Patient selected goals and satisfaction after bilateral subthalamic nucleus deep brain stimulation in Parkinson's disease.

Assessing patient goals is crucial in understanding patient centered outcomes and satisfaction. However, patient goals may change throughout treatment. Our objective is to identify the changes in patient-selected goals of Parkinson's disease (PD) patients undergoing bilateral subthalamic nucleus deep brain stimulation (STN-DBS) and examine the relationship among patient-selected goal achievement, standard DBS outcome measures, and overall patient satisfaction. Seventy-five patients undergoing bilateral STN-DBS listed three patient-selected goals before surgery. After six months, patients were asked to restate the three goals and to rate the degree of goal achievement and the overall satisfaction of surgery. The three most frequently selected goals were "dyskinesia", "gait disorder", and "medication off duration". After six months, 80.0% of patients could not accurately recall their pre-DBS goals. "Dyskinesia" was the most consistently selected goal, more patients selected "tremor" and "less medication" at post-DBS compared to pre-DBS, and less patients selected "gait disorder" at post-DBS compared to pre-DBS. 74.7% of patients reported overall satisfaction by stating they were "very much" or "much better after surgery". Patient satisfaction significantly correlated with goal achievement (r = 0.640; p < 0.001). Interestingly, change in UPDRS motor scores did not correlate with patient satisfaction (r = 0.100; p = 0.395). Although recalled goals do not accurately represent the pre-surgical goals, the achievement score for recalled goals significantly correlated with patient satisfaction. Patient goals change due to many reasons. Therefore, follow-up patient counseling to discuss goals and outcomes is important in improving patient satisfaction after STN-DBS.

A 3-year observation of excessive daytime sleepiness after subthalamic deep brain stimulation in patients with Parkinson's disease.

OBJECTIVE: Subthalamic nucleus deep brain stimulation (STN DBS) has a positive effect on sleep quality, but its effect on wake functions is controversial. This study evaluated the longitudinal changes of the quality of sleep and excessive daytime sleepiness (EDS) in Parkinson's disease (PD) patients undergoing STN DBS and identify which factors are associated with the presence of EDS before and after STN DBS. PATIENT AND METHODS: A total of 33 PD patients who underwent bilateral STN DBS between July 2011 and October 2015 were recruited. We evaluated subjective sleep quality assessed by Parkinson's Disease Sleep Scale (PDSS) and EDS using Epworth Sleepiness Scale (ESS) preoperatively and 6 months, 1 year, and 3 years postoperatively. RESULTS: There is a significant improvement in PDSS, and a noticeable change occurs immediately after the surgery. After DBS, the number of patients with persistent EDS gradually decreased, but patients with newly developed EDS were added. Baseline ESS score was highly correlated with EDS at 6 months and 1 year postoperatively, and older age of PD onset was highly associated with EDS at 1 year after DBS. At 3 years after DBS, the total PDSS score is a main contributing factor for EDS. There was no significant difference in dopamine agonist dose (agonist LED) and levodopa equivalent daily dose (LEDD) between groups with and without EDS at any time points. CONCLUSION: Bilateral STN DBS improves the subjective sleep quality, but EDS may improve or worsen. The risk factors for EDS change over time after STN DBS. Interestingly, dopaminergic medication did not affect EDS in DBS-treated PD patients.

Determinants of Functional Independence or Its Loss following Subthalamic Nucleus Stimulation in Parkinson's Disease.

