Short Latency Somatosensory Research Articles

Effect of guipizide maleate with hyperbaric oxygen therapy on neurophysiology and coagulation indices in patients with severe craniocerebral injury

Purpose: To assess the effect of guipizide maleate combined with hyperbaric oxygen therapy on neurophysiological and coagulation indices in patients with heavy craniocerebral injury.Methods: The study involved a total of 80 patients with craniocerebral injuries who were admitted to The 900th Hospital of China Joint Logistic Support Force, Fuzhou, China from January 2017 to June 2021. Patients were randomly divided into study group and a control group comprising 40 patients each. The study group received guipizidine maleate combined with hyperbaric oxygen therapy while control group received hyperbaric oxygen therapy. Differences in neurophysiological and coagulation indices were recorded for the two groups after treatment.Results: Short latency somatosensory evoked potential (SLSEP) N20 wave amplitude of the study group was significantly greater than that of control group (p < 0.05). At 3 months follow-up, Glasgow outcome score (GOS), Karnofsky performance status (KPS) score, and Barthel index in the study group were significantly lower than in control group (p < 0.05). The combined incidence of complications in the study group was 5 % (2/40), which was lower than in control group, 17.50 % (7/40)Conclusion: The combination of guipizide maleate with hyperbaric oxygen has good therapeutic effect on patients with severe craniocerebral injury. It significantly improves neuro-physiological and coagulation indices, reduces the incidence of complications during treatment, and improves neurological function. However, further clinical trials are required to validate these findings

Study of Short Latency Somatosensory and Brain Stem Auditory Evoked Potentials Patients with Acute Ischemic Stroke Involving Middle Cerebral Artery Territory.

Background The precise timings of evoked potentials in evaluating the functional outcome of stroke have remained indistinct. Few studies in the Indian context have studied the outcome of early prognosis of stroke utilizing evoked potentials. Objective The aim of this study was to determine somatosensory evoked potentials (SSEPs) and brain stem auditory evoked potentials (BAEPs), their timing and abnormalities in acute ischemic stroke involving the middle cerebral artery (MCA) territory and to correlate SSEP and BAEP with the functional outcome (National Institutes of Health Stroke Scale (NIHSS), modified Rankin scale (mRS) and Barthel’s index) at 3 months. Methods MCA territory involved acute ischemic stroke patients ( n = 30) presenting consecutively to the hospital within 3 days of symptoms onset were included. Details about clinical symptoms, neurological examination, treatment, NIHSS score, mRS scores were collected at the time of admission. All patients underwent imaging of the brain and were subjected to SSEP and BAEP on two occasions, first at 1 to 3 days and second at 4 to 7 days from the onset of stroke. At 3 months of follow-up, NIHSS, mRS, and Barthel’s index were recorded. Results P37 and N20 amplitude had a strong negative correlation (at 1–3 and 4–7 days) with NIHSS at admission, NIHSS at 3 months, mRS at admission, and mRS at 3 months and a significant positive correlation with Barthel’s index ( p < 0.0001). BAEP wave V had a negative correlation (at 1–3 and 4–7 days) with NIHSS at admission, NIHSS at 3 months, mRS at admission, and mRS at 3 months and a positive correlation with Barthel’s index ( p < 0.0001). Conclusion SSEP abnormalities recorded on days 4 to 7 from onset of stroke are more significant than those recorded within 1 to 3 days of onset of stroke; hence, the timing of 4 to 7 days after stroke onset can be considered as better for predicting functional outcome.

Neurophysiological parameters of sensory perception and cognition among different modalities of learners.

