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Swallowing is a complex sensorimotor behaviour that includes precisely-timed bilateral activation and relaxation of muscles of the face, lips, tongue, cheeks, palate, larynx, pharynx and oesophagus. These events of activation and inhibition are controlled by many structures of the brain and are executed by cranial nerves that carry motor and sensory information to and from the swallowing muscles. Swallowing disorders are common sequelae of many neurological and structural disorders, including stroke, Parkinson’s disease, and head and neck cancer. Changes to swallowing physiology are also prevalent in older individuals, but these changes do not necessarily translate to dysphagia. Decreased muscle strength, changes to motor unit properties, and hypotrophic changes in skeletal muscles can result in age-related changes in swallowing physiology. In addition to muscular changes, neural changes might also change swallowing function in older subjects. The motor-learning literature presents a clear distinction between the differential applications and effects of skill- and strength-training approaches for rehabilitation of limb movement. In contrast to limb-movement rehabilitation, swallowing rehabilitation approaches consist mainly of strength training, although the pathophysiological basis for dysphagia is not always weakness. Therefore, this Phase I clinical-trial critically evaluated a unique swallowing skill training protocol in which the goal of intervention is to increase precision of motor control during swallowing. A Phase I clinical-trial was necessary to identify the appropriate protocol for inducing neurophysiological, biomechanical, and structural adaptations, to estimate effect sizes, and to identify adverse effects. The first and primary question addressed in this thesis was whether swallowing skill training would produce greater physiological effects in healthy subjects than a traditional swallowing strength training approach. In order to answer this question, three levels of assessment were included. Neurophysiological assessment consisted of delivering single-pulse transcranial magnetic stimulation (TMS) over the M1 area that sends efferent projections to the submental muscle group during a functional task of volitional saliva swallowing, and during a non-functional task of submental muscle group contraction. Biomechanical assessments consisted of pharyngeal and upper esophageal sphincter (UES) pressure measurements using pharyngeal manometry during effortful and non-effortful swallowing tasks, submental muscle activation measurements using surface electromyography (sEMG) during effortful and non-effortful swallowing tasks, and hyoid displacement using ultrasonography. Structural assessment consisted of measuring the cross sectional area of the submental muscle group. Finally, motor performance during training, and subjective ratings of the training protocols were assessed. Two skill training protocols were developed to assess the use of immediate versus delayed visual feedback in swallowing skill training. In addition, a pilot study aimed at examining the effects of increased dosage of training sessions was conducted. Forty healthy subjects (20 young, and 20 old; 20 females and 20 males) were allocated to skill and strength training groups in a counterbalanced manner. Strength training consisted of execution of the effortful swallowing technique targeting increased demand for strength. Skill training targeted precise timing and force execution during swallowing execution. Several motor-learning principles were considered in devising the training protocols, including the principles of task specificity and high intensity of training. Biofeedback was included to promote motor learning. Since the submental muscle group plays an important role in hyolaryngeal excursion, the current study utilized submental sEMG biofeedback using custom-made training software. The training protocols consisted of 1000 repetition of swallowing over a 2-week period. Subjects trained for an hour, five days a week, for 2 weeks (i.e., 10 training sessions). The extended dosage protocol included 10 subjects and comprised an additional eight sessions. The results indicated that there was a significant difference in submental activation following training, with strength training having an increase in sEMG peak amplitude in comparison to skill training. There were no other differences between groups at the 5% error level. Patterns of change were revealed when marginally significant results (0.05 < p ≤ 0.10) were investigated as well. Strength training resulted in a trend towards increased neural drive for volitional effortful-type tasks (i.e., effortful saliva swallowing, effortful water swallowing, and submental muscle contraction) as indicated by increased MEP magnitude (p = 0.07) which was consistent with significantly increased peak amplitude of submental activity measures (p < 0.001). This finding supports the task specificity principle of motor learning. Skill training resulted in no changes in MEP magnitude. There was a trend (p = 0.06) towards increased submental muscles activity during functional swallowing tasks (i.e., non-effortful swallowing) in young subjects,. Males in skill training had decreased duration of UES opening in 10 mL water effortful swallowing task (p = 0.02), a trend towards increased UES pressure in non-effortful saliva swallowing task (p = 0.07), and reduced hyoid displacement following training (p < 0.001). Changes in pharyngeal pressures were detected for skill training with delayed visual feedback that resulted in decreased pressure at mid-pharynx in effortful and non-effortful tasks (p < 0.05). No difference in submental CSA changes was detected in either training group. Both groups improved motor performance measured by data collected during the session (target hit-rate and muscle activity). The results of the pilot study that examined the effects of an extended dosage of training were difficult to interpret due to the small sample size. However, there were significant and marginally significant effects of skill training on mid-pharyngeal and UES pressure duration events. Dysphagia is common in patients with Parkinson’s disease, but no specific training programme exists for these patients, leading to the second question addressed through this research. Since movement planning is compromised due to dysfunction of the basal ganglia, providing external information for planning and executing swallowing was hypothesized to alleviate dysphagic symptoms. Ten subjects were recruited. Swallowing skill training with immediate feedback was administered for one hour