Abnormal Latency Research Articles

Cold-evoked potentials in Fabry disease and polyneuropathy.

Fabry disease (FD) causes cold-evoked pain and impaired cold perception through small fiber damage, which also occurs in polyneuropathies (PNP) of other origins. The integrity of thinly myelinated fibers and the spinothalamic tract is assessable by cold-evoked potentials (CEPs). In this study, we aimed to assess the clinical value of CEP by investigating its associations with pain, autonomic measures, sensory loss, and neuropathic signs. CEPs were examined at the hand and foot dorsum of patients with FD (n = 16) and PNP (n = 21) and healthy controls (n = 23). Sensory phenotyping was performed using quantitative sensory testing (QST). The painDETECT questionnaire (PDQ), FabryScan, and measures for the autonomic nervous system were applied. Group comparisons and correlation analyses were performed. CEPs of 87.5% of the FD and 85.7% of the PNP patients were eligible for statistical analysis. In all patients combined, CEP data correlated significantly with cold detection loss, PDQ items, pain, and autonomic measures. Abnormal CEP latency in FD patients was associated with an abnormal heart frequency variability item (r = -0.684; adjusted p = 0.04). In PNP patients, CEP latency correlated significantly with PDQ items, and CEP amplitude correlated with autonomic measures (r = 0.688, adjusted p = 0.008; r = 0.619, adjusted p = 0.024). Furthermore, mechanical pain thresholds differed significantly between FD (gain range) and PNP patients (loss range) (p = 0.01). Abnormal CEPs were associated with current pain, neuropathic signs and symptoms, and an abnormal function of the autonomic nervous system. The latter has not been mirrored by QST parameters. Therefore, CEPs appear to deliver a wider spectrum of information on the sensory nervous system than QST alone.

Auditory Cortex Maturation and Language Development in Children with Hearing Loss and Additional Disabilities.

A significant portion of hearing-impaired children have additional disabilities, but data about the maturation of their auditory cortex are scarce. In these children, behavioral tests are often unreliable, and objective tests are needed for diagnostics and follow-up. This study aimed to explore auditory cortical maturation and language development, and the usability of an objective electroencephalogram-based biomarker in children with multiple disabilities. In 65 hearing aid and cochlear implant users (36 females; 36 with multiple disabilities; 44.3 ± 18.5 months of age, mean ± SD), auditory processing was examined using the P1 cortical auditory evoked response biomarker, and language development with the Preschool Language Scales 5th edition (PLS-5). During the study, all of the children received intensive extra language therapy for six months. No significant differences were found between the groups in P1 latency development, the proportion of abnormal P1 latencies, or the number of children whose P1 latencies changed from abnormal to normal during the study. The PLS-5 total language scores, auditory comprehension scores, or expressive communication scores did not differ between groups either. The P1 latencies showed meaningful negative correlations with the language scores. The results suggest that auditory cortex development is similar in hearing-impaired children with/without additional disabilities, and the P1 biomarker is a feasible tool to evaluate central auditory maturation in children with multiple disabilities.

Granuloma, vasculitis, and demyelination in sarcoid neuropathy.

Despite the suggestion that direct compression by granuloma and ischemia resulting from vasculitis can cause nerve fiber damage, the mechanisms underlying sarcoid neuropathy have not yet been fully clarified. We examined the clinicopathological features of sarcoid neuropathy by focusing on electrophysiological and histopathological findings of sural nerve biopsy specimens. We included 18 patients with sarcoid neuropathy who had non-caseating epithelioid cell granuloma in their sural nerve biopsy specimens. Although electrophysiological findings suggestive of axonal neuropathy were observed, particularly in the lower limbs, all but three patients showed ≥1 abnormalities in nerve conduction velocity or distal motor latency. Additionally, a conduction block was observed in 11 of the 16 patients for whom waveforms were assessed; five of them fulfilled motor nerve conduction criteria strongly supportive of demyelination as defined in the European Academy of Neurology/Peripheral Nerve Society (EAN/PNS) guideline for chronic inflammatory demyelinating polyneuropathy (CIDP). In most patients, sural nerve biopsy specimens revealed a mild to moderate degree of myelinated fiber loss. Fibrinoid necrosis was observed in one patient, and electron microscopy analysis revealed demyelinated axons close to granulomas in six patients. Patients with sarcoid neuropathy may meet the EAN/PNS electrophysiological criteria for CIDP due to the frequent presence of conduction blocks. Based on our results, in addition to the ischemic damage resulting from granulomatous inflammation, demyelination may play an important role in the mechanism underlying sarcoid neuropathy.

