Motion-onset visual evoked potentials (MO VEPs) are robust to dioptric blur when low contrast and low spatial frequency patterns are used for stimulation. To reveal mechanisms of MO VEPs robustness, we studied whether the resistance to defocus persists even when using a high-contrast checkerboard using digital defocus in the emmetropic eyes of 13 subjects (males 20-60 years). We compared the dominant components of MO VEPs to pattern-reversal VEPs (PR VEP), which are sensitive to the blur. For stimulation, we used checkerboard patterns with 15 ́ and 60 ́ checks. To defocus the checkerboard, we rendered it with a second-order Zernike polynomial ( Z20 ) with an equivalent defocus of 0, 2, or 4 D. For PR VEP, the checkerboards were reversed in terms of their contrast. To evoke MO VEP, the checkerboard of 60 ́ checks moved for 200 ms with a speed of 5 or 10 deg/s in the cardinal directions. The MO VEP did not change in peak time (P ≥ 0.0747) or interpeak amplitude (P > 0.0772) with digital blur. In contrast, for PR VEP, the results showed a decrease in interpeak amplitude (P ≤ 6.65ˑ10-4) and an increase in peak time (P ≤ 0.0385). Thus, we demonstrated that MO VEPs evoked by checkerboard, structure containing high spatial content, can be robust to defocus.
- MeSH
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- světelná stimulace MeSH
- vnímání pohybu fyziologie MeSH
- zrakové evokované potenciály * fyziologie MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
PURPOSE: The aim of this neurophysiological study was to retrospectively analyze visual evoked potentials (VEPs) acquired during an examination for diagnosing optic nerve involvement in patients with Lyme neuroborreliosis (LNB). Attention was focused on LNB patients with peripheral facial palsy (PFP) and optic nerve involvement. METHODS: A total of 241 Czech patients were classified as having probable/definite LNB (193/48); of these, 57 were younger than 40 years, with a median age of 26.3 years, and 184 were older than 40 years, with a median age of 58.8 years. All patients underwent pattern-reversal (PVEP) and motion-onset (MVEP) VEP examinations. RESULTS: Abnormal VEP results were observed in 150/241 patients and were noted more often in patients over 40 years (p = 0.008). Muscle/joint problems and paresthesia were observed to be significantly more common in patients older than 40 years (p = 0.002, p = 0.030), in contrast to headache and decreased visual acuity, which were seen more often in patients younger than 40 years (p = 0.001, p = 0.033). Peripheral facial palsy was diagnosed in 26/241 LNB patients. Among patients with PFP, VEP peak times above the laboratory limit was observed in 22 (84.6%) individuals. Monitoring of patients with PFP and pathological VEP showed that the adjustment of visual system function occurred in half of the patients in one to more years, in contrast to faster recovery from peripheral facial palsy within months in most patients. CONCLUSION: In LNB patients, VEP helps to increase sensitivity of an early diagnostic process.
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- dítě MeSH
- dospělí MeSH
- faciální paralýza patofyziologie diagnóza MeSH
- lidé středního věku MeSH
- lidé MeSH
- lymská neuroborelióza * patofyziologie diagnóza komplikace MeSH
- mladiství MeSH
- mladý dospělý MeSH
- nemoci zrakového nervu * patofyziologie diagnóza MeSH
- nervus opticus patofyziologie MeSH
- retrospektivní studie MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- zraková ostrost fyziologie MeSH
- zrakové evokované potenciály * fyziologie MeSH
- Check Tag
- dítě MeSH
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
In the age homogenous group of 13 healthy volunteers, we examined visual evoked potentials (VEP) visually evoked cognitive potentials (event-related potentials - ERP) and choice reaction time (CRT) five times during the day (from 10.00 a.m. up to midnight) to verify whether there are significant changes of the measured parameters of the cortical evoked potentials and CRT which might reflect the level of the mental fatigue. The electrophysiological testing was done with the use of a new portable VEP device named "VEPpeak" enabling to perform the examination outside standard labs in almost any conditions. It was found that the latency of ERP (P300 peak time) and CRT displayed significant prolongation toward midnight while VEP latency and all amplitudes did not change significantly. This pilot study supports our idea that the portable VEP device possibly might be used for the objective examination of mental fatigue that is needed in many situations. This should be confirmed in a larger study also including a comparison with non-electrophysiological fatigue testing.
