Victor Hugo Bastos

Amyotrophic lateral sclerosis: new perpectives and update

Amyotrophic lateral sclerosis (ALS), Charcot’s disease or Lou Gehrig’s disease, is a term used to cover the spetrum of syndromes caracterized by progressive degeneration of motor neurons, a paralytic disorder caused by motor neuron degeneration. Currently, there are approximately 25,000 patients with ALS in the USA, with an average age of onset of 55 years. The incidence and prevalence of ALS are 1-2 and 4-6 per 100,000 each year, respectively, with a lifetime ALS risk of 1/600 to 1/1000. It causes progressive and cumulative physical disabilities, and leads to eventual death due to respiratory muscle failure. ALS is diverse in its presentation, course, and progression. We do not yet fully understand the causes of the disease, nor the mechanisms for its progression; thus, we lack effective means for treating this disease. In this chapter, we will discuss the diagnosis, treatment, and how to cope with impaired function and end of life based on of our experience, guidelines, and clinical trials. Nowadays ALS seems to be a more complex disease than it did two decades – or even one decade – ago, but new insights have been plentiful. Clinical trials should be seen more as experiments on pathogenic mechanisms. A medication or combination of medications that targets more than one pathogenic pathway may slow disease progression in an additive or synergistic fashion.

Amyotrophic lateral sclerosis: one or multiple causes?

The Amyotrophic lateral sclerosis (ALS) is the most common form of motor neuron disease in the adulthood, and it is characterized by rapid and progressive compromise of the upper and lower motor neurons. The majority of the cases of ALS are classified as sporadic and, until now, a specific cause for these cases still is unknown. To present the different hypotheses on the etiology of ALS. It was carried out a search in the databases: Bireme, Scielo and Pubmed, in the period of 1987 to 2011, using the following keywords: Amyotrophic lateral sclerosis, motor neuron disease, etiology, causes and epidemiology and its similar in Portuguese and Spanish. It did not have consensus as regards the etiology of ALS. Researches demonstrates evidences as regards intoxication by heavy metals, environmental and occupational causes, genetic mutations (superoxide dismutase 1), certain viral infections and the accomplishment of vigorous physical activity for the development of the disease. There is still no consensus regarding the involved factors in the etiology of ALS. In this way, new research about these etiologies are necessary, for a better approach of the patients, promoting preventive programs for the disease and improving the quality of life of the patients.

Gamma band oscillations under influence of bromazepam during a sensorimotor integration task: An EEG coherence study

The goal of the present study was to explore the dynamics of the gamma band using the coherence of the quantitative electroencephalography (qEEG) in a sensorimotor integration task and the influence of the neuromodulator bromazepam on the band behavior. Our hypothesis is that the needs of the typewriting task will demand the coupling of different brain areas, and that the gamma band will promote the binding of information. It is also expected that the neuromodulator will modify this coupling. The sample was composed of 39 healthy subjects. We used a randomized double-blind design and divided subjects into three groups: placebo (n=13), bromazepam 3mg (n=13) and bromazepam 6 mg (n=13). The two-way ANOVA analysis demonstrated a main effect for the factors condition (i.e., C4-CZ electrode pair) and moment (i.e., C3-CZ, C3-C4 and C4-CZ pairs of electrodes). We propose that the gamma band plays an important role in the binding among several brain areas in complex motor tasks and that each hemisphere is influenced in a different manner by the neuromodulator.

Botulinum Neurotoxin Type A in Neurology: Update

This paper reviews the current and most neurological (central nervous system, CNS) uses of the botulinum neurotoxin type A. The effect of these toxins at neuromuscular junction lends themselves to neurological diseases of muscle overactivity, particularly abnormalities of muscle control. There are seven serotypes of the toxin, each with a specific activity at the molecular level. Currently, serotypes A (in two preparations) and B are available for clinical purpose, and they have proved to be safe and effective for the treatment of dystonia, spasticity, headache, and other CNS disorders in which muscle hyperactivity gives rise to symptoms. Although initially thought to inhibit acetylcholine release only at the neuromuscular junction, botulinum toxins are now recognized to inhibit acetylcholine release at autonomic cholinergic nerve terminals, as well as peripheral release of neuro-transmitters involved in pain regulation. Its effects are transient and nondestructive, and largely limited to the area in which it is administered. These effects are also graded according to the dose, allowing individualized treatment of patients and disorders. It may also prove to be useful in the control of autonomic dysfunction and sialorrhea. In over 20 years of use in humans, botulinum toxin has accumulated a considerable safety record, and in many cases represents relief for thousands of patients unaided by other therapy.

Neuromodulatory effect of bromazepam on motor learning: an electroencephalographic approach.

To investigate the effects of bromazepam on motor performance and electroencephalographic activity (qEEG) in healthy subjects, during the process of learning a typewriting task, with a focused attention demand. A randomized double-blind model was used to allocate subjects in one of the following conditions: placebo (n=13), bromazepam 3 mg (n=13) or bromazepam 6 mg (n=13). Forty minutes after treatment administration, subjects were submitted to the motor task. EEG activity was recorded simultaneously. The analyzed variables were: number of errors and execution time, which were extracted from each block of the typewriting task, and mean relative power values in the beta band (13-35 Hz), extracted from the qEEG. A significantly lower number of typing errors was observed in both bromazepam conditions (Br 3 mg and Br 6 mg) when compared to the placebo. There was no difference between the two bromazepam conditions. For the execution time variable, a better performance was observed in the Br 3 mg condition, but with no statistical significance. The highest degree of cortical activation during the task was observed in Br 3 mg and Br 6 mg when compared to placebo. The medications anxiolytic effect intensifies the attentional focus over predictable events occurring in reduced perceptual fields. The qEEGs accentuated response in pre-motor and primary motor areas suggests a greater effort directed to the most relevant aspects of the task. In short, the doses employed (3 and 6 mg) seem to enhance the learning of motor tasks that involve focused attention, such as typewriting.