Preserved Auditory Steady State Response and Envelope-Following Response in Severe Brainstem Dysfunction Highlight the Need for Cross-Checking.

Commercially available auditory steady state response (ASSR) systems are widely used to obtain hearing thresholds in the pediatric population objectively. Children are often examined during natural or induced sleep so that the recorded ASSRs are of subcortical origin, the inferior colliculus being often designated as the main ASSR contributor in these conditions. This report presents data from a battery of auditory neurophysiological objective tests obtained in 3 cases of severe brainstem dysfunction in sleeping children. In addition to ASSRs, envelope-following response (EFR) recordings designed to distinguish peripheral (cochlear nerve) from central (brainstem) were recorded to document the effect of brainstem dysfunction on the two types of phase-locked responses. Results obtained in the 3 children with severe brainstem dysfunctions were compared with those of age-matched controls. The cases were identified as posterior fossa tumor, undiagnosed (UD), and Pelizaeus-Merzbacher-Like Disease. The standard audiological objective tests comprised tympanograms, distortion product otoacoustic emissions, click-evoked auditory brainstem responses (ABRs), and ASSRs. EFRs were recorded using horizontal (EFR-H) and vertical (EFR-V) channels and a stimulus phase rotation technique allowing isolation of the EFR waveforms in the time domain to obtain direct latency measurements. The brainstem dysfunctions of the 3 children were revealed as abnormal (weak, absent, or delayed) ABRs central waves with a normal wave I. In addition, they all presented a summating and cochlear microphonic potential in their ABRs, coupled with a normal wave I, which implies normal cochlear and cochlear nerve function. EFR-H and EFR-V waveforms were identified in the two cases in whom they were recorded. The EFR-Hs onset latencies, response durations, and phase-locking values did not differ from their respective age-matched control values, indicating normal cochlear nerve EFRs. In contrast, the EFR-V phase-locking value and onset latency varied from their control values. Both patients had abnormal but identifiable and significantly phase-locked brainstem EFRs, even in a case with severely distorted ABR central waves. ASSR objective audiograms were recorded in two cases. They showed normal or slightly elevated (explained by a slight transmission loss) thresholds that do not yield any clue about their brainstem dysfunction, revealing the method's lack of sensitivity to severe brainstem dysfunction. The present study, performed on 3 sleeping children with severe brainstem dysfunction but normal cochlear responses (cochlear microphonic potential, summating potential, and ABR wave I), revealed the differential sensitivity of three auditory electrophysiological techniques. Estimated thresholds obtained by standard ASSR recordings (cases UD and Pelizaeus-Merzbacher-Like Disease) provided no clue to the brainstem dysfunction clearly revealed by the click-evoked ABR. EFR recordings (cases posterior fossa tumor and UD) showed preserved central responses with abnormal latencies and low phase-locking values, whereas the peripheral EFR attributed to the cochlear nerve was normal. The one case (UD) for which the three techniques could be performed confirms this sensitivity gradient, emphasizing the need for applying the Cross-Check Principle by avoiding resorting to ASSR recording alone. The entirely normal EFR-H recordings observed in two cases further strengthen the hypothesis of its cochlear nerve origin in sleeping children.

Electrophysiologic Findings in Pediatric Guillain Barre Syndrome

Objective: To describe electrophysiologic findings in the pediatric GuillianBarre syndrome (GBS).
 Study design: Comparative prospective study.
 Place and Duration of Study: Department of Neurology, The Children’s Hospital and Institute of Child Health, Lahore Pakistan, from Jun to Dec 2015.
 Methodology: Children below 18 years of age, presenting in medical emergency/neurology OPD and fulfilling the clinical case definition of GBS were included for the study. Electrophysiologic studies were performed within 24 hours of admission in all patients.
 Results: Out of 83 patients with GBS, 59% were male and 80% were between 3-12 years of age. According to the electrophysiological findings, acute inflammatory demyelinating polyradiculoneuropathy (AIDP) was the most common subtype followed by acute motor axonal neuropathy (AMAN). Reduced CMAP and absent F-response were the most common electrophysiologic findingspresented in 70% and 57.8% of patients respectively. However, absent F-response was not specific for any subtype (p>0.05). Prolonged motor DL, reduced NCV, temporal dispersion and abnormal F-wave latency were characteristicelectrophysiologic features of demyelination (p≤0.001). However, prolonged motor DL and absent F-wave occurred early in the course of disease while reduced NCV and temporal dispersion observed later.
 Conclusion: Electrophysiologic studieswere useful in making the appropriate diagnosis to initiate immunotherapy, particularly during first week after onset of weakness when albuminocytologic dissociation may not be present.