- MeSH
- duševní únava MeSH
- evokované potenciály * fyziologie MeSH
- kognice MeSH
- lidé MeSH
- pilotní projekty MeSH
- zrakové evokované potenciály * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
INTRODUCTION: We developed a new portable device called "VEPpeak" for the examination of visual evoked potentials (VEPs) to extend VEP examination beyond specialized electrophysiological laboratories and to simplify the use of this objective, noninvasive, and low-cost method for diagnostics of visual and central nervous system dysfunctions. METHODS: VEPpeak consists of a plastic headset with a total weight of 390 g containing four EEG amplifiers, an A/D converter, a control unit, and a visual LED stimulator built in the front, vertically adjustable peak. The device is powered and controlled via USB connection from a standard PC/notebook using custom software for visual stimuli generation and for VEP recording and processing. Up to four electrodes can be placed at any scalp location or in combination with two dry electrodes incorporated into the headset. External visual stimulators, such as a tablet, can be used with synchronization. Feasibility and validation studies were conducted with 86 healthy subjects and 76 neuro-ophthalmological patients including 67 who were during the same session also tested with a conventional VEP system. RESULTS: VEPpeak recordings to standard (pattern-reversal) and non-standard (motion-onset, red-green alternation) were robust and repeatable and obtained also in immobilized patients. Good comparability of results was achieved between VEPpeak and standard examination. Some systematic differences in peak latencies and amplitudes are consistent with differences in stimulus characteristics of the two compared systems. DISCUSSION: VEPpeak provides an inexpensive system for clinical use requiring portability. In addition to ISCEV standard VEP protocols, free choice of stimuli and bio-signal recordings make the device universal for many electrophysiological purposes.
BACKGROUND: Sensory deficits can result in limitations regarding how well neuropsychological test findings can be interpreted. Only a few studies have investigated the influence of vision alteration on neuropsychological tests. In 2012 the Czech Republic experienced mass methanol poisoning. Methanol metabolites cause histotoxic hypoxia to the optic nerve. OBJECTIVE: In the current study, the effect of the toxic damage on the parts of the visual pathway on visual and non-visual neuropsychological measures was investigated using electrophysiological methods (visual evoked potential (VEP) and optical coherence tomography (OCT) with retinal nerve fibre layer (RNFL) thickness measurement. METHODS: 53 individuals who experienced methanol poisoning participated in this research (76% men; ages 24 to 74 years, mean = 43.8±14.6 years; education 11.9±1.4 years). Each participant underwent comprehensive neurological, ophthalmological, and neuropsychological examinations. RESULTS: The results of mixed-effect models revealed significant small to a medium association between the Stroop test weak interference and Grooved Pegboard with the left eye global, nasal and temporal RNFL thickness. Also, medium associations between the Finger Tapping test and the Stroop test weak interference and left eye temporal RNFL, right eye temporal RNFL, and the latency P1 of VEP in the left eye were significant. CONCLUSION: The results of this study found a small to medium association (r = .15- .33; p = .010- .046) between RNFL thickness and cognitive visual test performance. Careful interpretation is suggested regarding results obtained from visual tests of the executive or motor functioning with participants with RNFL decrease or other types of early visual processing damage.
- MeSH
- kognice MeSH
- lidé MeSH
- methanol * MeSH
- neuropsychologické testy MeSH
- přežívající MeSH
- zrakové evokované potenciály * MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
BACKGROUND: The authors present a case study which describes the development of bilateral optic neuropathy as a complication of allogeneic hematopoietic stem cell transplantation (HSCT) in a patient who underwent a transplant for B-cell acute lymphoblastic leukemia (B-ALL). The patient, who was in remission with regard to the underlying hematological disease, developed edema of both optic discs and maculas three months after transplantation. The morphological finding regressed after treatment with corticoids and comprehensive systemic anti-infective therapy. However, the loss of function was not entirely restored. CASE REPORT: One year after the healing, the atrophy of the optic discs persisted, with corresponding findings in vessel density (VD), retinal nerve fibre layer (RNFL) and visual field changes. Electrophysiological examination by pattern electroretinogram (PERG) showed an alteration in retinal ganglion cells in the left eye, but with significant damage to nerve fibres on both sides. Visual evoked potential (VEP) verified bilateral non-inflammatory neurogenic lesions. This finding was also confirmed by functional magnetic resonance imaging (fMRI). Examination by structural magnetic resonance imaging (MRI) showed inflammatory changes in the optic nerve sheaths over time and a consequent marked narrowing of them. CONCLUSION: The authors believe that edema of the optic discs and maculas was caused by a combination of several factors. Firstly, MRI showed inflammatory changes in the optic nerve sheaths, which led to a blockade of axoplasmic transport. Another factor that may have played a part in the outcome was endothelial damage to blood vessels with impaired microcirculation supplying the optic nerve fibres, which contributed to the occurrence of macular edema.
