Nuestros investigadores

Jorge Guridi Legarra

Publicaciones científicas más recientes (desde 2010)

Autores: Rodríguez Oroz, María Cruz; Parras Granero, Olga María; Gorospe Osinalde, María de Aránzazu; et al.
ISSN 0885-3185  Vol. 35  2020  págs. S140 - S141
Autores: Guridi Legarra, Jorge (Autor de correspondencia); Rodriguez-Rojas, R.; Carmona Abellán, María del Mar; et al.
ISSN 0885-3185  Vol. 33  Nº 10  2018  págs. 1540 - 1550
For many years the subthalamic nucleus had a poor reputation among neurosurgeons as a result of the acute movement disorders that develop after its lesion or manipulation through different surgical procedures. However, this nucleus is now considered a key structure in relation to parkinsonism, and it is currently one of the preferred therapeutic targets for Parkinson's disease. The implication of the subthalamic nucleus in the pathophysiology of chorea and in the parkinsonian state is thought to be related to its role in modulating the basal ganglia, a fundamental circuit in movement control. Indeed, recent findings have renewed interest in this anatomical structure. Accordingly, this review aims to present a history of the subthalamic nucleus, evolving from the classic surgical concepts associated with the avoidance of this structure, to our current understanding of its importance based on findings from more recent models. Future developments regarding the relationship of the subthalamic nucleus to neuroprotection are also discussed in this review. (c) 2018 International Parkinson and Movement Disorder Society
Autores: Rodriguez-Rojas, R.; Carballo-Barreda, M.; Alvarez, L. ; et al.
ISSN 0022-3050  Vol. 89  Nº 6  2018  págs. 572 - 578
Objective Subthalamotomy is an effective alternative for the treatment of Parkinson's disease (PD). However, uncertainty about the optimal target location and the possibility of inducing haemichorea-ballism have limited its application. We assessed the correlation between the topography of radiofrequency-based lesions of the subthalamic nucleus (STN) with motor improvement and the emergence of haemichorea-ballism. Methods Sixty-four patients with PD treated with subthalamotomy were evaluated preoperatively and postoperatively using the Unified Parkinson's Disease Rating Scale motor score (UPDRSm), MRI and tractography. Patients were classified according to the degree of clinical motor improvement and dyskinesia scale. Lesions were segmented on MRI and averaged in a standard space. We examined the relationship between the extent of lesion-induced disruption of fibres surrounding the STN and the development of haemichorea-ballism. Results Maximum antiparkinsonian effect was obtained with lesions located within the dorsolateral motor region of the STN as compared with those centre-placed in the dorsal border of the STN and the zona incerta (71.3%, 53.5% and 20.8% UPDRSm reduction, respectively). However, lesions that extended dorsally beyond the STN showed lower probability of causing haemichoreaballism than those placed entirely within the nucleus. Tractography findings indicate that interruption of pallidothalamic fibres probably determines a low probability of haemichorea-ballism postoperatively. Conclusions The topography of the lesion is a major factor in the antiparkinsonian effect of subthalamotomy in patients with PD. Lesions involving the motor STN and pallidothalamic fibres induced significant motor improvement and were associated with a low incidence of haemichorea-ballism.
Autores: Jablonska, Paola Anna; Gimeno Morales, Marta; Garcia-Consuegra, A.; et al.
ISSN 1522-8517  Vol. 20  Nº Supl. 3  2018  págs. 253 - 253
Autores: Guridi Legarra, Jorge; Alegre Esteban, Manuel
ISSN 0885-3185  Vol. 32  Nº 1  2017  págs. 64 - 69
Over the past 10 years, research into the neurophysiology of the basal ganglia has provided new insights into the pathophysiology of movement disorders. The presence of pathological oscillations at specific frequencies has been linked to different signs and symptoms in PD and dystonia, suggesting a new model to explain basal ganglia dysfunction. These advances occurred in parallel with improvements in imaging and neurosurgical techniques, both of which having facilitated the more widespread use of DBS to modulate dysfunctional circuits. High-frequency stimulation is thought to disrupt pathological activity in the motor cortex/ basal ganglia network; however, it is not easy to explain all of its effects based only on changes in network oscillations. In this viewpoint, we suggest that a return to (C) 2016 International Parkinson and Movement Disorder Society
Autores: Merola, A.; Fasano, A. ; Hassan, A.; et al.
