Tissue Injury and Astrocytic Reaction, But Not Cognitive Deficits, Are Dependent on Hypoxia Duration in Very Immature Rats Undergoing Neonatal Hypoxia-Ischemia.

Preterm birth and hypoxia-ischemia (HI) are major causes of neonatal death and neurological disabilities in newborns. The widely used preclinical HI model combines carotid occlusion with hypoxia exposure; however, the relationship between different hypoxia exposure periods with brain tissue loss, astrocyte reactivity and behavioral impairments following HI is lacking. Present study evaluated HI-induced behavioral and morphological consequences in rats exposed to different periods of hypoxia at postnatal day 3. Wistar rats of both sexes were assigned into four groups: control group, HI-120 min, HI-180 min and HI-210 min. Neurodevelopmental reflexes, exploratory abilities and cognitive function were assessed. At adulthood, tissue damage and reactive astrogliosis were measured. Animals exposed to HI-180 and HI-210 min had delayed neurodevelopmental reflexes compared to control group. Histological assessment showed tissue loss that was restricted to the ipsilateral hemisphere in lower periods of hypoxia exposure (120 and 180 min) but affected both hemispheres when 210 min was used. Reactive astrogliosis was increased only after 210 min of hypoxia. Interestingly, cognitive deficits were induced regardless the duration of hypoxia and there were correlations between behavioral parameters and cortex, hippocampus and corpus callosum volumes. These results show the duration of hypoxia has a close relationship with astrocytic response and tissue damage progression. Furthermore, the long-lasting cognitive memory deficit and its association with brain structures beyond the hippocampus suggests that complex anatomical changes should be involved in functional alterations taking place as hypoxia duration is increased, even when the cognitive impairment limit is achieved.

Wearable sensors, cerebral palsy and gait assessment in everyday environments: is it a reality? - A systematic review.

This systematic review aimed to investigate emerging methods used to quantify gait parameters in children with cerebral palsy (CP) in everyday environments. The StArt computational tool automatically screened the following databases: ACM, Engineering Village, IEEE, PubMed, Scopus and Web of Science from inception to June 2018. Studies reporting the use of wearable sensors to assess gait in daily settings in children with CP were included. Data regarding 1563 studies were extracted, but only three studies could be included on the basis of the inclusion/ exclusion criteria. These studies proposed wearable technologies based on the use of signals provided by triaxial accelerometers and force resistive pressure sensors. These are able to track levels of activity and detect falls, gait deviations and gait symmetry in children with CP in their daily environments. To date, only two types of sensors have been tested in this population and it remains to be clarified how wearable sensors, used to quantify activity level, might benefit children with CP.

The required coefficient of friction in Parkinson's disease: people with freezing of gait.

The required coefficient of friction (RCOF) is frequently reported in the literature as an indicator of slip propensity, a consequence of the collisional aspect of legged locomotion. Little is known about the RCOF in pathological gait. Therefore, this study aimed to quantify the RCOF in subjects with Parkinson's disease (PD) and freezing of gait (FOG) during the OFF-pharma phase, and to investigate the interplay between RCOF parameters and ankle kinematic and kinetic gait variables. Fourteen subjects with PD and 14 healthy age-matched subjects were instructed to walk barefoot at self-selected speed over a force platform. The RCOF curve was obtained as the ratio between the tangential and vertical ground reaction forces. Then, the following discrete variables were identified: P1COF (the peak at the loading response phase), V1COF (the valley at midstance phase) and P2COF (the peak at push-off phase). Stepwise multiple regressions were applied to observe the influence of the gait speed and ankle kinematic and kinetic gait variables on RCOF variables. In subjects with PD and FOG the gait speed is a predictor of the RCOF in the loading response phase; plantarflexion and the plantarflexion moment are strong predictors of the RCOF in midstance; finally, push-off power is a predictor of RCOF increasing in the push-off phase. These results characterized the biomechanical strategies adopted by subjects with PD and FOG during gait in order to avoid falls.

Automated mechanical peripheral stimulation and postural control in subjects with Parkinson's disease and freezing of gait: a randomized controlled trial.

Individuals with Parkinson's disease (PD) and freezing of gait (FOG) have impaired postural control. Recent studies using foot sensory stimulation delivered by means of automated mechanical peripheral stimulation (AMPS) have demonstrated improvements of gait in individuals with PD. This study aimed to investigate the effects of AMPS on postural control in individuals with PD and FOG. Thirty-three subjects participated in this randomized controlled trial. Participants were allocated to two groups: AMPS and AMPS SHAM. Subjects underwent eight sessions of real (AMPS) or placebo AMPS (AMPS SHAM) once every three/four days. Postural control was assessed by means of posturography before the first and after the eighth session of treatment. We did not find positive effects of AMPS on center of pressure parameters. Thus, it seems that AMPS has no positive effect in terms of improving static postural control in individuals with PD and FOG.

Motor Skill Training Promotes Sensorimotor Recovery and Increases Microtubule-Associated Protein-2 (MAP-2) Immunoreactivity in the Motor Cortex after Intracerebral Hemorrhage in the Rat.

