Neurostimulation for Parkinson's disease with early motor complications.

BACKGROUND: Subthalamic stimulation reduces motor disability and improves quality of life in patients with advanced Parkinson's disease who have severe levodopa-induced motor complications. We hypothesized that neurostimulation would be beneficial at an earlier stage of Parkinson's disease. METHODS: In this 2-year trial, we randomly assigned 251 patients with Parkinson's disease and early motor complications (mean age, 52 years; mean duration of disease, 7.5 years) to undergo neurostimulation plus medical therapy or medical therapy alone. The primary end point was quality of life, as assessed with the use of the Parkinson's Disease Questionnaire (PDQ-39) summary index (with scores ranging from 0 to 100 and higher scores indicating worse function). Major secondary outcomes included parkinsonian motor disability, activities of daily living, levodopa-induced motor complications (as assessed with the use of the Unified Parkinson's Disease Rating Scale, parts III, II, and IV, respectively), and time with good mobility and no dyskinesia. RESULTS: For the primary outcome of quality of life, the mean score for the neurostimulation group improved by 7.8 points, and that for the medical-therapy group worsened by 0.2 points (between-group difference in mean change from baseline to 2 years, 8.0 points; P=0.002). Neurostimulation was superior to medical therapy with respect to motor disability (P<0.001), activities of daily living (P<0.001), levodopa-induced motor complications (P<0.001), and time with good mobility and no dyskinesia (P=0.01). Serious adverse events occurred in 54.8% of the patients in the neurostimulation group and in 44.1% of those in the medical-therapy group. Serious adverse events related to surgical implantation or the neurostimulation device occurred in 17.7% of patients. An expert panel confirmed that medical therapy was consistent with practice guidelines for 96.8% of the patients in the neurostimulation group and for 94.5% of those in the medical-therapy group. CONCLUSIONS: Subthalamic stimulation was superior to medical therapy in patients with Parkinson's disease and early motor complications. (Funded by the German Ministry of Research and others; EARLYSTIM ClinicalTrials.gov number, NCT00354133.).

Quadruple deep brain stimulation in Huntington's disease, targeting pallidum and subthalamic nucleus: case report and review of the literature.

Deep brain stimulation (DBS) represents an established treatment option in a growing number of movement disorders. Recent case reports suggest beneficial effect of globus pallidus internus (GPi)-DBS in selected patients suffering from Huntington's disease with marked disabling chorea. We present a 41-year-old man with genetically confirmed HD following quadruple GPi- and subthalamic nucleus (STN)-DBS. Motor function was assessed by Abnormal Involuntary Movement Scale (AIMS) and by Unified Huntington Disease Rating Scale (UHDRS) presurgery and postsurgery for up to 4 years. Furthermore, cognitive, neuropsychiatric state and quality of life (QoL) including life satisfaction (QLS) were annually evaluated. Chorea assessed by AIMS and UHDRS subscores improved by 52 and 55 %, 45 and 60 %, 35 and 45 % and 55-66 % at 1-4 years, respectively, compared to presurgical state following GPi-STN-DBS. During these time periods bradykinesia did not increase following separate STN- and combined GPi-STN-DBS compared to presurgical state. Mood, QoL and QLS were ameliorated. However, dysexecutive symptoms increased at 4 years postsurgery. The present case report suggests that bilateral GPi- and STN-DBS may represent a new treatment avenue in selected HD patients. Clinically, GPi-DBS attenuated chorea and was associated with a larger effect-adverse effect window compared to STN-DBS. However, GPi-DBS-induced bradykinesia may emerge as one main limitation of GPi-DBS in HD. Thus, quadruple GPi-STN-DBS may be indicated, if separate GPi-DBS does not result in sufficient control of motor symptoms. Future controlled studies need to confirm if the present anecdotal observation of additive beneficial effects of GPi- and STN-DBS in a HD patient with severe generalized chorea and relatively intact cognitive and affective functions indeed represents a new therapeutic option.