ISSN 0885-3185  Vol. 32  Nº 8  2017  págs. 1240 - 1244
Background: We report the accumulated experience with ventral intermediate nucleus deep brain stimulation for medically refractory orthostatic tremor. Methods: Data from 17 patients were reviewed, comparing presurgical, short-term (0-48 months), and long-term (>= 48 months) follow-up. The primary end point was the composite activities of daily living/instrumental activities of daily living score. Secondary end points included latency of symptoms on standing and treatment-related complications. Results: There was a 21.6% improvement (P = 0.004) in the composite activities of daily living/instrumental activities of daily living score, which gradually attenuated (12.5%) in the subgroup of patients with an additional long-term follow-up (8 of 17). The latency of symptoms on standing significantly improved, both in the shortterm (P = 0.001) and in the long-term (P = 0.018). Three patients obtained no/minimal benefit from the procedure. Conclusions: Deep brain stimulation of the ventral intermediate nucleus was, in general, safe and well tolerated, yielding sustained benefit in selected patients with medically refractory orthostatic tremor. (C) 2017 International
Autores: Martínez Simón, Antonio (Autor de correspondencia); Alegre Esteban, Manuel; Honorato Cia, María Cristina; et al.
Vol. 126  Nº 6  2017  págs. 1033 - 1042
Autores: Honorato Cia, María Cristina; Martínez Simón, Antonio; Guridi Legarra, Jorge; et al.
ISSN 1878-8750  Vol. 101  2017  págs. 114 - 121
BACKGROUND: The anesthetic management of patients requiring surgery for movement disorders needs to balance microrecording quality and patient cooperation with safety and comfort. Anesthetics can alter microrecording, although the effect on outcome is debatable. They also provide a rested and cooperative patient and minimize complications such as intracranial hemorrhage by providing better hemodynamic control. Most teams use local anesthesia with monitored anesthesia care or conscious sedation with propofol. Recently, dexmedetomidine has emerged as an alternative that, at low doses, does not affect microrecording, and that does not impair respiratory drive. METHODS: In the past 15 years, we have used in our institution local anesthesia, remifentanil, or dexmedetomidine sedation. We compared functional outcome and rate of complications in a group of 145 patients with similar characteristics. RESULTS: We found 5 (3.4%) intracranial hemorrhages. Two (1.4%) were symptomatic. The remifentanil group had the highest risk of having systolic blood pressure > 160 mm Hg during surgery (odds ratio [OR], 2.8; 95% confidence interval [CI], 0.9-9.9), whereas the dexmedetomidine group had the lowest (OR, 0.7; 95% CI, 0.2-1.8), compared with the local anesthesia group. Surgical time was shortest with dexmedetomidine (mean, 283 minutes) and longest with local anesthesia only (mean, 328 minutes). Functional outcome (Unified Parkinson's Disease Rating Scale, Part III motor component scale) was similar among groups. The dexmedetomidine group had a statistically significant lower risk of perioperative neurologic events compared with the local anesthesia group (OR, 0.09; 95% CI, 0.002-0.68). CONCLUSIONS: Sedation can be used safely without affecting outcome, and dexmedetomidine provides better hemodynamic management. Clinical significance remains unclear and larger studies need to be undertaken.
Autores: García García, David; Guridi Legarra, Jorge; Toledo Atucha, Jon; et al.
