Impact of subthalamic nucleus stimulation on urinary dysfunction and constipation in Parkinson's disease.

OBJECTIVE: The effect of subthalamic nucleus (STN) deep brain stimulation (DBS) on urinary dysfunction and constipation in Parkinson's disease (PD) is variable. This study aimed to identify potential surgical and nonsurgical variables predictive of these outcomes. METHODS: The authors used the Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) Part I to assess urinary dysfunction (item 10) and constipation (item 11) preoperatively and at 6-12 months postoperatively. A multiple linear regression model was used to investigate the impact of global cerebral atrophy (GCA) and active electrode contact location on the urinary dysfunction and constipation follow-up scores, controlling for age, disease duration, baseline score, motor improvement, and levodopa-equivalent dose changes. An electric field model was applied to localize the maximal-effect sites for constipation and urinary dysfunction compared with those for motor improvement. RESULTS: Among 74 patients, 23 improved, 28 deteriorated, and 23 remained unchanged for urinary dysfunction; 25 improved, 15 deteriorated, and 34 remained unchanged for constipation. GCA score and age significantly predicted urinary dysfunction follow-up score (R2 = 0.36, p < 0.001). Increased GCA and age were independently associated with worsening urinary symptoms. Disease duration, baseline constipation score, and anterior active electrode contacts in both hemispheres were significant predictors of constipation follow-up score (R2 = 0.31, p < 0.001). Higher baseline constipation score and disease duration were associated with worsening constipation; anterior active contact location was associated with improvement in constipation. CONCLUSIONS: Anterior active contact location was associated with improvement in constipation in PD patients after STN DBS. PD patients with greater GCA scores before surgery were more likely to experience urinary deterioration after DBS.

Localization of deep brain stimulation trajectories via automatic mapping of microelectrode recordings to MRI.

Objective. Suboptimal electrode placement during subthalamic nucleus deep brain stimulation (STN DBS) surgery may arise from several sources, including frame-based targeting errors and intraoperative brain shift. We present a computer algorithm that can accurately localize intraoperative microelectrode recording (MER) tracks on preoperative magnetic resonance imaging (MRI) in real-time, thereby predicting deviation between the surgical plan and the MER trajectories.Approach. Random forest (RF) modeling was used to derive a statistical relationship between electrophysiological features on intraoperative MER and voxel intensity on preoperative T2-weighted MR imaging. This model was integrated into a larger algorithm that can automatically localize intraoperative MER recording tracks on preoperative MRI in real-time. To verify accuracy, targeting error of both the planned intraoperative trajectory ('planned') and the algorithm-derived trajectory ('calculated') was estimated by measuring deviation from the final DBS lead location on postoperative high-resolution computed tomography ('actual').Main results. MR imaging and MERs were obtained from 24 STN DBS implant trajectories. The cross-validated RF model could accurately distinguish between gray and white matter regions along MER trajectories (AUC 0.84). When applying this model within the localization algorithm, thecalculatedMER trajectory estimate was found to be significantly closer to theactualDBS lead when compared to theplannedtrajectory recorded during surgery (1.04 mm vs 1.52 mm deviation,p< 0.002), with improvement shown in 19/24 cases (79%). When applying the algorithm to simulated DBS trajectory plans with randomized targeting error, up to 4 mm of error could be resolved to <2 mm on average (p< 0.0001).Significance. This work presents an automated system for intraoperative localization of electrodes during STN DBS surgery. This neuroengineering solution may enhance the accuracy of electrode position estimation, particularly in cases where high-resolution intraoperative imaging is not available.

Perceived social support declines after deep brain stimulation surgery in patients with Parkinson's disease.

