Suture-Needle Management Device and Novel Port Configuration for Robotic Sacrocolpopexy

IMPORTANCE

Robot-assisted sacrocolpopexy (SCP) is a commonly performed procedure for the repair of apical pelvic organ prolapse; therefore, novel devices and techniques to improve safety and efficacy of this procedure should be explored.

OBJECTIVE

The objective of this study was to assess safety and efficacy of 8-mm trocar site for use of a disposable suture/needle management device (StitchKit; Origami Surgical, Madison, NJ) for robot-assisted SCP with a 4-arm configuration and no assistant port.

STUDY DESIGN

This is a retrospective case series of patients undergoing robot-assisted SCP at a tertiary center from 2018 to 2021. All surgical procedures were performed using four 8-mm robotic trocars and StitchKit device. Our objective was to review all cases in which this technique was used to determine whether the approach resulted in a safely completed procedure and any complications or adverse events. Secondary objectives were to describe patient and operative characteristics.

RESULTS

In total, 422 patients underwent robot-assisted SCP for pelvic organ prolapse. The mean age was 60 ± 10 years, and mean body mass index was 27 ± 6 (calculated as weight in kilograms divided by height in meters squared). Most patients had stage 3 prolapse (73%) and underwent concomitant hysterectomy (70%). Ninety-nine percent (n = 416) of cases were completed robotically. StitchKit was successfully inserted and removed in all robotic cases with correct needle counts. All patients had postoperative visits, and 80% followed up at 3 months. No umbilical/port site hernias, operative site infections, or adverse events were reported.

CONCLUSIONS

Robot-assisted SCP can be performed safely using a 4-arm robotic configuration and suture kit device. This setup eliminates incisions greater than 8 mm and an assistant port, allowing for surgical efficiency without compromising patient outcomes.

Race and Ethnicity Reporting and Representation in Obstetrics and Gynecology Clinical Trials and Publications From 2007-2020

Importance

Clinical trials guide evidence-based obstetrics and gynecology (OB-GYN) but often enroll nonrepresentative participants.

Objective

To characterize race and ethnicity reporting and representation in US OB-GYN clinical trials and their subsequent publications and to analyze the association of subspecialty and funding with diverse representation.

Design and Setting

Cross-sectional analysis of all OB-GYN studies registered on ClinicalTrials.gov (2007-2020) and publications from PubMed and Google Scholar (2007-2021). Analyses included logistic regression controlling for year, subspecialty, phase, funding, and site number. Data from 332 417 studies were downloaded. Studies with a noninterventional design, with a registration date before October 1, 2007, without relevance to OB-GYN, with no reported results, and with no US-based study site were excluded.

Exposures

OB-GYN subspecialty and funder.

Main Outcomes and Measures

Reporting of race and ethnicity data and racial and ethnic representation (the proportion of enrollees of American Indian or Alaskan Native, Asian, Black, Latinx, or White identity and odds of representation above US Census estimates by race and ethnicity).

Results

Among trials with ClinicalTrials.gov results (1287 trials with 591 196 participants) and publications (1147 trials with 821 111 participants), 662 (50.9%) and 856 (74.6%) reported race and ethnicity data, respectively. Among publications, gynecology studies were significantly less likely to report race and ethnicity than obstetrics (adjusted odds ratio [aOR], 0.54; 95% CI, 0.38-0.75). Reproductive endocrinology and infertility trials had the lowest odds of reporting race and ethnicity (aOR, 0.14; 95% CI, 0.07-0.27; reference category, obstetrics). Obstetrics and family planning demonstrated the most diverse clinical trial cohorts. Compared with obstetric trials, gynecologic oncology had the lowest odds of Black representation (ClinicalTrials.gov: aOR, 0.04; 95% CI, 0.02-0.09; publications: aOR, 0.06; 95% CI, 0.03-0.11) and Latinx representation (ClinicalTrials.gov: aOR, 0.05; 95% CI, 0.02-0.14; publications: aOR, 0.23; 95% CI, 0.10-0.48), followed by urogynecology and reproductive endocrinology and infertility. Urogynecology (ClinicalTrials.gov: aOR, 0.15; 95% CI, 0.05-0.39; publications: aOR, 0.24; 95% CI, 0.09-0.58) had the lowest odds of Asian representation.