OBJECTIVE: This study aimed to describe the change in functional status following bilateral subthalamic nucleus stimulation (STN-DBS) in Parkinson's disease (PD) and to identify predictors of postoperative functional dependence. METHODS: We included PD patients with bilateral STN-DBS who had complete Schwab & England Activities of Daily Living (S&E ADL) Scale data at baseline and 6 months after surgery from our prospective registry. Functional dependence was defined as an S&E ADL score of less than 80%. All data were collected from the on-medication state and on-stimulation state (after surgery). Logistic regression analyses were performed to determine the factors predictive of functional dependence after surgery. RESULTS: A total of 196 patients were included. At baseline, 41 patients were functionally dependent and the other 155 were functionally independent. Among the patients with preoperative dependence, 32 (78%) became functionally independent after surgery, and this conversion was associated with a lower baseline axial score (p = 0.012). Among the patients with preoperative independence, 21 (14%) developed postoperative dependence, and this conversion was associated with a higher baseline axial score (p = 0.013) and its smaller improvement (p < 0.001). Female sex (odds ratio [OR] 3.214; 95% confidence interval [CI] 1.210-8.542; p = 0.019) and a higher baseline axial score (OR 1.184; 95% CI 1.056-1.327; p = 0.004) significantly predicted the risk of postoperative functional dependence. CONCLUSIONS: We found that functional status following bilateral STN-DBS is closely related to preoperative axial symptoms. When loss of independence is a potential target for STN-DBS, clinicians should take into consideration the severity of axial impairment before surgery.

Clinical differences in patients with Parkinson's disease according to tandem gait performance.

Some of patients with Parkinson's disease (PD) have abnormal tandem gait (TG) performance without any symptoms and signs of cerebellar dysfunction. Clinical difference between patients with good and poor TG performance has not yet been studied. We report the relationship between tandem gait performance and clinical characteristics including 37 patients with PD who had no evidence of cerebellar dysfunction. Using tandem gait test, the patients were divided into two groups (good-TG and poor-TG). We evaluated the two groups with Montreal Cognitive Assessment (MoCA), Mini Mental Status Examination (MMSE), Frontal Assessment Batter (FAB), Beck Depression Index (BDI-II), REM Sleep Behavior Disorder Single-Question Screen (RBD1Q), MDS-UPDRS items related to axial disability and freezing. Fifteen participants were classified as good-TG group and 22 were as poor-TG group. Participants in good-TG group had higher MoCA score and lower BDI-II score. The proportion of participants who answered "yes" to RBD1Q was lower in good-TG group (27%, 4 of 15) than that in poor-TG group (55%, 12 of 22). All participants in good-TG group marked "0" for the MDS-UPDRS item 2.13 which addresses freezing event over the past week, whereas 18% (4 of 22) of participants in poor-TG group marked "1". In conclusion, tandem gait performance may be related to various clinical characteristics including cognitive function, mood, RBD, and freezing in patients with PD.

Effect of unilateral subthalamic deep brain stimulation in highly asymmetrical Parkinson's disease: 7-year follow-up.

OBJECTIVEFor patients with highly asymmetrical Parkinson's disease (PD), unilateral subthalamic nucleus (STN) deep brain stimulation (DBS) has been suggested as a reasonable treatment. However, the results of a previous 2-year follow-up study involving patients with prominently asymmetrical PD who had unilateral STN DBS suggested that simultaneous bilateral surgery should be performed. In the present study, the authors analyze 7-year follow-up data from the same patient group to examine changes in motor benefit from unilateral STN DBS over time and the interval between initial unilateral surgery and a second (contralateral) STN DBS surgery.METHODSEight patients with highly asymmetrical parkinsonism who underwent unilateral STN DBS were evaluated. The factors measured were scores on the motor part of the Unified Parkinson's Disease Rating Scale (UPDRS III), Hoehn and Yahr (HY) stage, and levodopa equivalent daily dose (LEDD). Evaluations occurred at 3, 6, and 12 months after the initial surgery and annually thereafter.RESULTSThe mean follow-up period was 91.5 months (range 36-105 months). Three years after the initial unilateral surgery, motor benefits on the contralateral side continued; however, an aggravation of the ipsilateral parkinsonism attenuated the improvement in total UPDRS III scores, which reverted to baseline. Axial motor score, LEDD, and HY stage did not differ from the baseline. Seven of 8 patients (87.5%) were considered candidates for a second surgery to offer additional motor benefits. Of the 7 candidates, 4 patients (50% of total patients) underwent the second surgery at 58.5 ± 11.6 (mean ± SD) months after the initial surgery. Three patients were not able to have the second surgery: one patient died of gastric cancer, one patient was severely immobilized by an accident, and one patient could not afford the second surgery. One patient remained content with the initial unilateral surgery throughout the follow-up period.CONCLUSIONSSeven of 8 patients with unilateral STN DBS became candidates for second surgery before battery replacement surgery of the first implanted device. Baseline asymmetry alone may not predict appropriate candidates for unilateral STN DBS. This study provides further evidence that, from a long-term perspective, initial simultaneous bilateral STN DBS should be considered for PD patients with prominently asymmetrical motor symptoms.