Retinal structure and visual pathway function at school age in children born extremely preterm: a population-based study

BackgroundChildren born extremely preterm (gestational age < 28 weeks) show reduced visual function even without any cerebral or ophthalmological neonatal diagnosis. In this study, we aimed to assess the retinal structure with optical coherence tomography (OCT) and visual function with pattern-reversal visual evoked potentials (PR-VEPs) in a geographically defined population-based cohort of school-aged children born extremely preterm. Moreover, we aimed to explore the association between measures of retinal structure and visual pathway function in this cohort.MethodsAll children born extremely preterm from 2006–2011 (n = 65) in Central Norway were invited to participate. Thirty-six children (55%) with a median age of 13 years (range = 10–16) were examined with OCT, OCT-angiography (OCT-A), and PR-VEPs. The foveal avascular zone (FAZ) and circularity, central macular vascular density, and flow were measured on OCT-A images. Central retinal thickness, circumpapillary retinal nerve fibre layer (RNFL) and inner plexiform ganglion cell layer (IPGCL) thickness were measured on OCT images. The N70-P100 peak-to-peak amplitude and N70 and P100 latencies were assessed from PR-VEPs.ResultsParticipants displayed abnormal retinal structure and P100 latencies (≥ 2 SD) compared to reference populations. Moreover, there was a negative correlation between P100 latency in large checks and RNFL (r = -.54, p = .003) and IPGCL (r = -.41, p = .003) thickness. The FAZ was smaller (p = .003), macular vascular density (p = .006) and flow were higher (p = .004), and RNFL (p = .006) and IPGCL (p = .014) were thinner in participants with ROP (n = 7).ConclusionChildren born extremely preterm without preterm brain injury sequelae have signs of persistent immaturity of retinal vasculature and neuroretinal layers. Thinner neuroretinal layers are associated with delayed P100 latency, prompting further exploration of the visual pathway development in preterms.

A Cross-Sectional Study Using STROBE Platform to Examine Sleep Characteristics, Mental Health and Academic Performance of Female Applied Medical Sciences Students in the Southwest of Saudi Arabia.

Background: Medical students are expected to excel in their academics. Hence exposing them to a certain amount of strain may sometimes cause sleep disruptions. The purpose of this study was to determine the sleep quality among Saudi Applied Medical Sciences students and its potential connections with their academic performance and mental health. Methods: This online cross-sectional questionnaire-based study was conducted at Jazan University's College of Applied Medical Sciences in Saudi Arabia. The Pittsburgh Sleep Quality Index (PSQI), a known indicator of sleep quality, a validated mental health measure; Depression Anxiety Stress Scales-21 (DASS-21), and Academic Performance Scale (APS) with 89 internal consistencies were included in the questionnaire. The cumulative grade point average (GPA) was also used as a covariate to evaluate students' academic success. Results: 112 people responded (response rate = 93%), and 105 of them presented comprehensive information about their backgrounds, way of life, academic standing, sleep patterns, and mental health. Participants' average GPA and APS scores were 4.23 ± 0.52 and 33.16 ± 5.63, respectively. The mean global PSQI score was 6.47 with 2.34 of standard deviation (SD). The majority of individuals (60%) had poor sleep quality particularly due to abnormal sleep latency and lesser sleep duration, as determined by their PSQI score. The prevalence rates for depression, anxiety, and stress were higher; 53%, 54% and 40%, respectively. Both depression and anxiety were substantially correlated with poor sleep quality (p-value = 0.008, p-value = 0.01, respectively). Sleep quality had no significant effect on GPA while global PSQI and depression were significantly negatively correlated with an APS score of participants (p-value = 0.007 and 0.015, respectively). Conclusions: Higher rates of poor sleep quality and psychologically negative emotions were prevalent. Unhealthy sleep patterns were linked to increased levels of anxiety and depression. Self-perceived academic performance was negatively impacted by inadequate sleep and negative emotions, despite the fact that the GPA results were unaffected.