The dystonia discomfort scale (DDS): a novel instrument to monitor the temporal profile of botulinum toxin therapy in cervical dystonia.

BACKGROUND AND PURPOSE: Conventional scales measure the effect of botulinum toxin (BT) therapy only at specific points in time. The Dystonia Discomfort Scale (DDS), a novel, easy-to-use, self-assessment scale to record temporal profiles of the effect of BT therapy in cervical dystonia (CD), is introduced and evaluated against the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS). METHODS: Seventy-six patients with CD (age 54.4 ± 10.9 years, 34% male) receiving ≤5 cycles of incobotulinumtoxinA (Xeomin); Merz Pharmaceuticals, Frankfurt am Main, Germany) injections at intervals ≥10 weeks used DDS to record the severity of their symptoms daily. DDS data were compared with TWSTRS-Total scores and patients' subjective estimation (SE) of the onset (TO) and waning (TW) of the treatment effect. RESULTS: The Toronto Western Spasmodic Torticollis Rating Scale - Total scores correlated significantly with DDS (P ≤ 0.028 at all visits evaluated). TO-DDS and TO-SE were 7.9 ± 8.6 and 7.1 ± 4.1 days, respectively; TW-DDS and TW-SE were 41.8 ± 19.2 and 45.1 ± 21.5 days, respectively. CONCLUSION: The Dystonia Discomfort Scale is a novel, easy-to-use, self-assessment scale for valid and sensitive monitoring of the temporal profile of the effect of BT therapy in patients with CD. DDS provides important additional information about onset, duration, waning, stability and reproducibility of the effects of BT therapy.

Midbrain serotonin transporters in de novo and L-DOPA-treated patients with early Parkinson's disease--a [123 I]-ADAM SPECT study.

BACKGROUND: Dopaminergic availability is known to linearly decline in Parkinson's disease (PD). In contrast, temporal characteristics of serotonergic markers like the serotonin transporter (SERT) in relation to clinical staging of PD and dopaminergic cell loss are less clear. This study investigated SERT availability using [(123) I]-ADAM and single-photon emission tomography (SPECT) in drug-naive, de novo patients, i.e., in a PD stage where dopaminergic decline starts to lead to the occurrence of the characteristic motor symptoms. METHODS: Nine de novo patients with PD and 9 age-matched healthy controls were studied. Measurements were repeated after 3 months of levodopa treatment in patients with PD, and dopaminergic transporter (DAT) binding was examined at baseline using [(123) I]-FP-CIT SPECT. RESULTS: No alterations of SERT availability were found between groups, and neither correlation between SERT and DAT nor effects of levodopa treatment on SERT was found in patients with PD. CONCLUSIONS: These preliminary findings indicate that midbrain SERT is preserved in unmedicated patients at this early stage of PD, supporting the view that serotonergic decline temporally follows dopaminergic cell loss.

[Botulinum toxin in the treatment of adult spasticity. An interdisciplinary German 10-point consensus 2010]. / Botulinum-Neurotoxin in der Behandlung der Spastizität im Erwachsenenalter. Ein interdisziplinärer deutscher 10-Punkte-Konsensus 2010.

