INTRODUÇÃO: O Acidente Vascular Cerebral Isquêmico (AVCI) é o evento mais freqüente dentre os AVCs, sendo caracterizado pela interrupção da irrigação sanguínea ao cérebro, a qual pode acarretar em lesão celular e alterações nas funções neurológicas. As manifestações clínicas desta doença podem incluir alterações das funções motoras, sensitivas, cognitivas, perceptivas, da linguagem entre outras. Sendo assim, é extremamente importante que sejam identificadas possíveis alterações nas vias auditivas, periférica e central, as quais podem prejudicar a qualidade de vida destes indivíduos. OBJETIVO: caracterizar os achados das avaliações comportamentais, eletroacústicas e eletrofisiológicas da audição em indivíduos destros com lesão isquêmica do hemisfério cerebral direito, bem como compará-los aos obtidos em indivíduos normais da mesma faixa etária. MÉTODOS: foram realizadas audiometria tonal, logoaudiometria, medidas de imitância acústica, potencial evocado auditivo de tronco encefálico (PEATE), potencial evocado auditivo de média latência (PEAML) e potencial cognitivo (P300) em 17 indivíduos com lesão do hemisfério direito (grupo pesquisa) e 25 normais (grupo controle), com idades entre 20 e 70 anos. RESULTADOS: Na análise dos dados qualitativos não foram encontradas alterações na avaliação comportamental da audição para os dois grupos. Ambos os grupos apresentaram alterações nos resultados do PEATE e do PEAML, sendo que houve diferença estatisticamente significante entre os grupos, para esses dois potenciais, nas quais o grupo pesquisa apresentou maior ocorrência de alterações. No PEATE a alteração mais freqüente foi do tipo tronco encefálico baixo, sendo que, entre os grupos, houve diferença estatisticamente significante, na qual o grupo pesquisa mostrou maior ocorrência dessa alteração. No PEAML a alteração predominante foi do tipo ambas (efeito orelha e efeito eletrodo ocorrendo concomitantemente) para o grupo pesquisa, e do tipo efeito eletrodo para o grupo controle. Na análise dos dados quantitativos (realizada apenas para os potenciais evocados auditivos) verificou-se, no PEATE, que ocorreu diferença estatisticamente significante entre os grupos com relação às latências das ondas III e V e interpicos I-III e I-V. Para o PEAML, a diferença estatisticamente significante entre os grupos ocorreu apenas para a latência da onda Na na posição C3/A1. Para o P300, ocorreu diferença entre os grupos com relação à latência da onda P300, sendo que o grupo pesquisa apresentou tempo médio de latência maior; além disso, houve uma tendência estatisticamente significante entre as orelhas direita e esquerda dentro do grupo pesquisa, mostrando aumento de latência da onda P300 na orelha direita. CONCLUSÃO: Indivíduos destros com lesão de hemisfério direito apresentaram limiares auditivos dentro da normalidade na avaliação comportamental da audição, entretanto, apresentaram resultados indicativos de déficit no sistema nervoso auditivo central, nas avaliações eletrofisiológicas da audição. Foram observados comprometimentos em tronco encefálico baixo, bem como nas regiões subcorticais e corticais. Dificuldades auditivas não foram percebidas pelos indivíduos, sugerindo que, provavelmente tal sinal possa estar relacionado à uma heminegligência auditiva. Tornam-se necessários mais estudos que avaliem a via auditiva central destes indivíduos para uma melhor caracterização dos achados eletrofisiológicos / INTRODUCTION: The ischemic cerebral stroke (ICS) is the most frequent event among cerebral strokes. It is characterized by the interruption of blood supply to the brain, which can lead to cell damage and alterations in neurological functions. The clinical manifestations of this disease may include alterations in motor, sensory, cognitive, perceptual and language functions among others. Therefore, the identification of possible alterations in both peripheral and central auditory pathways that may impair the quality of life of these individuals is extremely important. OBJECTIVE: To characterize the findings of behavioral, electrophysiological and electroacoustic hearing evaluations in right-handed individuals with right hemisphere ischemic lesion, and to compare such data to those obtained in normal individuals with the same age. METHODS: Pure tone audiometry, speech audiometry, acoustic immittance measures, brainstem auditory evoked potential (BAEP), Auditory Middle-Latency Response (AMLR) and cognitive potential (P300) were carried out in 17 subjects with right hemisphere lesions (research group) and 25 normal individuals (control group), aged between 20 and 70 years. RESULTS: No alterations were found on the qualitative data analysis of the hearing behavioral assessment of both groups. Both groups showed alterations in the BAEP and AMLR results, with statistically significant differences between groups for both potentials and a higher occurrence of alterations in the research group. The lower brainstem was the most frequent alteration type in the BAEP, and a statistically significant difference between groups was observed, with higher occurrence of such alteration in the research group. With regards the AMLR, the alteration predominantly observed was the Both type one (ear effect and electrode effect occurring concurrently) for the research group, and the electrode effect type one for the control group. In the analysis of quantitative data (performed only for the auditory evoked potentials), a statistically significant difference between groups was observed with respect to the BAEP latencies of waves III, V and interpeaks I-III and I-V. Regarding the AMLR measures, a statistically significant difference between groups was observed only for the Na wave latency in the C3/A1 position. For the P300, a difference between groups was observed, with higher mean latencies for the research group. In addition, there was a trend to statistically significant difference between right and left ears in the research group, which showed increased latency of P300 wave in the right ear. CONCLUSION: Right-handed individuals with right hemisphere lesion showed hearing thresholds within normal limits in the behavioral hearing assessment. However, they presented results indicative of central auditory nervous system deficits on the electrophysiological assessment of hearing. Alterations were observed in lower brainstem and in sub-cortical and cortical regions. Hearing difficulties were not perceived by these individuals, suggesting that this signal can probably be related to an auditory hemineglect. Further studies that evaluate the central auditory pathway of individuals with ICS are needed to better characterize the electrophysiological findings

