The "Surprise Question" for Prognostication in People With Parkinson's Disease and Related Disorders

CONTEXT

Parkinson's disease and related disorders (PDRD) are fatal neurodegenerative disorders characterized by a fluctuating course that can complicate prognostication. The "surprise question" (SQ: "Would you be surprised if your patient died in the next year?") has been used to identify patients with limited prognosis but has not been assessed in PDRD.

OBJECTIVES

To determine the validity of the SQ in predicting 12-month mortality in PDRD.

METHODS

Data was analyzed from 301 patients and 34 community-based neurologists who were participating in a clinical trial of outpatient palliative care for patients with PDRD. Clinicians answered the SQ for each patient at baseline. Descriptive statistics at baseline, chi-square tests of independence, 2 × 2 and 2 × 3 cross tables were used. Survival analysis compared SQ responses using Kaplan-Meier curves. Risk estimate analyses identified patient characteristics associated with clinicians' responses.

RESULTS

Mortality was 10.3% (N = 31) at 1 year. The sensitivity and specificity of the SQ was 80.7% and 58.9%, respectively with AUC = 0.70, positive predictive value of 18.4% and negative predictive value of 96.4%. Older age, atypical parkinsonism, and dementia were associated with responding "no" to the SQ.

CONCLUSION

The SQ is sensitive to 12-month mortality in PDRD, with a high negative predictive value. The SQ may be useful for identifying patients less likely to die within a year and may be useful for identifying patients with palliative care needs outside of end-of-life care. This latter use may assist in mobilizing early and timely referral to specialist palliative care.

Patient and Family Outcomes of Community Neurologist Palliative Education and Telehealth Support in Parkinson Disease

Importance

Parkinson disease and related disorders (PDRD) are the fastest growing neurodegenerative illness in terms of prevalence and mortality. As evidence builds to support palliative care (PC) for PDRD, studies are needed to guide implementation.

Objective

To determine whether PC training for neurologists and remote access to a PC team improves outcomes in patients with PDRD in community settings.

Design, Setting, and Participants

This pragmatic, stepped-wedge comparative effectiveness trial enrolled and observed participants from 19 community neurology practices supported by PC teams at 2 academic centers from March 8, 2017, to December 31, 2020. Participants were eligible if they had PDRD and moderate to high PC needs. A total of 612 persons with PDRD were referred; 253 were excluded. Patients were excluded if they had another diagnosis meriting PC, were receiving PC, or were unable or unwilling to follow study procedures. Patients received usual care or the intervention based on when their community neurologist was randomized to start the intervention. Data were analyzed from January 2021 to September 2023.

Intervention

The intervention included (1) PC education for community neurologists and (2) team-based PC support via telehealth.

Main Outcomes and Measures

The primary outcomes were differences at 6 months in patient quality of life (QOL; measured by the Quality of Life in Alzheimer Disease Scale [QOL-AD]) and caregiver burden (Zarit Burden Interview) between the intervention and usual care.

Results

A total of 359 patients with PDRD (233 men [64.9%]; mean [SD] age, 74.0 [8.8] years) and 300 caregivers were enrolled. At 6 months, compared with usual care, participants receiving the intervention had better QOL (QOL-AD score, 0.09 [95% CI, -0.63 to 0.82] vs -0.88 [95% CI, -1.62 to -0.13]; treatment effect estimate, 0.97; 95% CI, 0.07-1.86; P = .03). No significant difference was observed in caregiver burden (Zarit Burden Interview score, 1.19 [95% CI, 0.16 to 2.23] vs 0.55 [95%, -0.44 to 1.54]; treatment effect estimate, 0.64; 95% CI, -0.62 to 1.90; P = .32). Advance directive completion was higher under the intervention (19 of 38 [50%] vs 6 of 31 [19%] among those without directives at the beginning of the study; P = .008). There were no differences in other outcomes.

Conclusions and Relevance

PC education for community neurologists and provision of team-based PC via telehealth is feasible and may improve QOL and advance care planning. Overall treatment effects were small and suggest opportunities to improve both the intervention and implementation.

