| 1. |
- Bjartmarz, Hjalmar, et al.
(författare)
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Comparison of accuracy and precision between frame-based and frameless stereotactic navigation for deep brain stimulation electrode implantation
- 2007
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Ingår i: Stereotactic and Functional Neurosurgery. - : S. Karger AG. - 1011-6125 .- 1423-0372. ; 85:5, s. 235-242
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Tidskriftsartikel (refereegranskat)abstract
- The accuracy and precision of frameless neuronavigation as compared to conventional frame-based stereotaxy for implantation of deep brain stimulation (DBS) electrodes were studied in 14 patients with essential tremor. DBS electrodes were implanted bilaterally in the ventrolateral thalamus [ventrointermediate nucleus ( VIM)] in one procedure. Frameless neuronavigation was used on one side and the conventional frame-based technique on the other. Targeting was guided by MRI and CT imaging. Intraoperative stereotactic plain X-ray verified final electrode positions and electrode deviations from the planned target were measured. Clinical outcome was evaluated with the Essential Tremor Rating Scale. Thirteen of the patients were eligible for measuring electrode deviations and 10 of them were available for a clinical follow-up. Electrode deviations from target were larger using the frameless technique in the mediallateral (x: 1.9 +/- 1.3 mm) and anterior- posterior (y: 0.9 +/- 0.8 mm) directions as compared to the frame-based technique (x: 0.5 +/- 0.5 and y: 0.4 +/- 0.4 mm) but similar in the superior- inferior direction (z). The vector of deviation was 2.5 +/- 1.4 mm with the frameless technique and 1.2 +/- 0.6 with the frame-based technique. The differences were statistically significant (p < 0.05-0.001). The dispersion was larger with the frameless technique as represented by the larger standard deviations in all three planes. At clinical follow-ups, tremor reduction was similar irrespective of the implantation technique. It is concluded that conventional frame-based stereotaxy has higher accuracy/precision for hitting a small brain target than the frameless technique. However, the difference is relatively small and does not influence the clinical result of DBS electrode implantations in the VIM when treating tremor. Copyright (c) 2007 S. Karger AG, Basel
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| 2. |
- Brundin, Patrik, et al.
(författare)
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Bilateral caudate and putamen grafts of embryonic mesencephalic tissue treated with lazaroids in Parkinson's disease
- 2000
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Ingår i: Brain. - 1460-2156. ; 123, s. 1380-1390
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Tidskriftsartikel (refereegranskat)abstract
- Five parkinsonian patients were transplanted bilaterally into the putamen and caudate nucleus with human embryonic mesencephalic tissue from between seven and nine donors. To increase graft survival, the lipid peroxidation inhibitor tirilazad mesylate was administered to the tissue before implantation and intravenously to the patients for 3 days thereafter. During the second postoperative year, the mean daily L-dopa dose was reduced by 54% and the UPDRS (Unified Parkinson's Disease Rating Scale) motor score in 'off' phase was reduced by a mean of 40%. At 10-23 months after grafting, PET showed a mean 61% increase of 6-L-[(18)F]fluorodopa uptake in the putamen, and 24% increase in the caudate nucleus, compared with preoperative values. No obvious differences in the pattern of motor recovery were observed between these and other previously studied cases with putamen grafts alone. The amount of mesencephalic tissue implanted in each putamen and caudate nucleus was 42 and 50% lower, respectively, compared with previously transplanted patients from our centre. Despite this reduction in grafted tissue, the magnitudes of symptomatic relief and graft survival were very similar. These findings suggest that tirilazad mesylate may improve survival of grafted dopamine neurons in patients, which is in agreement with observations in experimental animals.
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| 3. |
- Eriksson, Ola, 1967-, et al.
