Efferent Dysfunction Research Articles

Novel Moving Steady-State Visual Evoked Potential Stimulus to Assess Afferent and Efferent Dysfunction in Multiple Sclerosis.

Afferent and efferent visual dysfunction are prominent features of multiple sclerosis (MS). Visual outcomes have been shown to be robust biomarkers of the overall disease state. Unfortunately, precise measurement of afferent and efferent function is typically limited to tertiary care facilities, which have the equipment and analytical capacity to make these measurements, and even then, only a few centers can accurately quantify both afferent and efferent dysfunction. These measurements are currently unavailable in acute care facilities (ER, hospital floors). We aimed to develop a moving multifocal steady-state visual evoked potential (mfSSVEP) stimulus to simultaneously assess afferent and efferent dysfunction in MS for application on a mobile platform. The brain-computer interface (BCI) platform consists of a head-mounted virtual-reality headset with electroencephalogram (EEG) and electrooculogram (EOG) sensors. To evaluate the platform, we recruited consecutive patients who met the 2017 MS McDonald diagnostic criteria and healthy controls for a pilot cross-sectional study. Nine MS patients (mean age 32.7 years, SD 4.33) and ten healthy controls (24.9 years, SD 7.2) completed the research protocol. The afferent measures based on mfSSVEPs showed a significant difference between the groups (signal-to-noise ratio of mfSSVEPs for controls: 2.50 ± 0.72 vs. MS: 2.04 ± 0.47) after controlling for age (p = 0.049). In addition, the moving stimulus successfully induced smooth pursuit movement that can be measured by the EOG signals. There was a trend for worse smooth pursuit tracking in cases vs. controls, but this did not reach nominal statistical significance in this small pilot sample. This study introduces a novel moving mfSSVEP stimulus for a BCI platform to evaluate neurologic visual function. The moving stimulus showed a reliable capability to assess both afferent and efferent visual functions simultaneously.

Hepatobiliary scintigraphy in the assessment of bile outflow in patients with biliodigestive anastomosis

Aim. To determine the character of bile outflow in patients who underwent biliary tract reconstructive surgery without any clinical and instrumental evidence of the stricture of biliodigestive anastomosis.Materials and methods. The authors analyzed the findings of radionuclide biliary tract studies conducted in 102 patients with biliodigestive anastomosis from 2016 to 2020. The significant relationship between clinical data and hepatobiliary scintigraphy results was confirmed using Fisher’s exact test.Results. In 75 patients (73.5%), bile outflow disturbance was attributed to the efferent loop motility. Of these cases, 3 (4%) involved paresis of the efferent loop, while 70 (93.3%) exhibited multiple episodes of reflux from the efferent loop into the biliodigestive anastomosis and the intrahepatic bile ducts. In 2 patients (2.6%) showing no clinical signs of chronic cholangitis, a rare reflux from the efferent loop into the biliodigestive anastomosis and the intrahepatic bile ducts was noted.Conclusions. Efferent loop dysfunction can greatly disturb bile outflow following the formation of a biliodigestive anastomosis, thus creating conditions for the development of complications.

The Use of Systemic Steroids in the Treatment of Herpes Zoster Ophthalmicus–Related Ophthalmoplegia: Case Report and Case Meta-analysis

The role of systemic steroids in the treatment of ophthalmoplegia in the setting of herpes zoster ophthalmicus (HZO) is controversial. We conducted a case report-based meta-analysis to investigate the role of systemic steroid in the recovery of efferent dysfunctions in HZO. Case-report based meta-analysis. We report a case of herpes zoster ophthalmicus-related ophthalmoplegia (HZORO) in which systemic steroid led to complete resolution of external ophthalmoplegia. We further identified subjects from published cases of HZO-related ophthalmoplegia by searching PubMed and Google Scholar, which elicited 42 articles (49 cases) after excluding those younger than 18 years or with incomplete follow-up data. With the present case, a total of 50 cases are included in the analysis. Main outcome measure is the recovery of efferent dysfunction at the last known follow-up, coded as 1 for complete recovery or 0 for noncomplete recovery. We performed multivariable linear regression and Cox proportional hazards analysis to determine the contribution of steroid duration on the status of complete recovery. Multivariable linear regression showed significant association between duration of steroid treatment and status of complete recovery (P < .001). Cox proportional hazards analysis showed a hazard ratio of 1.1 (P= .04), indicating that longer treatment duration increased chance of complete recovery. Age, gender, and initial steroid dose did not contribute significantly to recovery status. Our meta-analysis suggests that extended steroid taper may aid the recovery of ophthalmoplegia in the setting of HZO and should be investigated further in the future.

