scholarly journals Pattern reversal visual evoked potentials in adults: variability with age

2017 ◽  
Vol 40 (6) ◽  
pp. 252 ◽  
Author(s):  
Raja Sawaya ◽  
Helen Sawaya ◽  
Gilbert Youssef
Keyword(s):  
Linear Trend ◽  
Age Groups ◽  
Normal Subjects ◽  
Pattern Reversal ◽  
Checkerboard Pattern ◽  
Check Size ◽  
Band Pass ◽  
The Difference ◽  
And Gender ◽  
Visual Evoked

Purpose: Pattern reversal visual evoked potential (PRVEP) is an electrophysiological test for evaluating the visual pathway. This study measured the changes in the latencies and amplitudes of the PRVEP with age and gender in normal subjects. Methods: Healthy participants (n=81; 162 total eyes), between the ages of 20 and 92 years were recruited for the study. Stimulation was performed monocularly with a high-contrast (>50%) black-white checkerboard pattern with a check size of 30° at a reversal rate of 2 Hz, a band-pass of 1-100 Hz, a sweep of 250 msec and an average of 150 stimulations in a dark room. Mean and standard deviations for three latencies (N75, P100 and N145) and the amplitude (N75-P100) for each decade were measured. Results: There was a linear trend by age for all three latencies, indicating that the higher age groups had longer latencies. The latencies decreased in the 5th decade before increasing in the higher age groups. The amplitude of N75-P100 decreased with age. The P100 latencies were longer in males than females in all age groups and the difference increased with increasing age.

scholarly journals Cortical Contrast Processing in Retinitis Pigmentosa: Evidence of PVEPs Spatial Functions

2020 ◽  
Vol 10 (4) ◽  
pp. 1010-1019
Author(s):  
Rafael Mancebo-Azor ◽  
José Antonio Sáez-Moreno ◽  
José Manuel Rodríguez-Ferrer
Keyword(s):  
Retinitis Pigmentosa ◽  
Evoked Potentials ◽  
Visual Evoked Potentials ◽  
Normal Subjects ◽  
Pattern Reversal ◽  
Check Size ◽  
Low Contrast ◽  
Control Subjects ◽  
The Right ◽  
Visual Evoked

Objective: To study the effect of check width size of the stimuli on the amplitude and latency of the P100 component of visual evoked potentials recorded in patients with retinitis pigmentosa (RP). Methods: Pattern reversal visual evoked potentials (PVEPs) were recorded in 16 RP patients and 20 visually normal subjects. Pattern reversal stimuli with five different check widths and 100% of contrast were projected in the right eye of both patients and control subjects. PVEPs induced by stimuli with 78%, 16%, and 6% of contrast were also recorded in 10 of the control subjects. Results: In RP patients, the amplitude of P100 was smaller than controls in all check sized used and the peak P100 amplitude was obtained with a larger check width than in controls. P100 was also delayed in RP patients in all check sizes studied. The P100 amplitude- and latency-check size functions of RP patients were like those found in control subjects with low contrast stimuli of 16% and 6%. Conclusion: The PVEPs spatial functions of RP patients show quantitative and qualitative changes, suggesting disease induced alteration in the neural processing of stimulus contrast.

Visual Evoked potential signal processing and analysis for normal and galucomic eyes

2015 ◽  
Vol 8 (2) ◽  
pp. 2106-2121
Author(s):  
Hamed Ibrahem Abdelkader ◽  
Mona Abdelkader ◽  
Mohammed Kabeel ◽  
Malak Alya
Keyword(s):  
Evoked Potentials ◽  
Visual Evoked Potential ◽  
Evoked Potential ◽  
Optic Tract ◽  
Pattern Reversal ◽  
Blue Color ◽  
Check Size ◽  
Retinal Stimulation ◽  
Normal Individuals ◽  
Visual Evoked