A 7-year observation of the effect of subthalamic deep brain stimulation on impulse control disorder in patients with Parkinson's disease.

INTRODUCTION: Previous studies have reported improvement of impulse control disorders (ICDs) after subthalamic nucleus (STN) deep brain stimulation (DBS) as well as some de novo ICDs. However, it is not clear how STN DBS changes ICDs in the long-term. METHODS MATERIALS: Eighty-nine patients with Parkinson's disease (PD) who had received a bilateral STN DBS from 2005 to 2009 and were included in our previous study were followed for 7 years with the modified Minnesota Impulsive Disorders Interview (mMIDI). Their mMIDI scores, medication, and frontal function tests measured preoperatively and at 1 and 7 years postoperatively were compared. RESULTS: A total of 61 patients were analyzed after excluding 10 and 18 patients due to death and lost to follow-up, respectively. The numbers of the patients with an ICD at each point were 8, 10, and 7, respectively. All preoperative ICDs disappeared after DBS. De novo ICDs within 1 year after DBS disappeared except for 1 patient. Six of the seven patients, who reported ICDs 7 years after the DBS developed that ICD between 1 and 7 years. Their total levodopa equivalent daily dose (LEDD) and dopamine agonist dose were not higher compared to the other 54 patients without ICDs. There was no correlation with the frontal lobe dysfunction and the electrode position in the subthalamus. CONCLUSION: STN DBS improves baseline ICDs and results in the development of "transient" de novo ICDs in the short-term. In addition, there is a unique group of the patients who develop ICDs a long time after DBS.

Hypothyroidism-induced Reversible Encephalopathy as a Cause of Aggravation of Parkinsonism and Myoclonus in Parkinson's Disease.

Background: Myoclonus and encephalopathy are unusual in patients with Parkinson's disease (PD). Case report: We describe the case of a 59-year-old male with PD who developed myoclonus and encephalopathy. Underlying hypothyroidism was revealed after admission and treated with levothyroxine. Myoclonus and encephalopathy were completely resolved following thyroid hormone replacement. Discussion: Hypothyroidism can cause reversible myoclonus and encephalopathy along with unusual aggravation of parkinsonism symptoms in patients with PD.

Liquid levodopa-carbidopa in advanced Parkinson's disease with motor complications.

While levodopa, carbidopa, ascorbic acid solution (LCAS) therapy has been used in patients with advanced Parkinson's disease (PD) for many years, long-term follow-up data is scarce. The present study aimed to determine the long-term retention rate for LCAS therapy, and to identify the causes of LCAS therapy withdrawal. Our study included a series of 38 patients with PD (14 men and 24 women) who underwent LCAS treatment between 2011 and 2013 to alleviate motor complications that were not satisfactorily controlled by optimized conventional anti-parkinsonian treatment at the Seoul National University Hospital. All patients were admitted to educate them about and initiate LCAS treatment for 2-5days, and were then followed up as outpatients. The mean follow-up duration was 12.8months, and three main reasons for LCAS treatment discontinuation were worsening of wearing-off symptoms (8 patients), persistent dyskinesia (4 patients), and poor drug adherence (4 patients). Fourteen patients (36.8%) maintained the LCAS treatment after 12months, and were categorized as the treatment-retention group. The mean percentage of on time without dyskinesia significantly increased from 33.6±17.6% to 57.0±27.7% after LCAS initiation (p=0.016) in the treatment-retention group. Twelve patients (31.6%) were still receiving LCAS treatment after 30months. LCAS treatment can be a non-device assisted therapeutic option for patients who have no access to advanced therapies such as deep brain stimulation and infusional treatments.

