Abnormal Latency Research Articles

Cortical Auditory Evoked Potentials in Children with Auditory Neuropathy/Dys-Synchrony.

Auditory neuropathy/spectrum disorder (ANSD), also referred to as auditory neuropathy/dys-synchrony (AN/AD) is a recently described form of hearing impairment. Many studies have shown that changing the pattern of afferent input to the cortex significantly affects cortical organization and there is little studies about cortical neuromaturation and plasticity in children with ANSD. Study of P1 component of cortical auditory evoked potentials (CAEPs) in children with ANSD. This survey was descriptive cross-sectional. During that 97 hearing impairment children were under hearing screening tests. Of these, 14 selected subjects (ear = 28) diagnosed with ANSD (an average age of 8.5years) and evaluated by P1 component of CAEPs. Based on latency results of p1 wave, the ears of the subjects fell into two seperate groups: Control (normal: n = 10) and case {total: n = 18 (delayed: n = 12) + (absent: n = 6)}. The averages of mean latency of P1 components of the case group in the right and the left ears compared to the control group had significant differences (p < 0.05). Abnormal latency of p1 component in ANSD children shows the possibility of different scales of disturbances in cortical auditory maturation and grow.

Cranial ultrasound and neurophysiological testing to predict neurological outcome in infants born very preterm.

Infants born preterm are at risk of cerebral palsy (CP) and motor or cognitive developmental delay. For clinicians, it is essential to know the relative predictive accuracy of the most commonly used neuroimaging and neurophysiological tests for the early prediction of adverse neurodevelopmental outcome. The aim of this study was to compare the accuracy of these tests in survivors of a population of infants born very preterm. A retrospective cohort study was performed in 163 children born before 32 weeks gestational age. We compared the accuracy in predicting adverse neurodevelopmental outcome at the age of 2 years 6 months of early and late cranial ultrasound (CUS), magnetic resonance imaging, somatosensory evoked potentials after stimulation of the posterior tibial nerve, and electroencephalography by calculating positive and negative likelihood ratios. An abnormal early CUS is the best predictor of the presence of CP (positive likelihood ratio 6.09), motor developmental delay (positive likelihood ratio 3.11), and cognitive developmental delay (positive likelihood ratio 5.66). Overall, negative likelihood ratios were poor, ranging between 0.49 and 0.98, meaning that a normal test result had only minimal influence on the probability of adverse neurological outcome. None of the diagnostic tests had a good performance in predicting future neurodevelopmental problems in infants born preterm. A normal test result provided very little clinically useful information. An abnormal early cranial ultrasound (positive test result) is the best predictor of adverse neurodevelopmental outcome. All negative results have poor predictive value of future neurodevelopmental problems.

Correlation between clinical and electrophysiological findings of carpal tunnel syndrome

Objective: correlate between clinical and electrophysiological findings of carpal tunnel syndrome Methods: cross sectional study at outpatient setting.109 patients (83females, 26males) with clinical manifestations of carpal tunnel syndrome participated in the study. All the patients had the following: Medical history and neurological examination including Tinel’s sign and Phalen test and nerve conduction studies including median-ulnar, median -radial comparative studies and electromyography of both upper extremities. Results: mean age 57.71±13.4. pain was mild in 9.2%, moderate in 25.7% and severe in 56% of patients. Numbness was present in 87.2%. Impaired sensory exam in 43.1% Impaired motor exam in 8.3%. Positive Tinel’s sign unilateral (38.5%) and bilateral (47.7%). Positive Phalen test unilateral (30.3%) and bilateral (34.9%). Unilateral thenar Muscle wasting in 4.6% and bilateral in 1.8%. Pure sensory median neuropathy was found in 65 patients (59.6%), sensory motor median neuropathy in 44 patients (40.37%). Demyelinating neuropathy in 91.7% and demyelinating-axonal neuropathy in 8.3% of patients. Abnormal distal motor latency was significantly correlated with severity of pain p=0.0025, impaired sensory exam p=0.0001, impaired motor exam p=0.0001, positive Tinel’s sign of both hands p=0.0001, positive Phalen test of both hands p=0.0001. as well as with unilateral or bilateral muscle wasting p=0.001. Prolonged peak median sensory latency was significantly correlated with numbness p=0.0001, severity of pain p=0.001, Impaired sensory exam p=0.005, positive Tinel’s sign for either one or both hands p=0.0001, positive Phalen test of one or both hands p=0.0001 Conclusion: Highly significant correlation was found between subjective and objective sensory manifestation and peak median sensory latency. While distal motor latency were significantly correlated with severe pain, only bilateral positive Tinel’s sign and Bilateral Phalen test and the objective sensory and motor deficit.