every day, five days a week, for 2 weeks, similar to the training dosage and frequency in the healthy group. Biomechanical and structural changes were assessed. Swallowing skill training with immediate feedback led to an increase in submental activity in effortful swallowing tasks but not non-effortful tasks. In addition, it was found that individuals with dysphagia secondary to Parkinson’s disease have deceased submental muscle reserve relative to healthy subjects. Preliminary analysis of MEP data led to exploration of submental MEP measures between younger and older subjects. This ‘discovery’ research shed light on the third topic addressed in this thesis. There are contradicting results in the literature regarding age-related brain activity during swallowing. Since submental MEPs were included as an outcome measure in the main study, it was important to evaluate them at baseline in order to understand and interpret changes in this measure. Unlike other measures, such as pharyngeal pressure and hyoid displacement that have been documented in the literature to change with age, no similar study has been conducted to assess for differences in swallowing-related MEPs. Baseline data from the main study were analysed. Older subjects produced larger MEP magnitude in comparison to young in volitional saliva swallowing and volitional submental contraction. This finding raised some questions regarding the use of MEPs as an outcome measure, since it is not clear what constitutes a ‘positive’ change. This study documented, for the first time, the application of skill training in swallowing in a healthy and dysphagic population. Positive effects of treatment were found in the dysphagic group; an indication of negative effects was identified in the healthy group. In addition, this is the first study to compare skill to strength training in swallowing. The only significant difference between the two was significantly greater submental activation in effortful swallowing tasks following strength training in comparison to skill training; although there were some significant interactions between age and training type and gender and training type. This project represents the first Phase I clinical-trial of an innovative approach for addressing swallowing impairments. Achieving the ultimate aim of finding the most appropriate training protocol for treating individuals with a specific pathophysiological basis of dysphagia, requires the implementation of a long-term on-going research programme characterized by a staged process. This research programme sets an initial reference framework from which further projects can estimate the sample size required to answer specific questions, control for effects of age and gender and their interaction with training, increase precision in choosing assessment tools, and test new specific questions.

Background and aims: The primary motor cortex (M1) controls voluntary motor behaviours. M1 has been identified to play a major role in the execution of voluntary corticospinal tasks as well as self-initiated corticobulbar tasks. However, the involvement of M1 in more complex corticubulbar tasks, such as swallowing, is not yet fully understood. Swallowing is quite different from other voluntary motor tasks as it has both voluntary and reflexive components. The degree of M1 involvement in the pharyngeal, or more reflexive, component of swallowing is unclear. Studies investigating the role of M1 in swallowing have yielded contradictory findings regarding the specific functional contribution of M1 to swallowing. Therefore, further investigation is warranted to clarify the role of M1 in pharyngeal swallowing. Discrete saliva or water swallowing has been utilized in most studies investigating neurophysiology of swallowing in health and disease. However, individuals most frequently complete multiple, consecutive swallows during the ingestion of liquid. Biomechanical differences between discrete and continuous water swallows have been identified using videofluoroscopic swallowing study (VFSS). However, no studies have investigated the pharyngeal pressure differences between these two swallowing tasks. Additional insights into task differences may be revealed through evaluation of pharyngeal pressure utilizing pharyngeal manometry. This research programme sought to clarify the role of M1 in reflexively and volitionally initiated pharyngeal swallowing. In order to understand M1 involvement in the execution of swallowing, comparative tasks that require known dependence on M1 were also included in this research programme. This research programme addressed the biomechanical changes in motor behaviours as a result of neural disruption during the performance of a number of motor tasks. This neural disruption was intrinsically generated through application of dual task (DT) paradigm and extrinsically generated using single pulse transcranial magnetic stimulation (TMS). A secondary aim of this research programme was to identify the differences in pharyngeal pressure generation between discrete and continuous swallowing. Methods: Twenty-four right handed participants (12 males, average age= 24.4, SD= 6.3) were recruited to this research programme. A number of motor tasks that vary in complexity were tested. These tasks included: volitional swallowing, reflexive swallowing, eyebrow movement, jaw movement and finger tapping with right, left, or bilateral index fingers. Participants performed multiple trials of several tasks in each study. Repetitions of tasks during a single session may affect performance due to factors such as fatigue or practice. A baseline study was undertaken to determine within-participant variability of measures across repeated trials. Following the baseline study, the role of M1 in pharyngeal swallowing was investigated in two main studies in counter balanced order. The role of M1 in pharyngeal swallowing was evaluated by investigating swallowing parameters during neural disruption using a DT paradigm. Participants performed tasks in isolation (baseline) and with interference that consisted of pairing swallowing with comparative task that activates M1 (fingers tapping and eyebrow movement tasks). In the other study, single pulse TMS was utilized to create an electrophysiological disruption to the areas of M1 associated with muscular representation of a number of motor behaviours (swallowing tasks, jaw movement and fingers tapping tasks). Stimulation was provided to both hemispheres in random order to evaluate laterality effects. Swallowing parameters and the performance of the other motor tasks were evaluated when performed with and without electrophysiological disruption. Differences in pharyngeal pressure