ISSN 0022-3085  Vol. 125  Nº 5  2016  págs. 1068 - 1079
OBJECTIVE Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is widely used in patients with Parkinson's disease (PD). However, which target area of this region results in the highest antiparkinsonian efficacy is still a matter of debate. The aim of this study was to develop a more accurate methodology to locate the electrodes and the contacts used for chronic stimulation (active contacts) in the subthalamic region, and to determine the position at which stimulation conveys the greatest clinical benefit. METHODS The study group comprised 40 patients with PD in whom bilateral DBS electrodes had been implanted in the STN. Based on the Morel atlas, the authors created an adaptable 3D atlas that takes into account individual anatomical variability and divides the STN into functional territories. The locations of the electrodes and active contacts were obtained from an accurate volumetric assessment of the artifact using preoperative and postoperative MR images. Active contacts were positioned in the 3D atlas using stereotactic coordinates and a new volumetric method based on an ellipsoid representation created from all voxels that belong to a set of contacts. The antiparkinsonian benefit of the stimulation was evaluated by the reduction in the Unified Parkinson's Disease Rating Scale Part III (UPDRS-III) score and in the levodopa equivalent daily dose (LEDD) at 6 months. A homogeneous group classification for contact position and the respective clinical improvement was applied using a hierarchical clustering method. RESULTS Subthalamic stimulation induced a significant reduction of 58.0% ± 16.5% in the UPDRS-III score (p < 0.001) and 64.9% ± 21.0% in the LEDD (p < 0.001). The greatest reductions in the total and contralateral UPDRS-III scores (64% and 76%, respectively) and in the LEDD (73%) were obtained when the active contacts were placed approximately 12 mm lateral to the midline, with no influence of the position being observed in the anteroposterior and dorsoventral axes. In contrast, contacts located about 10 mm from the midline only reduced the global and contralateral UPDRS-III scores by 47% and 41%, respectively, and the LEDD by 33%. Using the ellipsoid method of location, active contacts with the highest benefit were positioned in the rostral and most lateral portion of the STN and at the interface between this subthalamic region, the zona incerta, and the thalamic fasciculus. Contacts placed in the most medial regions of the motor STN area provided the lowest clinical efficacy. CONCLUSIONS The authors report an accurate new methodology to assess the position of electrodes and contacts used for chronic subthalamic stimulation. Using this approach, the highest antiparkinsonian benefit is achieved when active contacts are located within the rostral and the most lateral parts of the motor region of the STN and at the interface of this region and adjacent areas (zona incerta and thalamic fasciculus).
Autores: Honorato Cia, María Cristina; Martínez Simón, Antonio; Alegre Esteban, Manuel; et al.
ISSN 1011-6125  Vol. 93  Nº 6  2015  págs. 393-399
Dexmedetomidine provides adequate sedation during surgery for PD, but it might affect motor signs making intraoperative testing difficult or even impossible. Dosage appears not to be the determining factor in motor changes, whose cause remains unclear.
Autores: Toledo Atucha, Jon; lopez azcarate, Jon; García García, David; et al.
Vol. 64  2014  págs. 60 - 65
Autores: Obeso Inchausti, José Ángel; Guridi Legarra, Jorge; Nambu, A.; et al.
ISSN 0885-3185  Vol. 28  Nº 4  2013  págs. 416 - 418
Autores: Aldave Orzaiz, Guillermo; Pay Valverde, Eva María; Queipo Gutiérrrez, Francisco Javier; et al.
ISSN 1130-1473  Vol. 24  Nº 2  2013  págs. 78-81
Single metastasis from a prostate adenocarcinoma in the brainstem without systemic disease is exceptional. Due to the different diagnostic possibilities, biopsy should be performed in order to obtain a diagnosis, especially in the context of Muir-Torre syndrome.
Autores: Ortega Cubero, Sara; Clavero Ibarra, Pedro Luis; Irurzun, C.; et al.
ISSN 1353-8020  Vol. 19  Nº 5  2013  págs. 543 - 547
Background: Deep brain stimulation of the subthalamic nucleus (STN-DBS) reduces motor fluctuations in Parkinson's disease (PD) but its effect on non-motor fluctuations (NMF) is not well known. In this study we assess the efficacy of STN-DBS on NMF two years after surgery. Methods: Autonomic, cognitive, psychiatric and sensory NMF in 20 patients were evaluated using a questionnaire designed to assess the frequency and severity of the NMF preoperatively and after two years of follow-up. The UPDRS scale was used for assessing the motor state. Results: Compared with the preoperative situation, STN-DBS at 2 years of follow-up was associated with a significant reduction in the number and severity of autonomic and psychiatric NMF in the "off" state (without medication), and in the severity of sensory NMF, which were not observed in the "on" state (with medication). A cross-sectional analysis at the two-year time-point of the four possible motor conditions (combining medication and stimulation) showed a reduction in the total number of NMF and in the severity of autonomic and sensory NMF after switching on the stimulation in the "on" state. Improvement of the UPDRS-motor score was correlated with a reduction in the severity but not in the frequency of NMF. A worsening of motor function after suppressing stimulation in the "off" state was not paralleled by a worsening of NMF. Conclusion: After two years of follow-up, STN-DBS in the "off" medication was associated with a reduction in the frequency and severity of NMF. These results will need to be confirmed in controlled studies.