INTRODUÇÃO: A gagueira é um distúrbio da fluência multidimensional que resulta da interação de múltiplos processos fisiológicos, refletindo mais de um fator causal. Evidências científicas atuais sustentam a hipótese de que pessoas que gaguejam possuem conexões anômalas em regiões auditivas do hemisfério esquerdo, envolvidas no feedback sensorial dos sons da fala. Desta forma, é prudente pensar que déficits na sincronia neural, identificados por meio de alterações em testes comportamentais do processamento temporal e nos potenciais evocados auditivos (PEA), possam estar relacionados a este tipo de distúrbio. OBJETIVO: caracterizar os resultados do teste Gaps in Noise (GIN) e dos PEA com estímulos de diferentes complexidades em crianças gagas e em crianças em desenvolvimento típico. MÉTODOS: Dez crianças gagas com idades entre sete e 11 anos (grupo estudo - GE) e seus pares nãogagos (grupo controle - GC) foram submetidos a avaliações audiológicas e eletrofisiológicas da audição por meio dos seguintes testes: medidas de imitância acústica, audiometria tonal, logoaudiometria, teste GIN, potencial evocado auditivo de tronco encefálico (PEATE) com estímulos clique e de fala e potencial evocado auditivo de longa latência (PEALL) com estímulo tone burst e de fala. Os resultados obtidos no GC e GE foram comparados por meio de testes estatísticos. RESULTADOS: Ambos os grupos apresentaram resultados normais no teste GIN, de acordo com os critérios de normalidade adotados, contudo, observou-se melhor desempenho no GE. Não foram encontradas diferenças significantes entre os grupos para os resultados do teste GIN. No PEATE com estímulo clique, todos os sujeitos avaliados apresentaram resultados dentro dos padrões de normalidade. Observou-se no GE maior variabilidade nos tempos de latência, bem como tendência à diferença estatisticamente significante entre as orelhas direita e esquerda para o interpico I-III. No PEATE com estímulo de fala, verificaram-se valores de latência da onda C e de amplitude do complexo VA significantemente maiores no GE. No PEALL com estímulo tone burst não foi observada diferença estatisticamente significante entre os grupos. Contudo, observaram-se alterações (ausência de componentes do PEALL) em três sujeitos do GE e em um do GC. No PEALL com estímulo de fala, em ambos os grupos, verificou-se diferença estatisticamente significante entre as orelhas direita e esquerda no que tange a latência da onda N2 e amplitudes P2-N2 e da onda P300. Foram observadas alterações (ausência de componentes do PEALL) em um sujeito do GE. CONCLUSÃO: Embora não tenham sido verificadas alterações de resolução temporal no grupo de crianças gagas por meio do teste comportamental realizado, os resultados dos testes eletrofisiológicos sugerem a presença de diferenças nos processos neurais envolvidos no processamento da informação acústica, entre crianças em desenvolvimento típico e crianças gagas, principalmente em se tratando de elementos de maior complexidade, como a fala / INTRODUCTION: Stuttering is a multidimensional speech disorder that results from the interaction of multiple physiological processes, which means there is more than one causal factor. Current scientific evidence supports the hypothesis that people who stutter have anomalous connections in auditory regions of the left hemisphere, involved in the sensory feedback of speech sounds. Thus, it is reasonable to suppose that deficits in neural synchrony, showed by abnormal results in behavioral tests of temporal processing and auditory evoked potentials (AEP), may be related to this type of disorder. OBJECTIVE: to characterize the results of the Gaps in Noise Test (GIN) and the AEP using stimuli of different complexity, in children who stutter and in typically developing children. METHODS: Ten children who stutter aged between seven and 11 years (study group - SG) and their non-stuttering peers (control group - CG) underwent audiological and electrophysiological evaluation using the following tests: acoustic immittance measures, tonal audiometry, speech audiometry, GIN test, speech- and click-evoked Auditory Brainstem Response (ABR), and Long Latency Response (LLR) with tone burst and speech stimuli. Statistical tests were carried out for comparisons between CG and SG. RESULTS: Both groups presented normal results in the GIN test, according to the normality criteria. However, the SG showed better performance. No significant differences were found between groups for the GIN test results. In the click-evoked ABR, all subjects presented results within the normal range. The SG showed greater variability concerning the latency values, as well as a statistical trend toward significance regarding differences between the right and left ears for the interpeak I-III. In speech-evoked ABR, the latency values of wave C and the amplitude of VA complex were significantly higher in SG. No statistically significant difference between groups was observed in LLR with tone burst stimulus. However, abnormal results were observed (absence of LLR components) in three subjects from the SG and in one subject from the CG. In the LLR with speech stimuli, statistically significant differences were found for both groups, regarding the N2 latency, P2-N2, and P300 amplitudes, when the right and left ears were compared. Abnormal results were observed (absence of LLR components) in one subject from the SG. CONCLUSION: Although auditory temporal resolution deficits were not evidenced by the GIN test in the group of children who stutter, the results of the electrophysiological tests suggest the presence of differences in neural processes related to the acoustic information processing, when compared to typically developing children, especially when more complex elements, such as speech, are considered