generation between discrete and continuous swallowing were investigated using pharyngeal manometry. Pharyngeal pressures were recorded at three locations: upper pharynx, mid-pharynx and upper esophageal sphincter (UES) during four swallowing types: discrete saliva swallowing, discrete 10 ml swallowing, volitional continuous swallowing, and reflexive continuous swallowing. The research paradigm used in this research programme identified the effect of experimental conditions on the rate and regularity of task performance. In addition, pharyngeal manometry was utilised to measure the effect of experimental conditions on the pattern of the pharyngeal pressure generation during swallowing. Within subject differences from baseline were identified by means of Repeated Measures Analyses of Variance (RM-ANOVA). Results: Initial analysis of the data revealed that repetition of tasks within a session did not affect the rate and regularity of voluntary corticospinal tasks, voluntary corticiobulbar tasks nor swallowing tasks. In addition, repeating the swallowing tasks during a session did not affect pharyngeal pressure as measured by pharyngeal manometry. When motor tasks were performed concurrently in the DT paradigm, rate and regularity of eyebrow movements were significantly decreased when paired with swallowing tasks, whereas rate and regularity of swallowing were significantly decreased when paired with left finger tapping, but not right finger tapping. However, there was no significant effect of any task on the pattern of pharyngeal pressure generation. Extrinsically generated disruption using TMS significantly reduced rate and regularity of finger tapping tasks and regularity of jaw movement and swallowing tasks. In addition, interruption of pharyngeal M1 during the volitional swallowing task produced significant increase in the duration but not the amplitude of the pharyngeal pressure. Pharyngeal pressure generation differed between swallowing types and boluses types, in that saliva swallowing produced longer pharyngeal pressure duration and lower nadir pressure than water swallows. Discrete water bolus swallowing produced longer UES opening compared to both saliva swallowing or continuous water swallowing. Conclusion: The results of this research programme provided valuable methodological information regarding the effect of trials on task performance as well as identifying pharyngeal pressure differences between discrete and continuous swallowing. In addition to the methodological contribution, this research programme expanded on previous knowledge of neural control of swallowing, in that it extended the findings regarding potential role of M1 in pharyngeal swallowing. Given the absent effect of task repetition on the performance of corticospinal and corticobulbar motor tasks, it is speculated that outcomes of research investigating the effect of experimental manipulation on motor tasks performance is due to the experimental tasks, rather than natural variance in the data. The effect of swallowing on the rate and regularity of eyebrow movement, when performed concurrently using DT paradigm, suggest bilateral functional overlapping to a significant degree between neural substrates that control swallowing and orofacial muscles. These results offer partial support of bilateral representation of swallowing in the cortex. In addition, results further revealed potential involvement of right M1 in the regulation of pharyngeal swallowing as evidenced by a disruptive effect of left finger tapping on the rate and regularity of swallowing. The results from the hemispheric TMS disruption study support the active involvement M1 in the execution of voluntary corticospinal and corticobulbar motor tasks. In addition, the current findings extended previous knowledge of neural control of pharyngeal swallowing by documenting the effect of neural disruption on the regularity and pharyngeal pressure measures during volitional and reflexive swallowing. The current programme documented potential role of M1 in the control of pharyngeal swallowing possibly by modulating the motor plan at the swallowing CPG in the brainstem. This project is the first to document pharyngeal pressure differences between discrete and continuous swallowing. These findings contribute valuable information to the swallowing literature as limited number of studies investigated the biomechanical differences between discrete and continuous liquid ingestion. This knowledge will assist clinicians and researchers in identifying the pharyngeal pressure differences between normal and abnormal swallowing in different swallowing types and ultimately guide their rehabilitation decisions. Data from this research programme will add to the existing knowledge of neurophysiology of swallowing, thereby facilitating understanding of swallowing pathophysiology which is crucial for appropriate management of swallowing disorders.

A full-sine (biphasic) pulse waveform is most commonly used for repetitive transcranial magnetic stimulation (TMS), but little is known about how variations in duration or amplitude of distinct pulse segments influence the effectiveness of a single TMS pulse to elicit a corticomotor response. Using a novel TMS device, we systematically varied the configuration of full-sine pulses to assess the impact of configuration changes on resting motor threshold (RMT) as measure of stimulation effectiveness with single-pulse TMS of the non-dominant motor hand area (M1). In young healthy volunteers, we (i) compared monophasic, half-sine, and full-sine pulses, (ii) applied two-segment pulses consisting of two identical half-sines, and (iii) manipulated amplitude, duration, and current direction of the first or second full-sine pulse half-segments. RMT was significantly higher using half-sine or monophasic pulses compared with full-sine. Pulses combining two half-sines of identical polarity and duration were also characterized by higher RMT than fullsine stimuli resulting. For full-sine stimuli, decreasing the amplitude of the halfsegment inducing posterior-anterior oriented current in M1 resulted in considerably higher RMT, whereas varying the amplitude of the half-segment inducing anterior-posterior current had a smaller effect. These findings provide direct experimental evidence that the pulse segment inducing a posterior anterior directed current in M1 contributes most to corticospinal pathway excitation. Preferential excitation of neuronal target cells in the posterior-anterior segment or targeting of different neuronal structures by the two half-segments can explain this result. Thus, our findings help understanding the mechanisms of neural stimulation by full-sine TMS.

