Bilateral subthalamic deep brain stimulation initial impact on nonmotor and motor symptoms in Parkinson's disease: An open prospective single institution study

Effect of deep brain stimulation on sexual dysfunction among patients who had Parkinson's disease: a systematic review and meta-analysis

BACKGROUND

Patients who have Parkinson's disease (PD) present several non-motor issues, such as sexual dysfunction. Deep brain stimulation (DBS) is a great treatment for PD and could affect both motor and non-motor symptoms of patients.

AIM

The main goal of the current study is to evaluate the impact of DBS on the sexual dysfunction among patients with PD.

METHODS

Five databases (PubMed, Scopus, Embase, Web of Science, and Cochrane Library) were searched for records. Studies that measured the effect of DBS sexual function were included. The risk of bias assessment tool of non-randomized studies of interventions (ROBINS-I) was used to assess the quality of the included studies. The before and after data extraction and statistical analysis were performed using the Comprehensive Meta-analysis software (CMA) version 3.0.

RESULT

Ten studies were included in the systematic review; six of them were eligible to perform a meta-analysis with a total sample size of 532 participants and a mean age of 62.21 ± 1.59 years. All participants performed STN-DBS. The sexual function of participants after STN-DBS implantation significantly increased (SMD = -0.124, 95% CI: -0.209 to -0.038, P-value = 0.005). It also did not have any publication bias. Additionally, their quality of life mounts significantly (SMD = -0.712, 95% CI: -1.002 to -0.422, p-value <0.001).

CONCLUSION

Our systematic review highlights the potential effect of STN-DBS on reducing the sexual dysfunction of patients with PD and boosting their quality of life.

Impact of deep brain stimulation on urogenital function in Parkinson's disease: a systematic review and meta-analysis

Objectives

Deep Brain Stimulation (DBS) effectively treats Parkinson's motor symptoms, but its effects on the urogenital system are debated.

Methods

A research was conducted in PubMed, Embase, Cochrane Library, Web of Science, and Scopus until February 27, 2024. We primarily focused on DBS's impact on Parkinson's patients' Urine storage function, voiding function, sexual function, and quality of life.

Results

Our meta-analysis included 14 studies. The main results showed that DBS resulted in fewer instances of urinary urgency (OR = 1.85, 95% CI: 1.26 to 2.70, p = 0.002) and increased maximum bladder capacity (MD = -66.10, 95% CI: -119.37 to -12.82, p = 0.02) in terms of urinary storage function. However, there were no significant differences in first desire to void and strong desire to void. In terms of voiding function, DBS showed significant improvements in maximum flow rate (MD = -0.64, 95% CI: -1.23 to -0.05, p = 0.03), post-void residual (MD = -6.79, 95% CI: 4.54 to 9.05, P < 0.00001) and detrusor pressure during maximum flow (MD = -1.37, 95% CI: -2.73 to -0.02, p = 0.05). Additionally, there was no significant difference in sexual function between the two groups (MD = -1.41, 95% CI: -12.40 to 9.57, p = 0.80).

Conclusion

DBS has demonstrated a certain degree of efficacy in ameliorating urinary storage and voiding function in patients with Parkinson's disease. However, certain urodynamic parameters or scores do not demonstrate any statistically significant disparities. Furthermore, DBS has no significant impact on erectile function in male Parkinson's patients.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023476661, identifier CRD42023476661.

Alterations of non-motor symptoms in Parkinson's disease, after of subthalamic deep brain stimulation

The effect of subthalamic deep brain stimulation (STN DBS) on motor symptoms of Parkinson's disease (PD) has been thoroughly analyzed. The influence of STN DBS on non-motor symptoms (NMS) is still debatable. We analyzed the effect of STN DBS on NMS in PD.

Materials and methods

17 PD patients were qualified for STN DBS according to CAPSIT-PD criteria. Demographic data and clinical status according to the Hoehn-Yahr (H-Y) were recorded. The efficacy of STN DBS on NMS was measured with the NMS Scale before surgery and twelve months after surgery.

Results

Global NMS Scale score decreased by 1-75 points (mean 25,67) in 12 patients. No improvement or deterioration was reported in 5 patients (29%). The mean age of the improved group was 56 years and 59,8 years in the non-improved group. The mean duration of PD in the improved group was 11 years and 21 years in the non-improved group. In the non-improved group, four patients were rated 4 and one patients 3 according to the H-Y Scale. In the improved group, two patients were rated 4, six patients 3 and four patients 2 according to the H-Y Scale The most significant improvement of the NMS Scale was recorded in the domain IV- Perceptual problems/Hallucinations- (by 77%), domain I- Cardiovascular including falls- (by 68%) and domain III- Mood/Cognition- (by 58%). Deterioration of the NMS Scale was reported in the domain IX- Miscellaneous- (by 10%) and the domain VII- Urinary- (by 6%).