Visual evoked potentials (VEPS) are obtained from optic tract by recording the evoked potentials generated by retinal stimulation. The flash VEP (FVEP) is used less frequently than pattern reversal VEP (PRVEP) because; it shows great variation in both latency and amplitude. The present study was undertaken to evaluate the effect of change of wavelength of flash and change of check size on the parameters of visual evoked potential (amplitude and latency) in normal individuals and glaucoma patients. The group of healthy subjects in the age of 20-45 years while the group of glaucoma subjects where  in the age of 25-50 years.  The two groups were exposed to flash VEP with white light and blue color and they also were exposed to checks subtending a visual angles of 15, 30,60 and 120 minutes of arc. The measured data were statistically analyzed and summarized by histograms. The interindividual and intraindividual in latencies and amplitudes for FVEP were assessed using  the coefficient of variation (COV). In conclusion, monochromatic flash VEP was preferred than white as there were minimal inter and intra individual variation of latencies and amplitudes. The most preferred check size in PRVEP was 120' for  the two groups.  

EXPRESS: Serum Carbohydrate Antigen72-4 levels decrease with age in females but not males in Beijing, China

2021 ◽  
pp. 000456322110269
Author(s):  
Tongmei Duan ◽  
Xun Chen ◽  
Jing Wu ◽  
Ronghai Li ◽  
Huijuan Guo ◽  
...  
Keyword(s):  
Age Groups ◽  
Reference Interval ◽  
Carbohydrate Antigen ◽  
Female Group ◽  
Healthy Population ◽  
Age Difference ◽  
Significant Difference ◽  
The Difference ◽  
And Gender ◽  
Beijing China

Objective: Carbohydrate antigen 72-4 (CA72-4) is widely used in the diagnosis and monitoring of many cancers. However, there are few studies on the differences of CA72-4 levels in terms of age and gender. Methods: 10957 healthy subjects were divided into two groups according to gender and three age groups. The serum CA72-4 were detected. Statistical analysis was performed by SPSS. Results: The CA72-4 level in female group was significantly higher than that in male group. The level of CA72-4 gradually decreased with age. Compared with the age >60 group, the CA72-4 levels were increased in the age 46-60 group and 16-45 group (P >0.05, respectively). To better observe the age difference, the age 16-45 and 46–60 group were combined into the age 16-60 group. In comparison to the age >60 group, the CA72-4 level of age 16-60 group was significantly increased (P =0.000). In the age >60 group, there was no difference between genders. Nevertheless, the difference between the sexes in the age 16-60 group was significant (P =0.023). Conclusions: The reference interval of CA72-4 for local healthy population was established. CA72-4 levels gradually decreased with the increase of age, and CA72-4 level in females aged 16-60 years (0-18.0 U/mL) was higher than in males (0-14.5 U/mL), however there was no gender difference in the age group above 60 years old (0-14.5 U/mL). Moreover, male CA72-4 was no significant difference among all age groups, while the potential mechanism of female changes with age needed further study.

Primary Presenile Dementia: The Use of the Visual Evoked Potential as a Diagnostic Indicator

1985 ◽  
Vol 147 (5) ◽  
pp. 532-539 ◽  
Author(s):  
Graham F. A. Harding ◽  
Christine E. Wright ◽  
Arnold Orwin
Keyword(s):  
Visual Evoked Potential ◽  
Evoked Potential ◽  
Cortical Atrophy ◽  
Control Group ◽  
Pattern Reversal ◽  
Presenile Dementia ◽  
The Difference ◽  
Pattern Reversal Stimulation ◽  
Diagnostic Indicator ◽  
Visual Evoked

The use of the flash and pattern reversal visual evoked potential (VEP) in the diagnosis of primary presenile dementia was investigated. The results from 20 patients with primary presenile dementia were compared with those from a control group of normals of equivalent age and from a control group of 20 patients with cortical atrophy but no dementia. Presenile dementia caused a slowing of the major positive (P2) component of the VEP to flash stimulation. However, the VEP to pattern reversal stimulation (P100) was of normal latency. The difference between these two latencies characterises this unusual combination of results and is found to be a more specific diagnostic indicator of primary presenile dementia than the EEG or CT scan.