Conclusions and Relevance

Race and ethnicity reporting and representation in OB-GYN trials are suboptimal. Obstetrics and family planning trials demonstrate improved representation is achievable. Nonetheless, all subspecialties should strive for more equitably representative research.

Contrast Sensitivity Testing in Age-Related Macular Degeneration Using Motion Diamond Stimulus

Purpose

This study was performed to characterize changes in contrast sensitivity (CS) that occur in patients with age-related macular degeneration (AMD) using a novel test, the motion diamond stimulus (MDS).

Methods

This was a cross-sectional study in which 20 subjects with unilateral exudative AMD (eAMD) and contralateral dry AMD received 3 assessments: the Pelli-Robson (PR) CS Chart, the MDS test, and a visual function questionnaire-25 (VFQ-25). CS results from the PR, and MDS tests were compared across 3 groups: eyes with eAMD vs dry AMD, eAMD vs control, dry AMD vs control. Healthy, undilated eyes from another study served as the control group. Significance was determined using ANOVA analysis for the MDS output parameters (α: overall contrast threshold, β: adaptability of the visual system) and PR logCS. Patients were also administered the VFQ-25 to assess vision-related quality of life.

Results

The ANOVA of the MDS data demonstrated a significant difference in visual function according to the β parameter of the 3 groups, but no significant difference in the α parameter. PR CS results for the 3 groups were significantly different, further supporting the MDS results. Post-hoc analysis showed a significant difference in β and PR log CS between the eAMD and control eyes.

Conclusion

The MDS test is valuable in discerning CS impairments in patients with AMD. It can provide further insight into the visual changes experienced by patients with AMD and has potential to quantify visual function changes that are not found on visual acuity testing alone.

Contrast Sensitivity Testing in Retinal Vein Occlusion Using a Novel Stimulus

Purpose

This study evaluated a novel tool known as the motion diamond stimulus (MDS), which utilizes contrast-generated illusory motion in dynamic test regions to determine contrast sensitivity (CS).

Methods

Patients with treated unilateral retinal vein occlusions (RVOs) underwent three assessments: the MDS, the Pelli-Robson (PR), and the National Eye Institute's Visual Function Questionnaire (VFQ-25). The MDS assessment produced two data end points, α and β. The α value represents the overall contrast threshold level and the β value serves to quantify the adaptability of the visual contrast system. The CS parameters from the MDS and log CS PR output values were used to compare RVO eyes (n = 20) to control eyes (n = 20).

Results

The study participants had a mean composite VFQ-25 score of 89.5 ± 10.4 on the VFQ-25. A significant difference was observed between the RVO eyes and the control eyes in PR log CS scores (P value = 0.0001) and in MDS α value (P value = 0.01). No difference in MDS β value was found between the study groups (P value = 0.39).

Conclusions

The results for the MDS assessment's α parameter corroborated the PR scores, suggesting contrast sensitivity threshold impairment in patients with RVO. No significant difference in β value was observed, suggesting that adaptability of the visual system is maintained in treated RVO eyes.

Translational Relevance

Currently, visual complaints cannot be entirely identified by Snellen visual acuity alone. The MDS offers potentially a more complete look at visual function, by including contrast sensitivity and may be able to quantify changes otherwise overlooked in retinal disease progression.