Spasticity is one of the major causes of functional impairment in adults with lesions of the central nervous system. For instance, approximately 30% of post-stroke patients suffer from different degrees of spasticity with possible consecutive impairments. Numerous studies or meta-analyses showed that local injections of botulinum toxin in spastic muscles lead to dose-dependent reduction in muscle tone and improvement of passive movements (e. g. facilitated care), especially following repeated injections.However, country-specific regulations and patient-remote administration in German health care often do not allow adequate provision of this therapy. Thus, the present consensus statement based on the EBM analyses of the published international literature tries to highlight recent advances and the standard in the field of local spasticity treatment, aiming to facilitate communication between the decision makers and German reimbursement institutions in health care. Prior to initiation of BoNT-A injections, patient-oriented goals should be identified in a multiprofessional context to assure realistic goals for this specific treatment and patient expectations. In Germany for the treatment of focal spasticity following stroke three products have been approved: Botox® (Pharm Allergan, Ettlingen), Dysport® (Ipsen Pharma, Ettlingen) and Xeomin® (Merz Pharma, Frankfurt/Main). For all preparations safety has been repeatedly shown. Functional improvements have also been illustrated for selected patients concerning hand/arm function and gait. The dose per muscle and the selection of muscles to be injected have to be individualized according to the patient's symptoms and should be accompanied by modern neurorehabilitative therapies such as redression or repetitive activation of the injected and antagonistic muscles.

[Deep brain stimulation for neurological and psychiatric diseases: animal experiments on effect and mechanisms]. / Tiefe Hirnstimulation bei neurologischen und psychiatrischen Erkrankungen: Tierexperimentelle Untersuchungen zu Wirkung und Wirkmechanismen.

Deep brain stimulation at high frequencies has emerged as a powerful therapeutic strategy in the treatment of basal ganglia-related movement disorders. Attempts have also been made to establish this for the treatment of therapy-resistant psychiatric disorders. To date the mechanisms underlying the clinical efficacy of high frequency stimulation remain largely unknown. Their detailed description, however, is essential for promoting the extended application of high frequency stimulation as a therapeutic alternative and may simultaneously allow conclusions to be drawn on the pathophysiological mechanisms underlying the diseases benefiting from deep brain stimulation. This review demonstrates how animal models contribute to i) further understand the mechanisms underlying deep brain stimulation at high frequencies and ii) promote the establishment of high frequency stimulation for the treatment of therapy-resistant psychiatric disorders.

Long-term effects of bilateral pallidal deep brain stimulation in dystonia: a follow-up between 8 and 16 years.

OBJECTIVE: Observational study to evaluate the long-term motor and non-motor effects of deep brain stimulation (DBS) of the globus pallidus internus (GPi) on medically refractory dystonia. BACKGROUND: Dystonia is a chronic disease affecting mainly young patients with a regular life expectancy and lifelong need for therapy. Pallidal DBS is an established treatment for severe isolated dystonia but long-term data are sparse. METHODS: We considered 36 consecutive patients with isolated generalized (n = 14) and cervical/segmental (n = 22) dystonia operated at Charité-University Hospital between 2000 and 2007 in a retrospective analysis for long-term outcome of pallidal DBS. In 19 of these patients, we could analyze dystonic symptoms and disability rated by the Burke-Fahn-Marsden Dystonia Rating scale (BFMDRS) at baseline, short-term (ST-FU, range 3-36 months) and long-term follow-up (LT-FU, range 93-197 months). Quality of life and mood were evaluated using the SF36 and Beck Depression Index (BDI) questionnaires. RESULTS: Patients reached an improvement in motor symptoms of 63.8 ± 5.7% (mean ± SE) at ST-FU and 67.9 ± 6.1% at LT-FU. Moreover, a significant and stable reduction in disability was shown following DBS (54.2 ± 9.4% at ST-FU and 53.8 ± 9.2% at LT-FU). BDI and SF36 had improved by 40% and 23%, respectively, at LT-FU (n = 14). Stimulation-induced adverse events included swallowing difficulties, dysarthria, and bradykinesia. Pulse generator (n = 3) and electrodes (n = 5) were revised in seven patients due to infection. CONCLUSIONS: Pallidal DBS is a safe and efficacious long-term treatment for dystonia with sustained effects on motor impairment and disability, accompanied by a robust improvement in mood and quality of life.

Functional connectivity between motor cortex and globus pallidus in human non-REM sleep.