Reduced central sympathetic activity in Parkinson's disease.

ObjectiveWith a combination of different sympathetic tests, we aimed to elucidate whether impairment of sympathetic function in Parkinson's disease (PD) is the consequence of a central or peripheral efferent dysfunction.MethodsThirty‐five patients with early‐to‐intermediate PD (median age: 63 years; IQR: 57–67 years; disease duration 1–9 years, 15 women) and 20 age‐ and sex‐matched healthy controls (median age: 64.5 years; IQR: 58–68 years; 10 women) were recruited. Autonomic testing was performed in two subgroups and included the assessment of resting cardiovascular parameters, postprandial hypotension (PPH), orthostatic hypotension (OH), and vasoconstriction induced by intradermal microdialysis with different concentrations of norepinephrine (NE; 10–5; 10–6; 10–7; 10–8) and by cold through forehead cooling. We also used sympathetic multiunit microneurography (muscle sympathetic nerve activity; MSNA; burst frequency (BF): bursts per minute; burst incidence (BI): bursts per 100 heart beats) and evaluated the presence of phosphorylated α‐synuclein deposits in skin innervation in biopsies from the thighs by immunohistohemistry.ResultsDiastolic blood pressure was higher in the PD group at rest (p < .001) and during OH (F = 6.533; p = .022). Vasoconstriction induced by NE microdialysis and cold was unchanged in PD patients. MSNA was lower in PD patients than in controls (BF: p = .001; BI: p = .025). Phosphorylated α‐synuclein deposits could be found only in PD patients.ConclusionWe did not find indications for peripheral sympathetic nerve fiber dysfunction or adrenoreceptor sensitivity changes. The decreased MSNA argues in favor of central sympathetic impairment.

Differences in functional brain alterations driven by right or left facial nerve efferent dysfunction: Evidence from early Bell's palsy.

Bell's palsy is defined as idiopathic unilateral facial nerve palsy. Early Bell's palsy is characterized by emerging asymmetric motor conduction of the facial nerve and obvious imbalance of facial muscle movement, which can result in a substantial psychological impact on patients and trigger brain cortical functional reorganization. However, the differences between the brain functional alterations were driven by right or left facial nerve efferent dysfunction in patients with early Bell's palsy are not fully understood. The neuroimage study in patients with different-sided Bell's palsy in the early stage will help to understand the different mechanisms involved in functional integration driven by unilateral facial efferent nerve dysfunction and to provide the theoretical foundation for the choice of suitable treatment strategy. Sixty-seven patients and 37 age- and sex-matched healthy controls were recruited to undergo resting-state functional magnetic resonance imaging (R-fMRI). Regional brain activity was analyzed by comparing the fractional amplitude of low-frequency fluctuations (fALFF) between right palsy and healthy control, left palsy and healthy control, and right and left palsy groups. The altered brain regions were further selected as seeds in subsequent functional connectivity (FC) analysis, and the correlations between the Toronto Facial Grading System (TFGS) scores and the connectivity alterations were also analyzed. The right and left Bell's palsy groups showed fALFF alterations compared with the healthy control group, and several brain regions with different fALFF values between the right and left palsy groups were identified. In the right palsy group, overall inter-regional FC increased in the right supramarginal gyrus (SMG), bilateral superior frontal gyrus (SFG), and left precentral gyrus (PreCG), compared with the left palsy group. Furthermore, the brain region pairs with higher FC in the right palsy group were left temporal pole of the superior temporal gyrus (TPOsup) and right SMG, left TPOsup and middle cingulate cortex (MCC), left TPOsup and left PreCG, right SMG and SFG, MCC and left PreCG, left and right SFG, and right SFG and left PreCG. In the right palsy group, the left TPOsup and PreCG showed a negative correlation with the TFGS score, while the right SFG and left PreCG showed a positive correlation with the TFGS scores. In the left palsy group, the left TPOsup and right SMG, and the right SMG and SFG region pairs showed a negative correlation with the TFGS score. The fALFF and FC analyses revealed the remodeling of different brain functional networks driven by right or left facial nerve efferent dysfunction in patients with early Bell's palsy. The reintegration mechanisms differed between patients with right and left Bell's palsy. Additionally, the severity of the disease showed different associations with altered FC.

