Comparative evaluation of the effects of unilateral lesion versus electrical stimulation of the globus pallidus internus in advanced Parkinson's disease.

OBJECTIVE: To perform a prospective analysis on the effects of unilateral lesion versus unilateral electrical stimulation (ES) of the globus pallidus internus (Gpi) in the treatment of bilateral Parkinson's disease (PD). MATERIALS AND METHODS: We studied 18 patients with stages III-V on the Hoehn and Yahr (H-Y) scale having prominent rigidity, bradykinesia and gait disturbances. Nine patients were treated with lesions and 9 patients with ES. Both groups were evaluated using the New York Parkinson's Disease Scale, the Unified Parkinson's Disease Rating Scale part III, and the H-Y scale and with specific items of tremor, rigidity and bradykinesia independently on each side. Both lesions and electrodes for ES were placed stereotactically in the Gpi as confirmed by postoperative magnetic resonance images. Significance of changes was evaluated with the Wilcoxon test after 3 and 6 months. Significance of intergroup differences was evaluated using the Mann-Whitney U test. RESULTS: Lesions and ES significantly decreased rigidity (p < 0.01) and bradykinesia (p < 0.005) in the contralateral extremities. ES significantly decreased tremor in the contralateral extremities (p < 0.01) and rigidity and bradykinesia ipsilaterally (p < 0.01) at 3 months. There were no significant intergroup differences. The H-Y scale score showed improvement in self-sufficiency. L-DOPA dose was decreased by 31%. CONCLUSIONS: ES was a safer procedure and more efficient in controlling PD symptoms. Unilateral lesions and ES may improve bilateral symptoms to the point of making patients self-sufficient.

Double-blind, randomized controlled pilot study of bilateral cerebellar stimulation for treatment of intractable motor seizures.

PURPOSE: The efficacy and safety of cerebellar stimulation (CS) was reevaluated in a double-blind, randomized controlled pilot study on five patients with medically refractory motor seizures, and especially generalized tonic-clonic seizures. METHODS: Bilateral modified four-contact plate electrodes were placed on the cerebellar superomedial surface through two suboccipital burr holes. The implanted programmable, battery-operated stimulator was adjusted to 2.0 microC/cm(2)/phase with the stimulator case as the anode; at this level, no patient experienced the stimulation. Patients served as their own controls, comparing their seizure frequency in preimplant basal phase (BL) of 3 months with the postimplant phases from 10 months to 4 years (average, eight epochs of 3 months each). During the month after implantation, the stimulators were not activated. The patient and the evaluator were blinded as to the next 3-month epoch, as to whether stimulation was used. The patients were randomized into two groups: three with the stimulator ON and two with the stimulator OFF. After a 4-month postimplantation period, all patients had their stimulator ON until the end of the study and beyond. Medication was maintained unchanged throughout the study. EEG paroxysmal discharges also were measured. RESULTS: Generalized tonic-clonic seizures: in the initial 3-month double-blind phase, two patients were monitored with the stimulation OFF; no change was found in the mean seizure rate (patient 1, 100%, and patient 5, 85%; mean, 93%), whereas the three patients with the stimulation initially ON had a reduction of seizures to 33% (patient 2, 21%; patient 3, 46%; patient 4, 32%) with a statistically significant difference between OFF and ON phase of p = 0.023. All five patients then were stimulated and monitored. At the end of the next 6 months of stimulation, the five patients had a mean seizure rate of 41% (14-75%) of the BL. The second patient developed an infection in the implanted system, which had to be removed after 11 months of stimulation; the seizures were being reduced with stimulation to a mean of one per month from a mean of 4.7 per month (BL level) before stimulation. At the end of 24 months, three patients were monitored with stimulation, resulting in a further reduction of seizures to 24% (11-38%). Tonic seizures: four patients had these seizures, which at 24 months were reduced to 43% (10-76%). Follow-up surgery was necessary in four patients because of infection in one patient and lead/electrode displacement needing repositioning in three patients. The statistical analysis showed a significant reduction in tonic-clonic seizures (p < 0.001) and tonic seizures (p < 0.05). CONCLUSIONS: The superomedial cerebellar cortex appears to be a significantly effective and safe target for electrical stimulation for decreasing motor seizures over the long term. The effect shows generalized tonic-clonic seizure reduction after 1-2 months and continues to decrease over the first 6 months and then maintains this effectiveness over the study period of 2 years and beyond.

Temporo-spatial correlations between scalp and centromedian thalamic EEG activities of stage II slow wave sleep in patients with generalized seizures of the cryptogenic Lennox-Gastaut syndrome.