Effects of vestibular rehabilitation in the elderly: a systematic review

BackgroundAging is characterized by gradual physiological changes in body systems. Changes in the vestibular system can occur and cause dizziness, vertigo and imbalance, symptoms that are common in the elderly. Vestibular rehabilitation is a therapeutic resource that has been widely used to improve this condition.AimsTo complete a systematic review of the effects of vestibular rehabilitation on the elderly.MethodsA search for relevant publications was conducted in SCIELO, PUBMED, MEDLINE, COCHRANE and LILACS databases. Clinical trials and cohort studies that were written in the English language and published over the course of the last 10 years were selected. The methodological quality of the studies was assessed using the PEDro scale. A critical analysis of the studies was composed.ResultsEight studies that involved subjects who were over the age of 60 were selected for inclusion in the systematic review. The most common vestibular dysfunction identified was complaints about dizziness and imbalance. The Dizziness Handicap Inventory was the most frequently used assessment instrument, and the treatment protocol that prevailed was that suggested by Cawthorne and Cooksey.DiscussionThe PEDro scale showed that only one article was of an acceptable methodological quality and presented satisfactory outcome measures. This was due, in part, to a lack of a hidden randomization, masking of the subject, evaluators and therapists, and lack of outcome measures, which can reduce the quality of the evidence presented in this study.ConclusionClinical trials indicate that vestibular rehabilitation represents an effective means of treating elderly patients with vestibular disorders; however, evidence of its effectiveness remains lacking.

Responsiveness of sensorimotor cortex during pharmacological intervention with bromazepam

The aim of this study was to investigate the influence of bromazepam on EEG and the motor learning process when healthy subjects were submitted to a typewriting task. We investigated bromazepam due to its abuse by various populations and its prevalent clinical use among older individuals which are more sensitive to the negative effects of long half-life benzodiazepines. A randomized double-blind design was used with subjects divided into three groups: placebo (n=13), bromazepam 3mg (n=13) and bromazepam 6 mg (n=13). EEG data comprising theta, alpha and beta bands was recorded before, during and after the motor task. Our results showed a lower relative power value in the theta band in the Br 6 mg group when compared with PL. We also observed a reduction in relative power in the beta band in the Br 3mg and Br 6 mg when compared with PL group. These findings suggest that Br can contribute to a reduced working memory load in areas related to attention processes. On the other hand, it produces a higher cortical activation in areas associated with sensory integration. Such areas are responsible for accomplishing the motor learning task. The results are an example of the usefulness of integrating electrophysiological data, sensorimotor activity and a pharmacological approach to aid in our understanding of cerebral changes produced by external agents.

EEG SPECTRAL COHERENCE INTER AND INTRAHEMISPHERIC DURING CATCHING OBJECT FALL TASK

The aim of the present study was to evaluate coherence measures at Theta through qEEG during the accomplishment of a specific motor task. The sample consisted of 23 healthy individuals, both sexes, with ages varying between 25 and 40 years old. All subjects were submitted to a specific motor task of catching sequences of falling balls. A three-way ANOVA was employed for the statistical analysis, which demonstrated main effects for the following factors: time, block and position. However, there was no interaction between the factors. A significant and generalized coherence reduction was observed during the task execution time. Coherence was also diminished at the left frontal cortex and contralateral hemisphere of the utilizing limb (comparing to the right frontal cortex). In conclusion, these findings suggest a certain specialization of the neural circuit, also according to previous investigations. The inter-coherence reduction suggests a spatial inter-electrode dependence during the task, rather than a neuronal specialization.

Aprendizagem de procedimentos e efeitos ansiolíticos: medidas eletrencefalográficas, motora e atencional

The objective of the present study was to evaluate attentional, motor and electroencephalographic (EEG) parameters during a procedural task when subjects have ingested 6mg of bromazepam. The sample consisted of 26 healthy subjects, male or female, between 19 and 36 years of age. The control (placebo) and experimental (bromazepam 6mg) groups were submitted to a typewriting task in a randomized, double-blind design. The findings did not show significant differences in attentional and motor measures between groups. Coherence measures (qEEG) were evaluated between scalp regions, in theta, alpha and beta bands. A first analysis revealed a main effect for condition (Anova-2way - condition versus blocks). A second Anova 2-way (condition versus scalp regions) showed a main effect for both factors. The coherence measure was not a sensitive tool at demonstrating differences between cortical areas as a function of procedural learning.

Efeitos do Bromazepam observados pela eletroencefalografia quantitativa (EEGq) durante a prática de datilografia

The efficiency with which an information is processed by the brains neural circuitry can be altered by neuromodulators. The use of Bromazepam in the pharmacological treatment of anxiety disorders is due to its anxiolytic property. However, the effects of this benzodiazepine in motor learning tasks are not entirely understood. In this context, the goal of this study was to assess the effects of Bromazepam (6mg) on psychophysiological, behavioral, and electrophysiological variables, during the process of learning a motor task. The sample consisted of 26 healthy individuals, of both sexes, between 19 and 36 years of age. The control (placebo) and experimental (Bromazepam 6 mg) groups were submitted to a typewriting task, in a randomized, doble-blind design. The results did not reveal differences for phychophysiological and behavioral variables between the groups. Statistical tests pointed out to an interaction between condition and moment, and a hemisphere main effect, i.e. a reduction of relative power in the right hemisphere. This reduction suggests a specialization of the neural circuitry in the hemisphere contralateral to the finger used in the task. Such reduction is independent from the drug administration.