Subclinical Saccadic Eye Movement Dysfunction in Pediatric Multiple Sclerosis.

Efferent visual dysfunction in children could lead to impaired quality of life at home and school. Eye-tracking can detect subtle efferent dysfunction missed on bedside examination but has not been validated in the pediatric multiple sclerosis population. We sought to determine the feasibility of eye-tracking in children and associations with multiple sclerosis. Participants meeting criteria for pediatric multiple sclerosis without acute efferent vision abnormalities and healthy controls were recruited. Multiple sclerosis participants underwent a clinical assessment and saccade and antisaccade testing paradigms. Intraclass correlation coefficients were generated for intertest repeatability. Adjusting for age and intereye correlations, generalized estimating equations compared latencies with case status, Expanded Disability Status Scale and Symbol Digit Modalities Test (SDMT) scores. We eye-tracked 15 children with multiple sclerosis (n = 30 eyes, mean age 15.6 ± 2.1, mean disease duration 3.9 years, median Expanded Disability Status Scale 1.5) compared to 6 healthy controls (n = 12 eyes, age 14.3 ± .95). The intraclass correlation coefficient for repeated trials was 0.85. Adjusting for age, saccadic latency was 60 milliseconds (ms) longer for cases than controls (95% confidence interval = 26.4, 93.8; P = .0005). For antisaccadic latency, we observed a similar trend of 60 ms longer for cases than controls ( P = .06). Eye-tracking is a short noninvasive examination, and high intertest repeatability supports use of eye-tracking technology in pediatric multiple sclerosis. Longer saccadic latencies were seen in children with multiple sclerosis despite short disease duration and low Expanded Disability Status Scale scores.

Visual Dysfunction in Combat-related Mild Traumatic Brain Injury—A Review

Approximately half of all military personnel who have served in the conflicts in Iraq and Afghanistan are reported to have some degree of combat-related mild traumatic brain injury (TBI). Although in civilian concussion injuries symptoms typically resolve within several weeks, blast-induced mild TBI may be accompanied by prolonged symptoms and afferent and efferent visual dysfunction. Most commonly near vision problems and photophobia are the presenting symptoms. A complete eye exam including vision testing, oculomotor function, and near tasking, is highly recommended after blast-induced mild TBI to detect and improve symptoms in this young patient population. A review of the current literature is presented.