Autores: Alegre Esteban, Manuel; lopez azcarate, Jon; Obeso Martin, I.; et al.
ISSN 0014-4886  Vol. 239  2013  págs. 1 - 12
Normal actions and behaviors often require inhibition of unwanted and inadequate movements. Motor inhibition has been studied using the stop signal task, in which participants are instructed to respond to a go signal. Sporadically, a stop signal is also delivered after a short interval following the go signal, prompting participants to inhibit their already started response to the go signal. Functional MRI studies using this paradigm have implicated the activation of the subthalamic nucleus in motor inhibition. We directly recorded subthalamic nucleus activity from bilaterally implanted deep brain stimulation electrodes in a group of 10 patients with Parkinson's disease, during performance of the stop signal task. Response inhibition was associated with specific changes in subthalamic activity in three different frequency bands. Response preparation was associated with a decrease in power and cortico-subthalamic coherence in the beta band (12-30 Hz), which was smaller and shorter when the response was successfully inhibited. In the theta band, we observed an increase in frontal cortico-subthalamic coherence related to the presence of the stop signal, which was highest when response inhibition was unsuccessful. Finally, a specific differential pattern of gamma activity was observed in the "on" motor state. Performance of the response was associated with a significant increase in power and cortico-subthalamic coherence, while successful inhibition of the response was associated with a bilateral decrease in subthalamic power and cortico-subthalamic coherence. Importantly, this inhibition-related decrease in gamma activity was absent in the four patients with dopamine-agonist related impulse-control disorders. Our results provide direct support for the involvement of the subthalamic nucleus in response inhibition and suggest that this function may be mediated by a specific reduction in gamma oscillations in the cortico-subthalamic connection.
Autores: Alegre Esteban, Manuel (Autor de correspondencia); lopez azcarate, Jon; Alonso-Frech, F.; et al.
ISSN 0885-3185  Vol. 27  Nº 9  2012  págs. 1176 - 1179
From a neurophysiological viewpoint, patients exhibited oscillatory activity typical of the "on" medication state during diphasic dyskinesias. The minimal presence of gamma activity during diphasic dyskinesias, however, suggests that this "on" state might be incomplete or limited to dopaminergic mechanisms affecting the lower limbs.
Autores: Guridi Legarra, Jorge; Rodríguez Oroz, María Cruz; Alegre Esteban, Manuel; et al.
ISSN 1353-8020  Vol. 18  Nº 6  2012  págs. 765-769
It is important to identify this hardware problem in view of the growing number of patients receiving this therapy. A protocol for patients with loss of stimulation efficacy and electrode impedance increment needs to be created in clinical visits in order to detect the failed stimulation mechanism.
Autores: Guridi Legarra, Jorge; Aldave Orzaiz, Guillermo
ISSN 1130-1473  Vol. 22  Nº 1  2011  págs. 5-22
Autores: Rodríguez Oroz, María Cruz; lopez azcarate, Jon; García García, David; et al.