Motor skill learning may induce behavioral and neurophysiological adaptations after intracerebral hemorrhage (ICH). Learning a new motor skill is associated with dendritic reorganization and requires protein synthesis and expression of MAP-2. The purpose of this study was to evaluate motor performance and expression of MAP-2 in the motor cortex of rats submitted to intracerebral hemorrhage model (ICH) and skill task training (SK) or unskilled training (US) during 4 weeks. The Staircase test was used for behavioral evaluation, and relative optical densities and morphometrical analysis were used to estimate MAP-2 immunoreactivity and parameters of brain tissue in both motor cortices. Results show that skill task training performed with the impaired forelimb was able to increase MAP-2 immunoreactivity in the motor cortex either in sham or in ICH groups in both cortices: ipsilesional [F (5,35) = 14.25 (P < 0.01)] and contralesional hemispheres [F (5,35) = 9.70 (P < 0.01)]. ICH alone also increased MAP-2 immunoreactivity despite the absence of functional gains. Behavioral evaluation revealed that ICH-SK group performed better than ICH and ICH-US animals in the Staircase test. Data suggest that motor skill training induces plastic modifications in both motor cortices, either in physiological or pathological conditions and that skill motor training produces higher brain plasticity and positive functional outcomes than unskilled training after experimental intracerebral hemorrhage.

Effects of skilled and unskilled training on functional recovery and brain plasticity after focal ischemia in adult rats.

Stroke is a leading cause of morbidity and mortality worldwide. Recovery of motor function after stroke can be modified by post-injury experience, but most of surviving patients exhibit persistence of the motor dysfunctions even after rehabilitative therapy. In this study we investigated if skilled and unskilled training induce different motor recovery and brain plasticity after experimental focal ischemia. We tested this hypothesis by evaluating the motor skill relearning and the immunocontent of Synapsin-I, PSD-95 and GFAP (pre and post-synaptic elements, as well as surrounding astroglia) in sensorimotor cortex of both hemispheres 6 weeks after endothelin-1-induced focal brain ischemia in rats. Synapsin-I and PSD-95 levels were increased by skilled training in ischemic sensorimotor cortex. The content of GFAP was augmented as a result of focal brain ischemia in ischemic sensorimotor cortex and that was not modified by rehabilitation training. Unexpectedly, animals remained permanently impaired at the end of motor/functional evaluations. Significant modifications in protein expression were not observed in undamaged sensorimotor cortex. We conclude that skilled motor activity can positively affect brain plasticity after focal ischemia despite of no functional improvement in conditions here tested.

Effect of skilled and unskilled training on nerve regeneration and functional recovery.

The most disabling aspect of human peripheral nerve injuries, the majority of which affect the upper limbs, is the loss of skilled hand movements. Activity-induced morphological and electrophysiological remodeling of the neuromuscular junction has been shown to influence nerve repair and functional recovery. In the current study, we determined the effects of two different treatments on the functional and morphological recovery after median and ulnar nerve injury. Adult Wistar male rats weighing 280 to 330 g at the time of surgery (N = 8-10 animals/group) were submitted to nerve crush and 1 week later began a 3-week course of motor rehabilitation involving either "skilled" (reaching for small food pellets) or "unskilled" (walking on a motorized treadmill) training. During this period, functional recovery was monitored weekly using staircase and cylinder tests. Histological and morphometric nerve analyses were used to assess nerve regeneration at the end of treatment. The functional evaluation demonstrated benefits of both tasks, but found no difference between them (P > 0.05). The unskilled training, however, induced a greater degree of nerve regeneration as evidenced by histological measurement (P < 0.05). These data provide evidence that both of the forelimb training tasks used in this study can accelerate functional recovery following brachial plexus injury.

Skilled reaching training promotes astroglial changes and facilitated sensorimotor recovery after collagenase-induced intracerebral hemorrhage.

Spontaneous intracerebral hemorrhage (ICH) is the most devastating type of stroke and a leading cause of disability and mortality worldwide. Although rehabilitation improves recovery after ICH the cellular mechanisms involved are poorly understood. We decided to examine if skilled (SK) and unskilled (US) training after sham or intracerebral hemorrhage (ICH) surgeries would induce GFAP+ astrocytic changes and whether these modifications can be associated with functional improvement. A 4-week course of motor training, involving either skilled and unskilled training began seven days after surgery; sensorimotor recovery was evaluated using Staircase, ladder walk and cylinder tests. Histological and morphometric analyses were used to assess GFAP+ cell bilaterally in forelimb sensorimotor cortex and dorsolateral striatum. All behavioral tests showed that ICH-SK rats experienced a greater degree of recovery when compared to ICH no task or ICH-US groups; no behavioral differences were found among all sham groups. Astrocytic density was increased in all analyzed structures for ICH no task, ICH-SK and ICH-US rats. Morphological analysis revealed an increased number of primary processes in ipsilateral (to lesion) sensorimotor cortex for all ICH groups. Present results also revealed that both ICH and SK induced an increased length of GFAP+ primary process; there was a further increase in length processes for ICH-SK group in sensorimotor cortex and ipsilateral striatum. We suggest that skilled reaching is an effective intervention to promote astrocytic plasticity and recovery after ICH.