Cíl: Zrakové evokované potenciály (visual evoked potentials; VEP) představují objektivní, neinvazivní a levnou diagnostickou metodu, zejména v neurooftalmologii. Mnoho diagnostických aplikací je však limitováno tím, že k jejich vyšetření se dosud používá robustní, obtížně transportovatelné zařízení, přičemž imobilní nebo jinak handicapovaní pacienti nemohou navštěvovat specializované laboratoře. Cílem naší práce bylo vyvinout snadno přenosný, levný VEP přístroj použitelný prakticky kdekoliv. Metodika: Všechny části posledního prototypu přístroje (vestavěný zrakový stimulátor, snímací elektrody, čtyřkanálový EEG zesilovač, analogově-číslicový převodník a řídicí jednotka) s celkovou hmotností 390 g jsou uloženy v náhlavním nosiči (umělohmotný „kšilt“ s upínacím páskem). Snímací a vyhodnocovací software pro natáčení a vyhodnocení VEP je použitelný na standardním notebooku (PC). Parametry přístroje splňují doporučení mezinárodních společností pro klinickou elektrofyziologii zraku a klinickou neurofyziologii, ale také umožňují nové aplikace dosud běžně nepoužívaných variant evokovaných potenciálů. Testování přístroje zatím proběhlo u 91 kontrolních osob a 135 neurooftalmologických pacientů. Výsledky: Pilotní studie prokázaly srovnatelné parametry VEP a diagnostickou senzitivitu jako u standardního zařízení (shoda nálezů v 93 % případů). Byla ověřena možnost použití přístroje v různých prostředích, u lůžka pacienta i pro laické samovyšetření. Závěr: Přenosný přístroj pro VEP výrazně zvyšuje dostupnost vyšetření, a tím umožňuje daleko širší diagnostické aplikace této metody.
Aim: Visual evoked potentials (VEP) represent an objective non-invasive and inexpensive diagnostic method, particularly in neuro-ophthalmology. A lot of possible diagnostic applications are limited because they are only examined with the use of robust equipment which is hardly transportable and immobile and handicapped patients cannot visit the specialized labs. The aim of our research work was the development of a portable inexpensive VEP device that could be used almost anywhere. Methods: All parts of the last prototype of the device (built-in visual stimulator, recording electrodes, 4-channel EEG amplifier, analog-digital converter, and control unit) with a total weight of 390 g are placed in a headset (plastic “shield” with an adjustable strap). The software for VEP recording and evaluation is used on a standard notebook (PC). The parameters of the device fulfill recommendations of the international societies for clinical electrophysiology of vision and clinical neurophysiology also enabling new applications of so far not routinely used variants of evoked potentials. Testing of the device was done so far in 91 control subjects and 135 neuroophthalmological patients. Results: Pilot studies proved comparable parameters of VEP and diagnostic sensitivity as in standard devices (equal results in 93% of cases). It was verified that the device is usable in various environments, at the patient’s bedside, and also for basic self-examination. Conclusion: The portable device for VEP significantly increases the availability of their examination and thus enables much broader diagnostic applications of this method.