A Median Nerve Anterior Transposition Procedure for Multi-Recurrent Hemodialysis-Related Carpal Tunnel Syndrome.

Some long-term hemodialysis patients suffer from multi-recurrent carpal tunnel syndrome because amyloid originating from β2-microglobulin continues to be deposited mainly in the flexor tendons, tendon sheaths and flexor retinaculum during maintenance hemodialysis. These amyloid deposits inside carpal canal (tunnel) tissues increase carpal canal pressure and this leads to compression of the median nerve. When multi-recurrent carpal tunnel syndrome occurs, previous operative scarring of soft tissue may prohibit further enlargement of the carpal canal even if any carpal canal decompression procedure is used. For this reason, we developed a median nerve anterior transposition procedure, as a new approach in the treatment of multi-recurrent hemodialysis-related carpal tunnel syndrome. Median nerve anterior transposition procedures were performed on seven hands in six patients with multi-recurrent carpal tunnel syndrome. The mean age of the patients was 68.3 years and the mean hemodialysis duration was 35.3 years. Mean follow-up period was 9.9 months. The median nerve is transposed from inside to outside of the carpal canal under local and infiltration anesthesia without a pneumatic tourniquet on an outpatient basis. This procedure is based on the same principles applied in ulnar nerve anterior transposition procedures for cubital tunnel syndrome. Main preoperative patient complaints were intolerable tingling and/or pain in the diseased hands throughout the day. Following the surgeries, preoperative clinical symptoms began to subside and eventually improved in all hands. Postoperative abductor pollicis brevis muscle power using manual muscle testing improved except in one hand. Abnormal preoperative distal motor and sensory latency were improved except in two hands following the surgeries. The median nerve anterior transposition procedure is a beneficial treatment for patients suffering from hemodialysis-related multi-recurrent carpal tunnel syndrome.

Visual evoked potentials in women with and without preeclampsia during pregnancy and postpartum.

Preeclampsia is a severe hypertensive disorder of pregnancy which may lead to brain complications such as eclampsia. Visual symptoms are present in ∼25% of preeclamptic women suggesting the visual cortex to be altered during preeclampsia. Visual evoked potentials (VEPs) measure the functional neuronal integrity of the visual pathway from retina to the occipital cortex of the brain. The objective of this study was to compare neurophysiological changes in women with preeclampsia and other hypertensive disorders of pregnancy, using VEPs. We hypothesized that women with preeclampsia and other hypertensive disorders of pregnancy develop abnormal latency and amplitude of VEPs as compared with normotensive pregnant women. We performed a prospective observational study in 15 women with mild preeclampsia, 33 with severe preeclampsia (sPE), eight women with chronic hypertension, nine with pregnancy-induced hypertension, and 29 normotensive pregnant women. VEP measurements were made at four different time points of gestation (12-14 weeks, 26-28 weeks, 32-34 weeks, 36-40 weeks) and 6-8 weeks postpartum. We defined reference values for normotensive pregnant women. Normotensive pregnant women had a shorter latency during pregnancy compared to their postpartum value (P = 0.005). Women with sPE had a prolonged latency of VEPs compared with normotensive pregnant women (P = 0.006), a difference that disappeared postpartum. Our study showed neurophysiological adaptation to pregnancy of the visual cortex in normotensive pregnant women, that seemed to be absent in women with sPE. The study groups of women with chronic hypertension and pregnancy-induced hypertension were to small to draw any conslusions from.

