[Intercultural adaptation of the PUKSoPC in German language : A scale for perceived control in patients with Parkinson's disease]. / Interkulturelle Adaptation der PUKSoPC in deutscher Sprache : Eine Skala zur gefühlten Kontrolle von Parkinson-Patientinnen und -Patienten.

BACKGROUND: The level of perceived control in people with Parkinson's disease plays a significant role in affecting their quality of life. Simpson et al. developed a scale of perceived control specific to Parkinson's disease called the Parkinson's UK Scale of Perceived Control (PUKSoPC). In this work, we present a cross-culturally adapted German translation of the original English version. METHODS: After receiving approval by the original authors, an internationally established procedure was used for cross-cultural adaptation. Firstly, the original English version was translated into German independently by two bilingual neuroscientists, who then agreed on a consensus version. This was tested on 10 people with Parkinson's disease and independently back translated into English by two different neuroscientists. After forming a consensus version, this English version was compared with the original version by all four translators. Differences between the versions resulted in modifications to the German translation so that the back translation matched the original as closely as possible. The final version was approved by two of the original authors and clinically tested on 50 people with Parkinson's disease. RESULTS: During the translation process, the four translators agreed on a culturally adapted German version of the PUKSoPC. Testing of the final version on 50 people with Parkinson's disease did not reveal any linguistic or content-related problems. CONCLUSION: The linguistically validated German version of the PUKSoPC presented in this paper is now freely available for measuring the levels of perceived control in people with Parkinson's disease to advance both research and clinical practice.

Directional DBS leads show large deviations from their intended implantation orientation.

OBJECTIVE: Lead orientation is a new degree of freedom with directional deep brain stimulation (DBS) leads. We investigated how prevalent deviations from the intended implantation direction are in a large patient cohort. METHODS: The Directional Orientation Detection (DiODe) algorithm to determine lead orientation from postoperative CT scans was implemented into the open-source Lead-DBS toolbox. Lead orientation was analyzed in 100 consecutive patients (198 leads). Different anatomical targets and intraoperative setups were compared. RESULTS: Deviations of up to 90° from the intended implantation direction were observed. Deviations of more than 30° were seen in 42% of the leads and deviations of more than 60° in about 11% of the leads. Deviations were independent from the neuroanatomical target and the stereotactic frame but increased depending on which microdrive was used. DISCUSSION: Our results indicate that large deviations from the intended implantation direction are a common phenomenon in directional leads. Postoperative determination of lead orientation is thus mandatory for investigating directional DBS.

Beneficial effects of bilateral subthalamic stimulation on alexithymia in Parkinson's disease.

BACKGROUND AND PURPOSE: Subthalamic nucleus (STN) deep brain stimulation (DBS) improves quality of life (QoL) and motor and non-motor symptoms in advanced Parkinson's disease (PD). However, its effect on alexithymia and its relationship to other neuropsychiatric symptoms and QoL in PD is unclear. METHODS: In this prospective, observational study of 39 patients with PD undergoing STN-DBS, we examined the Parkinson's Disease Questionnaire-8 (PDQ-8), 20-item Toronto Alexithymia Scale (TAS-20), Hospital Anxiety and Depression Scale (HADS), Self-Report Manic Inventory (SRMI), Apathy Evaluation Scale (AES), Unified Parkinson's Disease Rating Scale (UPDRS) activities of daily living, UPDRS motor examination and UPDRS complications (UPDRS-II/-III/-IV) and levodopa-equivalent daily dose (LEDD) pre-operatively and at 5-month follow-up. Outcome changes were tested with Wilcoxon signed-rank or paired t-test when parametric tests were applicable and corrected for multiple comparisons. The relationship between outcome changes was explored with bivariate correlations. Additionally, partial correlations between PDQ-8 and TAS-20 were computed controlling for HADS, SRMI and AES change scores. Predictor analyses for PDQ-8 improvement were calculated for all baseline parameters. RESULTS: The baseline prevalence of alexithymia was 17.9%. We observed significant beneficial effects of STN-DBS on PDQ-8, TAS-20, HADS, UPDRS-II, -III and -IV scores and significant LEDD reduction. The correlation between TAS-20 and PDQ-8 improvements remained significant after controlling for all other aforementioned outcomes. Predictor analyses for PDQ-8 improvement were significant for PDQ-8 and TAS-20. CONCLUSIONS: This is the first report of beneficial effects of STN-DBS on alexithymia. Alexithymia was significantly associated with QoL outcome independent of anxiety, depression, mania and apathy. Our study highlights the importance of alexithymia for holistic assessments of DBS outcomes.

Dysarthria in pallidal Deep Brain Stimulation in dystonia depends on the posterior location of active electrode contacts: a pilot study.

BACKGROUND: Pallidal Deep Brain Stimulation (GPi-DBS) is an efficient treatment for primary dystonia. We investigated stimulation-induced dysarthria, which is the most frequent side-effect of GPi-DBS. METHODS: Speech was recorded while reading a standard text, and performing rapid syllable repetitions ON and OFF DBS in ten dystonia patients (6 men; 3 cervical, 4 segmental, 3 generalized, unselected for DBS-related speech impairments). Speech and articulation rate, pauses, and syllable repetition rates were extracted via acoustic analysis. Locations of active stimulation contacts and volumes of tissue activated (VTA) were calculated. RESULTS: The number of pauses increased significantly ON vs. OFF stimulation (Wilcoxon test, p < 0.05). More posteriorly localized active contacts were associated with slower syllable repetition (Pearson correlation, p < 0.05). VTA size did not correlate with any measure of dysarthria. CONCLUSION: Using quantitative acoustic signal analysis, this study demonstrates that GPi-DBS alters motor aspects of speech. Both inadvertent stimulation of parts of the internal capsule, or interference with GPi function and outflow are possible causes. Understanding causes of GPi-DBS-induced speech changes can improve DBS programming.