Effect of skilled and unskilled training on nerve regeneration and functional recovery

The most disabling aspect of human peripheral nerve injuries, the majority of which affect the upper limbs, is the loss of skilled hand movements. Activity-induced morphological and electrophysiological remodeling of the neuromuscular junction has been shown to influence nerve repair and functional recovery. In the current study, we determined the effects of two different treatments on the functional and morphological recovery after median and ulnar nerve injury. Adult Wistar male rats weighing 280 to 330 g at the time of surgery (N = 8-10 animals/group) were submitted to nerve crush and 1 week later began a 3-week course of motor rehabilitation involving either "skilled" (reaching for small food pellets) or "unskilled" (walking on a motorized treadmill) training. During this period, functional recovery was monitored weekly using staircase and cylinder tests. Histological and morphometric nerve analyses were used to assess nerve regeneration at the end of treatment. The functional evaluation demonstrated benefits of both tasks, but found no difference between them (P > 0.05). The unskilled training, however, induced a greater degree of nerve regeneration as evidenced by histological measurement (P < 0.05). These data provide evidence that both of the forelimb training tasks used in this study can accelerate functional recovery following brachial plexus injury.

Confiabilidade da tradução e adaptação do Test d'Évaluation des Membres Supérieurs de Personnes Âgées (TEMPA) para o português e validação para adultos com hemiparesia / Reliability of the translation and adaptation of the Test d'Évaluation des Membres Supérieurs des Personnes Âgées (TEMPA) to the Portuguese language and validation for adults with hemiparesis

INTRODUÇÃO: O Test d'Évaluation des Membres Supérieurs de Personnes Âgées (TEMPA) é composto por tarefas padronizadas, representando atividades da vida diária e avalia a função do membro superior (MS) de pessoas com alteração motora. Além da medida do tempo e da graduação funcional, o instrumento propõe uma análise das tarefas executadas. OBJETIVO: Os objetivos do estudo foram: traduzir e adaptar para a língua portuguesa o formulário e o manual de administração do TEMPA; avaliar a confiabilidade teste reteste e interobservadores e a validade para pacientes com hemiparesia. MÉTODOS: Participaram deste estudo 23 pacientes (61±13 anos) com hemiparesia (30±29 meses) e 23 controles (60±12 anos). A confiabilidade interobservadores foi testada comparando o resultado de dois observadores, em avaliações realizadas no mesmo dia. A confiabilidade teste reteste foi testada comparando o resultado das avaliações, repetidas no intervalo de uma semana. A validade para hemiparéticos foi avaliada por meio da correlação com a escala de Fugl-Meyer (EFM). RESULTADOS: Os resultados mostram adequada confiabilidade interobservadores (coeficiente de correlação intraclasse - CCI=0,93) e teste reteste (CCI=0,99) para os escores totais. Nos pacientes com comprometimento motor moderado a grave (EFM<50), todos os itens mostraram adequada confiabilidade teste reteste e interobservadores (CCI entre 0,70 e 1,00). Nos pacientes com comprometimento motor leve (EFM>50), a confiabilidade para a velocidade na execução assim como para o escore funcional total (interobservadores, ICC=0,79 e teste-reteste, ICC=0,78), foi adequada. A correlação do TEMPA com a EFM foi de r=-0,85 (p=0,001). CONCLUSÕES: Os resultados sugerem adequada confiabilidade para a versão brasileira do TEMPA e validade para pacientes com hemiparesia.

INTRODUCTION: The Test d'Évaluation des Membres Supérieurs de Personnes Âgées (TEMPA) is composed of standardized tasks that represent activities of daily living. This test evaluates upper limb function in individuals with motor deficits. In addition to measuring time and functional level, this instrument also provides analysis of the tasks performed. OBJECTIVE: The aims were: to translate and to adapt the TEMPA form and administration manual to the Portuguese language; and to assess interrater and test-retest reliability and the validity of TEMPA for patients with hemiparesis. METHODS: Twenty-three patients (61±13 years) with hemiparesis (30±29 months) and 23 controls (60±12 years) participated in this study. The interrater reliability was tested by comparing the results from two examiners, in evaluations on the same day. The test-retest reliability was tested by comparing the results from evaluations repeated within a one-week interval. The validity of TEMPA for hemiparetics was assessed by correlation with the Fugl-Meyer scale (FMS). RESULTS: The results showed adequate interrater reliability (intraclass correlation coefficient - ICC=0.93) and test-retest reliability (ICC=0.99) for the total scores. In patients with moderate to severe motor deficits (FMS<50), all the items showed adequate test-retest and interrater reliability (ICC between 0.70 and 1.00). In patients with mild motor deficits (FMS>50), the reliability regarding speed of execution and total functional score (interrater, ICC=0.79 and test-retest, ICC=0.78) was adequate. The correlation of TEMPA with FMS was r=-0.85 (p=0.001). CONCLUSIONS: The results suggest that the Brazilian version of TEMPA is reliable and that it is valid for patients with hemiparesis.