Association of Diopsys® Short-duration Transient Visual Evoked Potential Latency with Visual Field Progression in Chronic Glaucoma.

ABSTRACTAimTo determine the association of Diopsys® NOVA-LX amplitude and latency abnormality scores with perimetric staging of chronic glaucoma, and to explore potential single-visit short-duration transient visual evoked potential (SD-tVEP) trend detection ability utilizing Humphrey 30-2 field progression data.Materials and methodsSetting: Glaucoma subspecialty clinic. Participants: Treated adult chronic glaucoma patients undergoing SD-tVEP evaluation. Main outcome measures: (1) Proportion of eyes designated as suspect or abnormal by the NOVA-LX multifactorial algorithm were determined as a function of glaucoma severity using the most recent Humphrey visual field analyzer (HVFA) 30-2 field. (2) Association between long-term HVFA-guided progression analysis (GPA) annual slopes and SD-tVEP abnormality was assessed to determine whether a single VEP test might help to identify eyes more prone to progressive visual field (VF) loss.ResultsOne hundred and thirty-three eyes of 84 patients (mean age 68 years) were analyzed. The SD-tVEP abnormality increased proportionately with severity of VF loss under high-contrast (Hc) test conditions for both latency (p = 0.001) and amplitude (p < 0.01). The HVFA progression analysis printouts existed for 91 eyes (mean 12.3 fields per eye/range 5-18). Nearly three-quarters (72.5%) of eyes with mean annual HVFA progression >0.7 dB/year (n = 29) had single-visit VEP latency abnormalities. Fewer than half (46.7%) of the remainder (n = 62) showed latency abnormality. Mean progression for eyes with abnormal vs normal VEP latency was -0.87 ± 0.3 dB/year vs -0.32 ± 0.4 dB/year.ConclusionDiopsys NOVA-LX Hc latency abnormality shows strong association with VF loss among a diverse population of clinical patients undergoing active treatment for chronic glaucoma, and appears likely to afford clinically useful trend-detecting test.Clinical significanceThe SD-tVEP has the potential to serve as a single-visit clinical indicator to identify glaucoma patients at high risk for VF progression.How to cite this article: Trevino R, Sponsel WE, Majcher CE, Allen J, Rabin J. Association of Diopsys® Short-duration Transient Visual Evoked Potential Latency with Visual Field Progression in Chronic Glaucoma. J Curr Glaucoma Pract 2018;12(1):29-35.

Application of the P300 Event-Related Potential in the Diagnosis of Epilepsy Disorder: A Review.

Epilepsy is one of the most serious chronical neurological disorders, affecting more than 50 million people worldwide. It can be defined as a spectrum disorder, and patients with epilepsy possess abnormalities in cognitive functions. A number of factors can cause cognitive dysfunctions in epileptic syndromes, including etiology, the age of onset, type of seizure and severity, duration, and antiepileptic drugs. Event-related potentials (ERPs) are very useful clinical and research instruments to evaluate cognitive function in patients with neuropsychiatry disorders. Event-related potentials directly reflect cortical neuronal activity and provide a particular level of temporal resolution. Among various ERP components, the P300 is the most important component for assessing cognitive processes such as attention, working memory, and concentration. Numerous studies have reported the abnormalities in amplitude or latency of P300 component of ERP in epileptic patients, and these abnormalities are indicative of cognitive dysfunction. Therefore, the purpose of this review is to consolidate the existing literature in connection with the use of P300 in epileptic patients.

Neuroelectrophysiological characteristics of peripheral neuropathy in primary Sjögren's syndrome: study protocol for a prospective case series and pre-preliminary results

