Global resting‐state functional connectivity of neural oscillations in tinnitus with and without hearing loss

This study examined global resting‐state functional connectivity of neural oscillations in individuals with chronic tinnitus and normal and impaired hearing. We tested the hypothesis that distinct neural oscillatory networks are engaged in tinnitus with and without hearing loss. In both tinnitus groups, with and without hearing loss, we identified multiple frequency band‐dependent regions of increased and decreased global functional connectivity. We also found that the auditory domain of tinnitus severity, assayed by the Tinnitus Functional Index, was associated with global functional connectivity in both auditory and nonauditory regions. These findings provide candidate biomarkers to target and monitor treatments for tinnitus with and without hearing loss.     

Lower P300 amplitude in eight-year-old offspring of alcoholic fathers with a delinquent history

The aim of the present study was to investigate the P300 amplitude as a possible vulnerability marker in children of alcoholic (COA) fathers with and without paternal delinquency. Event-related potentials (ERPs) of 122 children aged 8 years (63 boys, 59 girls) were compared depending on father’s alcoholism subtype: 30 COAs without paternal delinquency, 10 COAs with paternal delinquency, and 82 children of non-alcoholic and non-delinquent fathers. ERPs were recorded from Fz, Cz, and Pz, using an auditory oddball paradigm. Sinus tones of 60 dB HL were presented binaurally at 1,000 Hz (standard stimulus) and 2,000 Hz (target stimulus), at a relative frequency ratio of 80:20. Two trial blocks of 250 stimuli each were collected. Results indicated that only COAs with paternal delinquency displayed significant differences from the control group, characterized by reduced P300 amplitude at frontal site and in the second trial block. Thus, the combination of fathers’ alcoholism and delinquency was more likely to relate to attenuated P300 amplitude in the offspring than paternal alcoholism alone. Our results suggest that both alcoholic and delinquent family history appear to play a role in P300 amplitude reduction in the offspring.     

Reduced P3 amplitudes are associated with both a family history of alcoholism and antisocial personality disorder

1. 1. Previous research has demonstrated that the amplitude of the P3 component of the event-related electroencephalographic potential (ERP) is influenced by the presence/absence of a family history of alcoholism (FHA). The present study extended this line of research by examining the P3 effects of both FHA and antisocial personality disorder (ASP) in a 2 × 2 factorial design.

2. 2. The task required subjects to judge the orientation of an infrequently-occurring outline drawing, representing an aerial view of a human head.

3. 3. Analyses of P3 amplitudes elicited by this drawing revealed reductions attributable to the effects of both FHA and ASP, but not their interaction. These effects were most apparent at frontal electrode sites. Analyses of P3 latency revealed no consistent pattern of findings. However, the interval between P3 and manual reaction time was shorter in the ASP+ group relative to the ASP- group.

Event-related potential components N1, P2 and P3 to rare and frequent stimuli in intellectually impaired neurological patients

Summary Event-related potentials (ERPs) and attention performance data were collected in an auditory oddball paradigm from 24 intellectually impaired neurological patients, and compared with normal controls (n=19). For the ERP components N1, P2 and P3, reference-independent measures (latency, global field power, current density at Cz, location of extreme potential, centroid location) were determined for the target stimulus and for the preceding and the following two frequent stimuli. In 8 of the 45 measures obtained, patients and controls differed significantly. To target stimuli, patients had shorter N1 latency and smaller current density, more posterior P2 location and longer P3 latency; to immediately following frequent stimuli, longer P2 latency; and to preceding and both following frequent stimuli, smaller P2 current density. Attention performance was significantly worse for the 15 patients who scored on at least one of the eight ERP measures above normal range than for the other 9 patients. Decreased N1 latency to targets is viewed as failure to activate normal attentional capacity; changed P2 location suggests activation of deviant neuronal populations in response to targets; and increased post-target P2 latency suggests abnormal persistence of induced state change.     