INTRODUCTION: The Social Provisions Scale (SPS) measures a person's perceived social support. We evaluated the perceived social support in Parkinson's disease (PD) patients before and after subthalamic nucleus (STN) deep brain stimulation (DBS) and its impact on clinical outcomes following DBS. METHODS: We analyzed 55 PD patients who underwent STN DBS surgery and completed the SPS, PDQ-39, and MDS-UPDRS Parts I-IV before and 6-12 months after surgery. Some patients also completed global cognitive, mood and apathy scales. Caregivers completed the CBI at each visit. Linear regression models and linear mixed models evaluated the association between the SPS baseline score, MDS-UPDRS and PDQ-39 scores, the association between MDS-UPDRS, CBI and the SPS follow-up score, and the association between SPS, global cognition and other psychological variables. RESULTS: DBS implantation improved MDS-UPDRS I-IV and PDQ-39 scores. Perceived social support declined after DBS (baseline SPS total 82.55 ± 7.52 vs. follow-up SPS total 78.83 ± 9.02, p = 0.0001). Baseline SPS total score was not significantly associated with the MDS-UPDRS or PDQ-39 scores at follow-up. MDS-UPDRS scores and the CBI at follow-up had no significant association with SPS total score at follow-up. Measures of global cognition, mood and apathy were associated with the SPS before and after DBS, and the association was independent of STN DBS. CONCLUSION: After STN DBS, PD patients experienced a decrease in perceived social support, but baseline perceived social support did not impact clinical outcomes. It is important to further identify factors that may contribute to this perception of worsened social support.

Clinically-derived oscillatory biomarker predicts optimal subthalamic stimulation for Parkinson's disease.

Objective. Choosing the optimal electrode trajectory, stimulation location, and stimulation amplitude in subthalamic nucleus deep brain stimulation (STN DBS) for Parkinson's disease remains a time-consuming empirical effort. In this retrospective study, we derive a data-driven electrophysiological biomarker that predicts clinical DBS location and parameters, and we consolidate this information into a quantitative score that may facilitate an objective approach to STN DBS surgery and programming.Approach. Random-forest feature selection was applied to a dataset of 1046 microelectrode recordings (MERs) sites across 20 DBS implant trajectories to identify features of oscillatory activity that predict clinically programmed volumes of tissue activation (VTAs). A cross-validated classifier was used to retrospectively predict VTA regions from these features. Spatial convolution of probabilistic classifier outputs along MER trajectories produced a biomarker score that reflects the probability of localization within a clinically optimized VTA.Main results. Biomarker scores peaked within the VTA region and were significantly correlated with percent improvement in postoperative motor symptoms (Part III of the Movement Disorders Society revision of the Unified Parkinson Disease Rating Scale,R= 0.61,p= 0.004). Notably, the length of STN, a common criterion for trajectory selection, did not show similar correlation (R= -0.31,p= 0.18). These findings suggest that biomarker-based trajectory selection and programming may improve motor outcomes by 9 ± 3 percentage points (p= 0.047) in this dataset.Significance. A clinically defined electrophysiological biomarker not only predicts VTA size and location but also correlates well with motor outcomes. Use of this biomarker for trajectory selection and initial stimulation may potentially simplify STN DBS surgery and programming.

Motor speech effects in subthalamic deep brain stimulation for Parkinson's disease.

OBJECTIVE: A motor speech disorder or dysarthria commonly arises in patients with Parkinson's disease (PD). The impact of subthalamic nucleus (STN) deep brain stimulation (DBS) on motor speech and the potential of intraoperative motor speech testing to predict outcomes are unknown. This study examined 1) the types and prevalence of motor speech changes observed with STN DBS and their relation to the preoperative condition, 2) the ability of intraoperative testing to predict postoperative changes in motor speech, and 3) the spatial relationship between stimulation sites producing maximal motor improvement, as measured by the Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS), and maximal motor speech deterioration. METHODS: Comprehensive preoperative, intraoperative, and postoperative motor speech/dysarthria evaluations were performed in consecutive patients with advanced idiopathic PD who underwent STN DBS surgery in the period from 2011 to 2016. Preoperative type of dysarthria and overall dysarthria severity rating along with intraoperative motor speech testing results were evaluated as predictors of postoperative change. Atlas-independent, fully individualized field modeling was used to identify stimulation sites associated with maximal MDS-UPDRS motor improvement and motor speech deterioration. RESULTS: Forty-three patients with PD treated with STN DBS were prospectively studied. Improved MDS-UPDRS motor scores and worsened dysarthria were demonstrated by a subset of patients (16/43). Preoperative dysarthria characteristics did not predict postoperative deterioration. Intraoperative assessment of motor speech strongly predicted postoperative outcomes (OR 4.4, p = 0.02). Sites of maximal MDS-UPDRS motor improvement and worsened dysarthria were distinct. Worsened dysarthria was associated with capsular stimulation, anterior and ventral to the site of maximal MDS-UPDRS motor improvement. CONCLUSIONS: The predictive reliability of intraoperative motor speech testing, together with the identification of distinct stimulation sites for motor speech impairment and improved MDS-UPDRS motor function, raise the possibility that DBS lead repositioning or reprogramming could reduce adverse effects on motor speech without impacting MDS-UPDRS motor outcomes in patients undergoing STN DBS.