PO-01-163 CHARACTERIZATION OF ATRIAL SUBSTRATE USING CLOSE-COUPLED PACED ELECTROGRAM FEATURE ANALYSIS (PEFA) IN PATIENTS WITH NON-VALVULAR ATRIAL FIBRILLATION

Mapping strategies that lead to a better understanding and therapy for persistent atrial fibrillation (AF) are urged. Paced electrogram feature analysis (PEFA) exposes slow conduction zones as substrate for ventricular arrhythmias and previous studies support its efficacy for guiding ablation. PEFA has not been studied in the left atrium (LA). Our goal was to demonstrate that PEFA exposes slow conduction areas in the LA that may trigger and perpetuate AF. Prospective exploratory cohort study. The intervention group was formed by patients with paroxysmal AF undergoing catheter ablation (Group A), compared to a control group of patients without AF and structurally normal heart presenting for left-sided electrophysiological procedures (Group B). Antiarrhythmic drugs were discontinued at least five half-lives before the study and amiodarone, at least 3 months LA effective refractory period (AERP) was defined while pacing from the LA appendage (LAA). PEFA protocol consisted of a paced (S1) at 600 ms with an extra stimulus (S2) at a fixed coupling interval of AERP+30ms. EGM conduction time (time from pacing artifact to first deflection), EGM latency (conduction time from pacing artefact to local activation time of the S2 less same value for S1), EGM duration (first deflection to last deflection), EGM propagation time (latency + EGM duration), and last deflection (sum of CT + EGM duration) were defined (Figure 1). Group B data was used as the reference values, the percentage of abnormal EGM features in group A compared to group B were calculated. Twenty-four AF and 8 control patients were included. EGM features were evaluated in 13 different locations of the LA with a total of 12,291 EGMs to analyze (Table 1). Compared to non-AF controls, AF patients had a higher percentage of abnormal latency (10.43%, p<0.001), propagation time (12.04%, p<0.001), and last deflection (10.49%, p<0.001) for all locations evaluated together, however, the LA roof expressed more remarkable abnormal EGM properties than other areas (Table 1). There was no statistically significant difference in EGM duration between groups (p=0.83). PEFA exhibits abnormal conduction properties (latency, propagation time and last deflection) in certain areas of the LA. This may be used in the future to characterize AF substrate; objective assessment of these responses may inform ablation sites in patients with atrial fibrillation and warrants further study.Tabled 1Paced electrogram fractionation characteristics in patients with AF (Group A) and controls (Group B)EGM characteristicLatency (CT in S2 less CT in S1)Propagation (latency + EGM duration)Last deflection (sum of CT + EGM duration)Group A (N=9823)Time in ms (SD)Group B (N=2464)Time in ms (SD)% Abnormalp-valueGroup A (N=9823)Time in ms (SD)Group B (N=2464)Time in ms (SD)% Abnormalp-valueGroup A (N=9359)Time in ms (SD)Group B (N=2468)Time in ms (SD)% Abnormalp-valueAll54.7 (27.7)45.4 (21.9)10.43%<0.001*111.1 (35.9)101.6 (25.7)12.04%<0.001*172.0 (43.0)157.7 (31.5)10.49%<0.001*Anterior wall51.3 (28.4)45.1 (18.1)11.17%<0.001*113.2 (35.7)98.1 (22.3)19.39%<0.001*158.9 (34.7)154.5 (33.3)6.195%0.057Floor52.9 (27.2)36.6 (22.3)18.06%<0.001*109.2 (35.5)96.6 (28.3)10.31%<0.001*168.2 (44.7)149.8 (32.8)11.30%<0.001*LAA43.6 (40.5)32.7 (24.6)2.80%0.001*106.7 (48.2)100.4 (32.5)6.54%0.1192138.8 (48.2)131.0 (28.3)9.91%0.047*Left anterior wall55.0 (22.6)45.3 (18.0)14.34%<0.001*109.5 (29.5)104.4 (23.6)7.46%0.005*175.4 (38.4)153.6 (22.6)14.14%<0.001*LIPV33.8 (30.3)52.8 (14.4)6.94%<0.001*79.3 (36.7)96.9 (18.8)7.67%0.009*151.7 (34.5)161.0 (17.8)6.99%0.1470LSPV44.6 (34.7)54.4 (17.3)9.38%0.011*101.7 (44.3)102.7 (24.2)13.13%0.8265173.9 (33.8)169.0 (23.3)6.25%0.2189Mitral isthmus46.0 (26.0)43.6 (26.1)0.94%0.3334105.5 (35.0)101.3 (29.8)5.82%0.19137.5 (38.7)128.0 (29.2)7.36%0.006*Posterior wall53.9 (23.6)41.7 (16.7)19.26%<0.001*108.8 (33.2)92.5 (16.8)25.64%<0.001*178.6 (38.0)151.8 (21.4)27.61%<0.001*Right anterior wall62.1 (26.4)55.5 (15.8)17.47%<0.001*112.6 (33.7)109.3 (24.9)11.43%0.01191.6 (46.5)179.4 (24.7)14.08%<0.001*RIPV53.8 (13.1)60.3 (12.3)4.00%<0.001*97.1 (33.2)98.4 (18.1)6.4%0.01182.8 (32.8)184.5 (16.2)3.01%0.0682Roof57.1 (22.5)46.9 (17.3)26.63%<0.001*117.3 (30.3)100.2 (28.3)39.95%<0.001*175.5 (34.3)154.0 (49.5)36.96%<0.001*RSPV72.6 (27.0)63.5 (15.1)18.47%0.003*128.8 (46.3)113.4 (28.6)16.30%0.003*199.3 (29.5)200.4 (23.1)4.324%0.7597Septum61.7 (27.7)44.4 (28.0)10.64%<0.001*118.3 (37.7)106.4 (28.2)15.51%<0.001*184.6 (37.6)161.7 (30.2)12.61%<0.001**Statistically significant, CT: Conduction time, EGM: Electrogram, LAA: Left atrium appendage, LIPV: Left inferior pulmonary vein, LSPV: Left superior pulmonary vein, RIPV: Right inferior pulmonary vein, LIPV: Left inferior pulmonary vein. Open table in a new tab