Sensorineural hearing loss in insulin-like growth factor I-null mice: a new model of human deafness

It has been reported that mutations in the gene encoding human insulin-like growth factor-I (IGF-I) cause syndromic hearing loss. To study the precise role of IGF-I in auditory function and to hypothesize the possible morphological and electrophysiological changes that may occur in the human inner ear, we have analysed the auditory brainstem response in a mouse model of IGF-I deficiency. We show here that homozygous Igf-1(-/-) mice present an all-frequency involved bilateral sensorineural hearing loss. Igf-1(-/-) mice also present a delayed response to acoustic stimuli; this increases along the auditory pathway, indicating a contribution of the central nervous system to the hearing loss in Igf-1(-/-) mice. These results support the use of the Igf-1(-/-) mouse as a new model for the study of human syndromic deafness.     

Valproate‐induced reversible sensorineural hearing loss: a case report with serial audiometry and pharmacokinetic modelling during a valproate rechallenge

Hearing loss has been reported with valproic acid (VPA) use. However, this is the first case of VPA‐induced hearing loss that was tested and confirmed with a VPA rechallenge, supported by serial audiometry and pharmacokinetic modelling. A 39‐year‐old truck driver with temporal lobe epilepsy was treated with VPA at 400 mg, twice daily, and developed hearing loss after each dose, but recovered within three hours. Hearing loss fully resolved after VPA discontinuation. Audiometry performed five hours after VPA rechallenge showed significant improvement in hearing thresholds. Pharmacokinetic modelling during the VPA rechallenge showed that hearing loss occurred at a level below the therapeutic range. Brainstem auditory evoked potential at three months after VPA discontinuation showed bilateral conduction defect between the cochlear and superior olivary nucleus, supporting a pre‐existing auditory deficit. VPA may cause temporary hearing threshold shift. Pre‐existing auditory defect may be a risk factor for VPA‐induced hearing loss. Caution should be taken while prescribing VPA to patients with pre‐existing auditory deficit.     

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

Purpose: The somatosensory event-related potential N140 is thought to be related to selective attention. This study aimed to compare the somatosensory event-related potential N140 in healthy subjects to that in patients with stroke to determine whether N140 and attentiveness are associated in patients with stroke with or without hemispatial agnosia.

Materials and Methods: Normal somatosensory event-related potential N140 values were determined using data from ten healthy subjects. Fifteen patients with stroke were divided into two groups based on the presence of hemispatial neglect. Somatosensory event-related potential N140 components were compared between the two groups.

Results: Stimulation of the affected limb in the hemispatial agnosia group resulted in significantly longer N140 latency at the contralateral vs. the ipsilateral electrode. This was the inverse of the relationship observed in normal subjects, with stimulation of the intact side in patients with hemispatial agnosia, and with stimulation of both the intact and affected sides in patients without agnosia. In the hemispatial agnosia group, the peak latency of N140 following stimulation of the affected side was significantly longer than it was following stimulation of the intact side and when compared to that in patients without agnosia. In addition, abnormal N140 peak latencies were observed at the Cz and ipsilateral electrodes in patients with hemispatial agnosia following stimulation of the intact side.

Conclusions: These findings suggest that somatosensory event-related potential N140 is independently generated in each hemisphere and may reflect cognitive attention.     

Patterns of hearing loss and psychiatric morbidity in elderly patients attending a hearing clinic

This study examines the relationship between hearing loss and psychiatric diagnosis in a geriatric population attending a hearing clinic. Major depression was the most frequent psychiatric disorder and was diagnosed in 30% of subjects. A sensorineural type hearing loss was diagnosed in 85% of the depressed subjects. More hearing loss was seen in subjects with onset of depression after age 55 years, in comparison to geriatric patients with depression onset before age 55 years, subjects with other psychiatric disorders and subjects without a psychiatric diagnosis (p <0.001). The audiogram and speech audiometry suggest involvement of auditory nerve and central auditory pathways in late onset depression.     

Encephalopathy, hearing loss and retinal occlusions (Susac’s syndrome): a new case

We describe a young woman with retinal arteriolar occlusions, encephalopathy, and hearing loss. At present this disorder is known as Susac’s syndrome, a microangiopathy of the brain and retina whose pathogenesis is, however, unknown. The article reviews the clinical features of this rare, but not unusual, syndrome that can easily be misdiagnosed as multiple sclerosis.