Revista: BRAIN
ISSN 0006-8950  Vol. 134  Nº 1  2011  págs. 36-49
Behavioural abnormalities such as impulse control disorders may develop when patients with Parkinson's disease receive dopaminergic therapy, although they can be controlled by deep brain stimulation of the subthalamic nucleus. We have recorded local field potentials in the subthalamic nucleus of 28 patients with surgically implanted subthalamic electrodes. According to the predominant clinical features of each patient, their Parkinson's disease was associated with impulse control disorders (n = 10), dyskinesias (n = 9) or no dopaminergic mediated motor or behavioural complications (n = 9). Recordings were obtained during the OFF and ON dopaminergic states and the power spectrum of the subthalamic activity as well as the subthalamocortical coherence were analysed using Fourier transform-based techniques. The position of each electrode contact was determined in the postoperative magnetic resonance image to define the topography of the oscillatory activity recorded in each patient. In the OFF state, the three groups of patients had similar oscillatory activity. By contrast, in the ON state, the patients with impulse control disorders displayed theta-alpha (4-10 Hz) activity (mean peak: 6.71 Hz) that was generated 2-8 mm below the intercommissural line. Similarly, the patients with dyskinesia showed theta-alpha activity that peaked at a higher frequency (mean: 8.38 Hz) and was generated 0-2 mm below the intercommissural line. No such activity was detected in patients that displayed no dopaminergic side effects. Cortico-subthalamic coherence was more frequent in the impulsive patients in the 4-7.5 Hz range in scalp electrodes placed on the frontal regions anterior to the primary motor cortex, while in patients with dyskinesia it was in the 7.5-10 Hz range in the leads overlying the primary motor and supplementary motor area. Thus, dopaminergic side effects in Parkinson's disease are associated with oscillatory activity in the theta-alpha band, but at different frequencies and with different topography for the motor (dyskinesias) and behavioural (abnormal impulsivity) manifestations. These findings suggest that the activity recorded in parkinsonian patients with impulse control disorders stems from the associative-limbic area (ventral subthalamic area), which is coherent with premotor frontal cortical activity. Conversely, in patients with l-dopa-induced dyskinesias such activity is recorded in the motor area (dorsal subthalamic area) and it is coherent with cortical motor activity. Consequently, the subthalamic nucleus appears to be implicated in the motor and behavioural complications associated with dopaminergic drugs in Parkinson's disease, specifically engaging different anatomo-functional territories
Autores: Wichmann, T.; DeLong, M. R.; Guridi Legarra, Jorge; et al.
ISSN 0885-3185  Vol. 26  Nº 6  2011  págs. 1032 - 1041
Progress in our understanding of the mechanisms underlying the cardinal motor abnormalities of Parkinson's disease (PD), in particular akinesia and bradykinesia and their treatment, has been remarkable. Notable accomplishments include insights into the functional organization of the basal ganglia and their place in the motor system as components of a family of parallel cortico-subcortical circuits that subserve motor and nonmotor functions and the development of models of the intrinsic organization of the basal ganglia, including delineation of the so-called direct, indirect, and hyperdirect pathways. Studies in primate models of PD have provided insight into the alterations of neuronal activity that are responsible for the motor features of PD, revealing both altered tonic levels of discharge and significant disturbances of the patterns of discharge throughout the motor circuitry and have led to the formulation of circuit models of PD, providing testable hypotheses for research and stimulating the development of new therapies. Most importantly, the discovery that lesions of the subthalamic nucleus, a key node of the indirect pathway, abolish the cardinal features of PD contributed to the renaissance in the use of surgical approaches to treating patients with PD, including ablation and deep brain stimulation.
Autores: Alegre Esteban, Manuel; Guridi Legarra, Jorge; Artieda González-Granda, Julio
Revista: Journal of the Neurological Sciences
ISSN 0022-510X  Vol. 310  Nº 1-2  2011  págs. 194 - 196
Autores: Krack, P; Hariz, M; Baunez, C; et al.
ISSN 0166-2236  Vol. 33  Nº 10  2010  págs. 474 - 484
Autores: Moro, E; Lozano, AM; Pollack, P; et al.