Motion-selectivity in human visual cortex comprises a number of different cortical loci including V1, V2, V3A, V3B, hV5/MT+ and V6 (Wandell et al., 2007). This thesis sought to investigate the specific functions of V3A and sub-divisions of hV5/MT+ (TO-1 and TO-2) by using transcranial magnetic stimulation (TMS) to transiently disrupt cortical activations within these areas during psychophysical tasks of motion perception. The tasks were chosen to coincide with previous non-human primate and human neuroimaging literature; translational, radial and rotational direction discrimination tasks and identification of the position of a focus of expansion. These results assert that TO-1 and TO-2 are functionally distinct subdivisions of hV5/MT+, as we have shown that both TO-1 and TO-2 are responsible for processing translational motion direction whilst only TO-2 is responsible for processing radial motion direction. In ipsilateral space, it was found that TO-1 and TO-2 both contribute to the processing of ipsilateral translational motion. Taken in a wider context, further results also suggested that these areas may form part of a network of cortical areas contributing to perception of self-motion (heading/egomotion), as TO-2 was not found to be responsible for processing the position of the central focus of expansion (imperative for self-direction). Instead, area V3A has been implicated as functionally responsible for processing this attribute of vision. Overall it is clear that TO-1, TO-2 and V3A have specific, distinct functions that contribute towards both parallel and serial motion processing pathways within the human brain.

Introdução: Esquizofrenia é um distúrbio psicótico complexo e heterogêneo. Alucinações auditivas verbais ocorrem em 50% a 70% dos pacientes portadores de esquizofrenia, e estão associadas a prejuízo significativo, pior qualidade de vida e funcionamento social. Estudos prévios mostraram que a estimulação magnética transcraniana repetida (EMTr) parece ser capaz de modular a severidade das alucinações auditivas em pacientes com esquizofrenia. Este estudo investigou os efeitos da rTMS de 1Hz aplicada ao córtex temporoparietal esquerdo, comparada a estimulação sham, na psicopatologia geral, severidade das alucinações auditivas, qualidade de vida e funcionalidade. Métodos: Dezessete pacientes apresentando alucinações auditivas verbais pelo menos cinco vezes ao dia forma randomicamente distribuídos para receber EMTr ativa ou sham. Um total de 384 minutos de EMTr a 90% do limiar motor foram administrados ao longo de 20 dias usando um desenho paralelo, duplo-cego e controlado por placebo. Resultados: Houve um efeito positivo nos escores da BPRS no grupo ativo comparado ao grupo sham. Não houve diferenças significativas entre os grupos no final do tratamento nos escores da QLS, AHRS, CGI e FAST. Conclusões: Comparada a estimulação sham, a EMTr do cortex temporoparietal esquerdo mostrou um efeito positivo na psicopatologia geral. Novos estudos com tamanhos de amostra maiores são necessários para investigar efeitos na qualidade de vida e funcionalidade, uma vez que o poder deste estudo foi menor que 50%. Além disso, seu efeito em alucinações auditivas refratárias não é claro, uma vez que os escores de alucinações auditivas globais e individuais não foram diferentes. / Background: Schizophrenia is a complex and heterogeneous psychiatric disorder. Auditory verbal hallucinations occur in 50% to 70% of patients with schizophrenia, and are associated to significant distress, decreased quality of life and social functioning. Data from previous studies have shown that 1-hertz left temporo-parietal repetitive transcranial magnetic stimulation (rTMS) appears to be able to modulate the severity of auditory hallucinations in patients with schizophrenia. This study aimed to investigate the effects of 1 Hz rTMS of the left temporo-parietal cortex on general psychopathology, severity of auditory hallucinations, quality of life and functionality, compared to sham stimulation. Methods: Seventeen patients experiencing auditory verbal hallucinations at least 5 times per day were randomly allocated to receive either rTMS or sham stimulation. A total of 384 minutes of rTMS was administered over 20 days at 90% motor threshold using a double-masked, sham-controlled, parallel design. Results: There was a positive effect on BPRS scores on the active group compared to sham group. There was no significant difference between groups at the end of the treatment on QLS, AHRS, CGI and FAST scores. Conclusions: Compared to sham stimulation, rTMS of the left temporo-parietal cortex showed a positive effect on general psychopathology. Further studies with larger sample sizes are needed to investigate effects on quality of life and functionality, since the power of the study was lower than 50%. Also, its effect on refractory auditory hallucinations is not clear, since global and individual scores of auditory hallucinations were not different.