Recent evidence suggests that the motor system undergoes very specific modulation in its functional state during the different sleep stages. Here we test the hypothesis that changes in the functional organization of the motor system involve both cortical and subcortical levels and that these distributed changes are interrelated in defined frequency bands. To this end we evaluated functional connectivity between motor and non-motor cortical sites (fronto-central, parieto-occipital) and the globus pallidus (GP) in human non-REM sleep in seven patients undergoing deep brain stimulation (DBS) for dystonia using a variety of spectral measures (power, coherence, partial coherence and directed transfer function (DTF)). We found significant coherence between GP and fronto-central cortex as well as between GP and parieto-occipital cortex in circumscribed frequency bands that correlated with sleep specific oscillations in 'light sleep' (N2) and 'slow-wave sleep' (N3). These sleep specific oscillations were also reflected in significant coherence between the two cortical sites corroborating previous studies. Importantly, we found two different physiological activities represented within the broad band of significant coherence between 9.5 and 17 Hz. One component occurred in the frequency range of sleep spindles (12.5-17 Hz) and was maximal in the coherence between fronto-central and parieto-occipital cortex as well as between GP and both cortical sites during N2. This component was still present between fronto-central and parieto-occipital cortex in N3. Functional connectivity in this frequency band may be due to a common input to both GP and cortex. The second component consisted of a spectral peak over 9.5-12.5 Hz. Coherence was elevated in this band for all topographical constellations in both N2 and N3, but especially between GP and fronto-central cortex. The DTF suggested that the 9.5-12.5 Hz activity consisted of a preferential drive from GP to the fronto-central cortex in N2, whereas in N3 the DTF between GP and fronto-central cortex was symmetrical. Partial coherence supported distinctive patterns for the 9.5-12.5 and 12.5 and 17 Hz component, so that only coherence in the 9.5-12.5 Hz band was reduced when the effects of GP were removed from the coherence between the two cortical sites. The data suggest that activities in the GP and fronto-central cortex are functionally connected over 9.5-12.5 Hz, possibly as a specific signature of the motor system in human non-REM sleep. This finding is pertinent to the longstanding debate about the nature of alpha-delta sleep as a physiological or pathological feature of non-REM sleep.

[Deep brain stimulation for Parkinson's disease. Consensus recommendations of the German Deep Brain Stimulation Association]. / Tiefe Hirnstimulation bei idiopathischem Parkinson-Syndrom. Empfehlungen der Deutschen Arbeitsgemeinschaft Tiefe Hirnstimulation.

Deep brain stimulation (DBS) has been shown to be effective for levodopa-responsive symptoms and tremor in Parkinson's disease (PD). The subthalamic nucleus (STN) is the preferred target for most patients suffering from late stage motor complications of the disorder. STN DBS is superior to best medical treatment concerning the control of motor fluctuations and the increase of on-time without dyskinesias. In contrast to DBS of the internal pallidum (GPi), STN stimulation also permits a reduction of the dopaminergic medication. Long-term data demonstrated sustained effectiveness of STN DBS despite progressive disease. DBS of the thalamic ventral intermediate nucleus (VIM) is an alternative target in older PD patients with severe PD tremor refractory to medication. In order to minimize potential risks and side effects, the use of DBS needs careful adherence to inclusion and exclusion criteria for eligible PD patients. This paper summarizes the current consensus recommendations of the German Deep Brain Stimulation Association for DBS in PD.

[Deep brain stimulation for essential tremor. Consensus recommendations of the German Deep Brain Stimulation Association]. / Tiefe Hirnstimulation bei essenziellem Tremor. Empfehlungen der Deutschen Arbeitsgemeinschaft Tiefe Hirnstimulation.

In Germany, deep brain stimulation (DBS) of the thalamic ventralis intermedius nucleus (VIM) is licensed for treatment of essential tremor in cases unresponsive to pharmacotherapy. Especially a bothersome hand tremor interfering with activities of daily living will improve, whereas head, tongue or vocal tremor shows less response. DBS was proven to be superior to lesional thalamotomy with better functional outcome and less adverse effects. The consensus statement presented here reflects the current recommendations of the German Deep Brain Stimulation Study Group for inclusion and exclusion criteria as well as for peri-, intra- and postoperative neurological management.