(författare)
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In vitro evaluation of brain lesioning electrodes (Leksell) using a computer-assisted video system
- 1999
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Ingår i: Neurological Research. - 0161-6412 .- 1743-1328. ; 21:1, s. 89-95
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Tidskriftsartikel (refereegranskat)abstract
- Radiofrequency (RF) generated thermal brain lesions are widely used in functional neurosurgery. The size, shape and development of the lesions depends on system parameter settings and the electrode configuration. Difficulties in studying the effect of these factors in vivo stimulated us to develop an in vitro system for standardized comparison between different electrodes and physical parameters. A computer-assisted video system was set-up allowing continuous video recording of RF-generated coagulations in either a standard albumin solution or in the fresh white of a hen's egg as transparent test substrates. Ten lesions were made with each test electrode (two bipolar and three monopolar) in each of the two substrates at 70 degrees, 80 degrees and 90 degrees C (t = 60 sec). Due to the better homogeneity the lesions in the albumin solution were much more regular and reproducible. This made it possible to calculate the size (width 2.2 +/- 0.1 to 5.3 +/- 0.1 mm and length 3.0 +/- 0.1 to 8.7 +/- 0.3 mm) as well as the volume (8.5 +/- 1.4 mm3 to 133.5 +/- 26.8 mm3). It is concluded that this in vitro system offers a reproducible way to study and document the effect of different electrode configurations and RF-generator settings on the formation of a heat lesion. Even if the results are not directly applicable to the living human brain they give an estimate of the form and size of a coagulation lesion and can be of value for standardized comparisons between different electrodes.
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| 4. |
- Fransson, Per-Anders, et al.
(författare)
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Deep Brain Stimulation in the Subthalamic Nuclei Alters Postural Alignment and Adaptation in Parkinson’s Disease
- 2021
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 16:12
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Tidskriftsartikel (refereegranskat)abstract
- Parkinson’s disease (PD) can produce postural abnormalities of the standing body position such as kyphosis. We investigated the effects of PD, deep brain stimulation (DBS) in the subthalamic nucleus (STN), vision and adaptation on body position in a well-defined group of patients with PD in quiet standing and during balance perturbations. Ten patients with PD and 25 young and 17 old control participants were recruited. Body position was measured with 3D motion tracking of the ankle, knee, hip, shoulder and head. By taking the ankle as reference, we mapped the position of the joints during quiet standing and balance perturbations through repeated calf muscle vibration. We did this to explore the effect of PD, DBS in the STN, and vision on the motor learning process of adaptation in response to the repeated stimulus. We found that patients with PD adopt a different body position with DBS ON vs. DBS OFF, to young and old controls, and with eyes open vs. eyes closed. There was an altered body position in PD with greater flexion of the head, shoulder and knee (p≤0.042) and a posterior position of the hip with DBS OFF (p≤0.014). With DBS ON, body position was brought more in line with the position taken by control participants but there was still evidence of greater flexion at the head, shoulder and knee. The amplitude of movement during the vibration period decreased in controls at all measured sites with eyes open and closed (except at the head in old controls with eyes open) showing adaptation which contrasted the weaker adaptive responses in patients with PD. Our findings suggest that alterations of posture and greater forward leaning with repeated calf vibration, are independent from reduced movement amplitude changes. DBS in the STN can significantly improve body position in PD although the effects are not completely reversed. Patients with PD maintain adaptive capabilities by leaning further forward and reducing movement amplitude despite their kyphotic posture.
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| 5. |
- Fransson, Per-Anders, et al.