Revista: Movement Disorders
ISSN 0885-3185  Vol. 25  Nº 5  2010  págs. 578 - 586
We report the 5 to 6 year follow-up of a multicenter study of bilateral subthalamic nucleus (STN) and globus pallidus internus (GPi) deep brain stimulation (DBS) in advanced Parkinson's disease (PD) patients. Thirty-five STN patients and 16 GPi patients were assessed at 5 to 6 years after DBS surgery. Primary outcome measure was the stimulation effect on the motor Unified Parkinson's Disease Rating Scale (UPDRS) assessed with a prospective cross-over double-blind assessment without medications (stimulation was randomly switched on or off). Secondary outcomes were motor UPDRS changes with unblinded assessments in off- and on-medication states with and without stimulation, activities of daily living (ADL), anti-PD medications, and dyskinesias. In double-blind assessment, both STN and GPi DBS were significantly effective in improving the motor UPDRS scores (STN, P < 0.0001, 45.4%; GPi, P = 0.008, 20.0%) compared with off-stimulation, regardless of the sequence of stimulation. In open assessment, both STN- and GPi-DBS significantly improved the off-medication motor UPDRS when compared with before surgery (STN, P < 0.001, 50.5%; GPi, P = 0.002, 35.6%). Dyskinesias and ADL were significantly improved in both groups. Anti-PD medications were significantly reduced only in the STN group. Adverse events were more frequent in the STN group. These results confirm the long-term efficacy of STN and GPi DBS in advanced PD. Although the surgical targets were not randomized, there was a trend to a better outcome of motor signs in the STN-DBS patients and fewer adverse events in the GPi-DBS group.
Autores: Guridi Legarra, Jorge
ISSN 1889-8203  Vol. 9  Nº 2  2010  págs. 153 - 161
La neurocirugía funcional se ha revitalizado con el tratamiento quirúrgico de la enfermedad de Parkinson, en la que la estimulación cerebral profunda (deep brain stimulation, DBS) produce un beneficio reversible al neuromodular los circuitos alterados de los ganglios basales. La DBS actualmente se está extendiendo al tratamiento de problemas neuropsiquiátricos como el trastorno obsesivo compulsivo y la depresión mayor.
Autores: Alvarez, M; Macias, R; Pavon, N; et al.
Revista: Journal of Neurology, Neurosurgery and Psychiatry
ISSN 0022-3050  Vol. 80  Nº 9  2010  págs. 979 - 985
BACKGROUND: Stereotactic thermocoagulative lesions of the subthalamic nucleus (STN) have been shown to induce significant motor improvement in patients with Parkinson's disease (PD). PATIENTS AND METHODS: 89 patients with PD were treated with unilateral subthalamotomy. 68 patients were available for evaluations after 12 months, 36 at 24 months and 25 at 36 months. RESULTS: The Unified Parkinson's Disease Rating Scale (UPDRS) motor scores improved significantly contralaterally to the lesion in the "off" and "on" states throughout the follow-up, except for the "on" state at the last evaluation. Axial features and signs ipsilateral to the lesion progressed steadily throughout the study. Levodopa daily doses were significantly reduced by 45%, 36% and 28% at 12, 24 and 36 months post-surgery. 14 patients (15%) developed postoperative hemichorea-ballism which required pallidotomy in eight. These 14 patients had significantly higher dyskinesia scores (levodopa induced) preoperatively than the entire cohort. CONCLUSION: Unilateral subthalamotomy was associated with significant and sustained motor benefit contralateral to the lesio
Autores: Bickel, S; Alvarez, I; Macías, R; et al.
Revista: Parkinsonism & Related Disorders
ISSN 1353-8020  Vol. 16  Nº 8  2010  págs. 535 - 539
Autores: lopez azcarate, Jon; Tainta, Mikel; Rodríguez Oroz, María Cruz; et al.
ISSN 1529-2401  Vol. 30  Nº 19  2010  págs. 6667 - 6677
Autores: Juri, C; Rodríguez Oroz, María Cruz; Burguera, JA; et al.
ISSN 0885-3185  Vol. 25  Nº 1  2010  págs. 130 - 132
Autores: Guridi Legarra, Jorge; Rodríguez Oroz, María Cruz
Libro:  Temblor
2011  págs. 175-199
Autores: Guridi Legarra, Jorge; Aldave Orzaiz, Guillermo
Libro:  Neurocirugía funcional y estereotáctica
2011  págs. 285 - 297
Autores: Guridi Legarra, Jorge; Alvarez, Lazaro; Macias, Raul; et al.
Libro:  Youmans Neurological Surgery
2011  págs. 963 - 967