Trial Registration

ClinicalTrials.gov Identifier: NCT03076671.

Development and Dissemination of a Neurology Palliative Care Curriculum: Education in Palliative and End-of-Life Care Neurology

Despite increasing awareness of the importance of a palliative care approach to meet the needs of persons living with neurologic illness, residency and fellowship programs report meeting this educational need due to a limited pool of neuropalliative care educators and a lack of adequate educational resources. To meet this need, a group of experts in neuropalliative care and palliative medicine leveraged resources from the Education in Palliative and End-of-life Care (EPEC) program and the National Institutes of Nursing Research (NINR) to create a library of modules addressing topics relevant for neurology trainees, palliative medicine fellows and clinicians in practice. In this manuscript, we describe the development and dissemination plan of the Education in Palliative and End-of-life Care Neurology (EPEC-N) program, initial evidence of efficacy, and opportunities for neurology educators and health services researchers to utilize these resources.

The TOPAZ study: a home-based trial of zoledronic acid to prevent fractures in neurodegenerative parkinsonism

The Trial of Parkinson’s And Zoledronic acid (TOPAZ, https://clinicaltrials.gov/ct2/show/NCT03924414) is a unique collaboration between experts in movement disorders and osteoporosis to test the efficacy of zoledronic acid, an FDA-approved parenteral treatment for osteoporosis, for fracture prevention in people with neurodegenerative parkinsonism. Aiming to enroll 3,500 participants age 65 years or older, TOPAZ is one of the largest randomized, placebo-controlled clinical trials ever attempted in parkinsonism. The feasibility of TOPAZ is enhanced by its design as a U.S.- wide home-based trial without geographical limits. Participants receive information from multiple sources, including specialty practices, support groups and websites. Conducting TOPAZ in participants’ homes takes advantage of online consent technology, the capacity to confirm diagnosis using telemedicine and the availability of research nursing to provide screening and parenteral therapy in homes. Home-based clinical research may provide an efficient, convenient, less expensive method that opens participation in clinical trials to almost anyone with parkinsonism.

Education Research: An experiential outpatient teleneurology curriculum for residents

OBJECTIVE

Telemedicine is rapidly becoming a major vehicle of delivering neurologic care to patients who have limited access to subspecialists and exaggerated travel hardship. However, neurology residents receive little to no training in telemedicine in outpatient clinics.

METHODS

We piloted, to our knowledge, the first formalized, experiential outpatient teleneurology curriculum. Neurology residents in their third and fourth postgraduate years (PGY3 and PGY4) at the University of California San Francisco completed an interactive lecture and 4 weeks of teleneurology clinics at the San Francisco Veterans Affairs Medical Center. Change in residents' telemedicine knowledge and perspectives on the utility, challenges, benefits, and future practice implementation of teleneurology were evaluated in 11 residents using precurriculum and postcurriculum quizzes and surveys after 2 of 4 weeks on the rotation.

RESULTS

Residents' performance on quizzes improved from 53% to 88% (p = 0.002). Residents' impression of video visits compared to in-person visits changed, with more individuals indicating video visits to be the same if not somewhat superior with regards to obtaining a focused history, formulating a focused assessment and plan, communicating recommendations, and the overall care provided (p ≤ 0.04). All residents felt more competent using telemedicine for patient care in their eventual career.

CONCLUSION

Our formal didactic and clinic-based teleneurology curriculum for neurology residents, which shared core themes suggested by the 2017 American Academy of Neurology Telemedicine Work Group's published recommendations, showed a statistically significant improvement in knowledge and perspectives about the promise and limitations of teleneurology practice, as well as increased comfort levels in future implementation.

Remote telemedicine evaluation of deep brain stimulation candidacy: Retrospective cohort analysis

Objective

To determine whether initial presurgical evaluation of deep brain stimulation (DBS) candidacy with video telemedicine (VTEL) can reliably predict surgical candidacy (patients who will eventually undergo DBS surgery) and decrease resource utilization when compared to an in-person evaluation.