Background and objectives: Sjogren's syndrome (SS) is a chronic progressive autoimmune disease. The incidence of peripheral nervous system damage in patients with primary SS (pSS) is 10–30%. Previous studies have shown that there are multiple electrophysiological manifestations in pSS patients presenting with peripheral neuropathy. However, there is no consensus on its neuroelectrophysiological manifestations. Peripheral neuropathy associated with pSS is easily confused with peripheral neuropathy of other etiologies. We hope to observe the neuroelectrophysiological manifestations of peripheral neuropathy associated with pSS to assist in the diagnosis of the disease. Design: A prospective case series. Methods: A total of 100 pSS patients with peripheral neuropathy receiving treatment in the Department of Neurology, First Affiliated Hospital of Kunming Medical University, China will be included in this study. Fifty-two patients presenting with peripheral neuropathy associated with pSS have been included in a preliminary investigation. Outcome measures and preliminary results: The primary outcome measure is the incidence of abnormal motor nerve conduction velocity in these patients. The secondary outcome measures are the incidences of abnormalities in terminal motor latencies, compound muscle action potential amplitudes, sensory nerve conduction velocities, sensory nerve action potential amplitudes, F waves, and sympathetic skin responses. The results of 52 patients included in the preliminary study showed that the incidences of each electrophysiological index was similar between the upper and lower extremities. Abnormal motor nerve conduction velocity occurred more frequently than abnormal compound muscle action potential amplitude. Abnormal sensory nerve conduction velocity was observed significantly more often than abnormal sensory nerve action potential amplitude. Abnormal motor nerve conduction velocity had a similar incidence to abnormal sensory nerve conduction velocity. Abnormal compound muscle action potential amplitude had a similar incidence to abnormal sensory nerve action potential amplitude. Abnormal F waves were observed significantly less frequently than abnormal motor nerve conduction study. Abnormal sympathetic skin response was seen with a similar incidence to abnormal motor nerve conduction study. Discussion: The results of this study, as indicated by the preliminary investigation, will reveal the neuroelectrophysiological abnormalities in peripheral neuropathy associated with pSS, which will aid diagnosis of the disease. Ethics and dissemination: This study was approved by Medical Ethics Committee of Kunming Medical University of China on October 14 th , 2005 (approval No. 20051014). The study protocol was designed in September 2016 and registered in April 2018. The study protocol received ethics approval from Medical Ethics Committee of Kunming Medical University of China on October 14 th , 2016 (approval No. 2016101411). Patient recuritment for the preliminary study was performed during January to October 2017. Patient recuritment for this study will begin in June 2018. Data collection will end in December 2020. The current study will be performed from June 2018 to December 2020. Results will be disseminated through presentations at scientific meetings and/or by publication in a peer-reviewed journal. Anonymized trial data will be published at www.figshare.com . Trial registration: This trial was registered with the Chinese Clinical Trial Registry (registration number: ChiCTR1800015669).

Treating amblyopia in adults with prosthetic occluding contact lenses.

To investigate the feasibility, effectiveness and acceptability of using prosthetic occluding contact lenses (OCLs) to treat moderate amblyopia in adults and of the role of the multifocal visual evoked potential (mfVEP) as a predictor of postamblyopic therapy. A comparative, prospective, interventional, case series pilot study with amblyopic adults (mean age: 40years, range 20-50years) allocated into two intervention groups: eye patching and OCL. The primary outcome variable was logarithm of the minimum angle of resolution (logMAR) best-corrected visual acuity (BCVA), and secondary outcomes were mfVEP amplitude and latency and patients' health-related quality of life National Eye Institute Visual Function Questionnaire (NEI VFQ-25). Significant improvements in pre- to postamblyopic therapy BCVA were seen at 1.5months in the OCL group [0.29 logMAR, 95% confidence interval (CI): 0.10-0.47 versus 0.11 logMAR, 95% CI: 0.02-0.19; p<0.001] and eye patching group (0.29 logMAR, 95% CI: 0.17-0.40 versus 0.18 logMAR, 95% CI: 0.12-0.23; p<0.01). Post-treatment BCVA was inversely related to age (R: 0.009, 95% CI: -0.02 to -0.001; p=0.04) and the presence of strabismus (R: -0.3, 95% CI: -0.434 to -0.17; p=0.001). No significant changes in the number and size of the abnormal mfVEP amplitude and latency defects were observed after occlusion. The NEI VFQ-25 composite score showed significant improvement in the OCL users at 12months compared to eye patching. Significant vision improvement can be achieved, making occlusion with OCLs an effective and more acceptable therapy for adults with amblyopia.

