Extradural Motor Cortex Stimulation Research Articles

Extradural Motor Cortex Stimulation in Parkinson's Disease: Long-Term Clinical Outcome.

Previous investigations have reported on the motor benefits and safety of chronic extradural motor cortex stimulation (EMCS) for patients with Parkinson’s disease (PD), but studies addressing the long-term clinical outcome are still lacking. In this study, nine consecutive PD patients who underwent EMCS were prospectively recruited, with a mean follow-up time of 5.1 ± 2.5 years. As compared to the preoperatory baseline, the Unified Parkinson’s Disease Rating Scale (UPDRS)-III in the off-medication condition significantly decreased by 13.8% at 12 months, 16.1% at 18 months, 18.4% at 24 months, 21% at 36 months, 15.6% at 60 months, and 8.6% at 72 months. The UPDRS-IV decreased by 30.8% at 12 months, 22.1% at 24 months, 25% at 60 months, and 36.5% at 72 months. Dopaminergic therapy showed a progressive reduction, significant at 60 months (11.8%). Quality of life improved by 18.0% at 12 months, and 22.4% at 60 months. No surgical complication, cognitive or behavioral change occurred. The only adverse event reported was an infection of the implantable pulse generator pocket. Even in the long-term follow-up, EMCS was shown to be a safe and effective treatment option in PD patients, resulting in improvements in motor symptoms and quality of life, and reductions in motor complications and dopaminergic therapy.

Extradural Motor Cortex Stimulation might improve episodic and working memory in patients with Parkinson\u2019s disease

Electric Extradural Motor Cortex Stimulation (EMCS) is a neurosurgical procedure suggested for treatment of patients with advanced Parkinson’s disease (PD). We report two PD patients treated by EMCS, who experienced worsening of motor symptoms and cognition 5 years after surgery, when EMCS batteries became discharged. One month after EMCS restoration, they experienced a subjective improvement of motor symptoms and cognition. Neuropsychological assessments were carried out before replacement of batteries (off-EMCS condition) and 6 months afterward (on-EMCS condition). As compared to off-EMCS condition, in on-EMCS condition both patients showed an improvement on tasks of verbal episodic memory and backward spatial short-term/working memory task, and a decline on tasks of selective visual attention and forward spatial short-term memory. These findings suggest that in PD patients EMCS may induce slight beneficial effects on motor symptoms and cognitive processes involved in verbal episodic memory and in active manipulation of information stored in working memory.

Unilateral Extradural Motor Cortex Stimulation Is Safe and Improves Parkinson Disease at 1 Year

The primary motor cortex, which is part of the corticobasal ganglia loops, may be an alternative option for the surgical treatment of Parkinson disease. To report on the 1-year safety and efficacy of unilateral extradural motor cortex stimulation in Parkinson disease. A quadripolar electrode strip was extradurally implanted over the motor cortex. Stimulation was continuously delivered through the electrode paddle contralateral to the most affected clinical side. Subjects were prospectively evaluated by the Unified Parkinson's Disease Rating Scale (UPDRS) and the Parkinson's Disease Quality of Life Questionnaire. In addition, an extensive cognitive and behavioral assessment and electroencephalogram recording were performed. Nine patients were included in this study. No surgical complications or adverse events occurred. Moreover, no cognitive or behavioral changes were observed. Under the off-medication condition, the UPDRS III at baseline was decreased by 14.1%, 23.3%, 19.9%, and 13.2%, at 1, 3, 6, and 12 months, respectively. The motor effects were bilateral, appeared after 3 to 4 weeks of stimulation, and outlasted the stimulation itself for 3 to 4 weeks in 1 case of stimulator accidental switching off. The UPDRS IV was decreased by 40.8%, 42.1%, and 35.5% at 1, 3, and 12 months, respectively. The scores on the Parkinson's Disease Quality of Life Questionnaire were increased at months 3, 6, and 12. Extradural motor cortex stimulation is a safe procedure. After 12 months, the patients demonstrated a moderate improvement of motor symptoms (particularly axial symptoms) and quality of life.