The impact of dispositional optimism and depression on post-operative motor functioning following deep brain stimulation surgery for Parkinson's disease.

INTRODUCTION: The primary goal of subthalamic nucleus (STN) deep brain stimulation (DBS) for Parkinson's disease (PD) is to improve motor function. Dispositional optimism has been associated with better physical outcomes following a rehabilitation program in PD but has not been investigated in relation to STN-DBS. This study investigated the influence of dispositional optimism on motor outcomes following STN-DBS in individuals with PD. METHODS: A retrospective data analysis of 33 individuals with PD who underwent STN-DBS was conducted. Linear regression was used to determine whether dispositional optimism, measured by the Life Orientation Test-Revised questionnaire, predicted change in motor symptoms following DBS surgery, as assessed by the Movement Disorder Society-sponsored revision of the Unified PD Rating Scale, Part III. Self-reported levels of depressive and anxiety symptoms were included as co-variates. RESULTS: Higher pre-operative dispositional optimism combined with less self-reported depressive symptoms predicted greater post-operative improvement in motor symptoms from the baseline OFF-medication to post-operative ON-medication/ON-stimulation state, accounting for 38.8% of the variance in post-operative change. CONCLUSION: The large percentage of variance in post-STN-DBS motor change predicted by pre-operative dispositional optimism and depressive symptoms suggests that assessment of these variables prior to surgery may provide valuable information for clinicians regarding the surgery's ultimate initial motor benefit for individuals with PD. If modifiable, these variables may provide cost-effective targets to improve motor outcomes of STN-DBS in PD.

Caregiver burden worsens in the second year after subthalamic nucleus deep brain stimulation for Parkinson's disease.

BACKGROUND: Caregiver burden (CB) in Parkinson's disease (PD) does not improve in the short term after bilateral subthalamic nucleus (STN) deep brain stimulation (DBS), despite motor improvement. This may be due to increased caregiver demands after surgery or the possibility that DBS unresponsive non-motor factors, such as executive dysfunction, contribute to CB. OBJECTIVE: To evaluate the trajectory of CB in year 2 following bilateral STN DBS surgery for PD, and to test whether post-operative CB changes correlate with changes in executive function in a subgroup with available neuropsychological testing. METHODS: This retrospective analysis included 35 patients with PD whose caregivers completed the Caregiver Burden Inventory (CBI) at baseline and between 9 and 24 months after bilateral STN DBS. 14 of these patients had neuropsychological testing both at baseline and within 6 months of their follow up CBI assessment. RESULTS: CBI scores showed worsened CB from baseline to follow-up (16.4-21.5, p = 0.006). There was no correlation between change in executive function and change in CBI in the smaller subsample. CONCLUSION: CB worsens in the 2 years after bilateral STN DBS despite improvement in motor symptoms and is not associated with change in executive dysfunction in the setting of advancing PD. These findings have implications on pre-operative counselling for patients and caregivers considering DBS for PD.

Acute readmission following deep brain stimulation surgery for Parkinson's disease: A nationwide analysis.

INTRODUCTION: Deep brain stimulation (DBS) surgery is an efficacious, underutilized treatment for Parkinson's disease (PD). Studies of DBS post-operative outcomes are often restricted to data from a single center and consider DBS in isolation. National estimates of DBS readmission and post-operative outcomes are needed, as are comparisons to commonly performed surgeries. METHODS: This study used datasets from the 2013 and 2014 Nationwide Readmissions Database (NRD). Our sample was restricted to PD patients discharged alive after hospitalization for DBS surgery. Descriptive analyses examined patient, clinical, hospital and index hospitalization characteristics. The all-cause, non-elective 30-day readmission rate after DBS was calculated, and logistic regression models were built to examine factors associated with readmission. Readmission rates for the most common surgical procedures were calculated and compared to DBS. RESULTS: There were 6058 DBS surgeries for PD in our sample, most often involving a male aged 65 and older, who lived in a high socioeconomic status zip code. DBS patients had an average of four comorbidities. With respect to outcomes, the majority of patients were discharged home (95.3%). Non-elective readmission was rare (4.9%), and was associated with socioeconomic status, comorbidity burden, and teaching hospital status. Much higher acute, non-elective readmission rates were observed for common procedures such as upper gastrointestinal endoscopy (16.2%), colonoscopy (14.0%), and cardiac defibrillator and pacemaker procedures (11.1%). CONCLUSION: Short-term hospitalization outcomes after DBS are generally favorable. Socioeconomic disparities in DBS use persist. Additional efforts may be needed to improve provider referrals for and patient access to DBS.