Blink Reflex Value in the Early Diagnosis of Guillain-Barre Syndrome

Introduction: Guillain Barre Syndrome (GBS) is an autoimmunemediated demyelinating or axonal polyradiculoneuropathy characterized by progressive ascending weakness plus areflexia. Three major subtypes are demyelinating, Axonal, and Miller-Fisher Syndrome. The hallmark of the definitive diagnosis of GBS is an electrodiagnostic study. The current study is aimed to assess the value of the blink reflex, as part of an electrodiagnostic study, in the diagnosis of GBS. Methods: The current census cross-sectional study has been conducted on 55 patients with the definitive diagnosis of GBS based on clinical and electrodiagnostic manifestations from January 2018 to February 2020 in Isfahan, Iran. The patients were categorized into three groups of demyelinated, axonal, and Miller-Fisher variants and blink reflex entities, including R1, R2i, and R2c were assessed for them. All data were analyzed by independent T-test paired T-test and Chi-square tests. Results: R1 was abnormal in R1 was abnormal in 17 (30.90%), R2i in two patients (3.63%), and R2c in two patients (3.63%). Among the studied patients, five (8.47%) had abnormal latency in R1, five (8.47%) in R2i, and five (8.47%) in R2c. The comparison of abnormality in blink reflex entities among diverse subtypes, including axonal, demyelinating, and Miller-Fisher variants, revealed no significant differences (P-value>0.05). Conclusion: At least one of the blink reflex indices was abnormal in up to 30.90% of the patients, it seems that the blinking reflex cannot be considered a reliable early diagnostic test for GBS, but this fact cannot completely rule out this method and additional studies should be done with more patients in other populations.

P3b Amplitude and Latency in Tic Disorders: A Meta-Analysis.

By searching PubMed, Embase, Web of Science, SCOPUS, Medline, and Google Scholar, we identified studies that compared P3b between TD patients and HCs. The amplitude and latency of P3b were then analyzed. Subgroup analyses were conducted to investigate the influence of different experimental factors on P3b indices. Overall, 19 articles involving 388 cases and 414 controls were evaluated. There were no significant abnormalities in P3b amplitude and latency in TD patients. The P3b amplitude of the TD patients was significantly decreased during the oddball task, and the P3b amplitude of the adult TD patients was also significantly decreased. TD patients may have an abnormal P3b compared to HCs under specified conditions.

Anterior Interosseous Nerve Syndrome.

Anterior interosseous nerve syndrome (AINS) is a rare form of peripheral neuropathy which involves disruption of the anterior interosseous nerve. The pathophysiology of AINS remains unclear. AINS typically initially presents with forearm pain and may gradually progress to palsy of the deep muscles of the anterior forearm. Diagnosis of AINS requires thorough patient history and physical exam. EMG is the preferred diagnostic study and classically reveals abnormal activity and prolonged latency periods within the evoked action potentials of the FPL and PQ. Due to the self-limiting nature of AINS, there is general agreement that conservative and symptomatic management should be explored for up to 6 months as first line therapy, which usually includes analgesics and nonsteroidal anti-inflammatory drugs, contracture prevention, hand therapy, and hand splinting. Surgical options such as internal neurolysis and minimally invasive endoscopic decompression may be explored if functional recovery from conservative management is limited.