OBJECTIVES: Temporo-spatial correlations between scalp and centromedian thalamic (CM) normal and abnormal electroencephalographic (EEG) activities of stage II slow wave sleep (SWS II) were investigated in 5 patients with cryptogenic Lennox-Gastaut syndrome (CLGS). METHODS: In each patient, 8h/all-night sleep studies were performed with routine methods; and a total of 1233 normal and 206 abnormal individual activities, spontaneously occurring during 200 epochs of early and late SWS II, were analyzed. Normal activities included scalp-CM K-complexes (KC-CMKC), vertex waves (VW-CMVW), and sleep spindles (SS-CMSS). Abnormal activities included: thalamo-cortical spikes (TCS-CMTCS), and epileptic (EPKC-CMEPKC) and W K-complexes (WKC-CMWKC). RESULTS: (1) All abnormal and normal spontaneous SWS II activities occurred associated in scalp and CM regions except the SS. Associated spindles were significantly larger (P<0.01) than dissociated ones, this occurring during both early and late SWS II. (2) The peak of VW significantly anticipated (P<0.02) that of its CM counterpart (CM-VW), while the peak of CMTCS anticipated that of its scalp counterpart. The onset of CMSS significantly anticipated (P=0.02) that of its scalp counterpart (SS). The behavior of VW-CMVW and TCS-CMTCS of the abnormal KC was similar to those of the normal complexes, while the onset of abnormal spindles was simultaneous in scalp and CM regions. Scalp VW, CTS, and SS attained maximal amplitude at the parietal region bilaterally with decreasing amplitude gradients to other scalp regions, while CMVW, CMTCS, and CMSS attained maximal amplitude in all thalamo-mesencephalic regions of CM. (3) Normal spindles significantly reduced (P<0.02) the amplitude of the positive CM, CMVW, and scalp TCS counterparts of the negative scalp VW and CM (CMTCS), respectively, while abnormal spindles reduced the amplitudes (P<0.01) of both negative VW and CMTCS and positive counterparts. CONCLUSION: These data suggest the following: (1) that all SWS II activities, including SS, are mediated by common thalamo-cortical systems; (2) that VW originate from the parietal scalp and normal spindles and TCS from the CM regions bilaterally while abnormal spindles originate either from widespread cortical and CM regions or from a site outside the thalamo-cortical systems, and (3) that the functional role of SS is to inhibit non-specific thalamo-cortical systems for sleep preservation.

Motor cortex stimulation in the treatment of deafferentation pain. I. Localization of the motor cortex.

MRI and electrophysiological techniques to localize the primary motor cortex (MC) were performed on patients considered for MC stimulation for the treatment of deafferentation pain. The representation and trajectory of the rolandic fissure (RF) were accurately localized by external cranial landmarks and radiopaque fiducials superimposed on oblique MRI sections. In addition, the scalp distribution of the corticocortical responses elicited by acute epidural stimulation [motor cortex (MC) in frontal and sensory cortex (SC) in parietal scalp regions], and analgesic responses at the topographical representation of the painful periphery elicited by subacute epidural stimulation were found to be simple and reliable procedures to localize MC, SC and RF.

Estimulación elécritica del tálamo en el tratamiento de la epilepsia de difícil control. Estudio a largo plazo / Electrical stimulation of the thalamus in the treatment of epilepsy of difficult control. A long-term study

En los últimos ocho años se han estudiado y tratado pacientes con crisis convulsivas de difícil control por estimulación eléctrica del núcleo centro mediano del tálamo. Estos enfermos no eran candidatos a tratamiento quirúrgico convencional de ablación del foco convulsivo por una o más de las siguientes razones: focos convulsivos múltiples, originados en áreas elocuentes de la corteza cerebral, o bilateral con evidencia de mal funcionamiento del área cerebral homóloga o con patrón de crisis generalizadas desde su inicio. La estimulación eléctrica se llevó a cabo en 46 pacientes en los núcleos centromedianos de ambos lados; en 15 de ellos utilizando un sistema de neuroestimulación totalmente internalizado. Los electrodos fueron colocados esterotáxicamente a través de trépanos frontales bilaterales y dirigidos a la comisura posterior del tercer ventrículo visualizado por ventriculografía. Después de la confirmación de su correcta posición por métodos electrofisiológicos de potenciales electrocorticales evocados por estimulación tálámica, el sistema fue internalizado a un neuroestimulador (IPG Medtronic Inc. Minneapolis, MN) en cada lado y se siguió un programa de estimulación automatizado de 60 cps, 0.450 ms, 4.5 V, un minuto de estimulación en un lado, cuatro minutos de intervalo y un minuto de estimulación en el lado contralateral, para repetir el esquema las 24 horas del día. Las crisis convulsivas disminuyeron en todos los casos en forma diferencial de acuerdo a su tipo clínico: las crisis focales motoras desparecieron, las crisis generalizadas tónico clónicas disminuyeron drásticamente o desaparecieron (p<0.001); las crisis de tipo ausencia atípica disminuyeron en forma progresiva y significativa (p<0.01); y las crisis parciales complejas disminuyeron no sgnificativamente. Este efecto se ha mantenido por periodos de dos a ocho años

Conocimientos que tiene el Personal de Enfermería sobre Métodos y Técnicas de Desinfección y Esterilización en dos Instituciones Hospitalarias de la ciudad de Cochabamba en el año de 1993

Dentro su estructura física un quirófano debe contar con las salas de operaciones y sus varios locales anexos absolutamente integrados y funcionales. Uno de estos es central de esterilización ambiente importante del quirófano y el resto de la institución. I. Introducción; II. Justificación; III. Formulación del problema; IV. Objetivo general, Objetivos específicos; V. Antecedentes, Desinfección; VI. Variables; VII. Diseño metodológico; VIII. Presentación de análisis y datos; IX. Conclusiones; X. Recomendaciones; XI. Anexos; XII. Bibliografía