INTRODUCTION:Different types of learners based on sensory modalities are observed. Cognition or physiological alterations in the sensory pathways might play its role in different modalities of visual, auditory, read and write, and kinesthetic learners which are based on different sensory modalities of perceptionOBJECTIVE:The objective of this study is to ascertain an objective parameter (neurophysiological parameters) for the classification of learners based on their preferred sensory modalityMATERIALS AND METHODS:An experimental cross-sectional study was conducted among 100 medical students. Learners were classified into visual, auditory, read-write, and kinesthetic learners based on the interpretation drawn on the basis of the VARK questionnaire. Sensory-evoked potentials (SEPs), including pattern shift visual (PSVEPs), brain stem auditory (BAEPs), short-latency somatosensory (SSEP), and event-related potentials (P300) were measured. SEPs measured in microvolts were recorded from the scalp with the help of active and reference electrodes. Multiple responses to sensory stimuli (using NIHON KOHDEN Corporation Neuropack X1, Tokyo, Japan) were recored and averaged using the computerized signal averging technique.RESULTS:No statistically significant difference was observed in conduction velocities (in terms of latency and amplitude) of SEP among different type of learners, except latency N145 wave form in VEP (P < 0.05). A characteristic pattern of minimal comparative latency was observed among the majority of visual learners. Similary, P300 has shown a characteristic pattern of decreased comparative latency among majority of read and write learners.CONCLUSION:Study findings suggested that among existing teaching and learning modalities, visual modalities were observed faster but to retain it in memory and for abstract thinking, students should utilize read and writing skills which are lacking in the era of digitalization and overuse of electronic devices.

Effects of short-term immobilization of the upper limb on the somatosensory pathway: a study of short-latency somatosensory evoked potentials.

[Purpose] Previous studies have reported that the nervous system is influenced during short-term cast immobilization. However, the effects of short-term inactivity on somatosensory information processing systems are not well understood. This study investigated the effect of 10 h of upper limb immobilization on the somatosensory pathway using short-latency somatosensory evoked potentials. [Participants and Methods] Twenty right-handed healthy participants (mean age 21.7 years) were enrolled in this study. The participants’ left hands and forearms were wrapped in a soft bandage at a 90° elbow flexed position. The participants were instructed not to move their left hand for 10 h. To obtain short-latency somatosensory evoked potentials, we used a multimodal evoked potential system. The left median nerve was electrically stimulated at a rate of 5 Hz for a duration of 0.2 ms. The intensity of the stimulus was adjusted to induce mild twitches of the thumb. The amplitudes and latencies of the short-latency somatosensory evoked potential components (N9, N13, and N20) were measured before and after immobilization. [Results] The amplitude of the N9 component significantly increased after immobilization. [Conclusion] Our results indicated that the changes in the excitability of the peripheral somatosensory nerve were due to 10 h of inactivity.

The determination of brain death in coma children with Glasgow coma scale score 3

Objective To summarize the clinical features and technical key points on brain death during decision-made process in children with suspected brain death. Methods Twenty-four coma children with Glasgow coma scale score 3 and no spontaneous respiration were collected from May 2015 to February 2017 in Beijing Children′s Hospital, Capital Medical University to make the brain death determination.All children received at least one confirmatory test.According to the Chinese standards for determining brain death (pediatric), all patients were divided into brain death group and non-compliance group.The clinical features were analyzed.The sensitivity, specificity, false positive rate and false negative rate of electroencephalogram (EEG), short latency somatosensory evoked potential (SLSEP) and transcranial Doppler sonography (TCD) were calculated. Results Among these 24 cases, there were 16 males and 8 females, aged 5.6 (2.0, 8.8) years old.Ten cases met the criteria of brain death.Twelve (50%, 12/24 cases) cases received autonomic breathing test.A total of 25 tests were conducted, of which 21 were successful.The completion rates of EEG, TCD and SLSEP were 100.0% (24/24 cases), 83.3% (20/24 cases) and 54.2% (13/24 cases), respectively.EEG had the highest sensitivity (100%) and specificity (79%). SLSEP had good sensitivity (100%), but the specificity was only 40%.The combination of EEG with SLSEP had the highest specificity and sensitivity, both of which were 100%, and the false positive rate and false negative rate were 0. Conclusions The key to determine brain death successfully is to make adequate preparations, to receive formal training and to apply standard operation.In the determination of brain death in children, EEG has a good sensitivity and specificity in single confirmation test, which is the priority item.The combination of EEG with SLSEP is the most advantageous. Key words: Glasgow coma scale; Coma; Child; Brain death

Short-Latency Somatosensory Evoked Potentials in Restless Leg Syndrome

Short-Latency Somatosensory Evoked Potentials in Restless Leg Syndrome

The role of middle latency evoked potentials in early prediction of favorable outcomes among patients with severe ischemic brain injuries

