[Stereotactic neurosurgery in Spain].
Explore the source record for details and available documents.
Humans↗
Biomedical subjects
J Guridi
Publications and source records attributed to J Guridi.
[Primary low-grade non-Hodgkin's B lymphoma mimicking meningioma].
Primary dural lymphomas are rare. Usually they present themselves as diffuse lesions and are infrequently well-delimited. We present a 44 year old male, who was admitted into our Centre after a generalised seizure. Neuroimage studies (CT scan, MRI and angiography) were performed, demonstrating a right hemispheric well-delimited extra-axial mass, being diagnosed initially as meningioma. The patient underwent surgery with radical scission of the mass and dural margins. Histopathological diagnosis was Non-Hodgkin B-Cell lymphoma (marginal B-Cell lymphoma), which nowadays is considered as MALT lymphoma (Mucosa Associated Lymphoid Tissue). Studies directed to establish tumour extension didn't demonstrate the existence of another lesions in the organism.
Adult↗
[Discrepancy between imaging and neurophysiology in deep brain stimulation of medial pallidum and subthalamic nucleus in Parkinson's disease].
OBJECTIVE: The objective of this work is to assess the discrepancy in distance between the target chosen by magnetic resonance imaging (MRI) and the final electrode placement after intraoperative microrecording in patients submitted to deep brain stimulation (DBS) for alleviating the Parkinson's disease (PD). METHODS: Thirty patients with PD and motor complications were operated with stereotactic surgery by MRI and microrecording. In 19 patients, the target chosen was the subthalamic nucleus (STN) and in 11 others the target was globus pallidus internus (GPi). In this work it is considered that the electrode has a current field below usual parameters of 1.5 mm radius. Consequently, when the distance error between the final physiological target and the MRI target, is between 1.5 and 3 mm was considered as partial discrepancy and distances of 3 mm or more were considered as total discrepancy. RESULTS: Partial discrepancy for STN and GPi were in 25 and 33% of the cases respectively and total discrepancy was 57 and 42% for each nucleus. The average distance error between both targets, final and image, for X stereotactic coordinate (mediolateral distance) was 1.54 mm for STN and 0.8 mm for GPi. The average distance for Y coordinate (anteroposterior distance) was 2.3 mm for STN and 2.2 mm for GPi. CONCLUSION: There is a significant discrepancy between the final physiological target after microrecording and the target chosen by MRI during surgery for alleviating PD that may induce variations or absence of clinical efficacy in parkinsonian patients submitted to the DBS surgery. Authors suggest the necessity of the microelectrode recording in order to reach the surgical target with the best clinical condition.
Electric Stimulation↗
Lesion of the basal ganglia and surgery for Parkinson disease.
Explore the source record for details and available documents.
Basal Ganglia↗
Dorsal subthalamotomy for Parkinson's disease.
We report our experience of unilateral subthalamotomy in patients with Parkinson's disease (PD). Eleven patients were included in a pilot, open-labeled study to assess the effect of unilateral lesion of the subthalamic nucleus (STN) with a minimum of 12 months of follow-up. The guidelines of CAPIT (Core Assessment Program for Intracerebral Transplantation) were followed for recruitment into the study and follow-up assessment. Levodopa equivalents daily intake (mean 967 mg) were unchanged during the first 12 months in all but one patient who stopped medication. The sensorimotor region of the STN was defined by semimicrorecording and stimulation and a thermolytic lesion was placed accordingly. There was a significant reduction in both UPDRS parts II and III in the "off" state at 1-, 6-, and 12-month follow-up. This effect was maintained in four patients up to 24 months. The dyskinesia score did not change postoperatively. Lesion-induced dyskinesias were not a management problem except in one patient who developed a large infarction several days postsurgery. This initial study indicates that a lesion of the STN is not generally associated with hemiballismus in PD. Subthalamotomy may induce considerable motor benefit and could become another surgical option under specific circumstances.
Aged↗
The subthalamic nucleus, hemiballismus and Parkinson's disease: reappraisal of a neurosurgical dogma.