(författare)
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Deep brain stimulation in the subthalamic nuclei alters postural alignment and adaptation in Parkinson's disease
- 2021
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 16:12
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Tidskriftsartikel (refereegranskat)abstract
- Parkinson's disease (PD) can produce postural abnormalities of the standing body position such as kyphosis. We investigated the effects of PD, deep brain stimulation (DBS) in the subthalamic nucleus (STN), vision and adaptation on body position in a well-defined group of patients with PD in quiet standing and during balance perturbations. Ten patients with PD and 25 young and 17 old control participants were recruited. Body position was measured with 3D motion tracking of the ankle, knee, hip, shoulder and head. By taking the ankle as reference, we mapped the position of the joints during quiet standing and balance perturbations through repeated calf muscle vibration. We did this to explore the effect of PD, DBS in the STN, and vision on the motor learning process of adaptation in response to the repeated stimulus. We found that patients with PD adopt a different body position with DBS ON vs. DBS OFF, to young and old controls, and with eyes open vs. eyes closed. There was an altered body position in PD with greater flexion of the head, shoulder and knee (p≤0.042) and a posterior position of the hip with DBS OFF (p≤0.014). With DBS ON, body position was brought more in line with the position taken by control participants but there was still evidence of greater flexion at the head, shoulder and knee. The amplitude of movement during the vibration period decreased in controls at all measured sites with eyes open and closed (except at the head in old controls with eyes open) showing adaptation which contrasted the weaker adaptive responses in patients with PD. Our findings suggest that alterations of posture and greater forward leaning with repeated calf vibration, are independent from reduced movement amplitude changes. DBS in the STN can significantly improve body position in PD although the effects are not completely reversed. Patients with PD maintain adaptive capabilities by leaning further forward and reducing movement amplitude despite their kyphotic posture.
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| 6. |
- Fransson, Per-Anders, et al.
(författare)
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Exploring the Effects of Deep Brain Stimulation and Vision on Tremor in Parkinson's Disease : Benefits from Objective Methods
- 2020
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Ingår i: Journal of NeuroEngineering and Rehabilitation. - : Springer Science and Business Media LLC. - 1743-0003. ; 17:1
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Tremor is a cardinal symptom of Parkinson's disease (PD) that may cause severe disability. As such, objective methods to determine the exact characteristics of the tremor may improve the evaluation of therapy. This methodology study aims to validate the utility of two objective technical methods of recording Parkinsonian tremor and evaluate their ability to determine the effects of Deep Brain Stimulation (DBS) of the subthalamic nucleus and of vision.METHODS: We studied 10 patients with idiopathic PD, who were responsive to L-Dopa and had more than 1 year use of bilateral subthalamic nucleus stimulation. The patients did not have to display visible tremor to be included in the study. Tremor was recorded with two objective methods, a force platform and a 3 dimensional (3D) motion capture system that tracked movements in four key proximal sections of the body (knee, hip, shoulder and head). They were assessed after an overnight withdrawal of anti-PD medications with DBS ON and OFF and with eyes open and closed during unperturbed and perturbed stance with randomized calf vibration, using a randomized test order design.RESULTS: Tremor was detected with the Unified Parkinson's Disease Rating Scale (UPDRS) in 6 of 10 patients but only distally (hands and feet) with DBS OFF. With the force platform and the 3D motion capture system, tremor was detected in 6 of 10 and 7 of 10 patients respectively, mostly in DBS OFF but also with DBS ON in some patients. The 3D motion capture system revealed that more than one body section was usually affected by tremor and that the tremor amplitude was non-uniform, but the frequency almost identical, across sites. DBS reduced tremor amplitude non-uniformly across the body. Visual input mostly reduced tremor amplitude with DBS ON.CONCLUSIONS: Technical recording methods offer objective and sensitive detection of tremor that provide detailed characteristics such as peak amplitude, frequency and distribution pattern, and thus, provide information that can guide the optimization of treatments. Both methods detected the effects of DBS and visual input but the 3D motion system was more versatile in that it could detail the presence and properties of tremor at individual body sections.
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| 7. |
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| 8. |
- Hagell, Peter, et al.
(författare)
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Dyskinesias following neural transplantation in Parkinson's disease.