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Sommario Riportiamo il caso di una giovane donna che ha presentato una sindrome caratterizzata da occlusioni delle arterie retiniche, encefalopatia e riduzione dell’udito. Attualmente tale sindrome viene riconosciuta sotto il nome di Sindrome di Susac, che individua una microangiopatia cerebrale e retinica, la cui etiopatogenesi è comunque sconosciuta. Viene riportata anche una rivisitazione della letteratura su questa rara, ma non inusuale, sindrome, che può essere erroneamente diagnosticata come sclerosi multipla.

     

P3 amplitude attenuation secondary to increases in target-to-target interval (TTI) during spatial serial order recall: implications for EEG models of working memory function

Abstract

Research suggests that increasing delays in stimulus read-out can trigger declines in serial order recall accuracy due to increases in cognitive demand imposed by the delay; however, the exact neural mechanisms associated with this decline are unclear. Changes in neural resource allocation present as the ideal target and can easily be monitored by examining changes in the amplitude of an ERP component known as the P3. Changes in P3 amplitude secondary to exogenous pacing of stimulus read-out via increased target-to-target intervals (TTIs) during recall could reflect decreased neural resource allocation due to increased cognitive demand. This shift in resource allocation could result in working memory storage decay and the declines in serial order accuracy described by prior research. In order to examine this potential effect, participants were administered a spatial serial order processing task, with the recall series consisting of a series of correct (‘match’) or incorrect (‘non-match’ or ‘oddball’) stimuli. Moreover, the recall series included either a brief (500?ms) or extended (2000?ms) delay between stimuli. Results were significant for the presence of a P3 response to non-match stimuli for both experimental conditions, and attenuation of P3 amplitude secondary to the increase in TTI. These findings suggest that extending the delay between target recognition could increase cognitive demand and trigger a decrease in neural resource allocation that results in a decay of working memory stores.     

Regulation of NT-3 and BDNF levels in guinea pig auditory brain stem nuclei after unilateral cochlear ablation

Injury to areas of the central nervous system can alter neurotrophin levels, which may influence postlesion neuronal survival and plasticity. To determine if sensorineural hearing loss induces such changes, we used an enzyme-linked immunosorbent assay (ELISA) to measure neurotrophin-3 (NT-3) and brain-derived neurotrophic factor (BDNF) levels in adult guinea pig brain stem auditory nuclei 3-60 days after a unilateral cochlear ablation (UCA). After UCA, which destroyed the cochlea and cochlear nerve on one side, NT-3 levels were usually depressed at 3 days by 22-44% but became elevated transiently at 7 days by 28-124%. BDNF levels were elevated transiently by 50% on the ablated side in the anteroventral (AVCN) and posteroventral (PVCN) cochlear nucleus at 3 days and may have signaled support for the survival of deafferented neurons. Coincident elevation at 3 and 7 days of BDNF or NT-3 and phosphorylated extracellular signal-regulated protein kinase 2 (ERK2-P) suggested a relationship to stimulated signal transduction activity. Elevated neurotrophin levels may have contributed to synaptogenesis in the AVCN and the superior olive and to changes in the synaptic biochemistry in the auditory nuclei after UCA. In contrast, deficiencies or failure to elevate neurotrophin levels within several days of the UCA correlated with upregulation of phosphorylated stress-activated protein kinase (SAPK-P), suggesting a relationship with stress-activated signal transduction and with the sparse degeneration of fibers observed in some of the auditory nuclei after UCA.     

