The impact of subthalamic deep-brain stimulation in restoring motor symmetry in Parkinson's disease patients: a prospective study.

BACKGROUND AND OBJECTIVES: The impact of subthalamic deep-brain stimulation (STN-DBS) on motor asymmetry and its influence on both motor and non-motor outcomes remain unclear. The present study aims at assessing the role of STN-DBS on motor asymmetry and how its modulation translates into benefits in motor function, activities of daily living (ADLs) and quality of life (QoL). METHODS: Postoperative motor asymmetry has been assessed on the multicentric, prospective Predictive Factors and Subthalamic Stimulation in Parkinson's Disease cohort. Asymmetry was evaluated at both baseline (pre-DBS) and 1 year after STN-DBS. A patient was considered asymmetric when the right-to-left MDS-UPDRS part III difference was ≥ 5. In parallel, analyses have been carried out using the absolute right-to-left difference. The proportion of asymmetric patients at baseline was compared to that in the post-surgery evaluation across different medication/stimulation conditions. RESULTS: 537 PD patients have been included. The proportion of asymmetric patients was significantly reduced after both STN-DBS and medication administration (asymmetric patients: 50% in pre-DBS MedOFF, 35% in MedOFF/StimON, 26% in MedON/StimOFF, and 12% in MedON/StimON state). Older patients at surgery and with higher baseline UPDRS II scores were significantly less likely to benefit from STN-DBS at the level of motor asymmetry. No significant correlation between motor asymmetry and ADLs (UPDRS II) or overall QoL (PDQ-39) score was observed. Asymmetric patients had significantly higher mobility, communication, and daily living PDQ-39 sub-scores. CONCLUSIONS: Both STN-DBS and levodopa lead to a reduction in motor asymmetry. Motor symmetry is associated with improvements in certain QoL sub-scores.

Freezing of gait depends on cortico-subthalamic network recruitment following STN-DBS in PD patients.

INTRODUCTION: Subthalamic deep-brain-stimulation (STN-DBS) is an effective means to treat Parkinson's disease (PD) symptoms. Its benefit on gait disorders is variable, with freezing of gait (FOG) worsening in about 30% of cases. Here, we investigate the clinical and anatomical features that could explain post-operative FOG. METHODS: Gait and balance disorders were assessed in 19 patients, before and after STN-DBS using clinical scales and gait recordings. The location of active stimulation contacts were evaluated individually and the volumes of activated tissue (VAT) modelled for each hemisphere. We used a whole brain tractography template constructed from another PD cohort to assess the connectivity of each VAT within the 39 Brodmann cortical areas (BA) to search for correlations between postoperative PD disability and cortico-subthalamic connectivity. RESULTS: STN-DBS induced a 100% improvement to a 166% worsening in gait disorders, with a mean FOG decrease of 36%. We found two large cortical clusters for VAT connectivity: one "prefrontal", mainly connected with BA 8,9,10,11 and 32, and one "sensorimotor", mainly connected with BA 1-2-3,4 and 6. After surgery, FOG severity positively correlated with the right prefrontal VAT connectivity, and negatively with the right sensorimotor VAT connectivity. The right prefrontal VAT connectivity also tended to be positively correlated with the UPDRS-III score, and negatively with step length. The MDRS score positively correlated with the right sensorimotor VAT connectivity. CONCLUSION: Recruiting right sensorimotor and avoiding right prefrontal cortico-subthalamic fibres with STN-DBS could explain reduced post-operative FOG, since gait is a complex locomotor program that necessitates accurate cognitive control.

Personality Related to Quality-of-Life Improvement After Deep Brain Stimulation in Parkinson's Disease (PSYCHO-STIM II).

BACKGROUND: Deep brain stimulation of the sub-thalamic nucleus (DBS-STN) reduces symptoms in Parkinson's disease (PD) patients with motor fluctuations. However, some patients may not feel ameliorated afterwards, despite an objective motor improvement. It is thus important to find new predictors of patients' quality of life (QoL) amelioration after DBS-STN. We hypothesized that personality dimensions might affect QoL after DBS-STN. OBJECTIVE: To evaluate associations between personality dimensions and QoL improvement one year after DBS-STN. METHODS: DBS-STN-PD patients (n = 303) having answered the "Temperament and Character Inventory" (TCI) before surgery and the PDQ-39 before and one year after surgery were included, from the cohort study PREDI-STIM. Linear regression models were used to evaluate associations between TCI dimensions and change in PDQ-39 scores after DBS-STN. RESULTS: Novelty Seeking and Cooperativeness scores before surgery were positively associated with PDQ-39 scores improvement after DBS-STN (FDR-adjusted p < 0.01). Moreover, paradoxically unimproved patients with deterioration of their PDQ-39 scores after DBS-STN despite improvement of their MDS-UPDRS-IV scores had lower Cooperativeness scores, while paradoxically improved patients with amelioration of their PDQ-39 scores despite deterioration of their MDS-UPDRS-IV scores had higher Reward Dependence scores. CONCLUSION: Some presurgical personality dimensions were significantly associated with QoL amelioration and discrepancy between motor state and QoL changes after DBS-STN in PD. Educational programs before DBS-STN should take in account patient personality dimensions to better deal with their expectations.

