The advances of Deep Brain Stimulation (DBS) for treatment of Parkinson's disease (PD)

Advanced Parkinson's disease (PD) is characterized by the presence of motor fluctuations, various degrees of dyskinesia, and disability with functional impact on daily living and independence. Therapeutic management aims to extend levodopa (L-DOPA) benefit while minimizing motor complications and includes, in selected cases, the implementation of drug infusion and surgical techniques. The concept of deep brain stimulation (DBS) for PD was introduced over 20 years ago, but our understanding of the nuances of this procedure continues to improve. This review aims to demonstrate the advances of DBS in the treatment of PD patients. (AU)

Subtalamotomía bilateral diferida guiada por microrregistros. Resultados motores a un año / Bilateral delayed subtalamotomy guided by micro-records. One-year motor results

Introducción: diferentes técnicas quirúrgicas representan una alternativa para el tratamiento de la enfermedad de Parkinson avanzada (EP). El gran desarrollo en las últimas décadas de modernas técnicas de imágenes sumado a los avances del registro neurofisiológico nos permiten localizar y generar lesiones en forma precisa, con bajo número de complicaciones y excelentes resultados funcionales. Objetivo: Describir los resultados motores obtenidos a los 12 meses post-operatorios de pacientes con diagnóstico de EP avanzada sometidos a subtalamotomía bilateral diferida guiada por microrregistro. Material y Métodos: Se seleccionaron 9 pacientes con diagnóstico de EP avanzada de acuerdo a los criterios de la United Kingdom Parkinson´s Disease Brain Bank, evaluando los efectos de la subtalamotomía bilateral en dos tiempos quirúrgicos. Resultados: Una marcada mejoría de los síntomas cardinales como rigidez, bradicinesia y temblor se observó en todos los pacientes, fundamentalmente en la condición de “off”, y en menor medida también en condición “on”. Se destaca un significativo control de las fluctuaciones motoras y discinesias. Conclusión: La subtalamotomía bilateral diferida guiada por microregistro es un método útil y efectivo en el tratamiento de los síntomas motores de la Enfermedad de Parkinson.

Introduction: in the treatment of advanced Parkinson´s disease (PD) there are different surgical techniques that represent a valid alternative. The development of modern images techniques and neurofisiological recording allow us to generate accurate lesions, with low complications and excellent functional results. Objective: Describe motor results 12 months post-surgical of patients with advanced PD submitted to bilateral and deferred subthalamotomy guided by microrecording. Material and Methods: We selected 9 patients with advanced PD diagnosis in concordance with United Kingdom Parkinson`s Disease Brain Bank criteria, evaluating the effects of bilateral subthalamotomy in two different surgical steps. Results: A marked improvement of cardinal symptoms such as rigidity, bradykinesia and tremor was observed in all patients, fundamentally in “off” condition, and lesser extent in “on” condition. We highlighted a significant control of motor fluctuations and dyskinesias. Conclusion: Bilateral and deferred suthalamotomy guided by microrecording is an effective and useful method in treatment of cardinal motor symptoms of PD.

Pallidotomy Guided by MRI and Microrecording for Parkinson's Disease

OBJECTIVE: The exact position of the lesion during the pallidotomy is critical to obtain the clinical improvement of parkinson's disease without damage to surrounding structure. Ventriculogrphy, CT(computed tomograpy) or MRI(magnetic resonance imaging) have been used to determine the initial coordinates of stereotactic target for pallidotomy. The goal of this study was to determine whether microelectrode recording significantly improves the neurophysiologic localization of the target obtained from MRI. METHODS: Twenty patients were studied. They underwent a unilateral pallidotomy. Leksell frame was applied and T1 axial images parallel to the AC-PC(anterior commissure-posterior commissure) plane using a 1.5 Tesla MRI with 3mm slice thickness were obtained. Anteroposterior coordinate of target was chosen at 2mm in front of the midcommissural point and lateral coordinate between 19 and 22mm from the midline. The vertical coordinate was calculated on coronal slice using a fast spin echo inversion recovery sequence(FSEIR) related to the position of the choroidal fissure and ranged over 4-5mm below the AC-PC plane. Confirmation of the anatomical target was done on axial slices using the same FSEIR sequence. Microrecording was done at the pallidum contralateral to the symptomatic side using an electrode with a tip diameter of 1nm diameter tip and 1.1-1.4 mOhm impedance at 1000Hz. Electrophysiologic localization of the target was also confirmed intraoperatively by macrostimulation. RESULTS: Microrecording techniques were reliable to define the transition from the base of the pallidum which was characterized by the disappearance of spike activity and by the change of the audible background activity. Signals from high amplitude neurons firing at 200-400Hz were recorded in the pallidal base. X, Y and Z coordinates of target obtained from the MRI were within 1mm from the X, Y, Z coordinates obtained with microrecording in 16 patients (80%), 15 patients(75%), 10 patients(50%) respectively. The difference of Y coordinate between on MRI and on microrecording was 4mm in only one patient. CONCLUSION: The MRI was accurate to localize the target within 1mm of the error from microrecording target in 70% of the patients. 4mm discrepancy was observed only once. We conclude that MRI alone can be used to determine the target for pallidotomy in most patients. However, microrecording technique can still be extremely valuable in patents with aberrant anatomy or unusual MRI coordinates. We also consider physiologic confirmation of the target using macrostimulation to be mandatory in all cases.