Flávia Doná

Modulation of Seizures and Synaptic Plasticity by Adenosinergic Receptors in an Experimental Model of Temporal Lobe Epilepsy Induced by Pilocarpine in Rats

Summary:  Purpose: Adenosine is a major negative neuromodulator of synaptic activity in the central nervous system and can exert anticonvulsant and neuroprotective effects in many experimental models of epilepsy. Extracellular adenosine can be formed by a membrane‐anchored enzyme ecto‐5′‐nucleotidase. The purposes of this study were to characterize the role of adenosine receptors in modulating status epilepticus (SE) induced by pilocarpine and evaluate its neuroprotective action. Ecto‐5′‐nucleotidase activity was studied during the different phases of pilocarpine‐induced epilepsy in rats.

Alteration of purinergic P2X4 and P2X7 receptor expression in rats with temporal-lobe epilepsy induced by pilocarpine

SUMMARY Although ATP and P2X receptor activity have been lately associated with epilepsy, little is known regarding their exact roles in epileptogenesis. Temporal-lobe epilepsy (TLE) in rat was induced by pilocarpine in order to study changes of hippocampal P2X(2), P2X(4) and P2X(7) receptor expression during acute, latent or chronic phases of epilepsy. During acute and chronic phases increased P2X(7) receptor expression was principally observed in glial cells and glutamatergic nerve terminals, suggesting participation of this receptor in the activation of inflammatory and excitotoxic processes during epileptogenesis. No significant alterations of hippocampal P2X(2) and P2X(4) receptor expression was noted during the acute or latent phase when compared to the control group, indicating that these receptors are not directly involved with the initiation of epilepsy. However, the reduction of hippocampal P2X(4) receptor immunostaining in the chronic phase could reflect neuronal loss or decreased GABAergic signaling.

Physical exercise during the adolescent period of life increases hippocampal parvalbumin expression

In order to investigate whether physical exercise during development would promote changes the calcium-binding protein parvalbumin (PV) expression in the hippocampal formation, we performed an immunostaining study after an aerobic exercise program in rats during adolescent period of life. Wistar rats were submitted to daily exercise program in a treadmill between postnatal day 21 and 60. Running time and speed were gradually increased during the subsequent days until 18m/min for 60min. After the aerobic exercise program, animals of all groups were killed and PV immunostaining procedures were performed. The results showed significant increase of protein level in the hippocampal formation and PV-immunoreactive neurons in CA1 and CA2/CA3 regions of rats submitted to exercise when compared with control rats. This finding indicates that aerobic exercise program during adolescent period promotes neuroplastic changes in hippocampal formation.

Protective effect of the organotelluroxetane RF-07 in pilocarpine-induced status epilepticus.

Temporal lobe epilepsy is the most common form of epilepsy in humans. Caspase activation is a mechanism of cell death induced by seizures. Tellurium (IV) compounds present antitumoral, immunomodulatory and neuroprotective effects due to their ability to inhibit cysteine proteases. We studied the activity of caspase-1, -3 and -8 in the hippocampus of rats exhibiting status epilepticus induced by pilocarpine. All three caspases were activated. Tellurium (IV) compounds RF-07, RF-03 and AS-101 inhibited caspases in vitro, showing high second-order inhibition rate constants. The intraperitoneal injection of RF-07 prior to pilocarpine suppressed the behavioral and electroencephalographic seizure occurrence. According to our results, the caspases are activated as early as 90 min following SE. Tellurium (IV) compounds exerted anticonvulsant effects associated with the inhibition of caspases. These results suggest a promising therapeutic potential of organotellurium (IV) compounds as antiepileptogenic agents.

Resultados do Balance Rehabilitation Unit na Vertigem Posicional Paroxística Benigna

UNLABELLED Posturography is a useful new tool to study the influence of vestibular diseases on balance. AIM to compare the results from the Balance Rehabilitation Unit (BRU) static posturography in elderly patients with Benign Paroxysmal Positional Vertigo (BPPV), before and after Epleys maneuver. MATERIALS AND METHODS a prospective study of 20 elderly patients with a diagnosis of BPPV. The patients underwent static posturography and the limit of stability (LE) and ellipse area were measured. We also applied the Dizziness Handicap Inventory (DHI) questionnaire to study treatment effectiveness. RESULTS 80% were females, with a mean age of 68.15 years. After the maneuver, the LE increased significantly (p=0.001). The elliptical area of somatosensory, visual and vestibular conflicts (2,7,8,9 situations) in BRU and the DHI scores decreased significantly (p<0.05) after treatment. CONCLUSION the study suggests that elderly patients with BPPV may present static postural control impairment and that the maneuver is effective for the remission of symptoms, to increase in the stability and improvement in postural control in situations of visual, somatosensory and vestibular conflicts.