The characteristics of vestibular-evoked myogenic potentials in unilateral Meniere's disease patients at different clinical stages

Objective:This study was to retrospectively analyze the results of vestibular-evoked myogenic potentials（VEMP） in unilateral Meniere's disease（MD） patients. Methods:The clinical assessment results of MD patients who visited the department between January 2016 to February 2022 were reviewed. Unilateral MD patients who met the inclusion and exclusion criteria were divided into three groups according to clinical stages, namely, group 1（stage Ⅰ+ stage Ⅱ）, group 2（stage Ⅲ） and group 3（stage Ⅳ）. The normal value data were used to investigate the incidence of abnormal P1 and N1 latencies, abnormal P1-N1 interwave latency, and abnormal interaural amplitude asymmetry ratio（IAR）. Afterwards, considering all the above mentioned parameters, the VEMP result of each patient was graded into four levels（grade 1 means VEMP result is normal, grade 2, 3 and 4 means the VEMP result is abnormal in different degrees）. The correlation between VEMP result level and pure tone average（PTA） of MD patients in different clinical stages was examined. Results:The prevalence of cVEMP in three groups was 84.2%, 70.0% and 33.3%, respectively（P<0.05）. The prevalence of oVEMP in three groups was 63.2%, 34.0% and 16.7%, respectively（P<0.05）. The incidence of abnormal P1 latency, N1 letancy and P1-N1 interwave latency of cVEMP was 21.1%, 26.3% and 24.6%, respectively. The incidence of abnormal P1 latency, N1 latency and interwave latency of oVEMP was 15.6%, 43.8% and 3.1%, respectively. The incidence of abnormal cVEMP IAR in group 1, group 2 and group 3 was 6.7%, 21.2% and 33.3%, respectively（P>0.05）. The incidence of abnormal IAR of oVEMP in group 1, group 2 and group 3 was 16.7%, 23.1% and 0, respectively（P>0.05）. cVEMP and oVEMP result levels were significantly correlated with PTA（r=0.339, P<0.01; r=0.362, P<0.01 ）, respectively. Conclusion:With the progression of MD, the function of saccule-vestibular inferior nerve pathway and utricle-vestibular superior nerve pathway would deteriorate in the same way as hearing.

Evaluation of visual evoked potentials in dysthyroid optic neuropathy

ABSTRACT Purpose To evaluate the findings of visual evoked potentials (VEP) in patients with dysthyroid optic neuropathy (DON). Methods In this observational, cross-sectional study 40 eyes (22 patients) with a diagnosis of DON were included. Results We discovered that in 16 out of 37 eyes with pattern-VEP (p-VEP), the latency of P100 wave was normal in spite of having a diagnosis of DON. The same pattern was also observed in the measurement of the amplitude of P100 wave: in 28 out of 37 eyes with p-VEP the amplitudes were observed as normal. In 3 eyes of 3 patients p-VEP showed no response, therefore a flash-VEP (f-VEP) was performed. Flash-VEPs of those patients indicated a prolonged P100 latency with a reduced amplitude. The sensitivity of abnormal P100 latency was 56.8% (95%CI 39.5–72.9%); and that of reduced P100 amplitude was 24.3% (95%CI 11.8–41.2%). Also, in 40 eyes color vision test by Arden was performed. In 36 eyes (20 patients) the tritan value was pathological (based on a threshold of ≥8%). Conclusion According our data, VEP seems to have a limited potential especially in patients with a good best-corrected visual acuity (BCVA ≤0.2 LogMAR) for identifying the optic nerve involvement. The fact that P100 latency and amplitude were normal even in cases with an optic nerve swelling makes us question the usefulness of the VEP for diagnosing cases of DON in daily clinical life.

Assessment of Saccular and Semicircular Canal’s Function in Behcet’s Disease

Background and Aim: Behcet’s disease (BD) is a multisystemic, chronic and progressive disorder with a relatively high prevalence in Iran. Therefore, this study aimed to compare the vestibular function between Iranian BD patients and normal subjects using cervical vestibular- evoked myogenic potentials (cVEMPs) and video head impulse test (vHIT). Methods: In this cross-sectional study, 44 patients with definitive BD in the inactive stage of disease and 30 age and sex matched normal subjects were evaluated via cVEMP and vHIT tests and dizziness handicap inventory (DHI). Then the parameters of the tests were compared between the two groups by statistical methods. Moreover, the effects of DHI scores and other contextual variables on the test results were examined. Results: In terms of the cVEMP test, the response rate and mean latency of p13 in the left ear were significantly lower, the amplitude of the cVEMP wave in the left ear and the amplitude asymmetry ratio were significantly higher in BD patients compared to normal subjects (p&lt;0.05). Fifteen BD patients had abnormal amplitude and nine patients had abnormal latency of cVEMP responses. In terms of the vHIT test, the mean vestibule-ocular reflex gain of the left posterior semicircular canal and the mean gain asymmetry ratio of lateral canals were significantly higher in BD patients than in the controls (p&lt;0.05). Conclusion: the vestibular system of some patients with BD is disturbed and the results of this study indicate the presence of unilateral vestibular weakness in BD. So vestibular assessment can be helpful for these patients. Keywords: Cervical vestibular evoked myogenic potentials; video head impulse test; saccule; semicircular canals; behcet’s disease