Chronic motor cortex stimulation in patients with advanced Parkinson’s disease and effects on striatal dopaminergic transmission as assessed by 123I-FP-CIT SPECT

The objective of this study was to assess striatal dopamine transporter availability in patients with advanced Parkinson's disease (PD) before and after 13 months of unilateral extradural motor cortex stimulation (EMCS) with [123I]N-ω-fluoropropyl-2-β-carbo-methoxy-3-β-(4-iodophenyl)nortropane single photon emission computed tomography (123I-FP-CIT SPECT). Six PD patients (five women and one man, aged 63.2 ± 5.6 years) underwent 123I-FP-CIT SPECT and clinical evaluation [Unified Parkinson's Disease Rating Scale (UPDRS) and Parkinson's Disease Quality of Life Scale (PDQL)] preoperatively, 8 and 13 months after EMCS. Striatum-to-occipital cortex, caudate-to-occipital cortex and putamen-to-occipital cortex 123I-FP-CIT uptake ratios were calculated using the region of interest method. Total and part III UPDRS scores significantly decreased at 8 and 13 months after stimulation (P=0.02 and 0.04, respectively); UPDRS part II and PDQL scores improved after 13 months (P=0.02 and 0.04, respectively). No significant differences in 123I-FP-CIT uptake ratios between baseline and follow-up were found in the examined regions. However, a progressive reduction in 123I-FP-CIT uptake ratios in the striatum contralateral to the implant was found. In contrast, no further decrease in 123I-FP-CIT uptake ratios was detected in the striatum ipsilateral to the implant. There were no correlations between changes in 123I-FP-CIT uptake ratios with disease duration, changes in medication dosage and motor UPDRS scores. Despite a small but highly selected sample of advanced PD patients, our results showed that no further dopamine transporter reduction occurred in the striatum ipsilateral to the implant side. This finding could lead to the hypothesis that EMCS might elicit a 'neuroprotective' effect, as suggested by significant clinical benefits.

Improvement of Secondary Fixed Dystonia of the Upper Limb After Chronic Extradural Motor Cortex Stimulation in 10 Patients

Fixed dystonic postures secondary to ischemic, traumatic, or postsurgical lesions located in the basal ganglia and brainstem constitute a major therapeutic challenge and limit motor rehabilitation efficacy. They are often refractory to conservative treatment. Aberrant cerebral plasticity developed after deep brain lesions is thought to lead to abnormal cortical representation of the affected part of the body and then to pathological fixed postures. To assess the efficacy of motor cortex stimulation in patients with upper limb fixed dystonia. Ten patients were submitted to computer-assisted and electromyography-monitored implantation of intracranial epidural electrodes over the central cortical sulcus contralateral to the affected limb. Patients were followed up from 1 to 9 years (9 patients), except for patient 10, whose follow-up was limited to 4 months. Seven of 7 patients showed > 30% improvement in the Disability of Shoulder, Arm, and Hand Scale and an overall 70% increase in the score of the Short Form-36 Physical Activity subscale with significant and stable improvement of quality of life during stimulation. The partial recovery of hand dexterity observed in most of the treated patients additionally contributed to a significant improvement of their quality of life. Although the pathophysiology of fixed dystonia is unknown, our results suggest a major role of the motor cortex in this condition and reinforce the hypothesis that postlesional delayed cortical rearrangements might take place in these forms and be the target of effective therapeutic neuromodulation.

P7.15 The motor and cognitive effects of extradural motor cortex stimulation for Parkinson's disease: a 1-year prospective open-label study

P7.15 The motor and cognitive effects of extradural motor cortex stimulation for Parkinson's disease: a 1-year prospective open-label study

Extradural motor cortex stimulation for Parkinson's disease: A review

Extradural motor cortex stimulation for Parkinson's disease: A review

High frequency extradural motor cortex stimulation transiently improves axial symptoms in a patient with Parkinson's disease