Introdução: A desnutrição energético-protéica é um dos maiores problemas de saúde pública no Brasil, ocorrendo mais frequentemente em pré-escolares e determinando o comprometimento do crescimento. A desnutrição pode provocar alterações no sistema nervoso central, dependendo da intensidade, da época de incidência e da duração da doença, comprometendo irreversivelmente as funções intelectuais. Levando-se em consideração a importância da integridade do Sistema Auditivo Periférico e Central na aquisição e desenvolvimento de fala, linguagem e aprendizado, torna-se imprescindível que anormalidades auditivas tanto periféricas como centrais sejam identificadas e tratadas precocemente nesta população. Objetivo: Caracterizar os achados das avaliações comportamentais, eletroacústicas e eletrofisiológicas da audição em crianças com desnutrição, bem como compará-los aos obtidos em crianças saudáveis da mesma faixa etária. Métodos: Foram realizados exames de audiometria tonal, logoaudiometria, teste dicótico de dígitos, imitanciometria, potencial evocado auditivo de tronco encefálico (PEATE) e potencial evocado auditivo de longa latência (PEALL) em 31 crianças desnutridas (grupo estudo) e 34 crianças saudáveis (grupo controle), com idade entre 7 e 12 anos, de ambos os gêneros. Resultados: Na análise dos dados quantitativos da audiometria tonal foi observada uma diferença estatisticamente significante entre os grupos para os limiares auditivos nas frequências de 250 e 8000 Hz, tendo o grupo estudo apresentado limiares auditivos mais elevados. Na análise qualitativa, não houve diferença estatisticamente significante entre os grupos, apesar de duas crianças do grupo estudo apresentarem perda auditiva discreta. Na análise dos dados qualitativos, não foram encontradas alterações na logoaudiometria para os dois grupos. No teste dicótico de dígitos, houve diferença estatisticamente significante entre os grupos, sendo observada uma maior proporção de crianças com alteração no grupo estudo. Ambos os grupos apresentaram resultados alterados na imitanciometria, não havendo diferença estatisticamente significante entre os grupos. Ambos os grupos apresentaram resultados normais do PEATE. Na análise dos dados quantitativos dos PEALL, verificou-se diferença estatisticamente significante entre os grupos para as latências dos componentes P1, N1 e P300, sendo que o grupo estudo apresentou latências maiores para todos os componentes. Na avaliação da amplitude do P300, houve diferença estatisticamente significante entre as orelhas direita e esquerda do grupo controle, sendo a amplitude do P300 maior na orelha direita. Por sua vez, no grupo estudo, não houve diferença significativa entre as orelhas direita e esquerda. Tanto o grupo controle quanto o grupo estudo apresentaram alterações nos resultados do PEALL, havendo diferença estatisticamente significante entre os grupos para os componentes P1, N1 e P300, sendo que o grupo estudo apresentou maior ocorrência de alterações. O tipo de alteração predominante nos componentes P1 e P300 foi o aumento de latência e, para o componente N1, foi a ausência de resposta no grupo estudo; para o grupo controle, o tipo de alteração predominante nos componentes P1, N1 e P300 foi o aumento de latência. Devido ao predomínio de crianças desnutridas de grau leve (58,1%), não foi possível estabelecer uma correlação entre o grau da desnutrição e a alteração dos PEALL. Conclusão: Crianças com desnutrição apresentaram mais alterações na avaliação comportamental da audição (audiometria tonal e teste dicótico de dígitos) e nos PEALL do que as crianças saudáveis, sugerindo déficit na via auditiva central e alteração no processamento da informação acústica. Há a necessidade de mais estudos para melhor caracterizar as alterações fonoaudiológicas e audiológicas desta população. / Introduction: Protein-energy malnutrition is a major public health problem in Brazil. It is more frequent among pre-school aged children and it compromises growth. Malnutrition may cause changes to the central nervous system depending on its intensity, time of incidence and duration, irreversibly compromising intellectual functions. Considering the importance of Peripheral and Central Auditory System integrity to the acquisition and development of speech, language and learning, it is crucial that both peripheral and central auditory abnormalities are identified and treated early in this population. Objective: To describe the findings of behavioral, electroacoustic and electrophysiological auditory assessments of malnourished children, as well as comparing them with findings from healthy children within the same age group. Methods: The following tests were performed in 31 malnourished children (study group) and 34 healthy children (control group), aged 7 to 12, from both genders: pure tone audiometry, speech audiometry, dichotic digit test, immittance measures, brainstem auditory evoked potential (BAEP) and long-latency auditory evoked potential (LLAEP). Results: While analyzing quantitative data from pure tone audiometry we observed statistically significant differences between groups for hearing thresholds at frequencies of 250 and 8000 Hz; the study group had higher hearing thresholds. As for quantitative analysis, there was no statistically significant difference between groups, although two children in the study group showed slight hearing loss. While analyzing qualitative data we did not find any changes in speech audiometry in any of the groups. As for the dichotic digit test, there was a statistically significant difference between groups, with a higher proportion of abnormal children in the study group. Both groups showed abnormal immittance measures results, although there was no statistically significant difference between the groups. Both showed normal BAEP results. When analyzing quantitative LLAEP data we observed a statistically significant difference between groups in terms of latency of components P1, N1 and P300; the study group had higher latencies for all components. When analyzing P300 amplitudes, there was a statistically significant difference between the right and left ears in the control group; P300 amplitudes was wider for the right ear. On the other hand, the study group did not show any statistically significant difference between the right and left ears. Both the control and study group shoed abnormal LLAEP results. There was a statistically significant difference between groups for components P1, N1 and P300; abnormalities were more frequent in the study group. The type of predominant abnormality in components P1 and P300 was increased latency and for component N1 it was lack of response in the study group; for the control group the type of predominant abnormality in components P1, N1 and P300 was increased latency. Because most children were only slightly malnourished (58.1%), it was not possible to establish a correlation between the level of malnutrition and LLAEP abnormalities. Conclusion: Malnourished children showed more abnormalities in auditory behavioral assessment (pure tone audiometry and dichotic digit test) and LLAEP than healthy children. This suggests a deficit in central auditory pathways and abnormalities in the processing of acoustic information. Further studies are necessary to better describe speech and language and hearing abnormalities in this population.