Introdução: Esquizofrenia é um distúrbio psicótico complexo e heterogêneo. Alucinações auditivas verbais ocorrem em 50% a 70% dos pacientes portadores de esquizofrenia, e estão associadas a prejuízo significativo, pior qualidade de vida e funcionamento social. Estudos prévios mostraram que a estimulação magnética transcraniana repetida (EMTr) parece ser capaz de modular a severidade das alucinações auditivas em pacientes com esquizofrenia. Este estudo investigou os efeitos da rTMS de 1Hz aplicada ao córtex temporoparietal esquerdo, comparada a estimulação sham, na psicopatologia geral, severidade das alucinações auditivas, qualidade de vida e funcionalidade. Métodos: Dezessete pacientes apresentando alucinações auditivas verbais pelo menos cinco vezes ao dia forma randomicamente distribuídos para receber EMTr ativa ou sham. Um total de 384 minutos de EMTr a 90% do limiar motor foram administrados ao longo de 20 dias usando um desenho paralelo, duplo-cego e controlado por placebo. Resultados: Houve um efeito positivo nos escores da BPRS no grupo ativo comparado ao grupo sham. Não houve diferenças significativas entre os grupos no final do tratamento nos escores da QLS, AHRS, CGI e FAST. Conclusões: Comparada a estimulação sham, a EMTr do cortex temporoparietal esquerdo mostrou um efeito positivo na psicopatologia geral. Novos estudos com tamanhos de amostra maiores são necessários para investigar efeitos na qualidade de vida e funcionalidade, uma vez que o poder deste estudo foi menor que 50%. Além disso, seu efeito em alucinações auditivas refratárias não é claro, uma vez que os escores de alucinações auditivas globais e individuais não foram diferentes. / Background: Schizophrenia is a complex and heterogeneous psychiatric disorder. Auditory verbal hallucinations occur in 50% to 70% of patients with schizophrenia, and are associated to significant distress, decreased quality of life and social functioning. Data from previous studies have shown that 1-hertz left temporo-parietal repetitive transcranial magnetic stimulation (rTMS) appears to be able to modulate the severity of auditory hallucinations in patients with schizophrenia. This study aimed to investigate the effects of 1 Hz rTMS of the left temporo-parietal cortex on general psychopathology, severity of auditory hallucinations, quality of life and functionality, compared to sham stimulation. Methods: Seventeen patients experiencing auditory verbal hallucinations at least 5 times per day were randomly allocated to receive either rTMS or sham stimulation. A total of 384 minutes of rTMS was administered over 20 days at 90% motor threshold using a double-masked, sham-controlled, parallel design. Results: There was a positive effect on BPRS scores on the active group compared to sham group. There was no significant difference between groups at the end of the treatment on QLS, AHRS, CGI and FAST scores. Conclusions: Compared to sham stimulation, rTMS of the left temporo-parietal cortex showed a positive effect on general psychopathology. Further studies with larger sample sizes are needed to investigate effects on quality of life and functionality, since the power of the study was lower than 50%. Also, its effect on refractory auditory hallucinations is not clear, since global and individual scores of auditory hallucinations were not different.

Introdução: Muitos estudos veem sendo realizados com a finalidade de identificar agentes que possam ter efeito benéfico no tratamento ou prevenção das lesões causadas nos neurônios devido à isquemia. A hipotermia já demonstrou resultados consistentes em estudos experimentais e a Estimulação Magnética Transcraniana (EMTr) já foi usada visando reduzir danos em neurônios hipocampais de animais submetidos a isquemia cerebral. Com a propriedade de aumentar ou diminuir a excitabilidade cortical a partir do estímulo magnético, estima-se que ocorra uma interferência na produção de alguns neurotransmissores e receptores de membrana, que promoveriam efeito protetor a estas células. Neste estudo avaliamos a capacidade da EMTr de proteger os neurônios de uma lesão por hipóxia, e sua possível interferência no efeito protetor da hipotermia, tentando identificar alguns mecanismos que possivelmente estariam envolvidos neste fenômeno. Métodos: Como modelo de isquemia, foram utilizados Gerbils previamente submetidos a uma avaliação de comportamento e memória por meio do teste de esquiva. O protocolo de EMTr foi a partir de sessões diárias com 25 séries de 5 segundo a 25Hz, com um intervalo de 45 segundos entre as séries, por sete dias consecutivos, com um total de 21 875 pulsos com uma intensidade de 100% do limiar motor, e sendo realizada a indução da isquemia logo após o término da última sessão, ou na isquemia após a EMTr, em sessões diárias com 25 séries de 5 segundos a 25Hz, com um intervalo de 45 segundos entre as séries, durante 3 dias consecutivos, começando imediatamente após a cirurgia. Foi mantida a temperatura de 36 °C durante o período de oclusão do vaso e os 30 minutos consecutivos, ou 31 a 32 °C quando em hipotermia. O preparo das lâminas teve cortes envolvendo a região do hipocampo, corados com hematoxilina e eosina, além de outros preparos, a marcação de TUNEL e Caspase, que visam evidenciar a ocorrência de apoptose. Resultados: Embora sem significância estatística, os animais que receberam EMTr aparentemente tiveram uma melhor performance no teste da esquiva, principalmente se aplicado após a indução da isquemia. A hipotermia demonstrou uma eficiência significativa, tanto na análise histológica quanto no teste da esquiva, associado ou não à EMTr, e nestes animais submetidos a isquemia durante a hipotermia, os que receberam EMTr tiveram área de sobrevida no hipocampo significativamente maior na análise histológica com hematoxilina e eosina. Nos animais submetidos à isquemia durante a temperatura normal, a EMTr não demonstrou aumentar a área de sobrevida das células do hipocampo. Conclusões: A EMTr (ativa ou placebo, prévia ou posterior à isquemia) pareceu ter um efeito positivo no teste de esquiva. O procedimento de estimulação pareceu bastante traumático e estressante para os animais, tendo ocorrido alguns óbitos durante a imobilização, provavelmente por asfixia. A EMTr apresentou efeito protetor significativo apenas nos animais submetidos a isquemia durante hipotermia / Introduction: Over the time many