Correlation of electrode position and clinical outcomes in globus pallidus stimulation for dystonia.

BACKGROUND: The correlation between the electrode location and the clinical outcome for internal globus pallidus (GPi) deep brain stimulation (DBS) has not been fully elucidated. OBJECTIVE: The aim of this study was to determine the discrepancies between the theoretical target planned by magnetic resonance imaging (MRI) and the actual electrode location in postoperative MRI, as well as to find the correlation between the final electrode locations and the clinical outcome after GPi DBS. METHODS: Thirty-six patients who underwent GPi DBS for dystonia were included in this retrospective study. The X coordinate was defined as the lateral distance from the midline, the Y coordinate as the anterior distance from the midcommissural point, and the Z coordinate as the inferior distance from the intercommissural line. RESULTS: All coordinates showed a significant difference between theoretical and actual values for all electrode locations (p < 0.05). In particular, greater differences were exhibited for Y than for the X and Z coordinates. There was no significant difference in the accuracy of the localization of the left-side versus the right-side electrode for any coordinates. The patients whose electrodes were located within or near the posteroventral GPi showed better clinical outcomes. CONCLUSIONS: The actual electrode location was slightly more posterior to the theoretically planned target. Electrodes concentrated near the posteroventral GPi tended to yield favorable outcomes.

Acupuncture does not protect against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced damage of dopaminergic neurons in a preclinical mouse model of Parkinson's disease.

Acupuncture treatment, a complementary and alternative medicine, is associated with a suggested neuroprotective effect in previous preclinical studies of Parkinson's disease (PD); however, results from human clinical trials have been mixed or unsuccessful. Recent systematic reviews of translational neuroprotective studies showed that the supposed efficacy is confounded by low methodological quality, particularly by a lack of randomization and concealed allocation. We sought to replicate previous experimental findings with a study design that mitigates the introduction of bias, including randomization, blinded outcome measures, sham acupuncture application, and allocation concealment by blinded neurotoxin administration. We performed 12 sessions of manual acupuncture at acupoint GB34 (yanglingquan) in mice that were administered the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine neurotoxin for five consecutive days. In this animal model of PD, acupuncture treatment did not attenuate tyrosine hydroxylase-immunoreactive neuronal death, depletion of striatal dopamine levels, or reduced striatal tyrosine hydroxylase expression. Our results indicate that acupuncture is not neuroprotective against nigrostriatal loss in a subacute 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine mouse model of PD.

Bilateral Deep Brain Stimulation of the Subthalamic Nucleus under Sedation with Propofol and Fentanyl.

Awakening during deep brain stimulation (DBS) surgery may be stressful to patients. The aim of the current study was to evaluate the effect on MER signals and their applicability to subthalmic nucleus (STN) DBS surgery for patients with Parkinson's disease (PD) under sedation with propofol and fentanyl. Sixteen consecutive patients with PD underwent STN-DBS surgery with propofol and fentanyl. Their MER signals were achieved during the surgery. To identify the microelectrodes positions, the preoperative MRI and postoperative CT were used. Clinical profiles were also collected at the baseline and at 6 months after surgery. All the signals were slightly attenuated and contained only bursting patterns, compared with our previous report. All electrodes were mostly located in the middle one third part of the STN on both sides of the brain in the fused images. Six months later, the patients were improved significantly in the medication-off state and they met with less dyskinesia and less off-duration. Our study revealed that the sedation with propofol and fentanyl was applicable to STN-DBS surgery. There were no significant problems in precise positioning of bilateral electrodes. The surgery also improved significantly clinical outcomes in 6-month follow-up.

Long-Term Clinical Outcome of Internal Globus Pallidus Deep Brain Stimulation for Dystonia.