Preoperative REM Sleep Behavior Disorder and Subthalamic Nucleus Deep Brain Stimulation Outcome in Parkinson Disease 1 Year After Surgery.

BACKGROUND AND OBJECTIVES: To determine whether patients with Parkinson disease (PD) eligible for subthalamic nucleus deep brain stimulation (STN-DBS) with probable REM sleep behavior disorder (RBD) preoperatively could be more at risk of poorer motor, nonmotor, and quality of life outcomes 12 months after surgery compared to those without RBD. METHODS: We analyzed the preoperative clinical profile of 448 patients with PD from a French multicentric prospective study (PREDISTIM) according to the presence or absence of probable RBD based on the RBD Single Question and RBD Screening Questionnaire. Among the 215 patients with PD with 12 months of follow-up after STN-DBS, we compared motor, cognitive, psycho-behavioral profile, and quality of life outcomes in patients with (pre-opRBD+) or without (pre-opRBD-) probable RBD preoperatively. RESULTS: At preoperative evaluation, pre-opRBD+ patients were older (61 ± 7.2 vs 59.5 ± 7.7 years; p = 0.02), had less motor impairment (Movement Disorder Society-sponsored version of the Unified Parkinson's Disease Rating Scale [MDS-UPDRS] III "off": 38.7 ± 16.2 vs 43.4 ± 7.1; p = 0.03) but more nonmotor symptoms on daily living activities (MDS-UPDRS I: 12.6 ± 5.5 vs 10.7 ± 5.3; p < 0.001), had more psychobehavioral manifestations (Ardouin Scale of Behavior in Parkinson's Disease total: 7.7 ± 5.1 vs 5.1 ± 0.4; p = 0.003), and had worse quality of life (Parkinson's Disease Questionnaire-39: 33 ± 12 vs 29 ± 12; p = 0.03), as compared to pre-opRBD- patients. Both pre-opRBD+ and pre-opRBD- patients had significant MDS-UPDRS IV score decrease (-37% and -33%, respectively), MDS-UPDRS III "med 'off'/stim 'on'" score decrease (-52% and -54%), and dopaminergic treatment decrease (-52% and -49%) after surgery, with no between-group difference. There was no between-group difference for cognitive and global quality of life outcomes. CONCLUSIONS: In patients with PD eligible for STN-DBS, the presence of probable RBD preoperatively is not associated with a different clinical outcome 1 year after neurosurgery. TRIAL REGISTRATION INFORMATION: NCT02360683. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that in patients with PD eligible for STN-DBS, the presence of probable RBD preoperatively is not associated with poorer outcomes 1 year post surgery.

Whispering dysphonia in TUBB4A-related disorders responsive to bipallidal deep brain stimulation.

BACKGROUND: Mutations in TUBB4A are associated with a wide phenotypic spectrum including generalized dystonia with whispering dysphonia (DYT-TUBB4A). METHODS: We report the case of a 44-year-old patient with DYT-TUBB4A with a clinical presentation of disabling progressive dystonia, with a prominent laryngeal, cervical and facial involvement. RESULTS: Bipallidal deep brain stimulation (DBS) resulted in a 55% reduction of dystonia severity assessed by the Burke-Fahn-Marsden scale score 6 months after surgery. The effect was obvious on the cervical and facial components of dystonia. CONCLUSION: We suggest that bipallidal DBS should be considered in patients with disabling dystonia related to TUBB4A variants.

Personality Dimensions Are Associated with Quality of Life in Fluctuating Parkinson's Disease Patients (PSYCHO-STIM).

BACKGROUND: Parkinson's disease (PD) negatively affects patients' Quality of Life (QoL) which depends on both objective criteria such as physical health and subjective ones such as worries and norms according to personal believes. Therefore, QoL could be also associated to personality dimensions in chronic neurological diseases such as PD. OBJECTIVE: Our objective was thus to study the potential association between personality dimensions and QoL in PD patients with motor fluctuations before Deep Brain Stimulation of the Sub-Thalamic Nucleus (DBS-STN). METHODS: Data were obtained from the French multicentric cohort study Predi-Stim. All PD patients awaiting DBS-STN and responding to the inclusion criteria at the time of the study were included. All participants answered the "Temperament and Character Inventory" (TCI) and the PDQ-39 before surgery. Analyses were made using adjusted univariate generalized linear regression models to evaluate a potential association between TCI dimensions and PDQ-39 scores. RESULTS: Three hundred thirty-three consecutive patients were included. The temperament Harm Avoidance was negatively associated with QoL (p = 1e-4, R2= 0.33), whereas the character Self-Directedness was positively associated with mental component of QoL (p = 2e-4, R2= 0.33) in PD patients with motor fluctuations awaiting DBS-STN. CONCLUSIONS: PD patients with motor fluctuations, with lower Harm Avoidance and higher Self-Directedness scores have the best QoL mainly at an emotional and social level. Therapeutic education of these PD patients focusing on their personal resources may thus be important to improve their well-being.