Gene regulatory networks controlling vertebrate retinal regeneration

Injury induces retinal Müller glia of certain cold-blooded vertebrates, but not those of mammals, to regenerate neurons. To identify gene regulatory networks that reprogram Müller glia into progenitor cells, we profiled changes in gene expression and chromatin accessibility in Müller glia from zebrafish, chick, and mice in response to different stimuli. We identified evolutionarily conserved and species-specific gene networks controlling glial quiescence, reactivity, and neurogenesis. In zebrafish and chick, the transition from quiescence to reactivity is essential for retinal regeneration, whereas in mice, a dedicated network suppresses neurogenic competence and restores quiescence. Disruption of nuclear factor I transcription factors, which maintain and restore quiescence, induces Müller glia to proliferate and generate neurons in adult mice after injury. These findings may aid in designing therapies to restore retinal neurons lost to degenerative diseases.

A possible link between intracranial lipomas and localization-related relapses in multiple sclerosis

Intracranial lipomas are congenital malformations representing less than 0.5% of intracranial tumors. They are found incidentally and are asymptomatic in the majority of patients. Here we present three patients with Multiple sclerosis (MS) and intracranial lipomas (IL). The patients showed increased flares and burden of disabling and worsening MS symptoms with cognitive, neurovestibular dysfunction, and gait alterations associated with the localization of the Lipoma. The parenchyma near the Lipomas showed areas of demyelination and atrophy. We postulate that the location and content of the Lipomas may participate in the pathophysiology of MS symptoms in these patients. We conclude that in concurrent IL and MS, the lipomas localization may provoke incapacitating relapses.

BMP- and TGFβ-signaling regulate the formation of Müller glia-derived progenitor cells in the avian retina

Müller glia-derived progenitor cells (MGPCs) have the capability to regenerate neurons in the retinas of different vertebrate orders. The formation of MGPCs is regulated by a network of cell-signaling pathways. The purpose of this study was to investigate how BMP/Smad1/5/8- and TGFβ/Smad2/3-signaling are coordinated to influence the formation of MGPCs in the chick model system. We find that pSmad1/5/8 is selectively up-regulated in the nuclei of Müller glia following treatment with BMP4, FGF2, or NMDA-induced damage, and this up-regulation is blocked by a dorsomorphin analogue DMH1. By comparison, Smad2/3 is found in the nuclei of Müller glia in untreated retinas, and becomes localized to the cytoplasm following NMDA- or FGF2-treatment. These findings suggest a decrease in TGFβ- and increase in BMP-signaling when MGPCs are known to form. In both NMDA-damaged and FGF2-treated retinas, inhibition of BMP-signaling suppressed the proliferation of MGPCs, whereas inhibition of TGFβ-signaling stimulated the proliferation of MGPCs. Consistent with these findings, TGFβ2 suppressed the formation of MGPCs in NMDA-damaged retinas. Our findings indicate that BMP/TGFβ/Smad-signaling is recruited into the network of signaling pathways that controls the formation of proliferating MGPCs. We conclude that signaling through BMP4/Smad1/5/8 promotes the formation of MGPCs, whereas signaling through TGFβ/Smad2/3 suppresses the formation of MGPCs.

Jak/Stat signaling regulates the proliferation and neurogenic potential of Müller glia-derived progenitor cells in the avian retina

Müller glia are capable of de-differentiating and proliferating to become Müller glia-derived progenitor cells (MGPCs) with the ability to regenerate retinal neurons. One of the cell-signaling pathways that drives the reprogramming of Müller glia into MGPCs in the zebrafish retina is the Jak/Stat-pathway. However, nothing is known about the influence of Jak/Stat-signaling during the formation of MGPCs in the retinas of warm-blooded vertebrates. Accordingly, we examined whether Jak/Stat-signaling influences the formation of MGPCs and differentiation of progeny in the avian retina. We found that Jak/Stat-signaling is activated in Müller glia in response to NMDA-induced retinal damage or by CNTF or FGF2 in the absence of retinal damage. Inhibition of gp130, Jak2, or Stat3 suppressed the formation of proliferating MGPCs in NMDA-damaged and FGF2-treated retinas. Additionally, CNTF combined with FGF2 enhanced the formation of proliferating MGPCs in the absence of retinal damage. In contrast to the zebrafish model, where activation of gp130/Jak/Stat is sufficient to drive neural regeneration from MGPCs, signaling through gp130 inhibits the neurogenic potential of MGPCs and promotes glial differentiation. We conclude that gp130/Jak/Stat-signaling plays an important role in the network of pathways that drives the formation of proliferating MGPCs; however, this pathway inhibits the neural differentiation of the progeny.