BACKGROUND: GPi (Internal globus pallidus) DBS (deep brain stimulation) is recognized as a safe, reliable, reversible and adjustable treatment in patients with medically refractory dystonia. OBJECTIVES: This report describes the long-term clinical outcome of 36 patients implanted with GPi DBS at the Neurosurgery Department of Seoul National University Hospital. METHODS: Nine patients with a known genetic cause, 12 patients with acquired dystonia, and 15 patients with isolated dystonia without a known genetic cause were included. When categorized by phenomenology, 29 patients had generalized, 5 patients had segmental, and 2 patients had multifocal dystonia. Patients were assessed preoperatively and at defined follow-up examinations postoperatively, using the Burke-Fahn-Marsden dystonia rating scale (BFMDRS) for movement and functional disability assessment. The mean follow-up duration was 47 months (range, 12-84). RESULTS: The mean movement scores significantly decreased from 44.88 points preoperatively to 26.45 points at 60-month follow up (N = 19, P = 0.006). The mean disability score was also decreased over time, from 11.54 points preoperatively to 8.26 points at 60-month follow up, despite no statistical significance (N = 19, P = 0.073). When analyzed the movement and disability improvement rates at 12-month follow up point, no significant difference was noted according to etiology, disease duration, age at surgery, age of onset, and phenomenology. However, the patients with DYT-1 dystonia and isolated dystonia without a known genetic cause showed marked improvement. CONCLUSIONS: GPi DBS is a safe and efficient therapeutic method for treatment of dystonia patients to improve both movement and disability. However, this study has some limitations caused by the retrospective design with small sample size in a single-center.

Perverted Head-Shaking and Positional Downbeat Nystagmus in Essential Tremor.

Even though the pathophysiology is not completely understood, cerebellar dysfunction has been invoked in essential tremor (ET). We evaluated cerebellar dysfunction in ET with the presence of perverted head-shaking (pHSN) and positional downbeat nystagmus (pDBN) which are known to reflect cerebellar dysfunction. First, we reviewed the videooculography (VOG) of 185 patients with ET from March 2007 to April 2010. Seventeen of 28 patients with pHSN and pDBN were followed up for at least a 1.8-year interval from baseline to determine the clinical course. And then, we recruited 52 consecutive patients with ET and compared their ocular motor findings with 51 normal controls using VOG. Among the 185 patients with ET, 28 (15.1 %) showed pHSN (n = 23, 12.4 %) or pDBN (n = 8, 4.3 %). Seventeen of them who were followed up did not develop Parkinsonism or other neurologic deficits during the observation period. The subsequent case-control study showed a higher prevalence of pHSN or pDBN (11/52, 21.2 %, pHSN in nine and pDBN in five) in patients with ET than in the normal controls (2/51, 3.9 %, pHSN only, P = 0.015). The tremor rating scale or involved body sites did not differ between the patients with and without pHSN/pDBN. pHSN and pDBN were more common in patients with ET than in the normal controls. This result supports that cerebellar dysfunction is associated with ET.

Rapid eye movement sleep behavior disorder after bilateral subthalamic stimulation in Parkinson's disease.

The effect of subthalamic nucleus (STN) deep brain stimulation (DBS) on rapid eye movement sleep behavior disorder (RBD) in Parkinson's disease (PD) is not well known. We evaluated the change in the incidence of probable RBD after bilateral STN DBS in PD patients. Ninety patients with PD treated with bilateral STN DBS underwent retrospective assessment of RBD by interview before and after DBS. Forty-seven (52.2%) of the 90 patients had RBD preoperatively. RBD was resolved only in one patient and persisted in 46 patients at 1 year after DBS. RBD developed de novo in 16 patients (de novo RBD group) within 1 year after DBS, resulting in 62 (68.9%) of the 90 patients having RBD 1 year after DBS. Patients with RBD at any time within 1 year after DBS (RBD group, n = 63) were older than the patients without RBD (non-RBD group, n = 27). The sum of the Unified Parkinson Disease Rating Scale (UPDRS) axial score for the "on" state was lower in the RBD group than in the non-RBD group after DBS (p = 0.029). Comparing the de novo RBD group and non-RBD group, the UPDRS Part III and total score and the levodopa equivalent daily doses for the "on" states decreased more in the de novo RBD group than in the non-RBD group (p < 0.05). The incidence of clinical RBD increased after bilateral STN DBS because de novo RBD developed and pre-existing RBD persisted after DBS.