[Deep brain stimulation for dystonia. Consensus recommendations of the German Deep Brain Stimulation Association]. / Tiefe Hirnstimulation bei Dystonie. Empfehlungen der Deutschen Arbeitsgemeinschaft Tiefe Hirnstimulation.

Medical treatment of dystonia, particularly generalised forms of the disorder, is often not satisfactory or causes intolerable side effects. In focal dystonia, a reasonable treatment option with botulinum toxin exists but some patients either do not respond well or develop neutralising antibodies with secondary therapy failure. Deep brain stimulation (DBS) of the globus pallidus internus has been shown to be effective in both generalised and focal dystonia. This paper gives recommendations regarding the use of DBS in different forms of dystonia based on the currently available scientific data as well as the longstanding personal experience of the authors. The inclusion criteria for DBS candidates as well as the peri- and postoperative patient management are addressed. These recommendations were developed in a consensus procedure in the German Deep Brain Stimulation Association.

[Deep brain stimulation for tremor in multiple sclerosis : consensus recommendations of the German Deep Brain Stimulation Association]. / Tiefe Hirnstimulation bei Multiple-Sklerose-Tremor : Empfehlungen der Arbeitsgemeinschaft Tiefe Hirnstimulation.

Deep brain stimulation (DBS) in the nucleus ventralis intermedius thalami (VIM) is a common procedure to treat disabling tremor in multiple sclerosis which is refractory to pharmacological treatment. The sparse studies on DBS in multiple sclerosis tremor remain controversial regarding the clinical effect on postural and action tremor of hands, trunk and head. Furthermore, it remains unclear whether DBS in multiple sclerosis tremor is superior to thalamotomy and whether patients show an overall improvement in quality of life and activities of daily living. Therefore, the consensus recommendations of the German Deep Brain Stimulation Study Group rely primarily on expert opinion and include (1) extensive preoperative characterisation of tremor, ataxia with accompanying disabilities, status of the multiple sclerosis, co-morbidities and burden of disease, (2) careful intraoperative testing of effects and side effects and (3) intensive postoperative testing and programming as well as regular re-evaluation of the therapeutic effect.

Myoclonus-dystonia: significance of large SGCE deletions.

Myoclonus-dystonia (M-D) is an autosomal-dominant movement disorder caused by mutations in SGCE. We investigated the frequency and type of SGCE mutations with emphasis on gene dosage alterations and explored the associated phenotypes. We tested 35 M-D index patients by multiplex ligation-dependent probe amplification (MLPA) and genomic sequencing. Mutations were found in 26% (9/35) of the cases, all but three with definite M-D. Two heterozygous deletions of the entire SGCE gene and flanking DNA and a heterozygous deletion of exon 2 only were detected, accounting for 33% (3/9) of the mutations found. Both large deletions contained COL1A2 and were additionally associated with joint problems. Further, we discovered one novel small deletion (c.771_772delAT, p.C258X) and four recurrent point mutations (c.289C>T, p.R97X; c.304C>T, p.R102X; c.709C>T, p.R237X; c.1114C>T, p.R372X). A Medline search identified 22 articles on SGCE mutational screening. Sixty-four unrelated M-D patients were described with 41 different mutations. No genotype-phenotype association was found, except in patients with deletions encompassing additional genes. In conclusion, a rigorous clinical preselection of patients and careful accounting for non-motor signs should precede mutational tests. Gene dosage studies should be included in routine SGCE genetic testing.

Movement-related synchronization of gamma activity is lateralized in patients with dystonia.

