Protocols of non-invasive brain stimulation for neuroplasticity induction.

Transcranial non-invasive brain stimulation (NIBS) has been widely applied in basic research and clinical intervention in the past few decades. It modulates cortical excitability through varies combinations of current form, stimulation position, strength, frequency, duration and intervals. In this review, protocols of different types of NIBS and their aftereffect are introduced. Moreover, evidences in physiology, pharmacology and behavior response are provided to support the effects of NIBS are plasticity-like effects because of their common mechanisms of synaptic plasticity. This is further confirmed by experiments on small animals at the cellular level.

Solutions for managing variability in non-invasive brain stimulation studies.

In the last three decades, a number of non-invasive brain stimulation (NIBS) protocols, capable of assessing and modulating plasticity in the human motor cortex (M1), have been described. For almost as long, NIBS has delivered the tantalising prospect of non-invasive neuromodulation as a therapeutic intervention for neurorehabilitation, psychiatry, chronic pain and other disease states. Apart from modest effects in depression, this early promise has not been realised since the symptomatic improvements produced by NIBS are generally weak. One key factor explaining this lack of clinical translation concerns variability in response to NIBS. Several studies have demonstrated a number of physiological, technical and statistical factors accounting for intra- and inter-subject variability. However, solutions to overcome this problem are still under debate. In the present review, we have provided a detailed description of methodological and technical solutions to control known factors influencing variability. We have also suggested potential strategies to strengthen and stabilize NIBS-induced after-effects. Finally, we propose new possible outcome variables which better reflect intrinsic cortical activity, allowing a more sensitive measurement and valid interpretation of responses to NIBS.

Análisis de la actividad y coordinación motora en ratas con cirugía estereotáxica e implante de cánula en el hipocampo dorsal / Analysis of activity and motor coordination in rats undergoing stereotactic surgery and implantation of a cannula into the dorsal hippocampus

Introducción: La cirugía estereotáxica permite el implante de electrodos o cánulas para estudiar el funcionamiento de diversas estructuras cerebrales a nivel preclínico. El hipocampo ha sido ampliamente estudiado con esta metodología, debido a su participación en desórdenes neurológicos, cognitivos, emocionales y afectivos. Sin embargo, el efecto per se de esta metodología sobre la coordinación y la actividad motora, para identificar o descartar alteraciones neurológicas que pudieran influir en los resultados de protocolos que la utilizan, requiere ser explorado. Métodos: Se evaluó el efecto de la cirugía estereotáxica y el implante de cánula en el hipocampo de ratas hembra Wistar en las pruebas de actividad locomotora, nado y Rota-rod. El análisis estadístico consideró la fase del ciclo estral de las ratas. Resultados:Ninguna de las variables evaluadas en las pruebas de actividad locomotora (cuadros cruzados, tiempo de acicalamiento y conducta vertical), nado (giros, nado lateral, latencia a la primera inmovilidad y tiempo de inmovilidad) o Rota-rod (latencia a la caída), fueron modificadas por la manipulación quirúrgica, en relación con ratas intactas. Independientemente de la manipulación quirúrgica, las ratas en metaestro-diestro cruzaron más cuadros y tuvieron mayor tiempo de inmovilidad, que las ratas en proestro-estro. Conclusión: La cirugía estereotáxica y el implante de cánula en el hipocampo dorsal carecen de efectos sobre la coordinación y la actividad locomotora de la rata, por lo que se descarta algún daño neurológico que pudiera interferir en la interpretación de resultados en protocolos que incluyen esta manipulación experimental (AU)

Introduction: Stereotactic surgery is used to place electrodes or cannulas in the brain in order to study the function of several brain structures in preclinical research. The hippocampus has been extensively studied with this methodology due to its involvement in a wide range of neurological, cognitive, emotional, and affective disorders. However, the effects of stereotactic surgery on coordination and motor activity should be evaluated in order to determine whether this surgical procedure causes any neurological alterations that may bias the results of studies incorporating this technique. Methods: We evaluated the effects of stereotactic surgery and implantation of a cannula into the hippocampus of female Wistar rats on the motor activity, forced swim, and rotarod tests. The stage of the oestrous cycle was included in the statistical analysis. Results: Stereotactic surgery had no impact on any of the motor activity variables assessed in the open field (squares crossed, time spent in grooming, and rearing), forced swim (turning behaviour, lateral swimming, latency to first immobility, and time spent immobile), and rotarod (latency to fall) tests, compared with intact rats. Regardless of surgical manipulation, rats in the metestrus and diestrus stages crossed a greater number of squares and displayed longer immobility times than those in the proestrus and estrus stages. Conclusion: Stereotactic surgery for cannula placement in the dorsal hippocampus does not affect coordination and motor activity in rats. We can therefore conclude that this procedure has no neurological complications that may interfere in the interpretation of results of studies applying this technique (AU)

[The course of the postoperative period in patients with cerebral gliomas after different volumes and kinds of surgery].

The investigation included 340 patients with cerebral gliomas. Under analysis there were age, gender, neurological status and Karnovsky status before and after operation, localization of the tumor, type and volume of surgical intervention, postoperative complications. It was shown that radical extirpation of glial formations facilitated more favorable course of the postoperative period. Partial ablation of gliomas is associated with greater risk of the development of postoperative complications and neurological dysfunctions. As the main method of surgical treatment of patients with gliomas located in the functionally significant and deep areas of the brain stereotaxic cryotomy is thought to be indicated.

Functional recovery after bilateral pallidotomy for the treatment of early-onset primary generalized dystonia.

This report describes the successful treatment of dystonia musculorum deformans with bilateral stereotactic pallidotomy in a 14-year-old girl in whom the dystonia was diagnosed when she was 7 years old. The patient presented with dystonia of the right upper extremity that progressed to generalized dystonia. Preoperatively, she required maximal assistance with all activities of daily living and transfers. She was not a functional ambulator. Postoperatively, she had remarkable functional recovery. At discharge, she was at modified independence level for all basic activities of daily living and required supervision for household ambulation. No postoperative complications were noted. We propose that bilateral stereotactic lysis of globus pallidus interna may be an alternative treatment for dystonia musculorum deformans. The technique of bilateral pallidotomy and theories of its effectiveness are discussed.