The chirp stimulus was designed seeking to compensate the delay of the sound wave through the cochlea, enabling simultaneous stimulation of nerve fibers along the auditory pathway, providing better neural synchrony and consequently higher amplitude responses. This study aims to analyze and compare the results of brainstem auditory evoked potential in newborns born at term, using the click and iChirp stimuli at different intensities, analyzing latency and amplitude of the V wave, tested ear and genre. The study analyzed 30 newborns at terms, and the protocol for BAEP registry with click and iChirp stimulus was: rarified polarity, 2048 scans, presentation rate of 27.7 stimuli/s, bandpass filter from 100 to 3,000 Hz, 100k gain, 12 ms window for the click and 24 ms for iChirp. Intensities researched with the two stimuli were 60, 40 and 20 dB nHL. When results with the two stimuli used in the study were compared regarding the values for the latency of the V wave, increased values with iChirp were observed in the three levels of performance. In regards to the magnitude of this component, the three researched intensities also revealed that the iChirp stimulus was able to generate statistically significant larger amplitudes when compared to the click stimulus. Additionally, subtle differences were observed between the ears and between the genres for the latency values and V wave amplitude with the different stimuli used, although with little clinical relevance. In conclusion, the use of iChirp stimulus may be interesting in the field of audiological diagnosis in children, since it evokes responses with larger amplitudes in the three intensity levels studied, facilitating the identification of the V wave. It is worth noting that when the iChirp was used, the latency of the V wave was higher when compared to research with the click. The variables ear tested and gender exhibited slight differences that were not considered clinically relavant. / O estímulo chirp foi projetado buscando compensar o atraso da onda sonora em sua viagem pela cóclea, possibilitando uma estimulação simultânea das fibras nervosas ao longo da via auditiva proporcionando uma melhor sincronia neural e consequentemente o registro de respostas com maiores amplitudes. Este estudo visa analisar e comparar os resultados do Potencial Evocado Auditivo de Tronco Encefálico em neonatos nascidos a termo, utilizando os estímulos clique e iChirp, em diferentes intensidades de apresentação, analisando latência e amplitude da onda V, orelha testada e gênero. A casuística do estudo foi de 30 neonatos a termos, e o protocolo para registro do PEATE com estímulo clique e iChirp foi: polaridade rarefeita, 2048 varreduras, taxa de apresentação de 27,7 estímulos/s, filtro passa banda de 100 a 3000 Hz, ganho de 100k, janela de 12 ms para o clique e 24 ms para o iChirp. As intensidades pesquisadas com os dois estímulos foi de 60, 40 e 20 dB nHL. Na comparação dos resultados obtidos com os dois estímulos utilizados no estudo, em relação aos valores para a latência da onda V, observou-se que valores aumentados com o iChirp, nos três níveis de apresentação. Em relação a amplitude deste componente, observou-se que o estímulo iChirp foi capaz de gerar amplitudes maiores estatisticamente significantes quando comparado ao clique, também nas três intensidades pesquisadas. Houve discretas diferenças entre as orelhas e entre os gêneros para os valores de latência e amplitude da onda V com os diferentes estímulos utilizados, entretanto com pouca relevância clínica. Conclui-se que a utlização do estímulo iChirp pode ser interessante no campo do diagnóstico audiológico infantil, por evocar respostas com maiores amplitudes, nos três níveis de intensidade pesquisadas, desta maneira faciliando a identificação da onda V. Cabe ressaltar que quando utilizou-se o iChirp a latência da onda V apresentou-se maior quando comparada a pesquisa com o clique. As variáveis orelha testada e gênero apresentaram discretas diferenças que não foram consideras relavantes clinicamente.