scholarly journals Tooth extraction: Pattern and etiology from extreme Northwestern Nigeria

2017 ◽  
Vol 11 (03) ◽  
pp. 335-339 ◽  
Author(s):  
Abdurrazaq Olanrewaju Taiwo ◽  
Adebayo Aremu Ibikunle ◽  
Ramat Oyebunmi Braimah ◽  
Omotayo Amidu Sulaiman ◽  
Olalekan Micah Gbotolorun
Keyword(s):  
Periodontal Disease ◽  
Tooth Extraction ◽  
Statistical Significance ◽  
Age Groups ◽  
Urban Region ◽  
Geographical Regions ◽  
Extraction Pattern ◽  
The Difference ◽  
And Gender ◽  
Age Range

ABSTRACT Objective: Tooth extraction is a commonly performed procedure in dental clinics. It has been shown that the reasons for and pattern of tooth extraction vary across geographical regions. Few reports on the pattern of extraction among a semi-urban populace exist. To the best of our knowledge, there is no study on the pattern and reasons for tooth mortality from Sokoto, Northwestern Nigeria, which is a semi-urban region. Materials and Methods: A review of the records of patients that had tooth extraction at our center between January 2009 and January 2016, was done. Data such as the age, gender, type of tooth extracted, and reasons for extraction were retrieved and analyzed. Cross tabulations for age and gender were also made. The level of statistical significance was set at P < 0.05. Results: A total of 1167 extractions were performed in 984 patients. An age range of 18–107 years with a mean (±standard deviation) of 34.8 (13.3) was observed. Most of the patients were in the 21–30 years age group accounting for 35.7% of cases. Dental caries and its sequelae (DCS) (631, 54.1%) were the most common reasons for extraction, followed by periodontal disease (192, 16.5%). The difference in proportions of reasons for tooth extraction between the gender was statistically significant (P = 0.02; df = 24). The difference in the reasons for extraction among the age groups was statistically significant (P < 0.001; df = 132). Conclusion: DCS along with periodontal disease were the major reasons for extractions. These are largely preventable causes of tooth extraction; therefore, there is a need for commencement of far-reaching preventative actions.

Effect of Head Circumference and Gender on Pattern Reversal Visual Evoked Potential

2016 ◽  
Vol 3 (3) ◽  
pp. 107
Author(s):  
Kuldip Singh Bhatia ◽  
Anil Kumar ◽  
Ali Ahanger ◽  
Pradeep Shingal ◽  
Vijay Kumar Roy
Keyword(s):  
Head Circumference ◽  
Visual Evoked Potential ◽  
Evoked Potential ◽  
Pattern Reversal ◽  
And Gender ◽  
Visual Evoked

scholarly journals Correlation between bone turnover and metabolic markers with age and gender: a cross-sectional study of hospital information system data

2020 ◽  
Author(s):  
Shao Ju ◽  
Shaosong Zhou ◽  
Yuan Qu ◽  
bibo liang ◽  
Qing-Hong Yu ◽  
...  
Keyword(s):  
Bone Turnover ◽  
Age Groups ◽  
Cross Sectional Study ◽  
Sectional Study ◽  
Cross Sectional ◽  
Age And Gender ◽  
Metabolic Markers ◽  
The Difference ◽  
Highly Correlated ◽  
And Gender