A Computerized Microelectrode Recording to Magnetic Resonance Imaging Mapping System for Subthalamic Nucleus Deep Brain Stimulation Surgery.

BACKGROUND: Accurate electrode placement is critical to the success of deep brain stimulation (DBS) surgery. Suboptimal targeting may arise from poor initial target localization, frame-based targeting error, or intraoperative brain shift. These uncertainties can make DBS surgery challenging. OBJECTIVE: To develop a computerized system to guide subthalamic nucleus (STN) DBS electrode localization and to estimate the trajectory of intraoperative microelectrode recording (MER) on magnetic resonance (MR) images algorithmically during DBS surgery. METHODS: Our method is based upon the relationship between the high-frequency band (HFB; 500-2000 Hz) signal from MER and voxel intensity on MR images. The HFB profile along an MER trajectory recorded during surgery is compared to voxel intensity profiles along many potential trajectories in the region of the surgically planned trajectory. From these comparisons of HFB recordings and potential trajectories, an estimate of the MER trajectory is calculated. This calculated trajectory is then compared to actual trajectory, as estimated by postoperative high-resolution computed tomography. RESULTS: We compared 20 planned, calculated, and actual trajectories in 13 patients who underwent STN DBS surgery. Targeting errors for our calculated trajectories (2.33 mm ± 0.2 mm) were significantly less than errors for surgically planned trajectories (2.83 mm ± 0.2 mm; P = .01), improving targeting prediction in 70% of individual cases (14/20). Moreover, in 4 of 4 initial MER trajectories that missed the STN, our method correctly indicated the required direction of targeting adjustment for the DBS lead to intersect the STN. CONCLUSION: A computer-based algorithm simultaneously utilizing MER and MR information potentially eases electrode localization during STN DBS surgery.

Influence of Intracranial Air on Electrode Position and Clinical Outcomes following Deep Brain Stimulation for Parkinson's Disease.

BACKGROUND: The introduction of intracranial air during deep brain stimulation (DBS) surgery is believed to negatively impact targeting accuracy and clinical outcomes. OBJECTIVE: To quantify the relationship between intracranial air (ICA) volumes, targeting accuracy, and clinical outcomes in patients undergoing subthalamic nucleus (STN) DBS for Parkinson's disease. METHODS: ICA in 73 consecutive STN DBS cases (146 leads) was measured by high-resolution CT and correlated with proximal lead bowing, electrode displacement, targeting accuracy, and clinical outcomes at 6 and 12 months. RESULTS: There was a statistically significant correlation of ICA volume (mean ± SEM: 21.3 ± 13.7 cm3) and proximal lead bowing (2.8 ± 1.4 mm, r = 0.34, p = 0.01). There was no significant correlation of ICA with targeting error (2.0 ± 1.2 mm), distal contact deviation (1.2 ± 0.7 mm), motor Movement Disorder Society-Unified Parkinson's Disease Rating Scale Part III improvement at 6 months (42.3 ± 4.5%) or 12 months (30.3 ± 7.7%), or dopaminergic medication reduction at 6 months (44.7± 4.2%) or 12 months (32.9 ± 5.9%). Comparison of top and bottom ICA quintile extremes also revealed no differences in these measures. CONCLUSIONS: Though the proximal DBS lead bends in association with ICA, movement of the distal contact, targeting error, and clinical outcomes are not affected by ICA. This unexpected finding is maintained at ICA quintile extremes.

Fatigue in Parkinson's disease: report from a mutidisciplinary symposium.