Event-related potentials in newborns with and without familial risk for dyslexia: principal component analysis reveals differences between the groups

Summary. Differences revealed by factor scores extracted by principal component analysis (PCA) from event-related potential (ERP) data of newborns with and without familial risk for dyslexia were examined and compared to results obtained by using original averaged ERPs. ERPs to consonant-vowel syllables (synthetic /ba/, /da/, /ga/; and natural /paa/, /taa/, /kaa/) were recorded from 26 at-risk and 23 control 1–7 day-old infants. The stimuli were presented equiprobably and with interstimulus intervals varying at random from 3,910 to 7,285ms. Statistically significant between-group differences were found to be relatively similar irrespective of the methods of analysis (original ERPs vs. factor scores from PCA). Responses to /ga/ differed from those to /ba/ and /da/ between the groups in the right hemisphere at the latencies of 50–170ms (Factor 4) and 540–630ms (Factor 3). The groups differed also in their responses to /da/ in the posterior electrode sites at 740–940ms (Factor 2). There were no group differences in the natural stimulus set. These results demonstrate that brain activation differences may be implicated in risk for dyslexia immediately after birth. The results also show that the PCA-ANOVA procedure is an effective way of identifying the group-related variance in the ERP-data when the component structure, such as those of infants, is not well-known in advance.Received April 7, 2002; accepted March 31, 2003 Published online June 30, 2003     

Prolonged latencies of the N2 and P3 of the auditory event-related potential in children at risk for schizophrenia

Summary In previous studies investigating long latency components of the event-related potential (ERP), schizophrenic patients generally showed reduced P3 amplitudes and in some studies prolonged N2 or P3 latencies. As there is a higher risk of offspring of schizophrenics than of mentally healthy parents developing this disease, the present study was intended to clarify whether ERP components (in particular the N2 and P3) differ between these two groups of children. Twelve high-risk and 12 age-matched control children (aged 9–16 years) performed an auditory oddball task in order to assess late ERP components. This task required the subject to covertly count rare target tone pips (P = 0.2) irregularly interspersed among frequent standard tone pips (P = 0.8) in two series of 400 pips. ERPs were recorded from midline electrodes (Fz, Cz, Pz). The results indicated distinctly prolonged N2 and P3 latencies in ERPs to target stimuli in children of schizophrenic patients. These findings suggest a slowed target classification in these children.     

An event-related potential observation of preposition processing in Chinese**★ Is N280 a specific component for Chinese prepositions?

BACKGROUND: Studies have shown that closed-class words, such as prepositions and conjunctions, induce a left anterior negativity (N280), indicating that N280 should be a specific component of the word category. OBJECTIVE: To observe if Chinese prepositions and verbs exhibit different linguistic functions, to determine whether they are processed by different neural systems, and to verify that N280 is a specific component. DESIGN, TIME AND SETTING: The observed neurolinguistics experiment was performed at Xuzhou Normal University between November and December 2006. PARTICIPANTS: Sixteen undergraduate students, comprising 8 females and 8 males, with no mental or neuropathological history, were selected. METHODS: A total of 15 verbs and prepositions were used as linguistic stimuli, and each verb and preposition was combined to produce four correct phrase collocations and four incorrect ones. MAIN OUTCOME MEASURES: Event-related potentials were recorded in the subjects while they read correct or incorrect phases flashed upon a video screen. RESULTS: Both verbs and prepositions elicited negativity at the frontal site in a 230–330 ms window, as well as at the fronto-temporal and central sites in a 350–500 ms window. Neither exhibited significant differences in peak [F (1, 15) = 0.144, P = 0.710] and latency [F (1, 15) = 0.144, P = 0.710]. Both verbs and prepositions elicited negativity at the left and right hemisphere in a 270–400 ms window. CONCLUSION: There was no significant difference between Chinese prepositions and verbs in the neural system process and N280 was not the specific component for closed-class words. Key Words: Chinese words; event-related potentials; prepositions; semantics; syntax; verbs     

云南省楚雄市彝族非综合征性感音神经性耳聋人群GJB2基因突变的研究

目的针对昆明市就诊聋儿进行民族流行病学调查,基本掌握云南省感音神经性聋儿民族分布情况,从中研究云南省楚雄市彝族自治州遗传性非综合征性感音神经性耳聋人群中GJB2基因的突变位点、突变频率。方法针对云南省楚雄州特殊教育学校的学生进行调查测试,选取出22名彝族非综合征性感音神经性耳聋患儿为研究组。对照组为汉族及彝族正常人群各25名、汉族非综合征性感音神经性耳聋患者15名,提取基因组DNA,进行GJB2基因PCR扩增,通过产物测序,检测GJB2基因突变。结果79G—A突变在彝族耳聋人群比例为3／22（13．7％）;彝族正常组未见突变;汉族耳聋人群分布则比例较高4／15（26．7％）,汉族正常对照组也检测出79G～A的杂合突变2／25（8％）。发现一种新突变形式56G～T,19位丝氨酸（Ser）转变为异亮氨酸（Ile）。结论在彝族非综合征性感音神经性耳聋人群中发现一个新的突变形式56G—T。     