Relationship between somatosensory event-related potential N140 aberrations and hemispatial agnosia in patients with stroke: a preliminary study

ABSTRACTPurpose: The somatosensory event-related potential N140 is thought to be related to selective attention. This study aimed to compare the somatosensory event-related potential N140 in healthy subjects to that in patients with stroke to determine whether N140 and attentiveness are associated in patients with stroke with or without hemispatial agnosia.Materials and Methods: Normal somatosensory event-related potential N140 values were determined using data from ten healthy subjects. Fifteen patients with stroke were divided into two groups based on the presence of hemispatial neglect. Somatosensory event-related potential N140 components were compared between the two groups.Results: Stimulation of the affected limb in the hemispatial agnosia group resulted in significantly longer N140 latency at the contralateral vs. the ipsilateral electrode. This was the inverse of the relationship observed in normal subjects, with stimulation of the intact side in patients with hemispatial agnosia, and with stimulation of both the intact and affected sides in patients without agnosia. In the hemispatial agnosia group, the peak latency of N140 following stimulation of the affected side was significantly longer than it was following stimulation of the intact side and when compared to that in patients without agnosia. In addition, abnormal N140 peak latencies were observed at the Cz and ipsilateral electrodes in patients with hemispatial agnosia following stimulation of the intact side.Conclusions: These findings suggest that somatosensory event-related potential N140 is independently generated in each hemisphere and may reflect cognitive attention.

Pattern Electroretinography and Visual Evoked Potentials Provide Clinical Evidence of CNS Modulation of High- and Low-Contrast VEP Latency in Glaucoma.

PurposeBoth pattern electroretinography (PERG) and visual evoked potentials (VEP) can be performed using low- (15%; Lc) and high- (85%; Hc) contrast gratings that may preferentially stimulate the magno- and parvocellular pathways. We observed that among glaucomatous patients showing only one VEP latency deficit per eye, there appeared to be a very strong tendency for an Hc delay in one eye and an Lc delay in the other.MethodsDiopsys NOVA-LX system was used to measure VEP Hc and Lc latency among a clinical glaucoma population to find all individuals with either a single Hc or Lc latency abnormality in each eye (group 1), or with greater than 0 and less than 4 Hc or Lc VEP latency abnormalities in the two eyes (group 2) to determine whether a significant inverse correlation existed for these values in either group. Hc and Lc PERG data were also evaluated to assess associated retinal ganglion cell responses.ResultsA strong inverse correlation (P = 0.0000003) was observed between the Hc and Lc VEP latency values among the 64 eyes in group 1. Group 2 provided a comparable result (n = 143; 286 eyes; P = 0.0005). PERG (n = 81; 162 eyes) also showed strong bilateral symmetry for magnitude values (P < 0.0001 for both Lc and Hc in groups 1 and 2).ConclusionsBilateral retention of both low-resolution/high-speed and high-resolution/low-speed function may persist with both eyes open despite symmetrically pathologic retinal ganglion cell PERG waveform asynchrony for Hc and Lc stimuli in the paired eyes.Translational RelevanceClinical electrophysiology strongly suggests binocular compensation for dynamic dysfunction operates under central nervous system (CNS) control in glaucoma.

Short-term and persistent impacts on behaviors related to locomotion, anxiety, and startle responses of Japanese medaka (Oryzias latipes) induced by acute, sublethal exposure to chlorpyrifos

