scholarly journals Measuring Latency Variations in Evoked Potential Components Using a Simple Autocorrelation Technique

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Jackie Campbell ◽  
Massimo Leandri
Keyword(s):  
Nervous System ◽  
Evoked Potentials ◽  
Somatosensory Evoked Potentials ◽  
Evoked Potential ◽  
Time Windows ◽  
Clinical Use ◽  
Noise Component ◽  
Additional Information ◽  
Latency Jitter ◽  
Potential Recording

Interpretation of averaged evoked potentials is difficult when the time relationship between stimulus and response is not constant. Later components are more prone to latency jitter, making them insufficiently reliable for routine clinical use even though they could contribute to greater understanding of the functioning of polysynaptic components of the afferent nervous system. This study is aimed at providing a simple but effective method of identifying and quantifying latency jitter in averaged evoked potentials. Autocorrelation techniques were applied within defined time windows on simulated jittered signals embedded within the noise component of recorded evoked potentials and on real examples of somatosensory evoked potentials. We demonstrated that the technique accurately identifies the distribution and maximum levels of jitter of the simulated components and clearly identifies the jitter properties of real evoked potential recording components. This method is designed to complement the conventional analytical methods used in neurophysiological practice to provide valuable additional information about the distribution of latency jitter within an averaged evoked potential. It will be useful for the assessment of the reliability of averaged components and will aid the interpretation of longer-latency, polysynaptic components such as those found in nociceptive evoked potentials.

The Spread of Somatosensory-Evoked Potentials Within the Nervous System

1985 ◽  
Vol 48 (1-6) ◽  
pp. 222-225
Author(s):  
A. Sólyom ◽  
S. Tóth ◽  
I. Holczinger ◽  
J. Vajda ◽  
Z. Tóth ◽  
...  
Keyword(s):  
Nervous System ◽  
Evoked Potentials ◽  
Somatosensory Evoked Potentials

Scalp topography of the short-latency components of the respiratory-related evoked potential in children

1996 ◽  
Vol 80 (5) ◽  
pp. 1785-1791 ◽  
Author(s):  
P. W. Davenport ◽  
I. M. Colrain ◽  
P. M. Hill
Keyword(s):  
Evoked Potentials ◽  
Somatosensory Evoked Potentials ◽  
Evoked Potential ◽  
Central Sulcus ◽  
Normal Children ◽  
Polarity Inversion ◽  
Negative Peak ◽  
Scalp Topography ◽  
Scalp Distribution ◽  
Latency Range

Respiratory-related evoked potentials (RREPs) have been elicited by inspiratory occlusion and recorded at electroencephalographic (EEG) sites overlying the somatosensory cortex in adults. The present study was the first to be conducted in normal children and was designed to identify the scalp distribution of the early RREP components. EEG responses to occlusion were recorded from CZ-C3, CZ-C4, and 17 sites referenced to the linked earlobes. The RREP was observed in all subjects in the CZ-C3 and CZ-C4 electrode pairs. The earlobe-referenced recordings revealed two RREP patterns. The P1 and N1 peaks were found in C3, C4, P3, P4, T3, and T4. The RREPs recorded from the F3, F4, F7, and F8 electrodes did not exhibit either the P1 or N1 peaks. A negative peak (NF) occurred approximately 13 ms after the P1 peak. The results show that the RREPs to inspiratory occlusions were present bilaterally but diminished greatly over midline sites. Furthermore, consistent with mechanically and electrically elicited somatosensory evoked potentials, the RREP displayed a polarity inversion over the central sulcus in the early component latency range.

scholarly journals Cortical Evoked Potentials in Children of Diabetic Mothers

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Mario Brinciotti ◽  
Angela Napoli ◽  
Antonio Mittica ◽  
Olimpia Bitterman ◽  
Maria Matricardi
Keyword(s):  
Evoked Potentials ◽  
Metabolic Control ◽  
Somatosensory Evoked Potentials ◽  
Visual Evoked Potential ◽  
Evoked Potential ◽  
Mean Value ◽  
Evoked Responses ◽  
The Mean ◽  
Diabetic Mothers