- MeSH
- diagnostické techniky neurologické přístrojové vybavení statistika a číselné údaje MeSH
- diagnostické techniky oftalmologické přístrojové vybavení statistika a číselné údaje MeSH
- lidé MeSH
- zrakové evokované potenciály * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- klinická studie MeSH
- práce podpořená grantem MeSH
Sensory processing is influenced by neuromodulators such as serotonin, thought to relay behavioural state. Recent work has shown that the modulatory effect of serotonin itself differs with the animal's behavioural state. In primates, including humans, the serotonin system is anatomically important in the primary visual cortex (V1). We previously reported that in awake fixating macaques, serotonin reduces the spiking activity by decreasing response gain in V1. But the effect of serotonin on the local network is unknown. Here, we simultaneously recorded single-unit activity and local field potentials (LFPs) while iontophoretically applying serotonin in V1 of alert monkeys fixating on a video screen for juice rewards. The reduction in spiking response we observed previously is the opposite of the known increase of spiking activity with spatial attention. Conversely, in the local network (LFP), the application of serotonin resulted in changes mirroring the local network effects of previous reports in macaques directing spatial attention to the receptive field. It reduced the LFP power and the spike-field coherence, and the LFP became less predictive of spiking activity, consistent with reduced functional connectivity. We speculate that together, these effects may reflect the sensory side of a serotonergic contribution to quiet vigilance: The lower gain reduces the salience of stimuli to suppress an orienting reflex to novel stimuli, whereas at the network level, visual processing is in a state comparable to that of spatial attention.
- MeSH
- akční potenciály fyziologie MeSH
- lidé MeSH
- Macaca mulatta MeSH
- serotonin MeSH
- světelná stimulace MeSH
- zraková percepce fyziologie MeSH
- zrakové evokované potenciály * MeSH
- zrakové korové centrum * fyziologie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Intramural MeSH
BACKGROUND: ADNP is essential for embryonic development. As such, de novo ADNP mutations lead to an intractable autism/intellectual disability syndrome requiring investigation. METHODS: Mimicking humans, CRISPR (clustered regularly interspaced short palindromic repeats)-Cas9 editing produced mice carrying heterozygous Adnp p.Tyr718∗ (Tyr), a paralog of the most common ADNP syndrome mutation. Phenotypic rescue was validated by treatment with the microtubule/autophagy-protective ADNP fragment NAPVSIPQ (NAP). RESULTS: RNA sequencing of spleens, representing a peripheral biomarker source, revealed Tyr-specific sex differences (e.g., cell cycle), accentuated in females (with significant effects on antigen processing and cellular senescence) and corrected by NAP. Differentially expressed, NAP-correctable transcripts, including the autophagy and microbiome resilience-linked FOXO3, were also deregulated in human patient-derived ADNP-mutated lymphoblastoid cells. There were also Tyr sex-specific microbiota signatures. Phenotypically, Tyr mice, similar to patients with ADNP syndrome, exhibited delayed development coupled with sex-dependent gait defects. Speech acquisition delays paralleled sex-specific mouse syntax abnormalities. Anatomically, dendritic spine densities/morphologies were decreased with NAP amelioration. These findings were replicated in the Adnp+/- mouse, including Foxo3 deregulation, required for dendritic spine formation. Grooming duration and nociception threshold (autistic traits) were significantly affected only in males. Early-onset tauopathy was accentuated in males (hippocampus and visual cortex), mimicking humans, and was paralleled by impaired visual evoked potentials and correction by acute NAP treatment. CONCLUSIONS: Tyr mice model ADNP syndrome pathology. The newly discovered ADNP/NAP target FOXO3 controls the autophagy initiator LC3 (microtubule-associated protein 1 light chain 3), with known ADNP binding to LC3 augmented by NAP, protecting against tauopathy. NAP amelioration attests to specificity, with potential for drug development targeting accessible biomarkers.
- MeSH
- autistická porucha * patologie MeSH
- exprese genu MeSH
- homeodoménové proteiny genetika MeSH
- lidé MeSH
- mentální retardace * genetika metabolismus MeSH
- mozek metabolismus MeSH
- myši MeSH
- proteiny nervové tkáně genetika MeSH
- proteiny tau MeSH
- tauopatie * metabolismus MeSH
- zrakové evokované potenciály MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, U.S. Gov't, Non-P.H.S. MeSH
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- MeSH
- diagnostické techniky oftalmologické * MeSH
- lidé MeSH
- optická koherentní tomografie metody MeSH
- optometrie metody MeSH
- roztroušená skleróza * komplikace MeSH
- štěrbinová lampa MeSH
- testy barvocitu metody MeSH
- testy zrakového pole metody MeSH
- zánět zrakového nervu * diagnóza etiologie MeSH
- zrakové evokované potenciály MeSH
- Check Tag
- lidé MeSH