Abstract Background: Bone turnover and metabolic indicators are related to age and gender. Age and gender should be matched in subjects in disease control research of bone turnover and metabolism, but strict matching of gender and age increases the difficulty and cost of the research. Therefore, the aim of this study was to solve the question of whether it is necessary to strictly match age and gender in clinical research in bone metabolism.METHODS: Patient data were extracted from the HIS of ZhuJiang Hospital, Southern Medical University. From these data, a cross-sectional study was conducted. Data relating to seven bone turnover and metabolic indicators from 1036 patients between January 2018 and October 2019 were analyzed. A total of 156 patients aged under 20 were identified and analyzed separately. RESULTS: P1NP, β-CTx and 25(OH)D were significant different in individuals younger than 20 years of age. ALP was significantly higher in those under 20 years of age and lower at age 20-39 compared with other age groups. The concentrations of Ca and P were different among the groups aged 0-19, 20-39, and 40-59 years of age groups but exhibited no difference above 60 years of age. PTH expression was not dependent on age. P1NP, β-CTx and PTH concentrations were not significantly different between the genders within the same age group. ALP was significantly different between genders within the age range 20-59 years. Ca and 25(OH)D were significantly different between the genders for those older than 60. Serum P was significantly different in the two genders for those aged 40-79. CONCLUSION: P1NP and β-CTx were highly correlated with age. If these two indictors require analysis in a case control study, the patients and controls should be strictly matched by age under 20 years. The demarcation point for ALP was 40 years of age. Ca and P were strongly recommended strict matching according to age in disease research. The difference in P1NP, β-CTx, 25(OH)D and ALP between genders depends on age differences.

scholarly journals Orientation-Specific Visual Evoked Potential Deficits in Multiple Sclerosis

1982 ◽  
Vol 9 (3) ◽  
pp. 331-337 ◽  
Author(s):  
Stuart G. Coupland ◽  
Trevor H. Kirkham
Keyword(s):  
Multiple Sclerosis ◽  
Visual Evoked Potential ◽  
Evoked Potential ◽  
Diagnostic Yield ◽  
Pattern Reversal ◽  
Checkerboard Pattern ◽  
Individual Subject ◽  
Subject Analysis ◽  
Check Condition ◽  
Visual Evoked

SUMMARY:Checkerboard pattern reversal visual evoked potentials (VEPs) have proved useful in the confirmation of optic nerve disease in patients with multiple sclerosis (MS). Recently, evidence of orientation-specific loss in contrast sensitivity and the presence of orientation-specific visual evoked potential (VEP) deficits in MS patients has been obtained using sinusoidal gratings as stimuli. This study reports the presence of orientation-specific VEP delay in MS using the conventional checkerboard pattern presented in two orientations: normally oriented (check condition) or diagonally oriented (diamond condition).Peak latency values of the N70 and P100 components of the VEP were statistically analyzed using appropriate ANOVA and nonparametric statistics. As a group MS patients showed significant VEP delays under check and diamond pattern conditions. However, individual subject analysis revealed that about 20% of the MS population show VEP delay to only one pattern orientation. It was shown that by including a diamond pattern condition the diagnostic yield of VEP delay in these clinically definite MS patients was increased 11% over that obtained with check stimulation alone.

>Checkerboard Visual Evoked Response in Evaluation and Management of Pituitary Tumors

Neurosurgery ◽  
1979 ◽  
Vol 5 (5) ◽  
pp. 553-558 ◽  
Author(s):  
Peggy S. Gott ◽  
Martin H. Weiss ◽  
Michael Apuzzo ◽  
Joseph P. Van Der Meulen
Keyword(s):  
Visual System ◽  
Pituitary Tumor ◽  
Visual Fields ◽  
Pattern Reversal ◽  
Checkerboard Pattern ◽  
Evoked Responses ◽  
Visual Evoked Response ◽  
Visual Evoked Responses ◽  
Suprasellar Extension ◽  
Visual Evoked

Abstract As a routine part of the evaluation of patients with pituitary tumor, visual evoked responses (VERs) to checkerboard pattern reversal were recorded from 83 patients with tomographically documented pituitary tumor. VER tests were correlated with examinations of visual acuity, color perception, and visual fields and with computerized tomographic scan evidence of suprasellar extension of the tumor. The purpose of the VER recording was to determine the presence of visual system compression by the tumor and thus contribute to the decision of whether surgery was necessary. Each of the patients who had suprasellar extension of the tumor sufficient to produce a visual field abnormality also had an abnormal VER. In addition, some patients with suprasellar extension had normal visual fields but abnormal visual evoked responses. Thus, the VER provided earlier evidence of suprasellar extension causing visual system compromise than did conventional visual tests.

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