The subthalamic nucleus (STN) currently is considered to play a key role in the pathophysiological origin of the parkinsonian state and is therefore the main target for surgical treatment of Parkinson's disease. The authors review the incidence of hemichorea/ballism (HCB) as a complication of thalamotomy, pallidotomy or campotomy procedures before the introduction of levodopa therapy, including the few reported cases accompanied by a neuropathological study. The literature shows that only a small number of parkinsonian patients with HCB had a lesion of the STN. Preliminary data in Parkinson's disease patients submitted to a subthalamotomy with current functional stereotaxy also indicate that HCB is a very rare complication. To explain this observation, we suggest that the parkinsonian state is characterized by an increased threshold for the induction of dyskinesia following STN lesioning. This arises as a consequence of reduced activity in the 'direct' GABA projection to the globus pallidus medialis (GPm) which accompanies dopamine depletion. Lesioning of the STN reduces excitation of the GPm, and theoretically this should induce dyskinesias. However, an STN lesion also, simultaneously, further reduces the hypoactivity in the globus pallidus lateralis (GPl) that is a feature of Parkinson's disease, and hence may compensate for GPm hypoactivity, thus self-stabilizing basal ganglia output activity and reducing the risk of HCB. We conclude that lesioning of the STN in Parkinson's disease is a feasible approach in some circumstances.
Adult↗
The subthalamic nucleus in Parkinson's disease: somatotopic organization and physiological characteristics.
Single-cell recording of the subthalamic nucleus (STN) was undertaken in 14 patients with Parkinson's disease submitted to surgery. Three hundred and fifty neurones were recorded and assessed for their response to passive and active movements. Thirty-two per cent were activated by passive and active movement of the limbs, oromandibular region and abdominal wall. All neurones with sensorimotor responses were in the dorsolateral region of the STN. Arm-related neurones were lateral (> or =14 mm plane) to leg-related neurones, which were found more medially (< or =12 mm). Representation of the oromandibular musculature was in the middle of the sensorimotor region (approximately 13 mm plane) and ventral to the arm and leg. Two hundred neurones were adequately isolated for 'off-line' analysis. The mean frequency of discharge was 33 +/- 17 Hz (13-117 Hz). Three types of neuronal discharges were distinguished: irregular (60.5%), tonic (24%) and oscillatory (15.5 %). They were statistically differentiated on the basis of their mean firing frequency and the coefficient of variation of the interspike interval. Neurones responding to movement were of the irregular or tonic type, and were found in the dorsolateral region of the STN. Neurones with oscillatory and low frequency activity did not respond to movement and were in the ventral one-third of the nucleus. Thirty-eight tremor-related neurones were recorded. The majority (84%) of these were sensitive to movement and were located in the dorsolateral region of the STN. Cross power analysis (n = 16) between the rhythmic neuronal activity and tremor in the limbs showed a peak frequency of 5 Hz (4-8 Hz). Neuronal activity of the substantia nigra pars reticulata was recorded 0.5-3 mm below the STN. Eighty neurones were recorded 'on-line' and 27 were isolated for 'off-line' analysis. A tonic pattern of discharge characterized by a mean firing rate of 71 +/- 28 Hz (35-122 Hz) with a mean coefficient of variation of the interspike interval of 0.85 +/- 0.29 ms was found. In only three neurones (11%) was there a response to sensorimotor stimulation. The findings of this study indicate that the somatotopic arrangement and electrophysiological features of the STN in Parkinson's disease patients are similar to those found in monkeys.
Action Potentials↗
Efficacy of levodopa therapy on motor function after posteroventral pallidotomy for Parkinson's disease.
Explore the source record for details and available documents.
Antiparkinson Agents↗
High frequency stimulation of the subthalamic nucleus and levodopa induced dyskinesias in Parkinson's disease.
Explore the source record for details and available documents.
Dyskinesia, Drug-Induced↗
Excitotoxic ablation.
Explore the source record for details and available documents.
1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
Targeting the basal ganglia for deep brain stimulation in Parkinson's disease.