Processamento cognitivo e equilíbrio corporal em idosos com disfunção vestibular

UNLABELLED Abnormal body balance and cognitive dysfunction may develop in elderly patients with chronic vestibular dysfunction. AIM To evaluate the relationship between cognitive processing and body balance in elderly patients with chronic peripheral vestibular disease. TYPE OF STUDY Cross-sectional. METHODS Seventy-six patients (> 60 years) with chronic peripheral vestibular dysfunction and dizziness for more than three months were enrolled. The tests for investigating body balance were: the Berg Balance Scale (BBS), Dynamic Gait Index (DGI), Timed Up and Go Test (TUGT) Timed Up and Go Test modified (TUGTm); the Mini Mental State Examination (MMSE), Test Clock (RT,) and Verbal Fluency Test (VF) were applied for assessing cognition. RESULTS The mean age was 69.03 years (SD=6.21 years); most were female (82.9%). There was a significant negative correlation between the MMSE and the TUGT (ρ=-0.312; p=0.01), MMSE and TUGTm (ρ=-0.306; p=0.01), FV and TUGT (ρ=-0.346; p=0.01), and FV and TUGTm (ρ=-0.536; p=0.01); there was a significant positive correlation between the TR and BBS (ρ=0.343; p=0.01), TR and DGI (ρ=0.298; p=0.01), FV and BBS (ρ=0.299; p=0.01), and FV and DGI (ρ=0.306; p=0.01). CONCLUSION Elderly patients with chronic peripheral vestibular disease and worse performance in body balance tests have functional impairment in cognitive skills.Abnormal body balance and cognitive dysfunction may develop in elderly patients with chronic vestibular dysfunction. AIM: To evaluate the relationship between cognitive processing and body balance in elderly patients with chronic peripheral vestibular disease. Type of Study: Cross-sectional. METHODS: Seventy-six patients (> 60 years) with chronic peripheral vestibular dysfunction and dizziness for more than three months were enrolled. The tests for investigating body balance were: the Berg Balance Scale (BBS), Dynamic Gait Index (DGI), Timed Up and Go Test (TUGT) Timed Up and Go Test modified (TUGTm); the Mini Mental State Examination (MMSE), Test Clock (RT,) and Verbal Fluency Test (VF) were applied for assessing cognition. RESULTS: The mean age was 69.03 years (SD=6.21 years); most were female (82.9%). There was a significant negative correlation between the MMSE and the TUGT (ρ=-0.312; p=0.01), MMSE and TUGTm (ρ=-0.306; p=0.01), FV and TUGT (ρ=-0.346; p=0.01), and FV and TUGTm (ρ=-0.536; p=0.01); there was a significant positive correlation between the TR and BBS (ρ=0.343; p=0.01), TR and DGI (ρ=0.298; p=0.01), FV and BBS (ρ=0.299; p=0.01), and FV and DGI (ρ=0.306; p=0.01). CONCLUSION: Elderly patients with chronic peripheral vestibular disease and worse performance in body balance tests have functional impairment in cognitive skills.

Postural Control in Older Patients with Benign Paroxysmal Positional Vertigo

Objective. To evaluate the effectiveness of a canalith-repositioning procedure in postural control of older patients with idiopathic benign paroxysmal positional vertigo (BPPV). Study Design. Prospective clinical trial. Setting. A tertiary referral center. Methods. A 9-month follow-up survey with a prospective design was conducted among 33 older patients with BPPV. Patients underwent static posturography (Balance Rehabilitation Unit [BRU]) and were administered the Dizziness Handicap Inventory (DHI) before and after the maneuver. After the treatment, they were compared with 33 healthy older subjects. The posturography parameters were the limit of stability (LOS), the center of body-pressure area (COP), and the velocity of oscillation (VOS) under conditions of visual, somatosensory, and visual-vestibular conflict. Results. One canalith-repositioning procedure relieved most patients’ complaints (54.5%), and 100% were relieved with 1 to 3 maneuvers. Total DHI score and all subscales improved after treatment (P < .01). The LOS values pretreatment (mean [SD] 134.27 [55.32] cm2) and posttreatment (181.03 [47.79] cm2) were significantly different (P < .01). Comparative analysis of COP values showed a relevant statistical difference in 8 of 10 postmaneuver conditions (P < .01). The postmaneuver VOS showed a significant difference under 7 conflict conditions. There were no differences between the healthy older subjects and treated patients for all VOS values under all conditions and for COP values under 9 conditions. Conclusion. The canalith-repositioning procedure promotes remission of symptoms, an increase in LOS, and improvement in postural control under conditions of somatosensory and visual conflict and visual-vestibular interaction.