Comparison of sleep and other non-motor symptoms between SWEDDs patients and de novo Parkinson's disease patients.

BACKGROUND: SWEDDs (Scans Without Evidence of Dopaminergic Deficits) was defined from a series of pharmaceutical trials on Parkinson's disease (PD). Non-motor features including sleep-related problems are common even in early-stage PD patients; however, little is known about the burden of the non-motor symptoms in SWEDDs patients. METHODS: The Non-motor Symptoms Assessment Scale (NMSS), revised version of the Parkinson's Disease Sleep Scale (PDSS-2), Epworth Sleepiness Scale (ESS), and EuroQol 5-Dimension (EQ-5D) were applied to evaluate 17 SWEDDs patients and 28 de novo PD patients. The presence of clinically probable rapid eye movement sleep behavior disorder (cpRBD) was assessed using the International Classification of Sleep Disorders-Revised (ICSD-R) criteria. RESULTS: The total NMSS score for the SWEDDs group was significantly lower than for the de novo PD group (p = 0.032). The most distinct difference was in taste or smell change (p < 0.000). Prevalence of cpRBD was higher in de novo PD patients than in SWEDDs patients (p = 0.030), though no significant differences in the PDSS-2 total score (p = 0.496) or the ESS score (p = 0.517) were found. The SWEDDs patients did not significantly differ from the de novo PD patients with regard to quality of life, as measured by the EQ-5D index score (p = 0.177). CONCLUSIONS: The patients with SWEDDs have less non-motor problems than newly diagnosed untreated PD patients. Given the difficulty distinguishing between SWEDDs and early PD, identifying some of non-motor symptoms, such as RBD or olfactory impairment, could aid clinicians in their work.

Should genetic testing for SCAs be included in the diagnostic workup for MSA?

OBJECTIVE: To examine the prevalence of mutations in spinocerebellar ataxia (SCA) genes in patients who were clinically diagnosed with multiple system atrophy (MSA). METHODS: Genetic tests for SCA were performed in 302 of 528 patients who met the diagnostic criteria for MSA based on clinical features. Generally, when a patient had cerebellar symptoms or cerebellar atrophy on neuroimaging, genetic tests for SCA types 1, 2, 3, 6, 7, and 17, and dentatorubropallidoluysian atrophy were done, and when a patient had parkinsonism without cerebellar symptoms, genetic tests for SCA types 2, 3, and 17 were done. RESULTS: Mutations in SCA genes were found in 22 of the 302 patients (7.3%) with SCA17 comprising more than half of the mutation-positive cases. The age at disease onset in these 22 patients was not different compared with the 280 patients without mutations (55.9 ± 9.3 vs 59.2 ± 8.9, p = 0.102). All patients had urinary symptoms, and 10 patients also had orthostatic dizziness or orthostatic hypotension. A family history was reported in only 3 patients. Of note, dream enactment behavior suggesting REM sleep behavior disorder was reported in 9 of the 11 patients (81.8%) asked. CONCLUSIONS: The high proportion of patients with SCA mutations in this study indicates that genetic testing for SCA should be included for patients with MSA, especially for patients with cerebellar dysfunctions.

REM sleep behavior disorder: association with motor complications and impulse control disorders in Parkinson's disease.