Fatigue is a severe problem for many people living with Parkinson's disease (PD). Best estimates suggest that more than 50% of patients experience this debilitating symptom. Little is known about its etiology or treatment, making the understanding of fatigue a true unmet need. As part of the Parkinson's Disease Foundation Community Choice Research Program, patients, caregivers, and scientists attended a symposium on fatigue on 16 and 17 October 2014. We present a summary of that meeting, reviewing what is known about the diagnosis and treatment of fatigue, its physiology, and what we might learn from multiple sclerosis (MS), depression, and cancer-disorders in which fatigue figures prominently too. We conclude with focused recommendations to enhance our understanding and treatment of this prominent problem in PD.

A suggested minimum standard deep brain stimulation evaluation for essential tremor.

BACKGROUND: A comprehensive, multidisciplinary screening process for deep brain stimulation (DBS) candidates is recommended, but is often time-consuming. OBJECTIVE: To determine the number of essential tremor (ET) referrals excluded from surgery and why, in order to develop recommendations for a minimum standard DBS evaluation process. METHODS: We reviewed the referrals of 100 consecutive potential DBS candidates with presumed ET at our center, identified reasons for excluding patients from DBS, and the point at which they dropped out of our evaluation process. RESULTS: Of the 100 tremor patients referred for DBS, 36 patients were approved for surgery. Patients were mainly excluded because of the movement disorders neurologist and neuropsychologist evaluations. Reasons included an inadequate medication trial (n=20), incorrect diagnosis (n=3), dementia (n=3), and antagonistic interactions with the team (n=1). 37 patients did not present, were uninterested or lost to follow-up. Neither neurosurgical evaluation nor brain imaging excluded candidates in this study, but are needed to proceed with DBS. CONCLUSIONS: Our suggested minimum standard DBS screening process begins with a movement disorders neurologist and neuropsychologist evaluation in order to determine eligibility. Neurosurgical evaluation and brain imaging can then be performed if candidates are deemed eligible.

Parkinson's disease-related fatigue: A case definition and recommendations for clinical research.

Fatigue is one of the most common and disabling symptoms in Parkinson's disease (PD). Since fatigue was first described as a common feature of PD 20 years ago, little progress has been made in understanding its causes or treatment. Importantly, PD patients attending the 2013 World Parkinson Congress voted fatigue as the leading symptom in need of further research. In response, the Parkinson Disease Foundation and ProjectSpark assembled an international team of experts to create recommendations for clinical research to advance this field. The working group identified several areas in which shared standards would improve research quality and foster progress including terminology, diagnostic criteria, and measurement. Terminology needs to (1) clearly distinguish fatigue from related phenomena (eg, sleepiness, apathy, depression); (2) differentiate subjective fatigue complaints from objective performance fatigability; and (3) specify domains affected by fatigue and causal factors. We propose diagnostic criteria for PD-related fatigue to guide participant selection for clinical trials and add rigor to mechanistic studies. Recommendations are made for measurement of subjective fatigue complaints, performance fatigability, and neurophysiologic changes. We also suggest areas in which future research is needed to address methodological issues and validate or optimize current practices. Many limitations in current PD-related fatigue research may be addressed by improving methodological standards, many of which are already being successfully applied in clinical fatigue research in other medical conditions (eg, cancer, multiple sclerosis). © 2016 International Parkinson and Movement Disorder Society.

Validity and Efficacy of Screening Algorithms for Assessing Deep Brain Stimulation Candidacy in Parkinson Disease.

BACKGROUND: Deep Brain Stimulation (DBS) for Parkinson disease (PD) may be underutilized because of limited access to care (most DBS surgeries are performed at specialized centers) or over-referral of poor candidates, leading to inequitable utilization of limited evaluative resources. There is a pressing need for a widely employable screening algorithm to aid in the evaluation of PD candidates for DBS. OBJECTIVE: To compare the validity and efficacy of two published screening algorithms, the Florida Surgical Questionnaire for PD and Stimulus, to predict candidacy for DBS. METHODS: We reviewed the clinical data at our DBS center for 147 consecutive PD DBS referrals between 9/1/2007 and 12/31/2011. Florida Surgical Questionnaire and Stimulus scores were applied retrospectively through a chart review of the Movement Disorder neurologist's initial clinical evaluation. The validity and accuracy of these two algorithms in predicting candidacy for DBS was compared to the decision to offer DBS surgery by our multidisciplinary DBS team. RESULTS: Of the 130 consecutive PD referrals who presented for initial evaluation, 50 were offered DBS after a standardized multidisciplinary evaluation. The Stimulus scale was a superior screening tool for predicting PD DBS candidacy in these referrals [Area under the Receiver operating curve = 0.8088] compared to the Florida Surgical Questionnaire for PD [Area under the Receiver operating curve = 0.6285]. CONCLUSION: In this single center study, Stimulus was a more appropriate screening measure than the Florida Surgical Questionnaire for PD to assess DBS candidacy for PD.