ObjectiveTo explore the role of middle latency evoked potentials (EPs) as predictors for favorable outcome in patients with severe ischemic brain injuries by comparing the prognostic ability of short latency somatosensory and auditory evoked potentials (SLSEP and BAEP) with middle latency somatosensory and auditory evoked potentials (MLSEP and MLAEP). MethodsMLSEP, MLAEP, SLSEP and BAEP were recorded in 112 patients with severe ischemic brain injuries (Glasgow Coma Scale≤8). Among them, 83 patients suffered from cerebral ischemic stroke and 29 suffered from anoxic–ischemic encephalopathy after cardiopulmonary resuscitation between 1 and 7days after the onset of stroke. Outcomes were reviewed 6months later using the Glasgow Outcome Scale (GOS). A GOS score of 4–5 was considered as a good outcome while a score of 1–3 was considered as poor. ResultsBy using the prognostic authenticity analysis of predictors for good outcome, at least unilateral N20 of the SLSEP exit and at least unilateral N60 of the MLSEP exit showed the highest sensitivity which was 100% (95% CI: 86.7%–100%). The bilateral normal N60 showed a high specificity of 97.5% (95% CI: 90.4%–99.6%). It also showed the highest positive likelihood ratio of 6.25% (95% CI: 1.28%–30.59%), which was superior to N20 of SLSEP, V of BAEP, and Pa of MLAEP. The analysis demonstrated that the area under the curve for MLSEP grading was the highest (0.838) compared to that of SLSEP grading (0.784), MLAEP grading (0.659) and BAEP grading (0.621). ConclusionsCompared with using N20 of SLSEP analysis alone, adding MLSEP improves the outcome prediction in patients with severe ischemic brain injuries. When an outcome is uncertain after initial evaluation using short-latency EPs, MLSEP is valuable to be used from the first week to further improve prognostication in these patients.

Brainstem lesions may be important in the development of epilepsy in multiple sclerosis patients: An evoked potential study

Objective Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system, with epileptic seizures sometimes observed in the same patients. In this study, we used evoked responses to study the pathogenesis of epilepsy in MS. Methods Patients with a diagnosis of definite MS and who had EPs performed (visual (VEP), brainstem auditory (BAEP) and short latency somatosensory (upper (USSEP) and lower (LSSEP))) were retrospectively included in this study. They were divided into three groups; Group I: Patients with no epilepsy and who were not taking anti-epileptic drugs (AED); Group II: Patients with epilepsy and taking AEDs; and Group III: Patients with no epilepsy who were taking AEDs for symptoms related to neuropathic pain. Results Three hundred and fifty-five patients were included in this study; Group I: 229 patients (64.5%), Group II: 20 patients (5.6%) and Group III: 106 patients (29.9%). The proportion of patients with abnormal BAEP and USSEP was higher in Group II. Conclusions A positive association exists between the presence of epilepsy in MS patients and BAEP and USSEP abnormalities. Analysis of Group III ruled out AED use as a factor. Significance Brainstem lesions may be the cause of epileptogenicity in MS.

The value of brainstem auditory evoked potential and lower limb short latency somatosensory evoked potential for predicting delayed encephalopathy after acute carbon monoxide poisoning

Objective To observe the changes of brainstem auditory evoked potential (BAEP) and lower limb short latency somatosensory evoked potential ( SLSEP) in acute carbon monoxide poisoning patients and explore the predictive value of BAEP and SLSEP for delayed encephalopathy after acute carbon monoxide poisoning (DEACMP). Methods Sixty-six acute CO poisoning patients was divided into a DEACMP group and a non-DEACMP group according to their symptoms. At the same time, 60 healthy subjects were included in the control group. BAEP and lower limb SLSEP dynamic testing were conducted at different time points. Results The abnormal rates in the first test of BAEP and lower limb SLSEP in the acute CO poisoning patients were 31.8% and 68.2% respectively.The BAEP results in the acute stage and later in the DEACMP group were comparable to those of the non-DEACMP group and the normal control group. Interpeak latency of Ⅰ-Ⅲ was not significantly different, but the remaining indices were significantly longer. Compared to the control group, the lower limb SLSEP readings in the acute DEACMP group and the non-DEACMP group were significantly longer. Compared to the non-DEACMP group and the control group, the SLSEP results of the DEACMP group were significantly extended. The specificity index of the BAEP predicted DEACMP up to 85.7% , significantly more than SLSEP testing. Conclusions Early detection of BAEP can help predict DEACMP. This finding should be promulgated and applied. Key words: Brainstem auditory evoked potential; Lower limb somatosensory evoked potential; Acute carbon monoxide poisoning; Delayed encephalopathy; Prediction