The revitalization of surgery for Parkinson's disease (PD) has fueled discussion about the best methodology to define the target. Placement of electrodes for deep brain stimulation (DBS) requires the usual stereotactic technique but the argument is mainly centered on whether or not microrecording neuronal activity is necessary. We compared the accuracy of calculating the coordinates X (medio-lateral) and Y (rostro-caudal) considered by the classic stereotactic method, i.e., definition of the AC-PC intercomissural line by MRI and a digitized version of the Schaltenbrand's atlas, with final electrode placement according with microrecording and microstimulation in 21 patients. For both the globus pallidum internum (GPi) (n = 21) and the subthalamic nucleus (STN) (n = 36) there was, respectively, a 43% and 45% mismatching of more than 3 mm between the theoretic coordinates and the final site of electrode location. This applies to both the X and Y planes. Accuracy was not improved in patients (n = 11) in whom the bilateral procedure was undertaken in a single day. We conclude that proper electrode positioning of the STN and GPi requires fine electrophysiologic assessment.
Adult↗
Deep brain stimulation of the globus pallidus pars interna in advanced Parkinson's disease.
Pallidotomy is now widely performed for the treatment of advanced Parkinson's disease (PD). Preliminary reports of the effect of globus pallidus pars interna deep brain stimulation (GPi DBS) have also been promising. We have analyzed a cohort of 22 consecutive patients enrolled in a multicenter study. Surgery was bilateral in 17 and unilateral in five patients. At 6-month follow-up, the bilaterally GPi-implanted patients demonstrated a marked improvement when examined after drug withdrawal ("off") and under optimal medication ("on") using the Unified Parkinson's Disease Rating Scale (UPDRS). The benefit induced by the stimulation in the "off" medication condition in the total motor score was 31% and in the activities of daily living (ADL) scores was 39%. During the "on" medication period, the reduction in the total "on" dyskinesias score was 66% and in the ADL score was 32%. A similar pattern of improvement was seen in the group of patients with unilateral GPi stimulation, although a second cohort of 12 patients not included in the multicenter study showed greater improvements in "on" motor functioning. Although the effect of DBS is predominantly reversible, electrode insertion alone resulted in measurable clinical effects in the absence of stimulation. Thus, at 6-month follow-up, the benefit observed without stimulation was up to 44% in the "on" dyskinesias score and 29% in timed tapping scores undertaken in the "off" medication state. Complications among 34 patients from all centers included perioperative infection (n=3), hardware fracture (n=2), and premature battery failure (n=3). These results show a positive antiparkinsonian effect of pallidal DBS. No specific complications were observed with bilateral procedures.
Adult↗
Bilateral deep brain stimulation of the subthalamic nucleus in Parkinson's disease.
Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is rapidly becoming the preferred surgical choice for the treatment of advanced Parkinson's disease (PD). We report initial results in 15 patients after 12 months and in nine patients evaluated between 30 and 36 months postoperatively. Our experience confirms the robust antiparkinsonian effect of DBS of the STN in advanced PD. The severity of "off" episodes, as assessed by the Unified Parkinson Disease Rating Scale (UPDRS), was drastically reduced by 74% at 12 months, and dyskinesia scores (Dyskinesia Rating Scale) decreased. The levodopa daily dose was reduced by 55% at 12 months. A double-blind assessment to determine the effect of stimulation performed in nine patients at 3 months in the "off" medication condition was very significant (p<0.05). Nine patients have been followed for 3 years with maintained efficacy in the UPDRS "off" score and the dyskinesia score. The experience of other groups using a similar technique is reviewed. The overall assessment indicates a high antiparkinsonian effect of DBS of the STN even in advanced patients. The existence of a learning curve for this procedure should be taken into account when initial results are evaluated.
Electric Stimulation Therapy↗
Pathophysiologic basis of surgery for Parkinson's disease.
Dopamine depletion induces a series of changes in the basal ganglia motor circuit that underlie the origin of the cardinal features of Parkinson's disease. It has now been established that hyperactivity of the subthalamic nucleus (STN) is an essential feature of the parkinsonian state. This leads to increased excitatory driving onto the globus pallidum internum (GPi) and substantia nigra reticulata (SNr) which, in turn, overinhibits the motor projections to the thalamus and brainstem. The STN and GPi have become the preferred targets for surgery to treat PD. In keeping with the classic pathophysiologic model, physiologic and neuroimaging studies in patients have shown that lesioning or functional blockades (by deep brain stimulation, or DBS) of these nuclei increased cortical activation, in parallel with clinical improvements of bradykinesia. Neuronal recording during surgery has also shown tremor-related activity in both the STN and GPi. However, the pathophysiologic model of the basal ganglia needs further refinement to provide a more detailed explanation of the origin of both tremor and rigidity in Parkinson's disease and to explain the antidyskinetic effect of surgery of the GPi and STN.