Subclinical Neuropathy in Children With Type I Diabetes Mellitus: Tertiary Care Centre Experience.

Introduction: Diabetic peripheral neuropathy is a common complication of diabetes mellitus (DM) type 1. However, it can occur without evidence of symptoms or clinical signs of neuropathy labeled as subclinical neuropathy, which neurophysiological studies can best detect.Purpose: To evaluate the prevalence of subclinical neuropathy among children with DM type 1, determine the association with blood sugar control, and evaluate the pattern of nerve involvement in neurophysiological studies.Methods: This cross-sectional study evaluated 100 children with DM type 1, aged five to 15 years, at least one year after the diagnosis. Subclinical neuropathy was evaluated using nerve conduction study. Glycemic control was assessed using hemoglobin A1c (HbA1c).Results: The mean age of subjects was 11.5 ± 0.25 years. The average age at the onset of the disease was 5.95 ± 0.25 years. There were 64 patients who had electrophysiological evidence of peripheral neuropathy. The most observed electrophysiological changes were distal latency abnormalities in the left and right peroneal nerves in 39 and 33 patients, respectively. Sensory nerve amplitude, peak latency, and conduction velocity were normal in all patients (100%). HbA1c level did not show a statistically significant association with the incidence of subclinical neuropathy.Conclusion: Subclinical neuropathy was prevalent in children with DM type 1. Poor glucose control was only associated with an increased odds ratio of subclinical neuropathy.

Subjective-objective sleepiness discrepancy in adult-onset myotonic dystrophy type 1.

Subjective-objective sleepiness discrepancy in adult-onset myotonic dystrophy type 1.

Evaluation of a new online cognitive assessment tool in breast cancer survivors with cognitive impairment: a prospective cohort study.

Currently cancer-related cognitive impairment (CRCI) is mainly assessed by means of questionnaires, which is very laborious for the patients and the supervising physician. We evaluated a new online cognitive assessment tool, the MyCognition Quotient (MyCQ, Cambridge) in breast cancer survivors with CRCI, and compared the results with a psychometric test measuring cognitive complaints, depression, and anxiety. In this prospective study, 46 adult patients between 18 and 70years old with a diagnosis of BC were studied, all complaining of disturbing cognitive impairment. They participated in a physical cognitive rehabilitation program. The patients had an online cognitive assessment (MyCQ Med by MyCognition) every 4weeks on their home computer. In addition patients were assessed in the outpatient clinic by the principal investigator at baseline, after 3 and 6months using the following validated neuro-psychological surveys: the Hospital Anxiety and Depression Scale (HADS), Beck Cognitive Insight Scale (BCIS), and Cognitive Failure Questionnaire (CFQ). MyCQ scores were correlated with the results of these surveys. Only weak correlations could be found between overall MyCQ or the MyCQ subtests with the psychometric tests (between - 0.43 and 0.458) at baseline and when combining data at time point 0, 3, and 6months. Linear mixed models showed there was a significant association between Latency Choice Reaction Time and CFQ (continuous; p = 0.026). An AUC of 0.640 and a cut-off of 481.5ms in Latency Choice Reaction Time were found to distinguish patients with CFQ below 44 to patients with CFQ above 44 (sensitivity 0.63 and specificity 0.73). In Latency Coding an AUC of 0.788 and a cut-off of 1316ms were found to distinguish non-depressive patients from patients likely to present with depressive symptoms (sensitivity 0.75 and specificity 0.76). MyCQ cannot replace the various psychometric tests. However, abnormal Latency in cognitive tests, Choice Reaction Time and Coding, seems promising to be used as a screening tool to detect specific aspects of abnormal cognitive functioning in patients with cognitive complaints and depressive symptoms.