Methods

In this retrospective, cohort analysis, all out-of-state referrals to the San Francisco Veterans Affairs from 2008 to 2013 for DBS therapy were reviewed and their surgical outcomes were assessed until 2017. Patients were designated as good, borderline, or poor surgical candidates after initial evaluation, and their rates of undergoing DBS were recorded. An assessment of patient travel costs was performed.

Results

There were 60 out-of-state DBS referrals identified out of the 148 initial presurgical DBS evaluations completed for surgical treatment of dystonia, essential tremor, or Parkinson disease; 24 patients underwent in-person consultation and 36 patients underwent evaluation via VTEL. There was no difference between the rates of undergoing surgical treatment with DBS based on surgical candidacy for patients in the in-person and VTEL cohorts. Patients who underwent initial presurgical screening via VTEL saved time and money.

Conclusions

VTEL can be used to facilitate presurgical screening for DBS and saves costs.

Patient Experience with Rechargeable Implantable Pulse Generator Deep Brain Stimulation for Movement Disorders

BACKGROUND/AIMS

Nonrechargeable deep brain stimulation implantable pulse generators (IPGs) for movement disorders require surgical replacement every few years due to battery depletion. Rechargeable IPGs reduce frequency of replacement surgeries and inherent risks of complications but require frequent recharging. Here, we evaluate patient experience with rechargeable IPGs and define predictive characteristics for higher satisfaction.

METHODS

We contacted all patients implanted with rechargeable IPGs at a single center in a survey-based study. We analyzed patient satisfaction with respect to age, diagnosis, target, charging duration, and body mass index. We tabulated hardware-related adverse events.

RESULTS

Dystonia patients had significantly higher satisfaction than Parkinson's disease patients in recharging, display, programmer, and training domains. Common positive responses were "fewer surgeries" and "small size." Common negative responses were "difficulty finding the right position to recharge" and "need to recharge every day." Hardware-related adverse events occurred in 21 of 59 participants.

CONCLUSION

Patient experience with rechargeable IPGs was largely positive; however, frustrations with recharging and adverse events were common. Dystonia diagnosis was most predictive of high satisfaction across multiple categories, potentially related to expected long disease duration with need for numerous IPG replacements.

Top Ten Tips Palliative Care Clinicians Should Know About Parkinson's Disease and Related Disorders

Parkinson's disease (PD) affects 1%-2% of individuals older than 60 years and is the 14th leading cause of death in the United States. People with PD, across all stages of the disease, suffer from a significant symptom burden that includes many nonmotor symptoms (such as depression, fatigue, pain, and dementia), and most will ultimately die from complications of this degenerative and incurable illness. Even at diagnosis, a palliative care (PC) approach can help the patient adjust to his or her diagnosis and maintain an optimal quality of life. We brought together a team of PD and PC experts to assemble practical tips for the care of people with PD. The "Top 10" format emphasizes the most relevant issues to enable PC clinicians to provide optimal care for those suffering with this complex neurodegenerative disease.

Neuropalliative care: Priorities to move the field forward

Neuropalliative care is an emerging subspecialty in neurology and palliative care. On April 26, 2017, we convened a Neuropalliative Care Summit with national and international experts in the field to develop a clinical, educational, and research agenda to move the field forward. Clinical priorities included the need to develop and implement effective models to integrate palliative care into neurology and to develop and implement informative quality measures to evaluate and compare palliative approaches. Educational priorities included the need to improve the messaging of palliative care and to create standards for palliative care education for neurologists and neurology education for palliative specialists. Research priorities included the need to improve the evidence base across the entire research spectrum from early-stage interventional research to implementation science. Highest priority areas include focusing on outcomes important to patients and families, developing serious conversation triggers, and developing novel approaches to patient and family engagement, including improvements to decision quality. As we continue to make remarkable advances in the prevention, diagnosis, and treatment of neurologic illness, neurologists will face an increasing need to guide and support patients and families through complex choices involving immense uncertainty and intensely important outcomes of mind and body. This article outlines opportunities to improve the quality of care for all patients with neurologic illness and their families through a broad range of clinical, educational, and investigative efforts that include complex symptom management, communication skills, and models of care.