Although most exposures to chlorpyrifos (CPF) in natural flowing waters are brief and episodic, there have been a few reports of the persistence of abnormal fish behaviors caused by such acute exposure. The present study focused on the behavioral and biochemical responses of Japanese medaka (Oryzias latipes) to acute, sublethal exposure to CPF, as well as the persistence of the effects during a 3-week recovery test in CPF-free water. The medaka became hyperactive and exhibited an elevated anxiety state after a 4-day exposure to 0.024mg/L of CPF, but they recovered from these abnormal behavioral responses within 7days of recovery treatment. In contrast, persistent impacts on some startle responses to a sudden stimulation (induced by a ball drop) were observed in medaka exposed to CPF. The reaction latency did not change immediately after the 4-day exposure, but was significantly prolonged by as much as 21days after the termination of exposure. The post-stimulus swimming distance within 5s significantly decreased on the day immediately after the 4-day exposure, but it significantly increased after 7days of recovery treatment. The activity of acetylcholinesterase (AChE) in the brains of medaka was significantly inhibited on the day immediately after the 4-day exposure, but it returned to 80% and 110% of that in control fish on days 7 and 21 of the recovery period, respectively. However, AChE activities in the eyes of exposed medaka were persistently inhibited and declined to 33%, 71%, and 72% of that in control fish on days 0 (immediately after the 4-day exposure), 7, and 21 of recovery, respectively. Correlation analysis suggested that the changes of AChE activities in the brains of medaka may underlie some of the observed acute behavioral changes, and the changes of AChE activities in the eyes may contribute to the persistence of the abnormalities in the reaction latency of the startle response. Our findings suggest that medaka need a long time to recover from acute, sublethal exposure to CPF, and the persistence of the behavioral abnormalities might affect their fitness in natural habitats.

P2-71. Saccadic eye movements in Spinocerebellar Degeneration – study of saccades in eight directions

Objectives The cerebellum is implicated in the control of saccadic eye movement but it is unknown how it differs for vertical and horizontal saccades, since vertical saccades have been rarely studied. To clarify the role of the cerebellum we studied saccades in hereditary spinocerebellar degeneration in two dimensional directions. Methods We compared saccade performance in 16 patients (SCA31 and SCA6) with that in 19 normal age-matched controls. We used the visual guided (VGS) and memory guided tasks (MGS) in which targets were presented in eight directions with 45 degrees separation, and recorded saccades with a video-based eye tracker. Results In SCA patients, latency of VGS was significantly delayed compared with normal subjects in vertical and oblique directions, which correlated with SARA scores. MGS latency was significantly delayed only in the oblique direction. Hypermetria was prominently detected in the vertical and oblique directions, but less in the horizontal directions. Conclusion Abnormal latency and dysmetria are easily detected for directions having vertical component. The cerebellum may be more involved in vertical than in horizontal saccade system, or vertical saccade system may be more susceptible to diseases than horizontal saccades. Further study of other diseases will be helpful to differentiate between these possibilities.

Post-concussion abnormalities in the m60 somatosensory evoked field recorded by magnetoencephalography

ObjectiveWe sought to determine whether magnetoencephalography (MEG) might reliably document the presence of neurophysiologic dysfunction after acute concussion. Based on a previous evoked potential study,1we analysed somatosensory evoked fields (SEFs) elicited by stimulation of the median nerve at the wrist.DesignCase-control study.SettingAcademic tertiary care centre.ParticipantsFive patients with acute concussion (&lt;10 days post-injury); mean age 32±18 yrs, 3 women. 23 age/sex matched controls with no history of concussion.Assessment of risk factorIndependent variable, concussion.Outcome measuresDependent variables, bilateral peak latencies of M20, M30, and M60 SEFs.Main resultsNo differences were found between patients (24 recorded values) and controls (46 recorded values) in M20 (21.7±1.6 ms vs. 22.3±1.5 ms) or M30 (35.4±3.8 ms vs. 33.5±3.3 ms) latencies. M60 latencies were significantly delayed in patients compared to controls (90.4±21.5 ms vs. 64.0±8.6 ms; Mann Whitney U-test, U=186.5, p=0.0001). All symptomatic patients had an abnormally delayed M60 value&gt;2 SDs from the control mean on at least one side. Follow-up patient recordings showed gradual decreases in abnormal M60 latencies over months; weekly MEG and ImPACT testing in one patient showed normalisation of verbal memory at week 2, visual memory and symptom scores at week 5 and M60 latencies at week 10.ConclusionsThe M60 SEF represents the first intracortical stage of neuronal processing of external somatosensory input to the brain. In this preliminary study we found significant differences in M60 latencies between subjects with acute concussion and controls, as well as within subject changes during recovery in the weeks after concussion.Competing interestsNone.