Two Patients with Congenital Insensitivity to Pain with Anhidrosis Showing Marked Prolongation of Central Conduction Time in Short Latency Somatosensory Evoked Potential

Two Patients with Congenital Insensitivity to Pain with Anhidrosis Showing Marked Prolongation of Central Conduction Time in Short Latency Somatosensory Evoked Potential

New depth short-latency somatosensory evoked potential (SEP) component recorded in human SI area

To analyse short and long-latency (SEPs) recorded by chronically stereotactically electrodes implanted in SI area of two epileptic patients. Two drug-resistant epileptic patients (2 females, 38 and 15 years, respectively) suffering from left temporal and right frontal epilepsy respectively, were investigated by an electrode-chronically implanted in SI area. Short and long latency somatosensory evoked potentials were recorded by depth electrodes 10 days after implantation. This is the first study to describe a depth N36 response by an intracerebral recording electrode in the SI area, probably generated by a radially oriented generator, located in area 1. Furthermore, we confirmed a role of SI in the genesis of N60 component. Finally, our present data suggest that the SI area is still active at 120 ms after the stimulus, since in one patient (no. 2) we identified a N120 potential, reaching its maximal amplitude at the same depth as the N20 response.

Motor and somatosensory evoked potentials in Autosomal Dominant Hereditary Spastic Paraparesis (ADHSP) linked to chromosome 2p, SPG4

The aim of our study was to evaluate Motor Evoked Potentials (MEPs) and cortical excitability, using Transcranial Magnetic Stimulation (TMS) as well as short latency Somatosensory Evoked Potentials (SEPs) in Autosomal Dominant Hereditary Spastic Paraparesis (ADHSP) patients. MEPs were recorded from upper and lower limb muscles in 12 patients (7 m and 5 f) affected by ADHSP with spastin mutation (SPG4). We measured: (i) motor threshold (MTh); (ii) total motor conduction time (TMCT); (iii) direct and indirect central motor conduction time (d-CMCT and i-CMCT) calculated by subtracting from the cortical latency those obtained on magnetic spinal stimulation (d-PMCT) and via the F-wave method (i-PMCT); (iv) MEP amplitude (MEP/Mmax ratio%) and (v) duration of the cortical silent period (CSP). Latency, amplitude and persistence of the F-wave obtained with electrical nerve stimulation were also considered; H reflex was also tested from lower extremities. SEPs were recorded from spine and scalp sites following median and posterior tibial nerve stimulation; conventional latency and amplitude measurements were performed. In a comparison with the control group, the MTh recording from lower limbs was significantly higher (67.5 ± 7.7% versus 52.5 ± 6.9%), MEPs were absent in one case and showed reduced amplitude in the remainders (22.9 ± 12.6% versus 66.3 ± 25.9% of M wave); TMCT resulted to be abnormal (36.5 ± 3.9 ms versus 27.1 ± 1.4 ms) and d-CMCT as well as i-CMCT were significantly prolonged (23.1 ± 3.5 ms versus 13.8 ± 1.3 ms; and 20.1 ± 3.4 ms versus 10.6 ± 1.3 ms, respectively). The CSP, which was normal from the hands, was significantly shortened from the legs and correlated with spasticity scoring (Ashworth scale). Cortical SEPs from lower limbs were abnormal in all cases, whereas SEPs by stimulation of median nerves were normal; F-wave parameters from upper limbs showed no abnormalities, whereas an increased persistence was detected from lower limbs; H reflex amplitudes resulted larger compared with controls. Moreover, shortening of the CSP, being correlated with the Ashworth scale, can be considered an electrophysiological marker of spasticity that seems to arise from impairment of the supraspinal or intracortical inhibitory pathways with an additional contribution of increased segmental motor neuron excitability. These data prove the existence of comparable neurophysiological abnormalities in ADHSP with spastin mutation (SPG4) when long ascending and descending pathways are involved.