- 2002
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Ingår i: Nature Neuroscience. - : Springer Science and Business Media LLC. - 1546-1726 .- 1097-6256. ; 5:7, s. 627-628
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Tidskriftsartikel (refereegranskat)abstract
- Severe dyskinesias during the 'off' phases (periods of increased Parkinson's disease (PD) disability) have been observed following intrastriatal transplantation of human embryonic mesencephalic tissue. Here we retrospectively analyzed 14 patients who were followed for up to 11 years after grafting, and found that dyskinesias (abnormal involuntary movements and postures) increased during postoperative off phases, but were generally of mild to moderate severity. Dyskinesia severity was not related to the magnitude of graft-derived dopaminergic re-innervation, as judged by (18)F-labeled 6-L-fluorodopa (FD) positron emission tomography (PET), indicating that off-phase dyskinesias probably did not result from excessive growth of grafted dopaminergic neurons.
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| 9. |
- Hagell, Peter, et al.
(författare)
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Sequential bilateral transplantation in Parkinson's disease: effects of the second graft
- 1999
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Ingår i: Brain. - : Oxford University Press (OUP). - 1460-2156. ; 122:6, s. 1121-1132
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Tidskriftsartikel (refereegranskat)abstract
- Five parkinsonian patients who had received implants of human embryonic mesencephalic tissue unilaterally in the striatum 10-56 months earlier were grafted with tissue from four to eight donors into the putamen (four patients) or the putamen plus the caudate nucleus (one patient) on the other side, and were followed for 18-24 months. After 12-18 months, PET showed a mean 85% increase in 6-L-[18F]fluorodopa uptake in the putamen with the second graft, whereas there was no significant further change in the previously transplanted putamen. Two patients exhibited marked additional improvements after their second graft: 'on-off' fluctuations virtually disappeared, movement speed increased, and L-dopa could be withdrawn in one patient and reduced by 70% in the other. The improvement in one patient was moderate. Two patients with atypical features, who responded poorly to the first graft, worsened following the second transplantation. These findings indicate that sequential transplantation in patients does not compromise the survival and function of either the first or the second graft. Moreover, putamen grafts that restore fluorodopa uptake to normal levels can give improvements of major therapeutic value.
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| 10. |
- Hariz, Gun-Marie, et al.
(författare)
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Women pioneers in basal ganglia surgery
- 2014
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Ingår i: Parkinsonism & Related Disorders. - : Elsevier BV. - 1873-5126 .- 1353-8020. ; 20:2, s. 137-141
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Forskningsöversikt (refereegranskat)abstract
- Background: Stereotactic functional neurosurgery on basal ganglia has a long history and the pioneers are mostly men. We aimed at finding out if there were women who have contributed pioneering work in this field. Methods: The literature was searched to identify women who have been first to publish innovative papers related to human basal ganglia surgery. Results: Six women fulfilling our criteria were found: Marion Smith, a British neuropathologist, made unique observations on stereotactic lesions of basal ganglia and thalamus on autopsied brains, and the lesions' relation to the reported clinical outcome. Natalia Bechtereva, a Russian neurophysiologist, pioneered the technique of therapeutic chronic deep brain stimulation to treat various brain disorders, including Parkinson's disease (PD). Denise Albe-Fessard, a French neurophysiologist, pioneered the technique of microelectrode recording (MER) in stereotactic functional neurosurgery. Gunvor Kullberg, a Swedish neurosurgeon, contributed in early CT imaging as well as early functional imaging of stereotactic lesions in PD and psychiatric patients. Hilda Molina, a Cuban neurosurgeon, established the Centro Internacional de Restauracion Neurologica (CIREN) and pioneered there MER-guided transplant surgery in PD patients. Veerle Vandewalle, a Belgian neurosurgeon, pioneered in 1999 deep brain stimulation (DBS) for Tourette Syndrome. Conclusion: Although men constitute the great majority of neurosurgeons, neurologists and other neuro-specialists who have made groundbreaking contributions in basal ganglia surgery, there are women who have made equally important and unique contributions to the field. The principal two techniques used today in functional stereotactic neurosurgery, MER and DBS, have once upon a time been pioneered by women. (C) 2013 Elsevier Ltd. All rights reserved.
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