National randomized controlled trial of virtual house calls for Parkinson disease

OBJECTIVE

To determine whether providing remote neurologic care into the homes of people with Parkinson disease (PD) is feasible, beneficial, and valuable.

METHODS

In a 1-year randomized controlled trial, we compared usual care to usual care supplemented by 4 virtual visits via video conferencing from a remote specialist into patients' homes. Primary outcome measures were feasibility, as measured by the proportion who completed at least one virtual visit and the proportion of virtual visits completed on time; and efficacy, as measured by the change in the Parkinson's Disease Questionnaire-39, a quality of life scale. Secondary outcomes included quality of care, caregiver burden, and time and travel savings.

RESULTS

A total of 927 individuals indicated interest, 210 were enrolled, and 195 were randomized. Participants had recently seen a specialist (73%) and were largely college-educated (73%) and white (96%). Ninety-five (98% of the intervention group) completed at least one virtual visit, and 91% of 388 virtual visits were completed. Quality of life did not improve in those receiving virtual house calls (0.3 points worse on a 100-point scale; 95% confidence interval [CI] -2.0 to 2.7 points; p = 0.78) nor did quality of care or caregiver burden. Each virtual house call saved patients a median of 88 minutes (95% CI 70-120; p < 0.0001) and 38 miles per visit (95% CI 36-56; p < 0.0001).

CONCLUSIONS

Providing remote neurologic care directly into the homes of people with PD was feasible and was neither more nor less efficacious than usual in-person care. Virtual house calls generated great interest and provided substantial convenience.

CLINICALTRIALSGOV IDENTIFIER

NCT02038959.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that for patients with PD, virtual house calls from a neurologist are feasible and do not significantly change quality of life compared to in-person visits. The study is rated Class III because it was not possible to mask patients to visit type.

Virtual visits for Parkinson disease: A multicenter noncontrolled cohort

BACKGROUND

Previous small-scale studies have demonstrated the feasibility of providing remote specialty care via virtual visits. We assessed the feasibility and benefits of a one-time consultation between a remote Parkinson Disease (PD) specialist and an individual with PD at home on a larger scale.

METHODS

We conducted a multicenter noncontrolled cohort of virtual visits administered over videoconferencing between remote PD specialists and individuals with PD in their home. Specialists performed a patient history and a PD-specific physical examination and provided recommendations to patients and their local physicians. The primary outcome measures were feasibility, as measured by the proportion of visits completed as scheduled, and the 6-month change in quality of life, as measured by the Parkinson's Disease Questionnaire 39. Additional outcomes included satisfaction with visits and interest in future virtual visits.

RESULTS

A total of 277 participants from 5 states enrolled, 258 participants completed virtual visits with 14 different physicians, and 91% of visits were completed as scheduled. No improvement in quality of life was observed at 6 months (0.4-point improvement; 95% confidence interval -1.5 to 0.6; p = 0.39). Overall satisfaction with virtual visits was high among physicians (94% satisfied or very satisfied) and patients (94% satisfied or very satisfied), and 74% of participants were interested in receiving future care via virtual visits.

CONCLUSIONS

Providing specialty care remotely into the homes of individuals with PD is feasible, but a one-time visit did not improve quality of life. Satisfaction with the visits was high among physicians and patients, who were interested in receiving such care in the future.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that for patients with PD, remote specialty care is feasible but does not improve quality of life.

CLINICALTRIALSGOV IDENTIFIER

NCT02144220.