Heparin-binding EGF-like growth factor (HB-EGF) stimulates the proliferation of Müller glia-derived progenitor cells in avian and murine retinas

Müller glia can be stimulated to de-differentiate, proliferate and form Müller glia-derived progenitor cells (MGPCs) that regenerate retinal neurons. In the zebrafish retina, heparin-binding EGF-like growth factor (HB-EGF) may be one of the key factors that stimulate the formation of proliferating MGPCs. Currently nothing is known about the influence of HB-EGF on the proliferative potential of Müller glia in retinas of birds and rodents. In the chick retina, we found that levels of both hb-egf and egf-receptor are rapidly and transiently up-regulated following NMDA-induced damage. Although intraocular injections of HB-EGF failed to stimulate cell-signaling or proliferation of Müller glia in normal retinas, HB-EGF stimulated proliferation of MGPCs in damaged retinas. By comparison, inhibition of the EGF-receptor (EGFR) decreased the proliferation of MGPCs in damaged retinas. HB-EGF failed to act synergistically with FGF2 to stimulate the formation of MGPCs in the undamaged retina and inhibition of EGF-receptor did not suppress FGF2-mediated formation of MGPCs. In the mouse retina, HB-EGF stimulated the proliferation of Müller glia following NMDA-induced damage. Furthermore, HB-EGF not only stimulated MAPK-signaling in Müller glia/MGPCs, but also activated mTor- and Jak/Stat-signaling. We propose that levels of expression of EGFR are rate-limiting to the responses of Müller glia to HB-EGF and the expression of EGFR can be induced by retinal damage, but not by FGF2-treatment. We conclude that HB-EGF is mitogenic to Müller glia in both chick and mouse retinas, and HB-EGF is an important player in the formation of MGPCs in damaged retinas.

Comparative analysis of glucagonergic cells, glia, and the circumferential marginal zone in the reptilian retina

Retinal progenitors in the circumferential marginal zone (CMZ) and Müller glia-derived progenitors have been well described for the eyes of fish, amphibians, and birds. However, there is no information regarding a CMZ and the nature of retinal glia in species phylogenetically bridging amphibians and birds. The purpose of this study was to examine the retinal glia and investigate whether a CMZ is present in the eyes of reptilian species. We used immunohistochemical analyses to study retinal glia, neurons that could influence CMZ progenitors, the retinal margin, and the nonpigmented epithelium of ciliary body of garter snakes, queen snakes, anole lizards, snapping turtles, and painted turtles. We compare our observations on reptile eyes to the CMZ and glia of fish, amphibians, and birds. In all species, Sox9, Pax6, and the glucocorticoid receptor are expressed by Müller glia and cells at the retinal margin. However, proliferating cells were found only in the CMZ of turtles and not in the eyes of anoles and snakes. Similar to eyes of chickens, the retinal margin in turtles contains accumulations of GLP1/glucagonergic neurites. We find that filamentous proteins, vimentin and GFAP, are expressed by Müller glia, but have different patterns of subcellular localization in the different species of reptiles. We provide evidence that the reptile retina may contain nonastrocytic inner retinal glial cells, similar to those described in the avian retina. We conclude that the retinal glia, glucagonergic neurons, and CMZ of turtles appear to be most similar to those of fish, amphibians, and birds.