There is evidence for synchronization at frequencies both under 30 Hz and over 60-80 Hz in the so-called gamma frequency band in patients with Parkinson's disease (PD). Gamma activity increases after dopaminergic therapy and during voluntary movement, suggesting that it might be physiological and relate to motor processing in the basal ganglia (BG). We recorded local field potential (LFP) activity during a choice reaction time task in 11 patients with dystonia undergoing implantation of the internal globus pallidus for therapeutic stimulation. The spectral content of the LFP was averaged with respect to movement onset over 6-11 Hz, 18-25 Hz and 60-80 Hz, separately for responses ipsilateral and contralateral to movement. There was a perimovement increase in 60-80 Hz activity in the LFP, but only contralateral to movement. In contrast, low-frequency LFP activity decreased symmetrically during movement. This occurred earlier in the 18-25 Hz band than in the 6-11 Hz band, and was followed by a postmovement increase in oscillatory activity in the 18-25 Hz band that was contralateral to movement. The presence of a lateralized movement-related increase in gamma activity in the BG of patients with dystonia, similar to that recorded in patients with treated PD, suggests that this may be a residual feature of normal BG function. Moreover, the results provide further support for functional distinctions between BG oscillatory activities of different frequency.

Anticipatory activity in the human thalamus is predictive of reaction times.

Responding to environmental stimuli in a fast manner is a fundamental behavioral capacity. The pace at which one responds is known to be predetermined by cortical areas, but it remains to be shown if subcortical structures also take part in defining motor swiftness. As the thalamus has previously been implicated in behavioral control, we tested if neuronal activity at this level could also predict the reaction time of upcoming movements. To this end we simultaneously recorded electrical brain activity from the scalp and the ventral intermediate nucleus (VIM) of the thalamus in patients undergoing thalamic deep brain stimulation. Based on trial-to-trial analysis of a Go/NoGo task, we demonstrate that both cortical and thalamic neuronal activity prior to the delivery of upcoming Go stimulus correlates with the reaction time. This result goes beyond the demonstration of thalamic activity being associated with but potentially staying invariant to motor performance. In contrast, it indicates that the latencies at which we respond to environmental stimuli are not exclusively related to cortical pre-movement states but are also correlated with anticipatory thalamic activity.

["Asleep-awake-asleep"-anaesthetic technique for awake craniotomy]. / "Schlaf-Wach-Schlaf"-Technik zur CS Wachkraniotomie.

Awake craniotomy in tumor and epilepsy surgery or for the implantation of electrodes for deep brain stimulation requires specific anesthesiological strategies. Propofol allows for quick emergence and has little effect on the respiratory function of the usually spontaneously breathing patient. Pain control may be instituted by hemiscalp block for trepanation or local infiltration for deep brain electrode implantation. In addition, low dose remifentanil is recommended for trepanation (i.e. tumor or epilepsy surgery). The airway may be secured by an ordinary Magill tube placed transnasally with its tip underneath the epiglottis. To protect the patient against vomiting an adequate antiemetic prophylaxis is required.

Long-term results of deep brain stimulation in a cohort of eight children with isolated dystonia.

Pallidal deep brain stimulation (DBS) is an established treatment for patients with severe isolated dystonia. However, clinical evidence for the long-term use of DBS in children is limited and controlled trials have not yet been conducted. Here, we provide the long-term results of up to 13 years of pallidal DBS in eight pediatric patients with generalized idiopathic or hereditary isolated dystonia (five males, mean age at surgery 12.5 ± 3.5 years), as assessed by retrospective video rating. Video rating was performed at three time points: pre-operative, 1-year short-term follow-up (1y-FU) and long-term last FU (LT-FU, up to 13 years). Symptom severity and disability were assessed using the Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS). Disability scores were obtained from clinical charts and during the last FU. The mean improvement in BFMDRS motor score was 54.4 ± 8.9 % at 1y-FU and 42.9 ± 11.6 % at LT-FU; the disability scores improved by 59.8 ± 10.3 and 63.3 ± 7.8 %, respectively. Electrode dislocation was noted in one patient and implantable pulse generator dislocation in another, both requiring surgical intervention; no further serious adverse events occurred. Our study presents the first blinded video rating assessment of the short- and long-term effects of pallidal DBS in children with idiopathic or hereditary isolated dystonia. Results confirm that pallidal DBS is a safe and efficacious long-term treatment in children, with overall motor improvement similar to that described in controlled trials in adults.