Basal Ganglia↗
Stereotactic targeting of the globus pallidus internus in Parkinson's disease: imaging versus electrophysiological mapping.
OBJECTIVE: The reintroduction of pallidotomy for the treatment of Parkinson's disease (PD) has generated various opinions regarding the ideal anatomic or physiological location of the target within the globus pallidus. The role of microelectrode recording guidance in pallidotomy for the treatment of advanced PD is presently under debate. The purpose of this study was twofold. The first goal was to determine the degree of accuracy in the targeting of the globus pallidus internus (GPi) with magnetic resonance imaging (MRI), by comparing these results with the final placement of the thermolytic lesions (as defined by electrophysiological assessment). The second goal was to ascertain the somatotopic arrangement of the GPi in PD. METHODS: The analysis involved 50 patients with PD who underwent microrecording-guided pallidotomy. The theoretical coordinates for lesioning were calculated after definition of the intercommissural line by MRI. The actual placement of the lesions was determined after mapping of the GPi by microrecording, using stimulation to identify the sensorimotor region and its somatotopic organization. RESULTS: In most cases, the lesions were placed posterior and lateral to the targets chosen by MRI. Mapping by microrecording revealed differences of 2.3 +/- 1.55 mm and 3 +/- 1.9 mm in the mediolateral and anteroposterior coordinates, respectively. The actual lesion overlapped the theoretical target for only 45% of the patients. The somatotopic organization of the GPi was analyzed. Most of the units with sensorimotor activity or tremor-related activity were in the lateral portion of the nucleus. Upper limb and axial units were in the most lateral region and mainly in the ventral one-third of the nucleus. Lower limb responses were recorded mainly in the dorsal one-third of the nucleus. Tremor-related cells were found throughout the sensorimotor region of the nucleus. CONCLUSION: These results indicate that lesion targeting based on MRI alone is not sufficiently accurate to guarantee placement of the lesion in the sensorimotor region of the GPi.
Adult↗
[Pallidotomy in the treatment of complicated Parkinson's disease: clinical results at two years and analysis of prognostic factors].
BACKGROUND: There is a renewed interest in pallidotomy as a treatment for complicated Parkinson's disease (PD). AIM: To present the clinical results as well as the analysis of prognostic factors obtained in 28 patients with PD and motor complications submitted to pallidotomy and followed by one year (n = 28) and 2 years (n = 12). RESULTS: The total motor score (Unified Parkinson's Disease Rating Scale [UPDRS]) in the off state improved by 33 and 23% at one and two years, respectively (p < 0.01). All the cardinal signs of the disease were significantly improved (p < 0.01): tremor (92%), rigidity (67%), bradykinesia (46%) and axial symptoms (21%). A slight tendency to worsening in axial symptoms was observed. Dyskinesias disappeared in all but one patient. The Schawb & England Scale in off was improved by 21%. No improvement in the non-operated side was observed. The subgroup of patients with an improvement of less than 30% in the UPDRS was older than the one with larger clinical benefit. The observed tendency to worsening in the total motor score was related mainly to the progression of the symptoms in the non-operated side. Complications were mild and transient. CONCLUSIONS: Pallidotomy is a relatively safe and effective therapeutic option for complicated PD patients. An adequate selection of patients is necessary, since efficacy is partial and limited to one hemibody.
Adult↗
[Pathophysiological bases, clinical results and indications for surgical treatment in Parkinson disease].
We review the present status of surgery for Parkinson's disease. Surgical options for Parkinson's disease are rapidly spanding. The main objectives of surgical techniques are to restore the dopaminergic deficit in the striatum (transplantation) and to normalize the neuronal activity of the subthalamic-pallidal circuit (pallidotomy and deep brain stimulation). Whereas cell transplantation is still considered an experimental procedure, ablative procedures and deep brain stimulation are widely used. Both types of surgical procedures are supported by strong scientific data. However, much work remains to be done in order to understand several aspects not clearly elucidated at present. The results and current indications for pallidotomy and deep brain stimulation are analyzed.
Brain↗