SSEPs and prognosis in postanoxic coma: Only short or also long latency responses?

Background: Short latency somatosensory evoked potential (SSEP) (N20) is a good predictor of poor outcome in postanoxic coma. It has been suggested that the long latency response (N70) may increase the sensitivity of SSEPs for predicting poor outcome. Methods: As part of a prospective cohort study in 407 adult patients unconscious 24 hours after cardiopulmonary resuscitation (CPR), N20 was recorded 24, 48, and 72 hours after CPR, and N70 was recorded at least once in 319 patients. Poor outcome was defined as death or persistent vegetative state 1 month after CPR. Results: Absent N20 had a 0% false positive test rate at all time intervals, with prevalence of poor test result varying from 37 to 48%. Addition of abnormal N70 (absent or delayed > 130 msec) with present N20 as poor test result added 21 to 28% to this prevalence, but at the cost of a false positive test rate of 4 to 15%. Good outcome could not be predicted reliably with either of the tests, as only 28% of patients with normal N20 and N70 had a good outcome. Conclusion: Determination of presence or absence of the N70 in patients with postanoxic coma gives additional information about the likelihood of poor outcome, but it is not precise enough to base treatment decisions solely on its absence.

Somatosensory amplification and its relationship to somatosensory, auditory, and visual evoked and event-related potentials (P300)

Somatosensory amplification refers to the tendency to experience benign and ambiguous somatic sensation as intense, noxious, and disturbing. The construct is helpful in assessing the perceptual style of a variety of somatizing conditions, but there is no human study clarifying the effects of neurological function on somatosensory amplification. The present study examines the relationship between somatosensory amplification and different types of evoked potentials. In 33 healthy volunteers (mean age 24 years, 18 men), latencies and amplitudes were recorded using the following parameters: short-latency somatosensory, brainstem-auditory, and visual evoked potentials (SSEP, BAEP, and VEP, respectively) and auditory event-related potentials (ERP). All subjects completed questionnaires for the Somatosensory Amplification Scale (SSAS), 20-item Toronto Alexithymia Scale (TAS-20), and Profile of Mood State (POMS). The SSAS scores were significantly associated with the P200 latency ( p = 0.020) and P300 amplitude of ERP ( p = 0.041), controlling for the significant effect of the TAS and POMS depression and tension–anxiety scales. The SSEP, BAEP, and VEP latencies or amplitudes were not statistically significant (all p > 0.05). When the subjects were divided into high and low SSAS groups based on the median of the SSAS scores, the P300 amplitude of ERP significantly discriminated the two groups ( p = 0.023) by multiple logistic regression analysis. Although the findings should be viewed as preliminary because of the small sample size, somatosensory amplification appears to reflect some aspects of long-latency cognitive processing rather than short-latency interceptive sensitivity from the viewpoint of encephalography.

SSEPs and prognosis in postanoxic coma

Short latency somatosensory evoked potential (SSEP) (N20) is a good predictor of poor outcome in postanoxic coma. It has been suggested that the long latency response (N70) may increase the sensitivity of SSEPs for predicting poor outcome. As part of a prospective cohort study in 407 adult patients unconscious 24 hours after cardiopulmonary resuscitation (CPR), N20 was recorded 24, 48, and 72 hours after CPR, and N70 was recorded at least once in 319 patients. Poor outcome was defined as death or persistent vegetative state 1 month after CPR. Absent N20 had a 0% false positive test rate at all time intervals, with prevalence of poor test result varying from 37 to 48%. Addition of abnormal N70 (absent or delayed > 130 msec) with present N20 as poor test result added 21 to 28% to this prevalence, but at the cost of a false positive test rate of 4 to 15%. Good outcome could not be predicted reliably with either of the tests, as only 28% of patients with normal N20 and N70 had a good outcome. Determination of presence or absence of the N70 in patients with postanoxic coma gives additional information about the likelihood of poor outcome, but it is not precise enough to base treatment decisions solely on its absence.