Caregiver burden in patients with Parkinson disease undergoing deep brain stimulation: an exploratory analysis.

BACKGROUND: Little is known about caregiver burden in Parkinson disease (PD) patients undergoing brain stimulation (DBS) surgery. OBJECTIVE: The aim of this exploratory analysis was to evaluate whether caregiver burden improves after bilateral subthalamic nucleus (STN) DBS for PD patients and identify baseline factors associated with caregiver burden. METHODS: We analyzed the motor, cognitive and behavioral data of 12 PD patients (9 men/3 women) who underwent bilateral STN DBS and whose caregivers completed the Caregiver Burden Inventory (CBI) both before and approximately 6 months after bilateral STN DBS. RESULTS: Total CBI score did not change from baseline (17.8 ± 10.7) to the 6 month evaluation (18.7 ± 13.1), despite a 29% improvement in the MDS-UPDRS motor score (baseline 40.3 ± 12.1 compared to 28.7 ± 8.4 at 6 months, p = 0.01). Change in total CBI score did not correlate with change in MDS-UPDRS Parts I-IV or MoCA from baseline to 6 months. In post-hoc analyses looking at baseline characteristics that may correlate with caregiver burden, only the disinhibition subscore on the Frontal Systems Behavioral Scale correlated positively with the baseline total CBI score (ρ = 0.763, p = 0.004). CONCLUSION: Caregiver burden for PD patients (as measured by the CBI) does not change 6 months after bilateral STN DBS, despite significant improvement in motor function. Only baseline behavioral problems, specifically disinhibition, correlated with higher baseline caregiver burden. Clinicians may need to better counsel patients on expectations for caregiver burden after DBS.

The MDS-UPDRS tracks motor and non-motor improvement due to subthalamic nucleus deep brain stimulation in Parkinson disease.

BACKGROUND: The Movement Disorders Society revision of the Unified Parkinson Disease Rating Scale (MDS-UPDRS) improves upon the original UPDRS by adding more non-motor items, making it a more robust tool to evaluate the severity of motor and non-motor symptoms of Parkinson disease. Previous studies on deep brain stimulation have not used the MDS-UPDRS. OBJECTIVE: To determine if the MDS-UPDRS could detect improvement in both motor and non-motor symptoms after bilateral subthalamic nucleus deep brain stimulation for Parkinson disease. METHODS: We compared scores on the entire MDS-UPDRS prior to surgery (baseline) and approximately six months following the initial programming visit in twenty subjects (12M/8F) with Parkinson disease undergoing bilateral subthalamic nucleus deep brain stimulation. RESULTS: STN DBS significantly improved the scores for every section of the MDS-UPDRS at the 6 month follow-up. Part I improved by 3.1 points (22%), Part II by 5.3 points (29%), Part III by 13.1 points (29%) with stimulation alone, and Part IV by 7.1 points (74%). Individual non-motor items in Part I that improved significantly were constipation, light-headedness, and fatigue. CONCLUSIONS: Both motor and non-motor symptoms, as assessed by the MDS-UPDRS, improve with bilateral subthalamic nucleus stimulation six months after the stimulator is turned on. We recommend that the MDS-UPDRS be utilized in future deep brain stimulation studies because of the advantage of detecting change in non-motor symptoms.

The anatomical and electrophysiological subthalamic nucleus visualized by 3-T magnetic resonance imaging.