OBJECTIVE: Clinical phenotypes such as old age, longer disease duration, motor disability, akineto-rigid type, dementia and hallucinations are known to be associated with REM sleep behavior disorder (RBD) in Parkinson's disease (PD). However, the relationship between motor fluctuations/impulse control and related behaviors (ICRB) and RBD is not clear. We designed this study to elucidate the clinical manifestations associated with RBD to determine the implications of RBD in PD. DESIGN: In a cross-sectional study, a total of 994 patients with PD were interviewed to determine the presence of RBD and their associated clinical features including motor complications and ICRB. RESULTS: Of the 944 patients, 578 (61.2%) had clinical RBD. When comparing the clinical features between patients with RBD (RBD group) and without RBD (non-RBD group), older age, longer disease duration, higher Hoehn and Yahr stage (H&Y stage), higher levodopa equivalent daily dose (LEDD), and the existence of wearing off, dyskinesia, freezing, and ICRB, especially punding, were associated with the RBD group compared to the non-RBD group (P < .05 in all). Multivariate analysis showed that motor complications including wearing off, peak dose dyskinesia, and diphasic dyskinesia were the only relevant factors for RBD after adjusting for age and disease duration. CONCLUSION: Motor complications and ICRB are more frequent in patients with RBD than in patients without RBD. In addition, motor complications are related to RBD even after adjusting for age and disease duration.

Long-term cognitive outcome of bilateral subthalamic deep brain stimulation in Parkinson's disease.

The effect of subthalamic deep brain stimulation (STN DBS) on cognition in Parkinson's disease (PD) remains controversial, and it is unclear which factors are related to cognitive decline and dementia after STN DBS, especially over the long term. To this end, we analyzed the cognitive outcome of 103 non-demented patients with PD who were followed-up for at least 12 months after bilateral STN DBS surgery. Preoperatively, the patients were evaluated with the Unified Parkinson's Disease Rating Scale and neuropsychological tests. The rate of global cognitive decline and the incidence of dementia during follow-up for up to 7 years (mean 42.4 ± 24.5 months) were calculated, and preoperative clinical and neuropsychological factors associated with postoperative global cognitive decline or dementia were analyzed. The prevalence of mild cognitive impairment (MCI) and its relation to later cognitive decline or dementia were also evaluated. The annual decline in the mini-mental state examination score was 0.4 ± 1.7 with impaired attention and executive function and a higher levodopa equivalent dose at baseline being the predictors of a faster global cognitive decline after STN DBS. Dementia developed in 13 patients with an incidence rate of 35.7 per 1,000 person-years. Impaired executive function at baseline predicted dementia. At baseline, 63.1 % of the patients had PD-MCI, and these patients were more likely to develop dementia than those without PD-MCI. This study showed that dysfunctions in the frontostriatal circuitry at baseline were associated with a risk of subsequent global cognitive decline and dementia in patients with PD who underwent STN DBS. In addition, preoperative PD-MCI was a risk factor for dementia after STN DBS.

Acute brain reaction to DBS electrodes after deep brain stimulation: chronological observation.

BACKGROUND: As increasing numbers of deep brain stimulation (DBS) procedures are performed, rare abnormal findings on postoperative images that are not attributable to well-known complications are reported. Between 2005 and 2012, we encountered several symptomatic patients with transient abnormal low-attenuation lesions on postoperative computed tomography (CT) scans. The aim of this study was to clarify this rare phenomenon using chronological observations and to suggest a feasible mechanism. RESULTS: In this period, seven (3.2 %) patients displayed transient increased low-attenuation signals, circumferentially surrounding the DBS electrodes and extending into the subcortical white matter. All these patients suffered from unexpected but transient neurological symptoms during the postoperative period. The abnormal low-attenuation lesions only disappeared completely a considerable time after the clinical symptoms had disappeared, without treatment in most patients. CONCLUSIONS: We report here our chronological observations of acute brain reactions after DBS procedures, which we believe are neither infectious nor vascular, but are possibly caused by the mechanical breakdown of the blood-brain barrier by microelectrode recordings or by anchored DBS electrodes. These lesions are thought to constitute a self-limiting disorder requiring no further treatment.