researches have been conducted with the aim of identifying agents that may have beneficial effects in the treatment or prevention of cerebral ischemia, hypothermia has shown consistent results in experimental trials and Repetitive Trans Cranial Magnetic Stimulation (rTMS) has been used in a study attempting to reduce damage in hippocampal neurons. With the property to increase or decrease cortical excitability from the repetitive magnetic stimulus, it is estimated that an interference occurs in the production of some neurotransmitters and receptors of neuronal membrane, which therefore protects these cells from hypoxia. In this study we evaluated the ability of rTMS to protect neurons from injury due to hypoxia, and its possible interference in the protective effect of hypothermia and we tried to identify some mechanisms that possibly are involved in this phenomenon. Methods: Ischemia model was performed using Gerbil that was subsequently submitted to an evaluation of behavior and memory through passive avoidance task. The rTMS protocol was daily sessions with 25 series of 5 seconds at 25Hz with an interval of 45 seconds between series, for 7 consecutive days, with a total of 21 875 pulses with an intensity of 100% of motor threshold, and being carried through the induction of ischemia soon after the end of the last session, or rTMS after ischemia, in daily sessions with 25 series of 5 seconds at 25Hz with an interval of 45 seconds between series, for 3 consecutive days, starting immediately after surgery. The temperature of 36 °C was maintained during the period of vessel occlusion and subsequent 30 minutes, or 31 °C to 32 °C when in hypothermia. The preparation of the slices had sections of the region involving the hippocampus, stained with hematoxylin and eosin in addition to other preparations, TUNEL and caspase, which aim to evidence the occurrence of apoptosis. Results: Although not statistically significant, animals that received rTMS, apparently had better performance in passive avoidance task especially when applied after ischemia. The hypothermia demonstrated a significant efficiency, both in the histological analysis and in the passive avoidance task, associated or not to applications of rTMS and, in these animals undergoing ischemia during hypothermia, the ones who received rTMS had survival area in hippocampus significantly higher in histological analysis with hematoxylin and eosin. In animals undergone to ischemia during normal temperature, the rTMS has not shown to increase the area of hippocampal cell survival. Conclusions: rTMS (placebo or active, after or before the ischemia) seems to have a positive effect on passive avoidance task. The stimulation procedure appeared to be very traumatic and stressful for the animal, in which a few deaths occurred during the procedure, probably from asphyxiation due to restraint. The rTMS had a significant protective effect only in animals undergoing ischemia during hypothermia, as demonstrated in the histological analysis with hematoxylin and eosin

Introdução: Esquizofrenia é um distúrbio psicótico complexo e heterogêneo. Alucinações auditivas verbais ocorrem em 50% a 70% dos pacientes portadores de esquizofrenia, e estão associadas a prejuízo significativo, pior qualidade de vida e funcionamento social. Estudos prévios mostraram que a estimulação magnética transcraniana repetida (EMTr) parece ser capaz de modular a severidade das alucinações auditivas em pacientes com esquizofrenia. Este estudo investigou os efeitos da rTMS de 1Hz aplicada ao córtex temporoparietal esquerdo, comparada a estimulação sham, na psicopatologia geral, severidade das alucinações auditivas, qualidade de vida e funcionalidade. Métodos: Dezessete pacientes apresentando alucinações auditivas verbais pelo menos cinco vezes ao dia forma randomicamente distribuídos para receber EMTr ativa ou sham. Um total de 384 minutos de EMTr a 90% do limiar motor foram administrados ao longo de 20 dias usando um desenho paralelo, duplo-cego e controlado por placebo. Resultados: Houve um efeito positivo nos escores da BPRS no grupo ativo comparado ao grupo sham. Não houve diferenças significativas entre os grupos no final do tratamento nos escores da QLS, AHRS, CGI e FAST. Conclusões: Comparada a estimulação sham, a EMTr do cortex temporoparietal esquerdo mostrou um efeito positivo na psicopatologia geral. Novos estudos com tamanhos de amostra maiores são necessários para investigar efeitos na qualidade de vida e funcionalidade, uma vez que o poder deste estudo foi menor que 50%. Além disso, seu efeito em alucinações auditivas refratárias não é claro, uma vez que os escores de alucinações auditivas globais e individuais não foram diferentes. / Background: Schizophrenia is a complex and heterogeneous psychiatric disorder. Auditory verbal hallucinations occur in 50% to 70% of patients with schizophrenia, and are associated to significant distress, decreased quality of life and social functioning. Data from previous studies have shown that 1-hertz left temporo-parietal repetitive transcranial magnetic stimulation (rTMS) appears to be able to modulate the severity of auditory hallucinations in patients with schizophrenia. This study aimed to investigate the effects of 1 Hz rTMS of the left temporo-parietal cortex on general psychopathology, severity of auditory hallucinations, quality of life and functionality, compared to sham stimulation. Methods: Seventeen patients experiencing auditory verbal hallucinations at least 5 times per day were randomly allocated to receive either rTMS or sham stimulation. A total of 384 minutes of rTMS was administered over 20 days at 90% motor threshold using a double-masked, sham-controlled, parallel design. Results: There was a positive effect on BPRS scores on the active group compared to sham group. There was no significant difference between groups at the end of the treatment on QLS, AHRS, CGI and FAST scores. Conclusions: Compared to sham stimulation, rTMS of the left temporo-parietal cortex showed a positive effect on general psychopathology. Further studies with larger sample sizes are needed to investigate effects on quality of life and functionality, since the power of the study was lower than 50%. Also, its effect on refractory auditory hallucinations is not clear, since global and individual scores of auditory hallucinations were not different.