In individuals claiming compensation for occupational noise induced hearing loss, a population with a high incidence of nonorganic hearing loss, a reliable and valid behavioural pure tone (PT) threshold is not always achievable. Recent studies have compared the accuracy of behavioural PT threshold estimation using the slow cortical auditory evoked potentials (SCAEP) and auditory steady-state responses (ASSR) but there is no consensus regarding recommended technique. A review of the literature indicated that no comparison has been completed on the use of SCAEP and a single frequency ASSR technique. A research project was therefore initiated with the aim of comparing the clinical effectiveness (accuracy) and clinical efficiency (time required) of SCAEP and ASSR for behavioural PT threshold estimation in adults exposed to occupational noise. Adult participants were divided into a group with normal hearing (behavioural PT thresholds < 20 dBHL; n = 15) and a group of participants with hearing loss (n = 16 adults), the latter of which were recruited from individuals referred for audiometric screening, as part of hearing conservation programs, and who were, therefore, exposed to occupational noise. The GSI Audera electrophysiological system was used for both SCAEP and ASSR threshold measurement at 0.5, 1, 2 and 4 kHz. Use was made of tone burst stimuli for the SCAEP (rise and fall of 10 ms with 80 ms plateau), while amplitude and frequency modulated (AM/FM) stimuli was used during ASSR testing. The system’s 40 Hz protocol was chosen for use during ASSR recording while participants slept because this led to lparticipants. ASSR thresholds could not be measured in two of the three sleeping participants in the preliminary study using an 80 Hz modulation rate due to excessive noise. The mean SCAEP difference scores (SCAEP threshold minus behavioural PT threshold) for both participant groups were -0.2+10.2, 2.8+10.1,5.8+9.7, 0.5+10.4 at 0.5, 1, 2, and 4 kHz respectively, while ASSR difference scores were 25.3+12.8, 21.7+11.3,32.3+12.2, 27.1+13.8. The SCAEP correlations with behavioural PT thresholds across frequencies (r = 0.85) were also stronger than ASSR correlations (r = 0.75). Therefore, with regard to proximity of auditory evoked potentials (AEP) to behavioural PT thresholds and consistency of this relationship, the SCAEP, rather than ASSR, is the AEP of choice. However, the SCAEP took on average 10.1 minutes longer to complete than the ASSR. Clinical effectiveness was given comparably more weight than the clinical efficiency of the AEP technique to estimate behavioural PT thresholds due to the impact on overcompensation for occupational noise induced hearing loss. As such, the study acknowledged the SCAEP as the AEP of choice for the purpose of behavioural PT thresholds in adults exposed to occupational noise. It is important to note that the conclusion reached in the current study arose from the comparison of the SCAEP with a specific ASSR technique. Accuracy of ASSR estimation of behavioural PT thresholds is strongly influenced by stimulus and recording parameters of the system used, and by the participant variables. Copyright / Dissertation (MCommunication Pathology)--University of Pretoria, 2010. / Speech-Language Pathology and Audiology / Unrestricted

<p>Degenerativne bolesti kičme nastaju kao posledica promena na dinamičkim segmentima kičmenog stuba. Klinički ove promene se mogu manifestovati u vidu radikulopatije, mijelopatije i radikulomijelopatije. Najče&scaron;će primenjivana metoda operativnog lečenja kod ovih pacijenata je prednja cervikalna diskektomija sa fuzijom koja omogućava adekvatnu anatomsku i funkcionalnu restituciju degenerativno promenjene cervikalne kičme. Imajući u vidu da su već kompromitovane nervne strukture u riziku od dodatnih o&scaron;tećenja u različitim fazama operativnog zahvata primena intraoperativnog neurofiziolo&scaron;kog monitoringa je dobila svoje mesto i u hirur&scaron;kim tretmanima degenerativnih oboljenja kičme. Svrha primene neuromonitoringa je da obezbedi povratnu informaciju hirurgu o promenama u funkciji nervnih struktura pre nego &scaron;to dođe do ireverzibilnih o&scaron;tećenja. Na ovaj način moguće je prevenirati nastanak novog ili pogor&scaron;anje postojećeg deficita. Takođe intraoperativni nalazi neurofiziolo&scaron;kih parametara mogu da ukažu na težinu postojećeg oboljenja i da budu prediktori ishoda lečenja. Ciljevi ove doktorske disertacije bili su utvrđivanje faza operativnog zahvata u kojima najče&scaron;će dolazi do promena u neurofiziolo&scaron;kim parametrima, kao i postojanje korelacije nalaza intraoperativnog neurofiziolo&scaron;kog monitoringa sa preoperativnim kliničkim nalazom pacijenta kao i rezultatima procene ishoda nakon prednje cervikalne diskektomije se fuzijom. Ova studija je obuhvatila 30 pacijenata kod kojih je indikovano operativno lečenje degenerativnih promena u vratnom segmentu kičmenog stuba prednjom mikrodiskektomijom sa fuzijom. Preoperativno je izvođen klinički pregled pacijenata i kori&scaron;teni su Numerička skala bola i Upitnik za pacijente sa bolom u vratnoj kičmi, koji su takođe popunjavani na otpustu i mesec dana nakon operacije. U toku hirur&scaron;ke procedure upotrebom intraoperativnog neurofiziolo&scaron;kog monitoringa registrovani su somatosenzorni (SSEP) i motorni evocirani potencijali (MEP), kao i spontana elektromiografija. Kod svih SSEP do&scaron;lo je do statistički značajnog povećanja amplitude (p&lt;0,05), dok je kod desnog n. medianusa zabeleženo i statistički značajno skraćenje latence (p&lt;0,05). Značajne promene se beleže između početka i kraja operativnog zahvata, kao i u fazi uklanjanja intervertebralnog diska kada dolazi do dekompresije. U vrednostima pražne struje potrebne za dobijanje MEP nije bilo statistički značajnih promena izuzev kod m. triceps brachii obostrano. Kod pacijenata sa radikulopatijom vrednost pražne struje za dobijanje mi&scaron;ićnog odgovora je