Relationship Between Cervical Nerve Root Entrapment Due to Cervical 6-7 Foraminal Stenosis and Sensory Nerve Action Potentials in Nerve Conduction Study

Objective To compare the sensory nerve action potentials (SNAPs) between patients with cervical 6-7 foraminal stenosis (FS) and those without. Methods We enrolled patients who underwent a bilateral nerve conduction study (NCS) between January 2016 and December 2017. The FS group (n=35) included patients whose lesion was located at C6-7 FS. The non-FS group (n=75) had no lesions at C6-7 foramen. The amplitudes and latencies of SNAPs on the affected side were compared between the two groups. The proportion of those with abnormal SNAP responses was also evaluated. Results Compared with the non-FS group, the FS group had a significantly lower amplitude (30.5 vs. 40.2 µV; age-adjusted p<0.001) and a longer latency (3.31 vs. 3.17 ms; age-adjusted p=0.001) of the median nerve. Abnormal amplitude was observed in 20.0% of the FS group and 4.0% of the non-FS group (age-adjusted p=0.007), and abnormal latency was observed in 45.7% of the FS group and 26.7% of the non-FS group (age-adjusted p=0.010). The median SNAP ratio between the affected side and the unaffected side was not significantly different between the two groups. Conclusion Patients with C6-7 FS had a lower amplitude and a longer latency of the median nerve than did those without. Abnormal SNAP amplitude and latency were significantly more common in patients with FS. SNAP amplitude may be used as a predictor of cervical FS. Keywords: Electrodiagnosis; Cervical foraminal stenosis; Sensory nerve action potential; Median nerve

Multimodal Evoked Potential Profiles in Woodhouse-Sakati Syndrome.

Woodhouse-Sakati syndrome is a rare autosomal recessive syndrome caused by homozygous mutations in the DCAF17 gene, characterized by marked neurologic and endocrine manifestations in the setting of brain iron accumulation and white matter lesions on neuroimaging. Here, we report electrophysiologic profiles in Woodhouse-Sakati syndrome and their possible value in understanding disease pathophysiology and phenotypic variability. Thirteen genetically confirmed Woodhouse-Sakati syndrome patients were evaluated via different evoked potential (EP) modalities, including brainstem auditory EPs, pattern reversal visual EPs, and somatosensory EPs to tibial and/or median nerves. All EP modalities showed variable abnormalities. Pattern reversal visual EPs were recorded in all patients, with nine patients exhibiting abnormal results. From those, seven patients showed prolonged P100 latencies after stimulation of right and left eyes for each in turn. Two patients showed P100 latency abnormality after single eye stimulation recorded from midoccipital electrode. Median somatosensory EPs were recorded in 10 patients, with 6 patients having a prolonged cortical N19 response. Tibial somatosensory EP was performed for 11 patients, and 8 patients showed abnormal results where P37 cortical response was absent or prolonged, whereas peripheral potentials at the popliteal fossa were normal. Brainstem auditory EPs were abnormal only in two patients, with prolonged wave III and V latencies. Five patients with hearing impairment presented with normal brainstem auditory EP results. Multiple EP abnormalities are observed in Woodhouse-Sakati syndrome patients, mainly in pattern reversal visual EPs and somatosensory EPs. These findings indicate potential myelin dysfunction that has a role in the underlying pathophysiology, disease course, and phenotypic variability.

Self-reported view on work capacity predicts abnormal Oxford Sleep Resistance Test results in patients with obstructive sleep apnea.

The Oxford Sleep Resistance Test is an objective vigilance test based on behavior. It is a modified version of the maintenance of wakefulness test and is considered less burdensome and less expensive than the maintenance of wakefulness test. Although professional drivers with obstructive sleep apnea in Europe must be assessed for their ability to maintain adequate wakefulness on a yearly basis, Oxford Sleep Resistance Test results are usually normal in this population. In this retrospective observational study, we searched for predictive factors of abnormal Oxford Sleep Resistance Test sleep latency. We included 1,071 Oxford Sleep Resistance Test results of patients with obstructive sleep apnea (95% men, aged 21-74 years). Mean sleep latency < 40 minutes was considered abnormal. Sleep latency was abnormal in 12.0% of tests. Participants at risk for abnormal test results self-reported as being sleepy, depressed, on sick leave, unemployed, or retired or considered themselves unable to work. In a logistic regression model, the self-reported view on work capacity was the most important predictor of abnormal Oxford Sleep Resistance Test sleep latency (odds ratio, 3.5). Ongoing sick leave was also an important predictor for abnormal test results. A self-reported good ability to work predicts that a patient with sleep apnea can maintain wakefulness in a vigilance test. This may help in reducing the increasing challenge with frequent tests.