Choice behavior and the accessibility of the reinforcer

In Experiment 1, matching of relative response rates to relative rates of reinforcement was obtained in concurrent variable-interval schedules when the absolute values of the two concurrent variable-interval schedules varied from 6 sec and 12 sec to 600 sec and 1200 sec. Increases in the duration of the changeover delay, however, produced decreases in the relative response rates and, consequently, some deviation from matching. In Experiment 2, matching of relative response rates to the relative duration of the reinforcer failed to occur when the equal variable-interval schedules arranging access to the two different reinforcer durations (1.5 and 6 sec) were varied in size from concurrent variable-interval 10-sec schedules to concurrent variable-interval 600-sec schedules.

A model for choice in simple concurrent and concurrent-chains schedules

Pigeons' responses in the presence of two concurrently available (initial-link) stimuli produced one of two different (terminal-link) stimuli. Entrance into the mutually exclusive terminal links was arranged by different and independent variable-interval schedules for each key, while responses during the mutually exclusive terminal-link stimuli produced a single food reinforcement according to indentical and independent variable-interval schedules. The pigeons emitted more initial-link responses on the key with the shorter average interreinforcement interval in the initial link. This difference in initial-link response rates varied directly with the difference between the average inter-reinforcement intervals of the initial-link schedules and decreased when the initial-link schedule with the longer average interreinforcement interval was followed by several consecutive food reinforcements on the variable-interval schedule in the terminal link on that key. These results are incompatible with previous formulations of choice behavior with the concurrent-chains procedure. A modified formulation with a multiplier for the overall rate of primary reinforcement obtained on each key provides a better description of choice. In addition, the new formulation applies to behavior in simple (concurrent) choice situations, an advantage not achieved by previous formulations.

Second-order schedules: discrimination of components

Pigeons were exposed to a series of second-order schedules in which the completion of a fixed number of fixed-interval components produced food. In Experiment 1, brief (2 sec) stimulus presentations occurred as each fixed-interval component was completed. During the brief-stimulus presentation terminating the last fixed-interval component, a response was required on a second key, the brief-stimulus key, to produce food. Responses on the brief-stimulus key before the last brief-stimulus presentation had no scheduled consequences, but served as a measure of the extent to which the final component was discriminated from preceding components. Whether there were one, two, four, or eight fixed-interval components, responses on the brief-stimulus key occurred during virtually every brief-stimulus presentation. In Experiment 2, an attempt was made to punish unnecessary responses on the brief-stimulus key, i.e., responses on the brief-stimulus key that occurred before the last component. None of the pigeons learned to withhold these responses, even though they produced a 15-sec timeout and loss of primary reinforcement. In Experiment 3, different key colors were associated with each component of a second-order schedule (a chain schedule). In contrast to Experiment 1, brief-stimulus key responses were confined to the last component. It was concluded that pigeons do not discriminate well between components of second-order schedules unless a unique exteroceptive cue is provided for each component. The relative discriminability of the components may account for the observed differences in initial-component response rates between comparable brief-stimulus, tandem, and chain schedules.

Surgical treatment of peroneal tendon tears

The focus of this article is the diagnosis and treatment of peroneal tendon tears. The article first describes mechanisms of injuries resulting in peroneal brevis and longus tears. Associated pathologies, such as ankle instability, hindfoot varus, hypertrophied peroneal tubercle, are discussed. Following sections on diagnosis and conservative treatment, the article describes operative treatment for isolated peroneus brevis tear, isolated peroneus longus tear, and tears of both the peroneus longus and brevis. The authors also discuss hamstring allograft reconstruction, the silicone rod technique, flexor digitorum longus transfer to the peroneus brevis, and treatment of associated pathology.

Dysphagia management for progressive neurological conditions

This article discusses some of the issues surrounding dysphagia management for patients with progressive neurological conditions. It is important that health professionals are aware of the available options and that they consider patients' wishes to meet their nutritional needs.