Uma abordagem interdisciplinar na avaliação e reabilitação do idoso com disfunção vestibular crônica

Introducao: disturbios auditivos como zumbido, perda de audicao e hiperacusia podem comprometer o desenvolvimento da linguagem nas criancas. Objetivo: verificar a ocorrencia de queixas auditivas (zumbido, desconforto a sons e dificuldades auditivas) em criancas de sete a 10 anos e relacionar a presenca ou nao dessas queixas ao desempenho escolar. Metodo: 31 criancas com idade entre nove a 12 anos, com media etaria de 10,22 anos, de ambos os generos. Os pacientes foram submetidos a entrevistas fechadas, por meio da aplicacao de um questionario pre-estabelecido baseado no trabalho de Coelho (2006). De acordo com a avaliacao realizada pela coordenacao pedagogica da escola quanto as dificuldades escolares, as criancas foram divididas em dois grupos, Grupo controle –G1(n=14) e Grupo de estudo-G2 (n=17). A analise dos resultados utilizada foi descritiva. Resultado: do total de pacientes (n=31), 38,70% apresentaram zumbido; 29,03% desconforto a sons e 29,03 dificuldades auditivas. Entre os pacientes com queixa de zumbido, 33,33% eram do G1 1 e 66,67,% do Grupo 2. Entre os pacientes com desconforto a sons, 33,33,% apresentavam a queixa no G1 e 66,67%, no G2. Discussao: O estudo encontrou maior ocorrencia da queixa de zumbido e de desconforto a sons, em criancas com dificuldade escolar. Conclusao: 38,70% das criancas estudadas referiram percepcao de zumbido e 29,03% referiram desconforto a sons. As queixas de zumbido e desconforto a sons foram mais frequentes nas criancas com dificuldade escolar.

Influence of sensory information on static balance in older patients with vestibular disorder

INTRODUCTION With aging, the sensory systems suffer an accumulation of degenerative, infectious and/or traumatic processes that may hinder the body balance maintenance. OBJECTIVE To assess the influence of sensory information on static body balance of elderly individuals with vestibular disorders. METHODS Cross-sectional study of elderly individuals with vestibular disorders. The Clinical Test of Sensory Interaction and Balance and posturography integrated with virtual reality (Balance Rehabilitation Unit) were used. Posturography parameters analyzed included center of pressure and velocity of body sway. RESULTS 123 individuals with mean age of 73.11 were assessed. Worst performance was observed in the Clinical Test of Sensory Interaction and Balance condition of visual dome-unstable surface. Differences between conditions were: firm surface-open eyes/firm surface-closed eyes, unstable surface-open eyes/unstable surface-closed eyes (p<0.001), and unstable surface-closed eyes/unstable surface-visual dome. Considering center of pressure and velocity of body sway, significant differences were observed between the following conditions: firm surface-open eyes/firm surface-closed eyes: firm surface-saccadic stimulus/firm surface-vertical optokinetic stimulus; firm surface-optokinetic stimuli/firm surface-visual-vestibular interaction; and firm surface-visual-vestibular interaction/unstable surface. Worse performances were observed in conditions firm surface-closed eyes, firm surface-vertical optokinetic stimulus, F-visual-vestibular interaction, and unstable surface-closed eyes. There was a difference in the center of pressure between firm surface-closed eyes/firm surface-saccadic stimulus, with a worse performance in the condition of firm surface-closed eyes, and of velocity of body sway, between firm surface-saccadic stimulus/firm surface-horizontal optokinetic stimulus (p<0.001). CONCLUSION Static body balance in elderly individuals with vestibular disorders is worse when the sensory conditions are more challenging, i.e. stable and unstable surfaces, visual stimuli, such as optokinetic and visual-vestibular interaction, and with the eyes closed.

Effect of Kinect games on postural control of patients with Parkinson's disease

Parkinsons disease is a neurodegenerative disorder that progressively compromises motor control and cognition. Recently, the new generation of video games has been used to promote motor cognitive training. These studies have shown improvement on postural control, cognition and performance of daily living activities in patients with Parkinsons disease. The purpose of this study was to assess the effects of playing Microsoft Kinect Adventures™ on postural control of patients with Parkinsons disease. The design of study was a case series that was conducted at the Associação Brasil Parkinson, Brazil. Six patients (four males, two female) with Parkinsons disease (Hoehn and Yahr Stages 1 to 3) participated of this study. Patients performed fourteen 60-minute sessions, three times per week, playing four games of Kinect Adventures. The main outcome measures was the Limits of Stability. Secondary outcome was the safety. One patient had back pain during the period of training. The Limits of Stability before training and after training were 118.5 (28.0) and 163.7 (38.3), respectively. The training with Kinect Adventures™ games were safety and promoted improvement on postural control of patients with PD on stages 1 to 3 of Hoehn & Yahr scale.