Chronic multisite brain recordings from a totally implantable bidirectional neural interface: experience in 5 patients with Parkinson's disease

OBJECTIVE Dysfunction of distributed neural networks underlies many brain disorders. The development of neuromodulation therapies depends on a better understanding of these networks. Invasive human brain recordings have a favorable temporal and spatial resolution for the analysis of network phenomena but have generally been limited to acute intraoperative recording or short-term recording through temporarily externalized leads. Here, the authors describe their initial experience with an investigational, first-generation, totally implantable, bidirectional neural interface that allows both continuous therapeutic stimulation and recording of field potentials at multiple sites in a neural network. METHODS Under a physician-sponsored US Food and Drug Administration investigational device exemption, 5 patients with Parkinson's disease were implanted with the Activa PC+S system (Medtronic Inc.). The device was attached to a quadripolar lead placed in the subdural space over motor cortex, for electrocorticography potential recordings, and to a quadripolar lead in the subthalamic nucleus (STN), for both therapeutic stimulation and recording of local field potentials. Recordings from the brain of each patient were performed at multiple time points over a 1-year period. RESULTS There were no serious surgical complications or interruptions in deep brain stimulation therapy. Signals in both the cortex and the STN were relatively stable over time, despite a gradual increase in electrode impedance. Canonical movement-related changes in specific frequency bands in the motor cortex were identified in most but not all recordings. CONCLUSIONS The acquisition of chronic multisite field potentials in humans is feasible. The device performance characteristics described here may inform the design of the next generation of totally implantable neural interfaces. This research tool provides a platform for translating discoveries in brain network dynamics to improved neurostimulation paradigms. Clinical trial registration no.: NCT01934296 (clinicaltrials.gov).

Clinical outcomes using ClearPoint interventional MRI for deep brain stimulation lead placement in Parkinson’s disease

OBJECT

The ClearPoint real-time interventional MRI-guided methodology for deep brain stimulation (DBS) lead placement may offer advantages to frame-based approaches and allow accurate implantation under general anesthesia. In this study, the authors assessed the safety and efficacy of DBS in Parkinson’s disease (PD) using this surgical method.

METHODS

This was a prospective single-center study of bilateral DBS therapy in patients with advanced PD and motor fluctuations. Symptom severity was evaluated at baseline and 12 months postimplantation using the change in Unified Parkinson’s Disease Rating Scale (UPDRS) Part III “off” medication score as the primary outcome variable.

RESULTS

Twenty-six PD patients (15 men and 11 women) were enrolled from 2010 to 2013. Twenty patients were followed for 12 months (16 with a subthalamic nucleus target and 4 with an internal globus pallidus target). The mean UPDRS Part III “off” medication score improved from 40.75 ± 10.9 to 24.35 ± 8.8 (p = 0.001). “On” medication time without troublesome dyskinesia increased 5.2 ± 2.6 hours per day (p = 0.0002). UPDRS Parts II and IV, total UPDRS score, and dyskinesia rating scale “on” medication scores also significantly improved (p < 0.01). The mean levodopa equivalent daily dose decreased from 1072.5 ± 392 mg to 828.25 ± 492 mg (p = 0.046). No significant cognitive or mood declines were observed. A single brain penetration was used for placement of all leads, and the mean targeting error was 0.6 ± 0.3 mm. There were 3 serious adverse events (1 DBS hardware-related infection, 1 lead fracture, and 1 unrelated death).

CONCLUSIONS

DBS leads placed using the ClearPoint interventional real-time MRI-guided method resulted in highly accurate lead placement and outcomes comparable to those seen with frame-based approaches.

National Randomized Controlled Trial of Virtual House Calls for People with Parkinson's Disease: Interest and Barriers

BACKGROUND

Delivering specialty care remotely directly into people's homes can enhance access for and improve the healthcare of individuals with chronic conditions. However, evidence supporting this approach is limited.

MATERIALS AND METHODS

Connect.Parkinson is a randomized comparative effectiveness study that compares usual care of individuals with Parkinson's disease in the community with usual care augmented by virtual house calls with a Parkinson's disease specialist from 1 of 18 centers nationally. Individuals in the intervention arm receive four virtual visits from a Parkinson's disease specialist over 1 year via secure, Web-based videoconferencing directly into their homes. All study activities, including recruitment, enrollment, and assessments, are conducted remotely. Here we report on interest, feasibility, and barriers to enrollment in this ongoing study.