School and neuropsychological performance of evacuated children in Kyiv 11 years after the Chornobyl disaster

This paper examines the cognitive and neuropsychological functioning of children who were in utero to age 15 months at the time of the Chornobyl disaster and were evacuated to Kyiv from the 30-kilometer zone surrounding the plant. Specifically, we compared 300 evacuee children at ages 10-12 with 300 non-evacuee Kyiv classmates on objective and subjective measures of attention, memory, and school performance. The evacuee children were not significantly different from their classmates on the objective measures (grades; Symbolic Relations subtest of the Detroit Test; forms 1 and 2 of the Visual Search and Attention Test; Benton Form A; Trails A; Underline the Words Test) or on most of the subjective measures (the attention subscale of the Child Behavior Checklist completed by mothers; the attention items of the Iowa Conners Teacher's Rating Scale; mother and child perceptions of school performance). The one exception was that 31.3% of evacuee mothers compared to 7.4% of classmate mothers indicated that their child had a memory problem. However, this subjective measure of memory problems was not significantly related to neuropsychological or school performance. No significant differences were found in comparisons of evacuees and classmates who were in utero at the time of the explosion, children from Pripyat vs. other villages in the 30-kilometer zone, and children manifesting greater generalized anxiety. For both groups, children with greater Chornobyl-focused anxiety performed significantly worse than children with less Chornobyl-focused anxiety on measures of attention. The results thus fail to confirm two previous reports that relatively more children from areas contaminated by radiation had cognitive deficits compared to controls. Possible reasons for the differences in findings among the studies are discussed.

Interventions for treating schistosomiasis haematobium

BACKGROUND

Schistosomiasis is a parasite that is carried by freshwater snails. There are two common forms, urinary schistosomiasis (which is considered in this review) and intestinal schistosomiasis.

OBJECTIVES

The objective of this review was to assess the effects of drugs for treatment of Schistosomiasis haematobium.

SEARCH STRATEGY

The Cochrane Infectious Diseases Group trials register, Medline and reference lists of articles were searched. The WHO Division of Control of Tropical Diseases was contacted.

SELECTION CRITERIA

Randomised trials of metrifonate or praziquantel or other drugs for treating Schistosomiasis haematobium.

DATA COLLECTION AND ANALYSIS

One reviewer assessed trial quality and extracted data, and this was checked by a review editor.

MAIN RESULTS

Five trials, all from Africa, were included. The quality of the trials was variable. There were no good randomised controlled trials of praziquantel single dose treatment versus current standard treatment with metrifonate of three doses of 10 milligrams per kilogram at two weekly intervals. Praziquantel at doses of 40 milligram per kilogram was more effective than single dose metrifonate 10 milligrams per kilogram (odds ratio 6.94, 95% confidence interval 4.85 to 9.92). In one trial of metrifonate compared with praziquantel, there was no difference demonstrated in a range of clinical outcomes including cessation of haematuria and proteinuria. Both drugs improved nutritional status and physical fitness.

REVIEWER'S CONCLUSIONS

Praziquantel (single dose) appears to be more effective than metrifonate (split dose) in terms of parasitological cure of Schistosomiasis haematobium, but the reinfection rate is high with both drugs.

Auditory brain stem responses in the mentally retarded: audiometric correlates

In previous reports we have suggested that the auditory brain-stem responses (ABRs) of adults with Down's syndrome exhibit two abnormalities unique to that population: a shortened central conduction time and an insensitivity of peak latencies to increases in stimulation rate. The current experiment assessed the possibility that these abnormalities were caused by hearing deficit rather than central auditory dysfunction. The ABRs of a group of adults with Down's syndrome were compared with those of a group of non-Down retarded and a control group of nonretarded adults. An audiometric examination consisting of pure-tone audiograms, tympanometry, and acoustic reflexes was given to all the retarded subjects. The incidence of serious hearing deficit in the Down's syndrome group was 73% compared to 22% in the non-Down retarded. Regardless of hearing status, the central conduction times in the Down group were shorter than in either of the other groups. The abnormal response to stimulation rate, however, was found to reflect high-frequency hearing loss and not central auditory dysfunction. The data suggest that a battery of objective tests including tympanometry, acoustic reflexes, and selected ABR measures may be useful in identifying hearing deficit in both Down-syndrome and non-Down retarded individuals.