Effects of deep brain stimulation on prepulse inhibition in obsessive-compulsive disorder.

Owing to a high response rate, deep brain stimulation (DBS) of the ventral striatal area has been approved for treatment-refractory obsessive-compulsive disorder (tr-OCD). Many basic issues regarding DBS for tr-OCD are still not understood, in particular, the mechanisms of action and the origin of side effects. We measured prepulse inhibition (PPI) in treatment-refractory OCD patients undergoing DBS of the nucleus accumbens (NAcc) and matched controls. As PPI has been used in animal DBS studies, it is highly suitable for translational research. Eight patients receiving DBS, eight patients with pharmacological treatment and eight age-matched healthy controls participated in our study. PPI was measured twice in the DBS group: one session with the stimulator switched on and one session with the stimulator switched off. OCD patients in the pharmacologic group took part in a single session. Controls were tested twice, to ensure stability of data. Statistical analysis revealed significant differences between controls and (1) patients with pharmacological treatment and (2) OCD DBS patients when the stimulation was switched off. Switching the stimulator on led to an increase in PPI at a stimulus-onset asynchrony of 200 ms. There was no significant difference in PPI between OCD patients being stimulated and the control group. This study shows that NAcc-DBS leads to an increase in PPI in tr-OCD patients towards a level seen in healthy controls. Assuming that PPI impairments partially reflect the neurobiological substrates of OCD, our results show that DBS of the NAcc may improve sensorimotor gating via correction of dysfunctional neural substrates. Bearing in mind that PPI is based on a complex and multilayered network, our data confirm that DBS most likely takes effect via network modulation.

Deep brain stimulation and cognitive decline in Parkinson's disease: The predictive value of electroencephalography.

Some Parkinson's disease (PD) patients treated with subthalamic nucleus deep brain stimulation (STN-DBS) develop new-onset cognitive decline. We examined whether clinical EEG recordings can be used to predict cognitive deterioration in PD patients undergoing STN-DBS. In this retrospective study, we used the Grand Total EEG (GTE)-score (short and total) to evaluate pre- and postoperative EEGs. In PD patients undergoing STN-DBS (N = 30), cognitive functioning was measured using Mini-Mental State Test and DemTect before and after surgery. Severity of motor impairment was assessed using the Unified Parkinson's Disease Rating Scale-III. Patients were classified into patients with or without cognitive decline after STN-DBS surgery. Epidemiological data, pre- and postoperative EEG recordings as well as neuropsychological and neurological data, electrode positions and the third ventricle width were compared. A logistic regression model was used to identify predictors of cognitive decline. Motor deficits significantly improved from pre- to post-surgery, while the mean GTE-scores increased significantly. Six patients developed cognitive deterioration 4-12 months postoperatively. These patients had significantly higher preoperative GTE-scores than patients without cognitive deterioration, although preoperative cognitive functioning was comparable. Electrode positions, brain atrophy and neurological data did not differ between groups. Logistic regression analysis identified the GTE-score as a significant predictor of postoperative cognitive deterioration. Data suggest that the preoperative GTE-score can be used to identify PD patients that are at high risk for developing cognitive deterioration after STN-DBS surgery even though their preoperative cognitive state was normal.

Subjectively perceived personality and mood changes associated with subthalamic stimulation in patients with Parkinson's disease.

BACKGROUND: Clinical and ethical implications of personality and mood changes in Parkinson's disease (PD) patients treated with subthalamic deep brain stimulation (STN-DBS) are under debate. Although subjectively perceived personality changes are often mentioned by patients and caregivers, few empirical studies concerning these changes exist. Therefore, we analysed subjectively perceived personality and mood changes in STN-DBS PD patients. METHOD: In this prospective study of the ELSA-DBS group, 27 PD patients were assessed preoperatively and 1 year after STN-DBS surgery. Two categories, personality and mood changes, were analysed with semi-structured interviews. Patients were grouped into personality change yes/no, as well as positive/negative mood change groups. Caregivers were additionally interviewed about patients' personality changes. Characteristics of each group were assessed with standard neurological and psychiatric measurements. Predictors for changes were analysed. RESULTS: Personality changes were perceived by six of 27 (22%) patients and by 10 of 23 caregivers (44%). The preoperative hypomania trait was a significant predictor for personality change perceived by patients. Of 21 patients, 12 (57%) perceived mood as positively changed. Higher apathy and anxiety ratings were found in the negative change group. CONCLUSIONS: Our results show that a high proportion of PD patients and caregivers perceived personality changes under STN-DBS, emphasizing the relevance of this topic. Mood changed in positive and negative directions. Standard measurement scales failed to adequately reflect personality or mood changes subjectively perceived by patients. A more individualized preoperative screening and preparation for patients and caregivers, as well as postoperative support, could therefore be useful.