Effect of Kudzuvine root in improving neuroelectrophysiological function of brain in patients with diabetes mellitus type 2

Objective: To investigate the effects of kudzuvine root on 3 kinds of brain evoked potential in patients with diabetes mellitus type 2 (DM2).Methods: Forty-six cases of DM2 were randomized into two groups: the control group and the treatment group, they were respectively treated orally with 50 ml of normal saline or 50ml of kudzuvine root decoction containing kudzuvine root 0.4 g/ml. The short latency somatosensory evoked potential (SSEP), brainstem auditory evoked potential (BAEP) and visual evoked potential (VEP) in patients were measured before and 40 min after treatment.Results: (1) SSEP in the control group was not changed significantly before and after taking normal saline (P>0.05), while in the treatment group there appeared a significant delay in peak latency (PL) of N13 wave (N13PL) and a significant shortening in N20PL and interpeak latency (IPL) between N13 wave and N20 wave (N13-N20 IPL) after kudzuvine treatment (P 0.05). (2) BAEP in the control group was not changed significantly after treatment (P>0.05), while in the treatment group I-III IPL and I-V IPL were significantly shortened, showing significant difference as compared with those in the control group (bothP 0.05), while in the treatment group the amplitude of P100 wave increased obviously (P 0.05).Conclusion: Kudzuvine could shorten the latent period of brain evoked potential and the central transmission time, increase the amplitude of cortex wave and turn it back to normal, thus to effectively protect and accommodate the brain function in patients with DM2.

Clinical and neuroimaging correlates of abnormal short-latency Somatosensory Evoked Potentials in elderly vascular dementia patients: A psychophysiological exploratory study.

BackgroundShort Latency Somatosensory Evoked Potentials (SEPs) may serve to the testing of the somatosensory tract function, which is vulnerable and affected in vascular encephalopathy. The aim of the current study was to search for clinical and neuroimaging correlates of abnormal SEPs in vascular dementia (VD) patients.Materials and MethodsThe study included 14 VD patients, aged 72.93 ± 4.73 years, and 10 controls aged 71.20 ± 4.44 years. All subjects underwent a detailed clinical examination, blood and biochemical testing, brain MRI and were assessed with the MMSE. SEPs were recorded after stimulation from upper and lower limbs. The statistical Analysis included 1 and 2-way MANCOVAs and Factor analysisResultsThe N13 latency was significantly prolonged, the N19 amplitude was lower, the P27 amplitude was lower and the N11-P27 conduction time was prolonged in severely demented patients in comparison to controls. The N19 latency was prolonged in severely demented patients in comparison to both mildly demented and controls. The same was true for the N13-N19 conduction time, and for the P27 latency. Patients with subcortical lesions had all their latencies prolonged and lower P27 amplitude.DiscussionThe results of the current study suggest that there are significant differences between patients suffering from VD and healthy controls in SEPs, but these are detectable only when dementia is severe or there are lesions located in the subcortical regions. The results of the current study locate the abnormal SEPs in the white matter, and are in accord with the literature.

N10 potential as an antidromic motor evoked potential in a median nerve short-latency somatosensory evoked potential study.

When stimulating the mixed nerve to record evoked potential, both sensory and motor fibers are activated before entering the spinal cord. The N10 potential has been described as an antidromic motor evoked potential based on results obtained by recording at the anterior midneck. In the present study, we examined the changes in latencies of Erb's potential, N10, and N13 by stimulating the median nerve distally at the wrist and proximally at the elbow. The conduction velocity of N10 calculated by the difference between N10 latencies at the two stimulation points was consistent with motor conduction velocity, although N13 conduction velocity estimated by the same method reflected a sensory conduction velocity. A positive relation was also observed between the indirect latency from the stimulation point to the anterior root as calculated using the equation (F - M - 1) / 2 (ms) and the direct latency to the negative peak of the N10 potential. Our data support the notion that N10 represents antidromic motor potential originating in the spinal entry zone of the anterior root.

Clinical Application of Short Latency Somatosensory Evoked Potentials in Cervical Myelopathy

Clinical Application of Short Latency Somatosensory Evoked Potentials in Cervical Myelopathy

Electrodiagnosis of the Spinal Cord Using the Motor Evoked Potentials and Short Latency Somatosensory Potentials in Patients with Cervical Myelopathy

Electrodiagnosis of the Spinal Cord Using the Motor Evoked Potentials and Short Latency Somatosensory Potentials in Patients with Cervical Myelopathy