A depressão pós-parto (DPP), tal como o episódio depressivo maior, é uma manifestação psiquiátrica comum, caracterizada pela presença de alterações de humor, cognitivas, comportamentais, psicomotoras e vegetativas. Afeta a qualidade da interação mãe-bebê prejudicando a responsividade materna o que pode repercurtir negativamente na manutenção salutar do desenvolvimento da criança. Esta manifestação apresenta prevalência estimada entre 10 e 20%, considerando as mulheres que desenvolvem sintomas nas primeiras semanas depois do parto. As opções de tratamento incluem drogas antidepressivas e eletroconvulsoterapia (com anestesia). Porém, como ambas terapêuticas envolvem abordagens farmacológicas, há contra-indicação devido à toxidade que impediria a amamentação. Entretanto, existe uma preocupação sobre como garantir a eficácia do tratamento sem prejudicar o bebê. A Estimulação Magnética Transcraniana Repetitiva (EMTr), por ser uma técnica já consagrada quanto a eficácia antidepressiva, não toxicológica, indolor, não invasiva e bem tolerada para estimular o cérebro, parece ser uma boa alternativa de tratamento. Nos quadros depressivos em geral, são observados prejuízos substanciais a várias funções cognitivas cujas alterações cognitivas apresentadas são, em grande parte, semelhantes àquelas relacionadas a alterações do funcionamento do córtex pré-frontal. A função executiva é um dos principais domínios cognitivos afetados nos transtornos depressivos, geralmente avaliada por testes como Trail Making e o teste de Stroop. A presença de depressão em pacientes puerperais parece intensificar as alterações cognitivas, especialmente as funções associadas ao lobo frontal, além do que, também prejudicam o comportamento causando danos no funcionamento social global. No presente estudo, randomizado, controlado e duplo-cego, investigaram-se os possíveis efeitos da EMTr no funcionamento cognitivo e sua repercussão comportamental: Estimulação Magnética Transcraniana de repetição (EMTr) aplicada ao córtex prefrontal dorsolateral esquerdo (CPFDLE). Uma amostra inicial de dez pacientes com DPP foram distribuídos em dois grupos. Sete participantes de um dos grupos receberam EMTr ativa e três, do grupo controle, EMTr placebo. Os parâmetros utilizados na EMTr foram: freqüência de 5 Hz, intensidade de 120% do limiar motor, em intervalos de 10 segundos ligado e 20 segundos desligado, com 25 séries por dia (2500 pulsos), durante 20 dias (quatro semanas) com dois dias de pausa semanal. Os pacientes e os avaliadores eram cegos ao tipo de tratamento de cada grupo. A avaliação neuropsicológica se deu através de testes cognitivos relacionados às funções prejudicadas em quadros depressivos e com a área estimulada (CPFDLE). Foram também aplicadas as escalas de Adequação Social (EAS) de Weissmann e Bothwell para avaliar o comportamento funcional social global, de depressão de Hamilton, 17 itens, e de depressão pós-parto de Edinburgh. As avaliações foram realizadas em três momentos: antes do início do tratamento (T0), após 4 semanas (T2) e após 6 semanas (T3). Como principais resultados foram observadas: melhora significativa no quadro depressivo ao longo do tratamento e um melhor ajustamento comportamental no funcionamento social global geral, especialmente no contexto das relações familiares; ausência de efeitos negativos em todos os testes cognitivos após o tratamento com EMTr; desempenho superior do grupo EMTr ativa em comparação com o grupo EMTr placebo, principalmente no teste de Rey auditory Verbal Learning (RAVLT) evocação pós-interferência e tardia pós-trinta minutos, no teste Trail Making Parte A e no teste de Stroop Cores. Além disso, o melhor desempenho cognitivo observado no grupo EMTr ativa viii comparado ao grupo EMTr placebo, entre T0 e T4, foi mantido na semana 6 (T6) e por vezes até melhorou sutilmente, indicando que o efeito da estimulação mantém-se estável por, pelo menos 2 semanas após o término do tratamento. Discutem-se como possíveis fatores para esses resultados: ação local da EMTr, alteração dos níveis de alguns neurotransmissores como dopamina e serotonina, relação com a melhoria do quadro depressivo e possível efeito de aprendizado pela repetição em curto período de tempo entre as testagens. Concluí-se que, baseados em uma amostra de apenas 10 pacientes, a EMTr, no que diz respeito aos efeitos antidepressivos, no comportamento frente ao funcionamento social global e às funções cognitivas, não produziu efeitos negativos e sim, produziu alguns efeitos positivos. Esta melhora é de fundamental importância, para o bem estar da mãe e conseqüentemente para o desenvolvimento neuropsicomotor, afetivo e comportamental do bebê. Isto trará desdobramentos que poderão perdurar por toda uma vida para esta criança. Além disto, a segurança da EMT, já amplamente comprovada em outros estudos, poderá, em um futuro próximo, torná-la terapêutica de primeira