statistčki značajno niža u odnosu na pacijente sa mijelopatijom (p&lt;0,05). SSEP koreliraju sa poremećajem senzibiliteta, refleksnim odgovorom i bolom. MEP koreliraju takođe sa refleksnim odgovorom, dok negativna korelacija sa manuelnim mi&scaron;ićnim testom pokazuje da klinički očuvana gruba mi&scaron;ićna snaga ne mora biti pokazatelj pravog stanja motornog sistema. Preoperativne vrednosti NDI su se statistički značajno smanjile mesec dana nakon operacije (p&lt;0,05). U vrednostima bola postoji statistčki značajna razlika između svih merenje (p&lt;0,008), izuzev između bola na otpustu i mesec dana nakon operacije (p&gt;0,008). Latenca desnog n.medianusa pokazuje negativnu, a amplituda pozitivnu korelaciju sa vrednostima bola mesec dana postoperativno (p&lt;0,05). Povećanje amplitude i skraćenje latence SSEP ukazuje na značajan stepen dekompresije. Stabilnost MEP ukazuje na intraoperativnu očuvanost motornih puteva i da nije do&scaron;lo do novog motornog deficita niti produbljivanja postojećeg. SSEP i MEP koreliraju sa kliničkim nalazom, dok su vrednosti bola i NDI statistički značajno manje nakon operacije. Ovi rezultati ukazuju da klinički nalaz pacijenta korelira sa neurofiziolo&scaron;kim nalazom, kao i da introperativne promene neurofiziolo&scaron;kih parametara mogu biti prediktivni faktor ishoda operativnog lečenja.</p> / <p>Degenerative spinal diseases are consequence of spondylotic changes on dynamic segments of spinal column. These changes can result in different clinical appearances such as radiculopathy, myelopathy and radiculomyelopathy. The most common surgical procedure used in treatment of this group of patients is anterior cervical discectomy and fusion (ACDF) which can provide adequate anatomical and functional restitution of degenerative cervical spine. Considering the fact that already compromised neural structure can be additionally damaged in different stages of surgical procedure, use of intraoperative neurophysiological monitoring (IONM) has role in surgical treatment of degenerative spinal diseases. The aim of use of IONM is to provide real time feedback for surgeon regarding changes in function of neural structures before irreversible damage occurs. This is the way to prevent new neurological deficit from occurring or to prevent worsening of preexisting deficit. Results of intraoperative monitoring can additionally emphasize severity of disease and help in outcome assessment. The aim of this doctoral thesis was to determine phases of surgical procedure in which changes in neurophysiological parameters occurs most commonly. Another aim was to determine correlation between findings of intraoperative neurophysiological monitoring and clinical assessment and outcome prediction in patients treated with anterior cervical discectomy with fusion. Thirty patients who met inclusion criteria were enrolled in this study. All of them were treated surgically due to degenerative changes of cervical spine and ACDF were performed in all cases. Patients were thoroughly examined before surgery. Detailed neurological examination were performed together with Numeric pain rating scale (NPRS) and Neck Disability index (NDI) questionnaire. NPRS and NDI were applied on discharge from the hospital and one month after surgery. During surgery we registered somatosensory evoked potentials (SSEP), motor evoked potentials (MEP) and spontaneous elektromiography. In all SSEP there were statistically significant increase in amplitude (p&lt;0.05), while in the case of right n. medianus statistically significant shortening of the latency (p&lt;0.05) was recorded. Significant changes are recorded between beginning and the end of the surgical procedure, as well as in the phase of removing of the intervertebral disc when decompression occurs. In the threshold intensity needed to elicit the MEP there were no statistically significant changes except for m. triceps brachii bilaterally. In patients with radiculopathy, the value of the stimulus intensity needed for obtaining muscular response was statistically significantly lower in comparison with patients with myelopathy (p&lt;0.05). SSEP showed the best correlation with sensory disorder, tendon reflexes and pain. MEPs also correlate with tendon reflexes, while a negative correlation with a manual muscle strength testing results shows that clinically preserved muscle strength does not have to be reliable indicator of the motor system condition. Preoperative NDI values were statistically significantly reduced a month after surgery (p&lt;0.05). In pain values there is a statistically significant difference between all measurements (p&lt;0.008), except between pain on release and a month after surgery (p&gt;0.008). The right n.medianus latency shows a negative, and the amplitude shows positive correlation with pain values one month postoperatively (p&lt;0.05). Increasing amplitude and shortening latency of the SSEP indicates a significant degree of decompression. The stability of the MEP indicates the intraoperative preservation of motor pathways and absence of both new motor deficiency or worsening of the existing one. SSEP and MEP correlate with clinical findings, while pain and NDI values are statistically significantly less after surgery. These results indicate that clinical findings in the patients correlate with the neurophysiological findings. Results also points out that the intraoperative changes in neurophysiological parameters can be a predictive factor for the outcome of surgical treatment.</p>