255 DRAMATIC REDUCTION IN URETHRAL SPHINCTER ACTIVITY FOLLOWING PELVIC NERVE CRUSH IN THE RAT

You have accessJournal of UrologyBladder and Urethra: Anatomy, Physiology and Pharmacology I1 Apr 2012255 DRAMATIC REDUCTION IN URETHRAL SPHINCTER ACTIVITY FOLLOWING PELVIC NERVE CRUSH IN THE RAT Christopher Chermansky, Qiang Wu, J. Christian Winters, and Matthew Fraser Christopher ChermanskyChristopher Chermansky New Orleans, LA More articles by this author , Qiang WuQiang Wu New Orleans, LA More articles by this author , J. Christian WintersJ. Christian Winters New Orleans, LA More articles by this author , and Matthew FraserMatthew Fraser Durham, NC More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2012.02.312AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES There is no established rat model for euglycemic non-obstructive underactive bladder (UAB). We present such a model for the purpose of testing therapies aimed at improving bladder emptying in patients with this condition. METHODS 44 female SD rats were divided into two experimental groups: bilateral pelvic nerve crush (PNC) and control. PNC was performed in 23 rats under isoflurane anesthesia. A straight Jacobson micro mosquito clamp was used to crush each pelvic nerve for 30 seconds. The crush was performed proximal to each pelvic nerve's entry into the major pelvic ganglion. Prior to crushing, the identity of the pelvic nerve was verified by electrical stimulation with a bipolar electrode to confirm visual bladder contraction. 21 control rats underwent a sham operation where pelvic nerves were exposed but not crushed. At 1, 2, and 4 weeks following PNC or sham surgery, the rats underwent continuous cystometry and external urethral sphincter (EUS) EMG testing under urethane anesthesia (1.2g/kg) using a PE90 transvesical catheter and a saline infusion rate of 0.04 ml/min. Periurethral EUS EMG fine wire electrodes were inserted percutaneously. Finally, isovolumetric cystometry was performed to measure bladder contractile strength by tying off the urethra. Data were collected using PowerLab from AD Instruments. Statistical comparisons between groups were performed using two-way ANOVA with GraphPad from Prism. RESULTS Following PNC, intercontraction interval (ICI) increased at 1 week and remained doubled at 4 weeks during continuous CMG. This was paralleled by similar increases in bladder compliance. A striking reduction (50%) in EUS EMG activity during filling was also seen with PNC. Isovolumetric CMG in the PNC groups revealed a 40% reduction in peak bladder contraction pressures over baseline and a 30% reduction in isovolumetric bladder contraction areas under the curves. CONCLUSIONS In this preliminary study, we have shown that bilateral pelvic nerve crush in the rat is a promising, long-lasting model of UAB, demonstrating both bladder and outlet dysfunction consistent with pelvic nerve denervation. Increased ICI, bladder compliance, and decreased EUS activity are consistent with decreased afferent sensitivity with PNC. Decreased bladder contraction strength is consistent with compromised efferent function. By establishing a chronic rat model for UAB in otherwise normal animals, we can test potential therapies for treating UAB and voiding dysfunction, thereby addressing both afferent and efferent dysfunction. © 2012 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 187Issue 4SApril 2012Page: e103-e104 Peer Review Report Advertisement Copyright & Permissions© 2012 by American Urological Association Education and Research, Inc.MetricsAuthor Information Christopher Chermansky New Orleans, LA More articles by this author Qiang Wu New Orleans, LA More articles by this author J. Christian Winters New Orleans, LA More articles by this author Matthew Fraser Durham, NC More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

256 EVALUATION OF INCREASED VOIDING FREQUENCY IN MICE WITH TYPE 2 DIABETES MELLITUS

creased at 1 week and remained doubled at 4 weeks during continuous CMG. This was paralleled by similar increases in bladder compliance. A striking reduction (50%) in EUS EMG activity during filling was also seen with PNC. Isovolumetric CMG in the PNC groups revealed a 40% reduction in peak bladder contraction pressures over baseline and a 30% reduction in isovolumetric bladder contraction areas under the curves. CONCLUSIONS: In this preliminary study, we have shown that bilateral pelvic nerve crush in the rat is a promising, long-lasting model of UAB, demonstrating both bladder and outlet dysfunction consistent with pelvic nerve denervation. Increased ICI, bladder compliance, and decreased EUS activity are consistent with decreased afferent sensitivity with PNC. Decreased bladder contraction strength is consistent with compromised efferent function. By establishing a chronic rat model for UAB in otherwise normal animals, we can test potential therapies for treating UAB and voiding dysfunction, thereby addressing both afferent and efferent dysfunction.

Quantitative analysis of cochlear active mechanisms in tinnitus subjects with normal hearing sensitivity: Time–frequency analysis of transient evoked otoacoustic emissions and contralateral suppression

Objective The aim of this study was to analyze the fine structure of transient evoked otoacoustic emissions (TEOAEs) and contralateral suppression effects in tinnitus subjects with normal hearing in order to assess whether a minor cochlear or efferent dysfunction, possibly limited in narrow cochlear regions, might play a role in tinnitus. Methods TEOAEs were recorded, both in the absence and in the presence of contralateral acoustic stimulation, in 23 tinnitus patients with normal hearing sensitivity and in 31 non-tinnitus control subjects. The broad-band TEOAE recordings were analyzed by using an innovative algorithm and separated into a set of 33 narrow-band frequency components, that represent the different cochlear contributions to the whole TEOAE response. In each frequency component, three different parameters were analyzed and compared between tinnitus and non-tinnitus subjects, i.e., reproducibility, latency, and the suppression effects induced by contralateral acoustic stimulation. Results Significantly lower reproducibility was observed in the frequency components of the tinnitus subjects compared to the controls, whereas no significant differences in latency and in suppression effects were observed between tinnitus and non-tinnitus ears. Conclusions The analysis of the fine structure of TEOAEs revealed that the tinnitus subjects involved in this study might, possibly, have a minor dysfunction of the cochlear active mechanisms that resulted in frequency components with lower reproducibility. Conversely, the analysis of suppression effects in the narrow-band frequency components of TEOAE indicated that the subjects involved showed no relevant damage to the efferent regulatory mechanisms that control the cochlear activity, neither through the cochlea as a whole, nor in limited cochlear regions.