escolha para este grupo de pacientes. / The postpartum depression (PPD) as the major depressive episode is a common psychiatric manifestation, characterized by the presence of mood, cognitive, behavioral, psychomotor and vegetative changes. It affects the quality of mother-infant interaction jeopardizing the maternal responsiveness, which may adversely affect the maintenance of a healthy development of children. This event presents the estimated dominance between 10 and 20%, taking into account women who develop symptoms in the first weeks after delivery. Treatment options include antidepressant drugs and electroconvulsive therapy (with anesthetic). However, as both treatments involve pharmacological approaches, there is counter-indication because of toxicity that would preclude breastfeeding. Nevertheless, there is concern about the efficiency of the treatment without causing any harm to the baby. The repetitive Transcranial Magnetic Stimulation (rTMS), as it is a technique already established for antidepressant efficacy, non-toxic, painless, non-invasive and well-tolerated to stimulate the brain, it seems to be a good alternative for treatment. For general depressive conditions, substantial damages have been noticed to several cognitive functions, in which the presented cognitive changes are, in large part, similar to those related to changes in the functioning of the pre-frontal cortex (PFC). The executive function is one of the major cognitive domains affected in depressive disorders, usually assessed by tests such as Trail Making and Stroop test. The presence of depression in puerperal patients seems to strengthen cognitive changes; especially those associated to frontal lobe functions, in addition to that, it also affects the behavior causing harm to the overall social functioning. In this study, randomized, controlled and double-blind, possible effects of rTMS in the cognitive functioning and its behavioral effect were assessed: Repetitive Transcranial Magnetic Stimulation (rTMS) applied to left-dorsum-lateral-prefrontal-cortex (LDLPC). An initial sample of ten patients with PPD was divided into two groups. Firstly, seven participants in one of the groups received active rTMS and, three, of the control group, placebo rTMS. The parameters used in rTMS were: frequency of 5 Hz, intensity of 120% of the motor threshold, at intervals of 10 seconds on and 20 seconds off, with 25 sets per day (2500 pulses), during 20 days (four weeks) with two days of rest per week. Patients and evaluators were blinded to the type of treatment for each group. The neuropsychological assessment was carried out by means of cognitive tests related to impaired functions in depressive conditions and with the stimulated area (LDLPC). Social Adjustment Scal (SAS-SR) of Weissmann & Bothwell was also applied to assess the overall social functional behavior, of Hamilton depression, 17 items, and Edinburg postpartum depression. Evaluations were performed on three occasions: before starting the treatment (T0), after 4 weeks (T2) and after 6 weeks (T3). The main results were: significant improvement regarding the depression condition throughout the treatment and a better behavioral adjustment in the general overall social functioning, especially in the context of family relationships, lack of negative effects on all cognitive tests after treatment with rTMS; superior performance of the active rTMS group compared to the placebo rTMS group, especially in the Rey Auditory Verbal Learning Test (RAVLT) post-interference and late evocation after thirty minutes in the Trail Making Test - Part A and the Colors - Stroop Test. Further, the best cognitive performance was observed in the active rTMS group compared to placebo rTMS group, between T0 and T4, was maintained at week 6 (T6) and sometimes even improved slightly, indicating that the effect of the stimulation remains stable by at least 2 x weeks after the end of the treatment. It has been discussed as possible factors for these results: local rTMS action, change in the levels of some neurotransmitters such as dopamine and serotonin, relationship with the improvement of the depressive condition and possible learning effect by repetition within a short period of time between tests. Ergo, based on a sample of only 10 patients, the rTMS, regarding antidepressant effects, the behavior compared to the overall social functioning and cognitive functions, it did not yield negative effects, however it rendered some positive effects. This improvement is of primary importance for the welfare of the mother hence to the babys neuro-psychomotor, emotional and behavioral development. This will bring further outcomes that may last for the whole life for this child. In addition, the safety of TMS, which has been already proven in other researches, may, in the near future, make it a first-choice therapy for this group of patients