RESULTS

During recruitment, 11,734 individuals visited the study's Web site, and 927 unique individuals submitted electronic interest forms. Two hundred ten individuals from 18 states enrolled in the study from March 2014 to June 2015, and 195 were randomized. Most participants were white (96%) and college educated (73%). Of the randomized participants, 73% had seen a Parkinson's disease specialist within the previous year.

CONCLUSIONS

Among individuals with Parkinson's disease, national interest in receiving remote specialty care directly into the home is high. Remote enrollment in this care model is feasible but is likely affected by differential access to the Internet.

Globus pallidus interna deep brain stimulation for tardive dyskinesia: case report and review of the literature

Tardive dyskinesia (TD) can be a disabling condition and is frequently refractory to medical therapy. Over the past decade there have been many reports of TD patients experiencing significant benefit with deep brain stimulation (DBS) of the globus pallidus interna (GPi). The growing literature on this treatment option for TD consists predominantly of case reports and series. The reported benefit ranges widely, but the majority of cases experienced at least a 50% improvement in symptoms. The anatomical distribution of dyskinesias has not clearly influenced outcome, though fixed postures appear less likely to improve than phasic movements. Onset of benefit can be immediate or take months, and benefit is sustained in most cases, for at least 6 months and up to several years. A wide variety of voltages, frequencies, and pulse widths have demonstrated efficacy. A small number of reports which examined psychiatric symptoms before and after surgery did not find any decline, and in some cases revealed improvement in mood. However, these overall positive results should be interpreted with caution, as the majority of reports lacked blinded assessments, control groups, or standardized therapy parameters. Finally, we present an illustrative case of refractory tardive dyskinesia treated with GPi-DBS with 5 years of follow-up and 4 accompanying video segments.

Clinical outcomes of PD patients having bilateral STN DBS using high-field interventional MR-imaging for lead placement

OBJECTIVE

Recently, an iMRI-guided technique for implanting DBS electrodes without MER was developed at our center. Here we report the clinical outcomes of PD patients undergoing STN DBS surgery using this surgical approach.

METHODS

Consecutive PD patients undergoing bilateral STN DBS using this method were prospectively studied. Severity of PD was determined using the UPDRS scores, Hoehn and Yahr staging score, stand-sit-walk testing, and the dyskinesia rating scale. The primary outcome measure was the change in UPDRS III off medication score at 6 months. DBS stimulation parameters, adverse events, levodopa equivalent daily dose (LEDD), and DBS lead locations were also recorded. Seventeen advanced PD patients (9M/8F) were enrolled from 2007 to 2009.

RESULTS

The mean UPDRS III off medication score improved from 44.5 to 22.5 (49.4%) at 6 months (p=0.001). Other secondary outcome measures (UPDRS II, III on medication, and IV) significantly improved as well (p<0.01). LEDD decreased by an average of 24.7% (p=0.003). Average stimulation parameters were: 2.9V, 66.4μs, 154Hz.

CONCLUSION

This pilot study demonstrates that STN DBS leads placed using the iMRI-guided method results in significantly improved outcomes in PD symptoms, and these outcomes are similar to what has been reported using traditional frame-based, MER-guided stereotactic methods.

Acute effects of thalamic deep brain stimulation and thalamotomy on sensorimotor cortex local field potentials in essential tremor

OBJECTIVE

Essential tremor (ET) is characterized by an action tremor believed to be due to excessive theta-alpha activity in the cerebello-thalamo-cortical system. This study aimed to test the hypothesis that therapeutic thalamic stimulation in patients with ET decreases theta-alpha oscillatory activity in primary motor (M1) and sensory (S1) cortices.

METHODS

During surgical treatment of ET in 10 patients, an electrocorticography (ECoG) strip electrode was placed temporarily over the arm region of M1 and S1. Local field potentials (LFP) were recorded at rest, during a tremor-inducing posture, during acute therapeutic thalamic stimulation, and following therapeutic thalamotomy (three patients). Power spectral density (PSD) was calculated using the Fast Fourier Transform.