Age-related changes in the guinea pig auditory cortex: relationship with brainstem changes and comparison with tone-induced hearing loss

Elderly people often show degraded hearing performance and have difficulties in understanding speech, particularly in noisy environments. Although loss in peripheral hearing sensitivity is an important factor in explaining these low performances, central alterations also have an impact but their exact contributions remained unclear. In this study, we focus on the functional effects of aging on auditory cortex responses. Neuronal discharges and local field potentials were recorded in the auditory cortex of aged guinea pigs (> 3 years), and several parameters characterizing the processing of auditory information were quantified: the acoustic thresholds, response strength, latency and duration of the response, and breadth of tuning. Several of these parameters were also quantified from auditory brainstem responses collected from the same animals, and recordings obtained from a population of animals with trauma-induced hearing loss were also included in this study. The results showed that aging and acoustic trauma reduced the response strength at both brainstem and cortical levels, and increased the response latencies more at the cortical level than at the brainstem level. In addition to the brainstem hearing loss, aging induced a 'cortical hearing loss' as judged by additive changes in the threshold and frequency response seen in the cortex. It also increased the duration of neural responses and reduced the receptive field bandwidth, effects that were not found in traumatized animals. These effects substantiate the notion that presbycusis involves both peripheral hearing loss and biological aging in the central auditory system.     

Event-related potential activity in the basal ganglia differentiates rewards from nonrewards: temporospatial principal components analysis and source localization of the feedback negativity

Event-related potential studies of reward processing have consistently identified the feedback negativity (FN), an early neural response that differentiates feedback indicating unfavorable versus favorable outcomes. Several important questions remain, however, about the nature of this response. In this study, the FN was recorded in response to monetary gains and losses during a laboratory gambling task, and temporospatial principal components analysis was used to separate the FN from overlapping responses. The FN was identified as a positive deflection at frontocentral recording sites that was enhanced for rewards compared with nonrewards. Furthermore, source localization techniques identified the striatum as a likely neural generator. These data indicate that this apparent FN reflects increased striatal activation in response to favorable outcomes that is reduced or absent for unfavorable outcomes, thereby providing unique information about the timing and nature of basal ganglia activity related to reward processing.     

曲安奈德配合金纳多治疗单侧急性低频下降型感音神经性聋

目的探讨耳后注射曲安奈德配合金纳多银杏叶提取物片治疗单侧急性低频下降型感音神经性聋(ALHL)临床疗效。方法选取2014-05—2016-09开封市祥符区中医院收治的78例单侧ALHL患者,通过随机数字表法分为研究组与对照组各39例。对照组采用舒血宁注射液+地塞米松注射液治疗,研究组采用曲安奈德+金纳多银杏叶提取物片治疗,2组均持续治疗10d。疗程结束后对比2组临床疗效、不良反应发生率,分析治疗前后血清免疫功能指标(IgM、IgG、CD3~+、CD4~+)水平变化。结果研究组总有效率为94.87%(37/39),高于对照组的74.36%(29/39),差异有统计学意义(P0.05);治疗前2组IgM、IgG、CD3~+、CD4~+水平比较差异无统计学意义(P0.05),治疗后研究组IgM、IgG、CD3~+、CD4~+水平高于对照组,差异有统计学意义(P0.05);研究组不良反应发生率7.69%(3/39),与对照组10.26%(4/39)比较,差异无统计学意义(P0.05)。结论耳后注射曲安奈德配合金纳多银杏叶提取物片治疗单侧ALHL效果显著,可有效提高患者听力水平,且对改善其免疫功能具有重要作用,安全性较高,值得推广。