 6, 12, and 18 cpd in NTG patients (r =  − 0.68, p< 0.002; r =  − 0.54, p< .02, and r =  − 0.88, p< 0.0001 respectively), however not in healthy control patients. Age, visual field defect MD, and PSD were not significantly correlated to CS in in the NTG group. MD and PSD were significantly correlated to CS at 3 cpd in healthy eyes (r = 0.55, p< 0.02; r =  − 0.47, p< 0.03). Conclusion Retinal blood flow alterations show a relationship with contrast sensitivity loss in NTG patients. This might reflect a disease-related link between retinal blood flow and visual function. This association was not recorded in healthy volunteers.

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