Coherent spike-wave oscillations in the cortex and subthalamic nucleus of the freely moving rat.

The basal ganglia play a critical role in controlling seizures in animal models of idiopathic non-convulsive (absence) epilepsy. Inappropriate output from the substantia nigra pars reticulata (SNr) is known to exacerbate seizures, but the precise neuronal mechanisms underlying abnormal activity in SNr remain unclear. To test the hypothesis that cortical spike-wave oscillations, often considered indicative of absence seizures, propagate to the subthalamic nucleus, an important afferent of SNr, we simultaneously recorded local field potentials from the frontal cortex and subthalamic nucleus of freely moving rats. Spontaneous spike-wave oscillations in cortex (mean dominant frequency of 7.4 Hz) were associated with similar oscillations in the subthalamic nucleus (mean of 7.9 Hz). The power of oscillations at 5-9 Hz was significantly higher during spike-wave activity as compared with rest periods without this activity. Importantly, spike-wave oscillations in cortex and subthalamic nucleus were significantly coherent across a range of frequencies (3-40 Hz), and the dominant (7-8 Hz) oscillatory activity in the subthalamic nucleus typically followed that in cortex with a small time lag (mean of 2.7 ms). In conclusion, these data suggest that ensembles of subthalamic nucleus neurons are rapidly recruited into oscillations during cortical spike-wave activity, thus adding further weight to the importance of the subthalamic nucleus in absence epilepsy. An increase in synchronous oscillatory input from the subthalamic nucleus could thus partly underlie the expression of pathological activity in SNr that could, in turn, aggravate seizures. Finally, these findings also reiterate the importance of oscillations in these circuits in normal behaviour.

Neurosurgical interventions in the treatment of idiopathic Parkinson disease: neurostimulation and neural implantation.

With the exception of thalamotomy for drug-refractory tremor, surgical therapy for Parkinson's disease has been almost abandoned as treatment for Parkinsonian symptoms between 1965 and 1985. Reasons for this development relate to inconsistent postoperative results, complications associated with stereotactic surgical techniques and, most importantly, the advent of levodopa, which is still considered to be the gold standard in pharmacotherapy for Parkinson's disease. However, both, the long-term experience with L-DOPA therapy on the one hand and the progress of advanced stereotactic techniques and fetal graft research on the other hand have lead to reconsideration of surgical therapy in Parkinson's disease for patients, who can not be treated satisfactorily with medication. Both lesions (via thermocoagulation) and/or neurostimulation (via chronic intracerebral implantation of electrodes) in thalamic nuclei (nucleus ventralis oralis posterior/intermedialis thalami; VOP/VIM) may alleviate rest tremor in PD patients. In principle neurostimulation has the significant advantage of reversibility with regard to side effects in comparison to lesion surgery. Furthermore ventro-posterior pallidotomy or chronic stimulation in this structures may ameliorate bradykinesia and levodopa-induced dyskinesias. Additionally, "switching-off" the subthalamic nucleus by neurostimulation has been reported to reduce rigidity, bradykinesia and levodopa-induced ON-OFF-fluctuations. On the other hand, neuronal transplantation of fetal nigral dopamine precursor cells aims at restoring the striatal dopamine deficit. Both animal and clinical experiments have shown that fetal grafts survive intrastriatal transplantation and may ensue moderate to satisfactory improvements, especially in regard to bradykinesia and ON-OFF-fluctuations. Further progress in the field of neuronal transplantation will largely depend on the development of alternative cell resources.