Le but de cette thèse était d'étudier l'organisation anatomo-fonctionnelle du système sensorimoteur humain et la façon dont les mouvements volontaires sont produits et contrôlés. Avec le développement de l’imagerie cérébrale, des méthodes de corrélation anatomo-clinique et de stimulation électrique directe cérébrale, de nombreuses avancées scientifiques ont pu être réalisée. Ces trois approches complémentaires ont été utilisé dans cette thèse afin d’améliorer la compréhension de l’organisation sensorimotrice cérébrale. Dans la première étude (soumise à publication), nous avons montré que la chirurgie cérébrale éveillée utilisant la stimulation électrique directe est une procédure sûre et efficace chez les enfants afin de réduire le déficit neurologique postopératoire. L'approche améliore la précision de la détection des zones éloquentes, avec une bonne tolérance neuropsychologique et psychologique. Une évaluation psychologique et neuropsychologique est essentielle. Dans une deuxième série de deux études, nous avons montré que la partie dorso-postérieure dorsal du cortex pariétal (DPPr) est une structure clé dans l'organisation complexe du mouvement manuel fin chez l'homme à travers la mise en oeuvre d'une boucle sensori-parieto-motrice.La première étude (publiée, Current Biology 2018) montre que la stimulation électrique directe d’une region corticale focale dans la partie dorso-postérieure du cortex pariétal entraine l’inhibition de la production du mouvement manuel, c’est-à-dire bloque l'initiation et la réalisation de ce dernier, sans produire de contraction musculaire ni de sensation consciente de mouvement. Dans la seconde étude (en cours de soumission), nous avions pour objectif d'identifier précisément les bases anatomiques du circuit parietal inhibiteur précédemment décrit. Grâce à la tractographie de diffusion (DTI), nous avons réussi à isoler des projections ipsilatérales spécifiques reliant les sites d’inhibition du DPPr, retrouvés dans la première étude, avec la zones dévolues au contrôle distal fin dans les cortex primaires moteur (M1) et sensoriel (S1). Ces données montrent que la boucle pariétale inhibitrice est directe depuis S1 vers DPPr vers M1 (même s'il n'est pas possible d'exclure l'existence d'échanges bidirectionnels entre ces aires). Dans la dernière étude (en cours de soumission), nous nous sommes intéressé à une structure motrice fondamentale, qui supporte 50 % des invasions tumorales chez l'enfant : le cervelet. Il s'agissait de déterminer si les lésions précoces étaient oui ou non prédictives d'une récupération déficitaire à long terme après prise en compte des covariables les plus critiques. Nous avons mesuré la récupération fonctionnelle à long terme chez 3 groupes survivants de lésion de la fosse postérieure. Les 3 groupes étaient comparables en ce qui concerne leurs caractéristiques tumorales mais opérés à différents âges : jeune (≤ 7 ans), moyen (> 7 ans et ≤ 13 ans) et tardif (> 13 ans). La qualité de vie (échelles cliniques : Health-related Quality of Life -hrQol- et Performance Status -PS-), les performances motrices (ataxie -ICARS- et motricité fine -Pegboard-) et cognitif (quotient intellectuel -FSIQ-) furent mesurés. L'âge précoce lors de la chirurgie, une lésion des noyaux profonds cérébelleux et la nécessité d'une radiothérapie postopératoire révélèrent une influence significativement négative et indépendante sur la récupération à long terme des participants. Ces résultats confirment l'existence d'une période critique de développement au cours de laquelle la "machine à apprendre" cérébelleuse revêt une importance cruciale / The aim of the thesis was to investigate the mapping of the anatomofunctional organization of the human sensorimotor system and how volutional movements of human are produced and controlled. Neuroimaging and especially DTI, fine anatomo-functional observation in patient and direct electrical stimulation were considered. This multi-modal approach permitted to improve our understanding of sensorimotor organization in humans. In the first study, we showed that awake brain surgery with the use of direct electrical stimulation is a safe and efficient procedure in children in order to decrease post-operative neurological deficit. It improves the accuracy of detecting eloquent area, with a good tolerance from a neuropsychological and psychological aspect. Age-adapted neuropsychologic preparation may enable offering ABS even to younger children on an individual basis. In a second series of two studies, we showed that the dorso-posterior part of the parietal cortex is a key structure in the complex organization of movement in human with a S1-DPPr-M1 loop. In the first study, direct electrical stimulation of focal cortical site in the dorso-posterior part of the parietal cortex triggered inhibition of movement production and blocked ongoing movement without producing muscle contraction or conscious movement sensation. In the second study, we aimed to find a direct projection from the PRR, defined in the first study (Desmurget et al., 2018), to the primary motor cortex and the primary somatosensory cortex. Thanks to the DTI state-of-the-art tractography, we succeeded in finding such major ipsilateral streamlines projecting in the well-known hand knob region giving new insights of the white matter structures involved in the inhibition of volitional hand movements. These observations confirm clinical per-operative data showing that stimulating the counterpart of PRR in humans can disrupt hand movements ipsilaterally, irrespective of the hemisphere. Moreover, our results shed light on the implication of the PRR for the volitional hand sensorimotor operating behavior. In the last study, we investigate the impact of early cerebellar damage on long-term functional recovery in 3 groups of posterior fossa survivors, comparable with respect to their tumoural characteristics but operated at different ages: young (≤ 7 years), middle (> 7 years and ≤ 13 years) and old (> 13 years). Daily (Health-related Quality of Life -hrQol-, Performance Status -PS-), motor (International Cooperative Ataxia Rating Scale -ICARS-, Pegboard Purdue Test -PegBoard-) and cognitive (Full Scale Intelligence Quotient -FSIQ-) functioning were measured. Early age at surgery, lesion of deep cerebellar nuclei and post-operative radiotherapy had a significant, independent negative influence on long term recovery. These results support the existence of an early critical period of development during which the cerebellar "learning machine" is of critical importance