Prevalence of organic Neuro-ophthalmologic disease in patients with functional visual loss

PurposeTo determine the concurrence of various patterns of functional visual loss (FVL) and organic disease. DesignA retrospective case series in a university neuro-ophthalmology practice. MethodsA retrospective case series in which we reviewed the clinical histories and neuro-ophthalmologic examinations of 133 consecutive patients diagnosed with FVL between July 1999 and August 2001. Functional visual loss was defined as an apparent afferent or efferent dysfunction that was unassociated with or far out of proportion with an identifiable lesion of the visual pathways. ResultsA total of 133 patients were identified. Nineteen were pediatric, and 76 were female. Fifty-six had concurrent head or eye pain. Nineteen had a recent history of trauma, and 17 had a recent surgical procedure. The most common pattern of FVL was a normal visual field in the presence of reduced visual acuity. Seventy-one patients (53%) with FVL presented with abnormal neuro-ophthalmologic examinations. Thirteen patients had central scotomata, and all had concurrent retinal or optic nerve pathology. Only 18 patients had a known disability claim pending. ConclusionAlthough FVL was found in patients with no pathology, it was more common to find objective abnormalities on examination. This concurrence rate underscores the clinical necessity for following patients closely despite the diagnosis of FVL. No pattern of visual field constriction was routinely predictive of ophthalmologic or neurologic pathology except the presence of a central scotoma. The presence of a central scotoma in a nonorganic visual field should alert the practitioner to search for organic pathology.

The effect of vestibular nerve section upon tinnitus.

This paper reviews the published evidence regarding the effect of vestibular nerve section upon tinnitus. This is of relevance not only for those performing and undergoing this procedure, but also for those considering the hypothesis that auditory efferent system dysfunction may be influential in tinnitus perception. The auditory medial efferent fibres within the internal auditory canal run within the inferior vestibular nerve, only joining the cochlear nerve at the anastomosis of Oort, a bundle of 1300 fibres running from the saccular branch of the inferior vestibular nerve to the cochlear nerve. Vestibular nerve section procedures therefore section this efferent olivocochlear pathway, and ablate efferent influence upon that cochlear. If auditory efferent dysfunction is involved in tinnitus perception, this ablation might influence the tinnitus status of that patient. A literature search identified 18 papers mentioning tinnitus status after vestibular nerve section, describing the experiences of a total of 1318 patients. The proportion of patients in whom tinnitus was said to be exacerbated postoperatively ranged from 0% to 60%, with a mean of 16.4% (standard deviation 14.0). The proportion of patients in whom tinnitus was unchanged was 17% to 72% (mean 38.5%, standard deviation 15.6), and in whom tinnitus was said to be improved was 6% to 61% (mean 37.2%, standard deviation 15.2). In the majority of patients undergoing this procedure, ablation of auditory efferent input (and thus total efferent dysfunction) to the cochlea was not associated with an exacerbation of tinnitus. The finding of this review is that efferent dysfunction after vestibular nerve section does not consistently worsen tinnitus.

Reduced baroreflex sensitivity in elderly humans is not due to efferent autonomic dysfunction

Reduced baroreflex sensitivity in elderly humans is not due to efferent autonomic dysfunction

Gastric accommodation in non-ulcer dyspepsia and the roles ofHelicobacter pylori infection and vagal function

BackgroundThe pathophysiological mechanisms in non-ulcer dyspepsia are incompletely understood.AimsTo compare gastric motor and sensory functions in Helicobacter pyloripositive or negative patients with non-ulcer dyspepsia.PatientsSeventeen patients with non-ulcer dyspepsia and 16...

Nonulcer Dyspepsia: A Look Into the Future

Nonulcer Dyspepsia: A Look Into the Future