A Comparison of Interside Asymmetries of Lower Extremity Somatosensory Evoked Potentials in Anesthetized Patients with Unilateral Lumbosacral Radiculopathy.

Study DesignProspective cohort study.PurposeThis study was to investigate interside asymmetries of three lower extremity somatosensory evoked potentials (SSEPs) in anesthetized patients with unilateral lumbosacral radiculopathy.Overview of LiteratureAlthough interside asymmetry is an established criterion of abnormal SSEP, little is known which of the lower SSEPs is more sensitive in detecting interside asymmetry in anesthetized patients.MethodsSuperficial peroneal nerve SSEP (SPN-SSEP), posterior tibial nerve SSEP (PTN-SSEP), and sural nerve SSEP were obtained in 31 lumbosacral surgery patients with unilateral lumbosacral radiculopathy, and compared with a group of 22 control subjects.ResultsThe lumbosacral group showed significant larger interside asymmetry ratios of P37 latencies in SPN-SSEP and PTN-SSEP, and significant larger interside asymmetry ratio of P37-N45 amplitude in SPN-SSEP, when comparing with the control group. Within the lumbosacral group but not the control group, SPN-SSEP displayed significant larger interside asymmetry ratio in P37 latency. When referencing to the control group, more patients in the lumbosacral group displayed abnormal interside SPN-SSEP latency asymmetries which corroborated the symptom laterality.ConclusionsThe data suggested that SPN-SSEP was more sensitive in detecting interside latency asymmetry in anesthetized patients.

Terminal latency abnormality in amyotrophic lateral sclerosis without split hand syndrome

Amyotrophic lateral sclerosis (ALS) has a peculiar involvement pattern; clinically it is known as split hand syndrome and electrophysiologically shows abnormalities in the abductor pollicis brevis (APB)/abductor digiti minimi (ADM) ratio. The aim of this study was to find a significant electrophysiological parameter in upper limb onset ALS patients with normal APB/ADM ratio when compared to cervical spondylotic amyotrophy (CSA) and healthy controls. We retrospectively reviewed the electrophysiological results of 47 upper limb onset ALS and 42 CSA cases; 20 healthy individuals were included as controls. We included ALS and CSA patients with normal ADM/APB ratio (≥0.6, and ≤1.7), and the parameters of electrophysiological study were compared. The electrophysiological parameters of statistical significance among ALS, CSA and normal controls were: amplitude of median and ulnar nerves, the terminal latency of median nerve, F-wave latency of median and ulnar nerves, terminal latency ratio of ulnar/median nerves, and F-wave latency ratio of ulnar/median nerves (p<0.05). Among these parameters, the terminal latency ratio of ulnar/median nerve and terminal latency of median nerve in ALS were significantly different with both of CSA and normal control (p<0.006). The abnormality in the terminal latency of the median nerve can be partly explained by the distal motor axonal dysfunction due to sodium and potassium channel abnormalities. The hypothesis of distal axonopathy is known to play an important role in the pathogenesis of ALS causing a significant prolongation of the terminal latency in the median nerve and the ulnar/median nerve ratio.

Evaluation of the Female Patients with Subclinical Hypothyroidism by Brainstem Auditory Evoked Potentials: Case-Control Study.

Hypothyroidism, a common endocrinological disorder is quite prevalent in its subclinical state in the adult population. Nervous system involvement is frequent in hypothyroidism with documentation of peripheral and central conduction delays as abnormal latency prolongations in Brainstem Auditory Evoked Potential (BAEP) records. Subclinical hypothyroidism however, has been less extensively studied for investigating the involvement of the auditory functions. To assess the auditory functions and Central Nervous System (CNS) involvement in the patients with subclinical hypothyroidism by recording BAEP. The study comprised of 50 females (25 females with subclinical hypothyroidism and 25 age-matched healthy females) in the age-group of 30-50 years. BAEP absolute and Interpeak Latencies (IPLs) (I, III and V, I-III, III-V and I-V) were compared between the two groups by unpaired t-test. The p<0.05 was considered as statistically significant. Mean BAEP absolute latencies (III and V) increased in the subjects with subclinical hypothyroidism as compared to controls (p<0.001) (both the ears) and wave I absolute latency also increased with p<0.001 (both the ears) by unpaired t-test. Among IPLs (interpeak latencies), III-V and I-V IPLs exhibited increase (p<0.01), while I-III IPL did not vary with statistical significance (both the ears) in the two groups. Patients with subclinical hypothyroidism were found to demonstrate central as well as peripheral auditory pathway affections. BAEPs can prove valuable and sensitive tests to detect involvement of the CNS and auditory dysfunctions earlier in hypothyroidism.