In a primate model of Parkinson's disease (PD), the benefit of extradural motor cortex stimulation (EMCS) was associated with high-frequency stimulation (130 Hz), whereas no significant motor improvement was achieved at 10 Hz or intermediate frequencies of stimulation. We report the case of a 72-year-old female patient affected by severe PD who underwent bilateral EMCS. In baseline med-off condition the patient was unable to arise from a chair and to stand without assistance. Stimulation at 3 and 60 Hz failed to provide any improvement of symptoms, whereas, when stimulating at 130 Hz, axial akinesia and walking improved consistently: the patient, in med-off condition, was able to arise from chair and to walk without assistance. The patient underwent two brain 99mTc- Ethylcysteinate Dimer-SPECT studies: semiquantitative and Statistical Parametric Mapping revealed that the regional cerebral perfusion was significantly increased in the supplementary motor area during stimulation at 130 Hz. After five months, the benefit of EMCS gradually disappeared.

Motor cortex stimulation in patients with Parkinson disease: 12-month follow-up in 4 patients

Since the initial 1991 report by Tsubokawa et al., stimulation of the M1 region of cortex has been used to treat chronic pain conditions and a variety of movement disorders. A Medline search of the literature published between 1991 and the beginning of 2007 revealed 459 cases in which motor cortex stimulation (MCS) was used. Of these, 72 were related to a movement disorder. More recently, up to 16 patients specifically with Parkinson disease were treated with MCS, and a variety of results were reported. In this report the authors describe 4 patients who were treated with extradural MCS. Although there were benefits seen within the first 6 months in Unified Parkinson's Disease Rating Scale Part III scores (decreased by 60%), tremor was only modestly managed with MCS in this group, and most benefits seen initially were lost by the end of 12 months. Although there have been some positive findings using MCS for Parkinson disease, a larger study may be needed to better determine if it should be pursued as an alternative surgical treatment to DBS.

Cerebral activity modulation by extradural motor cortex stimulation in Parkinson's disease: a perfusion SPECT study

Extradural motor cortex stimulation (EMCS) has been proposed as alternative to deep brain stimulation (DBS) in the treatment of Parkinson's disease (PD). Its mechanisms of action are still unclear. Neuroimaging evidenced motor cortical dysfunction in PD that can be reversed by therapy. We performed left hemisphere EMCS surgery in six advanced PD patients fulfilling CAPSIT criteria for DBS with the exception of age >70 years. After 6 months, we measured regional cerebral blood flow (rCBF) at rest with SPECT and Tc-99m cysteinate dimer bicisate off-medication with stimulator off and on. Clinical assessment included Unified Parkinson's Disease Rating Scale part II and III, Abnormal Involuntary Movement Scale and mean dopaminergic medication dosage. We used statistical parametric mapping for imaging data analysis. Clinically we observed no mean changes in motor scales, although blinded evaluation revealed some benefit in individual patients. We found significant rCBF decrements in the pre-central gyrus, pre-motor cortex and caudate nucleus bilaterally, left prefrontal areas and right thalamus. Perfusion increments were found in cerebellum bilaterally. EMCS determined significant modulation of neuronal activity within the cortico-basal ganglia-thalamo-cortical motor loop in our cohort of advanced PD patients. However, these effects were paralleled by mild and variable clinical efficacy.

Neuropsychologic Assessment of Patients With Advanced Parkinson Disease Submitted to Extradural Motor Cortex Stimulation

The aim of this study was to evaluate changes in cognitive functioning and emotive state in 3 inpatients with advanced Parkinson disease (PD) treated with extradural motor cortex stimulation (EMCS), an experimental neurosurgical procedure. Studies on the neuropsychologic assessment of patients with PD after EMCS are in process. The procedure has been applied for some years as an experimental method for treating PD. A battery of neuropsychologic tests and emotive assessment scales were administered to 3 inpatients with PD 2 days before the intervention and then again after 1 year to evaluate changes in cognitive functioning and emotive state. At 1-year postintervention, cognitive functions and depressive symptoms were steady; 2 patients showed a mild improvement in quality of life. In this patient group, EMCS, an experimental neurosurgical treatment, had a positive effect on motor symptoms. Neuropsychologic assessment after a 1-year follow-up period showed that cognitive functions had not changed with respect to baseline characteristics.