Over the last 30 or more years evidence has accumulated in favour of the view that memory is not a unitary faculty; rather, it can be subdivided into a num- ber of functionally independent subsystems. Whilst dividing memory phenomena into these distinct subsystems has undoubtedly advanced our understanding of memory as a whole, the approach of studying subsystems in isolation fails to address potential interactions between them. Over the last few decades there has been a gradual increase in the number of studies attempting to move be- yond dissociation by characterising functional interactions between subsystems of memory. The main aim of this thesis was to contribute to this endeavour, by examining interactions between two specific subsystems that are positioned on opposite sides of the declarative and non-declarative divide in long-term mem- ory: priming and episodic recognition. Event-Related Potentials (ERPs) were employed to monitor neural markers of repetition priming and episodic memory during recognition tests with masked priming of test cues. In the standard pro- cedure, half of the studied and unstudied test trials began with a brief (48ms) masked repetition of the to-be-recognized word prior to the onset of test items; the remaining unprimed trials were preceded by the word “blank”. The pattern of priming effects across experiments was reasonably consistent, with differences between experiments directly related to the intended manipulations. In contrast to priming effects, the pattern of memory effects was variable across experiments, demonstrating that the engagement of explicit recognition signals is influenced by the outcome of implicit processing, and suggesting that interactions between priming and explicit retrieval processes do occur. Taken together, results from experiments reported in this thesis indicate (1) that under certain circumstances, priming is sufficient to support accurate recognition and does not necessitate changes in memory performance, (2) that mid-frontal old/new effects indexing familiarity are not merely driven by repeated access to semantic information, and (3) that priming influences neural correlates of recollection by speeding their onset. Overall, the data clearly demonstrate that there are multiple potentially interacting routes to recognition.

The goal of this thesis is to track latency changes in three visual evoked potentials (VEP) stimuli as an indication of overall brain development, in order to provide a normative baseline to differentiate visual and neurological development from pathological processes. VEP- neural electrical activity recorded from the scalp surface and synchronized with visual stimulus transitions- is one of the common techniques in understanding infant vision development. Past work has concentrated on responses to pattern reversal and to the latency of the initial positive peak. Here we compare the timing of responses to pattern, orientation, and direction-reversal VEPs, and transient peak latencies to those calculated from the gradient of steady-state phase against reversal rate. The three stimuli were tested in 81 adults at 1- 16 r/s and 137 infants (3.6- 79.0 weeks) at 2- 8 r/s. Initial responses to orientation and direction were as fast as for contrast- around 100 ms, consistent with other findings that V1 is orientation selective. Cortical processing for both OR and DR yielded longer latencies (200 ms) by the calculated method, perhaps reflecting more involvement of higher visual processing in comparison to PR. Orientation and direction latencies also had a delayed onset and longer developmental period to reach maturity. Infants reached adult transient PR latency values by 15 weeks, for OR by 50 weeks, and for DR by 10 weeks. For the calculated latency, infants reached both adult PR and DR latencies by 30 weeks while OR showed little change across age. We successfully confirmed that (1) phase-based calculation of latency is effective, easy to use, and taps into a different cortical pathway; (2) motion processing has an additional, faster, subcortical pathway; (3) a parallel processing of initial contrast and orientation; and (4) later visual processing is not only developmentally delayed for all three stimuli but also more vulnerable to perinatal brain damage. These latency differences provided a baseline for clinical evaluations where identification of delayed latencies should aid early diagnosis and guide therapies for adults and infants.

Name of the thesis Reactive oxygen species and their neurophysiological role Aim of the thesis Aim of the theoretical part is to provide overview of reactive oxygen species (ROS) and show their place in organism - posstive and necessary effects for the organism on the one hand and source of serious diseases on the other hand. Futhermore, the theoretical part deals with the restoration balance between the production of free radicals and antioxidants protection. Theoretical part also deals with substance FeTTPS. Aim of the experimental part is to determinate whether the application of FeTTPS affects cerebral blood flow during trancallosal stimulation with increasing frequency. Futhermore, to determinate whether the applicatication of this substance affects the slope of the curve and threshold of evoked potencials and number and duration of afterdischargers. Research method The research took place at the premises of Onstitue of Physiology, Academy of Sciences, Czech Republic. Experiments were carried out on laboratory albine Wistar rats. General anesthesia was performed to rats, stimulating and sensing electrodes were implated in epidural area of sensorimotoor cortex and Laser Doppler flow probe was implated into the contralateral hemisphere. In the first part of experiment included 11 animals. We...