Slowing with end-stage renal disease: Attentive but unprepared to act

Dialyzed patients show longer response latencies to stimuli than healthy controls. This study was designed to learn if this abnormal latency may be related to an impairment in the networks that mediate the allocation of sensory-attention (inducing a delay in stimulus recognition-awareness) and/or an impairment of intentional motor preparation (inducing a delay in action-initiation). Dialyzed patients with end-stage renal disease and matched healthy controls were assessed using reaction time tasks from the ROtman-Baycrest Battery to Investigate Attention (ROBBIA) and event-related potentials (ERPs) to help elucidate the possible attentional and/or intentional brain mechanisms that may account for this slowing. The following ERP components were analyzed for single attentional and intentional processes: response preparation (Contingent Negative Variation); perceptual preparation (P1); selective attention and monitoring (P300/Late Positive Potential). Patients (vs. controls) had a decreased ability to sustain response preparation under the condition of a long (3s) but not a short (1s) preparation period. This action-intentional deficit was, however, not accompanied by impaired perceptual preparation and monitoring. Future research may investigate whether deficits observed in dialyzed patients can be reduced with treatments such as kidney transplantation.

Outer Hair Cell Damage: A Completely Different Listening Experience

Outer Hair Cell Damage: A Completely Different Listening Experience

OC-071 Dysphagia Patients with Normal Oesophageal High Resolution Manometry: Assessing The Diagnostic Value of Bread Swallows

Introduction High resolution manometry (HRM) is currently the gold standard technique to investigate oesophageal motility in patients with dysphagia. However, with routine HRM procedure and use of Chicago classification, a group of patients with dysphagia are considered as being normal and dysphagia remains unexplained. The aim of this study is to assess the diagnostic value of solid bolus swallows in patients with dysphagia and normal HRM. Methods Patients having dysphagia and normal HRM studies during January-October 2015 were selected. Solid bolus swallows of bread (1cm 3 single bread swallows and/or a sandwich meal) followed the routine water swallows on HRM. Patients with a double high pressure zone, oesophageal diverticulum or history of antireflux surgery were excluded. The patients were categorised to symptomatic and asymptomatic groups based on having dysphagia reproduced on bread swallows. Hospital odynophagia and dysphagia questionnaire (HODQ) score, integrated relaxation pressure (IRP), distal contractile integration (DCI), distal latency (DL) and peristaltic abnormality during water swallows were investigated and compared between groups. ROC curve was used to identify the optimum level of sensitivity and specificity of the significant parameters in identifying patients who have a meaningful abnormality on bread swallows. Student t-test is used to compare significance of differences. P value Results 72 patients referred with dysphagia and diagnosed with normal HRM were selected. In the asymptomatic group, 7/22 patients showed abnormality on bread swallows and in the symptomatic group, 45/50 showed abnormal motility (P = 0.0001). ROC analysis showed that having >33.3% abnormal bread swallows has sensitivity of 72%, specificity of 90.91% and likelihood ratio of 7.9 to detect patients who may have abnormal motility and dysphagia on bread swallows. Analysis of water swallow parameters comparing the asymptomatic group against the symptomatic group with abnormal motility on bread swallows did not reveal any significant difference in HODQ score (P = 0.2), IRP (P = 0.17), DL (P = 0.3) and peristaltic abnormalities (P = 0.4). Conclusion Performing solid swallows on HRM can explain dysphagia in a considerable number of patients with dysphagia and normal routine HRM. This complementary test is readily available, and avoids the need for Barium swallowing and radiation exposure. Disclosure of Interest None Declared