BACKGROUND: Accurate localization of the subthalamic nucleus (STN) is critical to the success of deep brain stimulation surgery for Parkinson disease. Recent developments in high-field-strength magnetic resonance imaging (MRI) have made it possible to visualize the STN in greater detail. However, the relationship of the MR-visualized STN to the anatomic, electrophysiological, or atlas-predicted STN remains controversial. OBJECTIVE: To evaluate the size of the STN visualized on 3-T MRI compared with anatomic measurements in cadaver studies and to compare the predictions of 3-T MRI and those of the Schaltenbrand-Wahren (SW) atlas for intraoperative STN microelectrode recordings. METHODS: We evaluated the STN by 3-T MRI and intraoperative microelectrode recordings in 20 Parkinson disease patients undergoing deep brain stimulation surgery. We compared our findings with anatomic cadaver studies and with the individually scaled SW atlas-based predictions for each patient. RESULTS: The dimensions of the 3-T MR-visualized STN were very similar to those of the largest anatomic study (MRI length, width, and height: 9.8 ± 1.6, 11.5 ± 1.6, and 3.7 ± 0.7 mm, respectively; n = 40; cadaver length, width, and height: 9.3 ± 0.7, 10.6 ± 0.9, and 3.1 ± 0.5 mm, respectively; n = 100). The amount of STN traversed during intraoperative microelectrode recordings was better correlated to the 3-T MR-visualized STN than the SW atlas-predicted STN (R = 0.38 vs R = -0.17). CONCLUSION: The STN as visualized on 3-T MRI corresponds well with cadaveric anatomic studies and intraoperative electrophysiology. STN visualization with 3-T MRI may be an improvement over SW atlas-based localization for STN deep brain stimulation surgery in Parkinson disease.

Change in fatigue after bilateral subthalamic nucleus deep brain stimulation for Parkinson's disease.

BACKGROUND: Bilateral subthalamic nucleus (STN) deep brain stimulation (DBS) improves motor function in patients with medically intractable Parkinson's disease (PD), but the effects of STN DBS on fatigue are unknown. The purpose of this study was to examine the effects of STN DBS on fatigue scores in patients with PD. METHODS: Twenty PD patients underwent bilateral STN DBS surgery at our institution from 2007 to 2009. Only data from the 17 patients who completed the Parkinson Fatigue Scale (PFS) and Unified PD Rating Scale (UPDRS) before and approximately 6 months after surgery were analyzed. Other evaluations included the Geriatric Depression Scale (GDS), Apathy Evaluation Scale (AES), and Epworth Sleepiness Scale (ESS). RESULTS: When the cohort was analyzed as a whole, there was no significant change in the mean or binary PFS score from baseline to the 6 month evaluation. However, the fatigue response of individual subjects was variable. Six of 12 subjects with fatigue before surgery were not fatigued post-operatively, while 3/5 subjects without fatigue before surgery became fatigued after DBS surgery. Fatigue in 8 subjects remained unchanged. Change in fatigue scores correlated significantly with change in the motor UPDRS, GDS and AES. Improvement in PFS also correlated with a higher PFS baseline score and higher baseline UPDRS motor off score. CONCLUSIONS: Changes in fatigue severity were not observed in our cohort as a whole, but there were changes in fatigue on an individual level. These changes appear to be related to the effects of STN DBS on motor improvement and mood.

Hospitalization in Parkinson disease: a survey of National Parkinson Foundation Centers.

OBJECTIVES: To explore current practices and opinions regarding hospital management of Parkinson disease (PD) patients in specialized PD Centers. METHODS: Fifty-one out of 54 National Parkinson Foundation (NPF) Centers worldwide completed an online survey regarding hospitalization of PD patients. RESULTS: Many Centers were concerned about the quality of PD-specific care provided to their patients when hospitalized. Primary concerns were adherence to the outpatient medication schedule and poor understanding by hospital staff of medications that worsen PD. Few Centers had a policy with their primary hospital that notified them when their patients were admitted. Rather, notification of hospitalization came often from the patient or a family member. Several Centers (29%) reported not finding out about a hospitalization until a routine clinic visit after discharge. Quick access to outpatient PD care following discharge was a problem in many Centers. Elective surgery, fall/fracture, infection, and mental status changes, were identified as common reasons for hospitalization. CONCLUSIONS: There is a perceived need for PD specialists to be involved during hospitalization of their patients. Improvement in communication between hospitals and PD Centers is necessary so that hospital clinicians can take advantage of PD specialists' expertise. Education of hospital staff and clinicians regarding management of PD, complications of PD, and medications to avoid in PD is critical. Most importantly, outpatient access to PD specialists needs to be improved, which may prevent unnecessary hospitalizations in these patients.