Effects of chronic administration of mestranol on alpha and beta adrenergic responsiveness in female rats

Several alpha and beta adrenergic responses were studied in female rats after treatment with a low dose of the synthetic estrogen, mestranol (15 micrograms i.p. biweekly), for 4 to 6 weeks and compared with untreated controls. The response of blood pressure to exogenously administered norepinephrine was measured in conscious rats by means of an indwelling catheter in the femoral artery. Basal systolic blood pressure was not different between control and treated groups, or was any difference observed in peak systolic pressure after acute i.v. administration of l-norepinephrine in concentrations of 0.0625, 0.125, 0.250 and 0.625 micrograms. In contrast, the half-time of the blood pressure response was significantly prolonged after administration of the various concentrations of norepinephrine to mestranol-treated rats. The half-time of the pressor response observed in control animals administered 0.625 micrograms of norepinephrine was elicited in mestranol-treated animals by only 0.250 micrograms of norepinephrine. Analysis of the time course of the pressor response indicates that mestranol treatment altered the duration of the blood pressure increase without an apparent change in the onset of the pressor response. No differences between groups were observed in beta adrenergic responsiveness measured in terms of the isoproterenol-induced increase in either heart rate (beta-1 response) or water intake (beta-2 response). Finally, the contractile response of aortic rings from mestranol-treated rats to both l-norepinephrine (10(-9) to 10(-5) M) and l-phenylephrine (10(-8) to 10(-4) M) was significantly less than that of aortic rings from control rats. These data indicate, therefore, that in vivo cardiovascular responsiveness to norepinephrine does not reflect the attenuated vascular reactivity of isolated aortic rings. Insofar as the dominant feature of the in vivo adrenergic response appears to be prolongation of pressor action, the present study suggests that processes involved in the inactivation of circulating norepinephrine may be altered by chronic treatment with a low-dose of mestranol.

Binaural interaction in auditory brainstem responses of mentally retarded and nonretarded individuals

The short-latency auditory brainstem responses of institutionalized mentally retarded individuals (Down syndrome and unknown etiology) and nonretarded control persons were recorded. The results showed that retarded individuals differed in the clarity of initial auditory brainstem response waves (I and II). Down syndrome individuals had significantly smaller auditory brainstem response amplitudes (Waves II and III) when compared with retarded individuals of unknown etiology. Down syndrome individuals also had significantly shorter latencies (Waves III and V) and shorter interwave conduction times (III-I and V-I) when compared with retarded individuals of unknown etiology. Retarded individuals did not differ from control subjects when amplitudes of binaural auditory brainstem responses were compared to the computer summation of such responses evoked by left and right ear stimulation; however, there was evidence for a general binaural interaction effect.

Auditory brain stem response abnormalities in severely and profoundly retarded adults

The auditory brain stem evoked responses (ABRs) of two groups of retarded adults (Down's syndrome and retarded of unknown etiology) were compared with those of a group of non-retarded control subjects as a function of changes in stimulus repetition rate and stimulus intensity. The absence of ABRs at the highest stimulus intensity suggested profound hearing deficits in one or both ears of 4 Down's syndrome and 2 unknown-etiology subjects. Other abnormalities were noted in particular individuals of each group of retarded. In addition, the ABRs of the Down's group as a whole showed a significant pattern of abnormalities. The intervals between peaks I and II and III and IV were shorter than normal white the IV--V interval was prolonged. Wave V also showed abnormally small latency increases at fast click rates. The ABRs of the unknown-etiology group showed a shortened III--IV interval and a prolongation of the IV--V interval, but were otherwise not significantly different from the normal controls. These data suggest a high incidence of hearing loss in both diagnostic categories studies, and abnormal functioning of the auditory brain stem pathway in the Down's syndrome group as a whole.