Type 1 diabetic mothers' infants show a delay of visual evoked potential (VEP) significantly related to some parameters of poor metabolic control during pregnancy. In the present paper we analyzed the characteristics of VEPs and somatosensory evoked potentials (SEPs) recorded in 16 three-year-old type 1 diabetic mothers' children (DMC). Compared with controls (23 nondiabetic mothers' healthy matched children), DMC showed significantly delayed mean latency of VEP (P2) and SEP (P22). In 3 cases (19%), we found pathological responses (+3 SD from the mean value of controls) of VEPs and SEPs. At the age of 3 years, the offspring of type 1 diabetic mothers showed delay of cortical evoked responses in both visual and somatosensory systems.

scholarly journals A wireless marker system to enable evoked potential recordings using a wireless EEG system (EPOC) and a portable computer

2013 ◽  
Author(s):  
Johnson Thie
Keyword(s):  
Evoked Potentials ◽  
Evoked Potential ◽  
Low Cost ◽  
Setup Time ◽  
Checkerboard Pattern ◽  
Marker System ◽  
Potential Recording ◽  
Receiver Unit ◽  
Small Form Factor ◽  
Wireless Eeg

As wireless EEG devices have become affordable at low cost, have a small form factor and quick setup time, they can be deployed at universities and schools for teaching purposes. However they have not been applied for evoked potential recording since they lack an option to receive stimulus markers. Meanwhile evoked potential recording is required for functional assessment of the sensory systems such as auditory and visual. This paper describes a wireless system that embeds information about the stimulus in the EEG channels. The transmitter unit is connected to the stimulus device to detect the stimulus and transmit the stimulus information to the receiver unit. The receiver unit attached to two of the EEG electrodes decodes the information and generates a pulse across the electrodes. The pulse width conveys the information about the stimulus. Hence the stimuli are synchronised with the EEG data allowing users to evaluate the evoked potentials in the offline processing. The wireless marker system was verified with audio stimuli consisting of 1000Hz and 1200Hz tones and reliably generated pulses with 100ms and 200ms width respectively. The delay between the onset of the tone and the onset of the pulse was 19.3 +/- 0.1ms. Since the variability of the delay was under 1ms and so negligible, the evoked potentials could be evaluated reliably. The evoked potential could be shifted back by 19.3ms to compensate for the delay. The system was also verified with a black-and-white checkerboard pattern stimuli and reliably generated pulses with 100ms width when the pattern reversed. The delay between the onset of the reversal and the onset of the pulse was 6.4ms. Similarly the variability of the delay was negligible.

scholarly journals Multimodal evoked potential abnormalities in patients with Wilson's disease

2005 ◽  
Vol 133 (7-8) ◽  
pp. 331-337 ◽  
Author(s):  
Tihomir Ilic ◽  
Marina Svetel ◽  
Stevan Petkovic ◽  
Vladimir Kostic
Keyword(s):  
Evoked Potentials ◽  
Visual Evoked Potentials ◽  
Somatosensory Evoked Potentials ◽  
Evoked Potential ◽  
Wilson’S Disease ◽  
Event Related Potentials ◽  
Wilson's Disease ◽  
Illness Duration ◽  
Functional Systems ◽  
Related Potentials

The aim of this study was to investigate the involvement of the following functional systems: somatosensory evoked potentials (SSEP), visual evoked potentials (VEP), and event related potentials (ERP), in twenty patients with Wilson's disease (WD). VEP and SSEP abnormalities were discovered in S patients respectively (40%), whereas ERP were either absent or, in the case of 10 patients (50%), had significantly prolonged P-300 latencies. Taken together, at least one evoked potential abnormality was discovered in 17 patients (85%]. Only in 3 patients (15%), involving either the isolated hepatic type of disease or short illness duration of the neurological type, were normal evoked potential findings observed. Our findings suggest the usefulness of multimodal evoked potential abnormalities in the evaluation of subclinical manifestations in patients with WD.

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