Extradural motor cortex stimulation in Parkinson's disease

Extradural motor cortex stimulation (EMCS) is a surgical procedure proposed for patients with advanced Parkinson's disease (PD) who cannot undergo deep brain stimulation (DBS). Five PD patients with motor fluctuations and dyskinesia underwent EMCS of the left hemisphere. All fulfilled CAPSIT criteria for DBS, with the exception of age > 70 years. Patients were assessed preoperatively and 6 months after surgery on and off medications, with stimulator on, and 2 weeks later with stimulator off. Outcome measures included changes in mean medication dosage (levodopa and dopamine agonists), Unified Parkinson's Disease Rating Scale (UPDRS Parts II-III and Item 39), and dyskinesias (Abnormal Involuntary Movements Scale [AIMS]). We found no significant mean changes following EMCS. However, there was a trend for a reduction of mean daily medication intake (-30%) and AIMS (-19%). There were 3 patients who reported reduced OFF time (UPDRS Item 39) and 4 of 5 who felt a subjective benefit in stability and gait. In our PD cohort, EMCS induced no objective benefit, although some subjective improvement was reported mostly on axial symptoms.

Extradural motor cortex stimulation as a method to treat advanced Parkinson’s disease: new perspectives in geriatric medicine

Motor fluctuations not controlled by pharmacological therapy are often encountered in long-term Parkinson's disease (PD). Neurosurgery treatment represented by deep brain stimulation (DBS) was considered a valid alternative to pharmacological treatment. Unfortunately this method is most effective in patients under age of 70. Recently it has been suggested that extradural motor cortex stimulation (EMCS) could be a valid cost-effective alternative to DBS to control motor symptoms in patients affected by Parkinson's disease. The relevant non-invasive surgical technique makes this treatment particularly indicated in geriatric patients. Brain atrophy, cognitive impairment, psychiatric symptoms are not an absolute contraindication to the treatment. We submitted to EMCS an outpatient afferent to our geriatric department, a woman 68 yrs old. The patient showed an improvement of 35% as measured by the Unified Parkinson Disease Rating Scale (UPDRS) scale after the surgery. If our findings will be confirmed in larger series, a new dimension will be added to the treatment of PD.

Extradural Motor Cortex Stimulation in Advanced Parkinson's Disease: The Turin Experience: Technical Case Report

At our institution, extradural motor cortex stimulation (EMCS) has recently been applied for treating Parkinson's disease symptoms. We report our results and review the literature supporting this application of EMCS. Since 1998, six patients affected by advanced Parkinson's disease and not fulfilling inclusion criteria for deep brain stimulation underwent EMCS. A quadripolar electrode was introduced in the extradural space over the motor cortex, opposite to the side on which parkinsonian symptoms had begun. Bipolar chronic electrostimulation was delivered at 2.5 to 6 V, 150 to 180 microseconds, and 25 to 40 Hz. Preoperative and postoperative clinical status was assessed by the Unified Parkinson's Disease Rating Scale (UPDRS) and recorded on videotapes. The follow-up of this series varied from 4 months to 2.5 years. After EMCS, the overall UPDRS score decreased by 42 to 62%; Section III UPDRS score (motility evaluation) by 32 to 83%; and Section IV UPDRS score (therapy complications) by 100% in two patients, by 50 to 67% in four patients, and by 33% in one patient. L-Dopa therapy was reduced by 11 to 33% in three patients and by 70 to 73% in the other two patients. No postoperative complications or negative side effects of electrostimulation were recorded, except for a misplacement of the electrodes in one patient. Unilateral EMCS relieves, at least partially, but sometimes dramatically, the whole spectrum of symptoms in advanced Parkinson's disease. L-Dopa may be reduced up to 70%. The symptoms of long-term L-dopa syndrome are usually markedly improved. The neurophysiological mechanisms involved are still under debate. Our clinical experience adds favorable data to enlarge the series of parkinsonian patients treated by EMCS.

Therapeutic extradural cortical stimulation for movement disorders: A review

Extradural motor cortex stimulation was introduced in 1989 for control of central pain. In recent years this has been found useful in several patients with movement disorders. This paper attempts to bring together all the relevant literature, discuss mechanisms and lay out guidelines for future research and clinical applications.