RESULTS

At rest, alpha activity (8-13Hz) in M1 was significantly decreased during high-frequency stimulation, while theta activity (4-8Hz) decreased in S1. Following thalamotomy, theta and beta (13-30Hz) was increased in M1. Induction of postural tremor reduced M1 theta, alpha and beta activity compared to the resting state.

CONCLUSIONS

High-frequency thalamic deep brain stimulation (DBS) significantly reduces alpha oscillatory activity in the primary motor cortex of patients with ET, though this change is probably not critical for therapeutic efficacy.

SIGNIFICANCE

We demonstrate that ECoG can be effectively used to study the effect of subcortical stimulation on cortical oscillations.

Oscillations in sensorimotor cortex in movement disorders: an electrocorticography study

Movement disorders of basal ganglia origin may arise from abnormalities in synchronized oscillatory activity in a network that includes the basal ganglia, thalamus and motor cortices. In humans, much has been learned from the study of basal ganglia local field potentials recorded from temporarily externalized deep brain stimulator electrodes. These studies have led to the theory that Parkinson's disease has characteristic alterations in the beta frequency band (13-30 Hz) in the basal ganglia-thalamocortical network. However, different disorders have rarely been compared using recordings in the same structure under the same behavioural conditions, limiting straightforward assessment of current hypotheses. To address this, we utilized subdural electrocorticography to study cortical oscillations in the three most common movement disorders: Parkinson's disease, primary dystonia and essential tremor. We recorded local field potentials from the arm area of primary motor and sensory cortices in 31 subjects using strip electrodes placed temporarily during routine surgery for deep brain stimulator placement. We show that: (i) primary motor cortex broadband gamma power is increased in Parkinson's disease compared with the other conditions, both at rest and during a movement task; (ii) primary motor cortex high beta (20-30 Hz) power is increased in Parkinson's disease during the 'stop' phase of a movement task; (iii) the alpha-beta peaks in the motor and sensory cortical power spectra occur at higher frequencies in Parkinson's disease than in the other two disorders; and (iv) patients with dystonia have impaired movement-related beta band desynchronization in primary motor and sensory cortices. The findings support the emerging hypothesis that disease states reflect abnormalities in synchronized oscillatory activity. This is the first study of sensorimotor cortex local field potentials in the three most common movement disorders.

Changes in regional brain perfusion during functional brain activation: comparison of [(64)Cu]-PTSM with [(14)C]-Iodoantipyrine

A dilemma in behavioral brain mapping is that conventional techniques immobilize the subject, extinguishing all but the simplest behaviors. This is avoided if brain activation is imaged after completion of the behavior and tissue capture of the tracer. A single-pass flow tracer proposed for positron emission tomography (PET) is a radiolabeled copper(II) complex of pyruvaldehyde bis(N(4)-methylthiosemicarbazone), [Cu(64)]-PTSM. [Cu(64)]-PTSM reaches steady-state cerebral distribution more rapidly than the metabolic tracer [(18)F]-fluorodeoxyglucose, allowing imaging with substantially greater temporal resolution. Using dual-label autoradiography, this study compares the relative regional cerebral blood flow tracer distribution (CBF-TR) of [(64)Cu]-PTSM to that of the classic perfusion tracer [(14)C]-iodoantipyrine in a rat model during treadmill walking. Rats were exposed to continuous walking on a treadmill and compared to quiescent controls. [(64)Cu]-PTSM was bolus injected (iv) after 1 min, followed by a 5-minute uptake and subsequent bolus injection of [(14)C]-iodoantipyrine. CBF-TR was quantified by autoradiography and analyzed in the three-dimensionally reconstructed brain by statistical parametric mapping, as well as by region-of-interest analysis. A high homology was found between the [(64)Cu]-PTSM and [(14)C]-iodoantipyrine patterns of cerebral activation in cortical and subcortical regions. For white matter, however, [(64)Cu]-PTSM showed lower perfusion than [(14)Cu]-iodoantipyrine. [(64)Cu]-PTSM is a useful tracer for functional brain mapping in freely-moving subjects. Its application in conjunction with PET promises to increase our understanding of the neural circuitry of behaviors dependent on locomotion.