Conclusions

STN DBS has a positive impact on NMS among PD patients. The most important factors that influence improvement are: young age, short disease duration, and good clinical status measured with the H-Y Scale. The NMS Scale domains that tend to respond the best are the domains I, III and IV. The NMS Scale domains that might deteriorate after STN DBS are the domains VII and IX.

Short term cardiovascular symptoms improvement after deep brain stimulation in patients with Parkinson's disease: a systematic review

BACKGROUND

Autonomic dysfunction is common and disabling in Parkinson's disease (PD). The effects of deep brain stimulation (DBS) on the cardiovascular system in PD remain poorly understood. We aimed to assess the effect of DBS on cardiovascular symptoms and objective measures in PD patients.

METHODS

We conducted a systematic literature search in PubMed/MEDLINE.

RESULTS

36 out of 472 studies were included, mostly involving DBS of the subthalamic nucleus, and to a lesser extent the globus pallidus pars interna and pedunculopontine nucleus. Seventeen studies evaluated the effect of DBS on patient-reported or clinician-rated cardiovascular symptoms, showing an improvement in the first year after surgery but not with longer-term follow-up. DBS has no clear direct effects on blood pressure during an orthostatic challenge (n = 10 studies). DBS has inconsistent effects on heart rate variability (n = 10 studies).

CONCLUSION

Current evidence on the impact of DBS on cardiovascular functions in PD is inconclusive. DBS may offer short-term improvement of cardiovascular symptoms in PD, particularly orthostatic hypotension, which may be attributed to dopaminergic medication reduction after surgery. There is insufficient evidence to draw conclusions on the direct effect of DBS on blood pressure and heart rate variability.

Neuroprosthetics: from sensorimotor to cognitive disorders

Neuroprosthetics is a multidisciplinary field at the interface between neurosciences and biomedical engineering, which aims at replacing or modulating parts of the nervous system that get disrupted in neurological disorders or after injury. Although neuroprostheses have steadily evolved over the past 60 years in the field of sensory and motor disorders, their application to higher-order cognitive functions is still at a relatively preliminary stage. Nevertheless, a recent series of proof-of-concept studies suggest that electrical neuromodulation strategies might also be useful in alleviating some cognitive and memory deficits, in particular in the context of dementia. Here, we review the evolution of neuroprosthetics from sensorimotor to cognitive disorders, highlighting important common principles such as the need for neuroprosthetic systems that enable multisite bidirectional interactions with the nervous system.

Downregulation of CDK5 signaling in the dorsal striatum alters striatal microcircuits implicating the association of pathologies with circadian behavior in mice

Dysfunction of striatal dopaminergic circuits has been implicated in motor impairment and Parkinson’s disease (PD)-related circadian perturbations that may represent an early prodromal marker of PD. Cyclin-dependent kinase 5 (CDK5) negatively regulates dopamine signaling in the striatum, suggesting a critical role of CDK5 in circadian and sleep disorders. Here, we used clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 gene editing to produce mice with a dorsal striatum (DS)-specific knockdown (KD) of the Cdk5 gene (referred to as DS-CDK5-KD mice) and investigate its role in vivo. DS-CDK5-KD mice exhibited deficits in locomotor activity and disturbances in activity/rest behavior. Additionally, Golgi staining of neurons in the DS revealed that CDK5 deletion reduced dendrite length and the number of functional synapses, which was confirmed by significant downregulation of MAP2, PSD-95, and synapsin I. Correlated with this, DS-CDK5-KD mice displayed reduced phosphorylation of Tau at Thr181. Furthermore, whole-cell patch-clamp recordings of green fluorescent protein-tagged neurons in the striatum of DS-CDK5-KD mice revealed a decreased frequency of spontaneous inhibitory postsynaptic currents and altered excitatory/inhibitory synaptic balance. Notably, anterograde labeling showed that CDK5 KD in the DS disrupted long-range projections to the secondary motor cortex, dorsal and ventral thalamic nuclei, and basolateral amygdala, which are involved in the regulation of motor and circadian rhythms in the brain. These findings support a critical role of CDK5 in the DS in maintaining the striatal neural circuitry underlying motor functions and activity/rest associated with circadian rhythms that are perturbed in neurodegenerative disorders.

Effects of subthalamic deep brain stimulation on non-motor symptoms of Parkinson's disease: A meta-analysis

Deep brain stimulation (DBS) is a well-defined treatment for motor symptoms in advanced PD. Although several studies have investigated the DBS effect on non-motor symptoms (NMS), controversial results exist regarding this matter. The aim of this meta-analysis and systematic review was to assess the bilateral subthalamic nucleus (STN) DBS effect on NMS of PD. We conducted a systematic search on the literature of Web of Science (WOS), PubMed/MEDLINE, Scopus, Cochrane, and Embase. An additional hand search was also done. Finally, a meta-analysis was conducted on 10 studies containing pre- and post-bilateral STN-DBS data regarding NMS acquired using Non-Motor Symptoms Scale for Parkinson's Disease (NMSS) or Non-Motor Symptoms Questionnaire (NMSQ). A random-effects model was used to determine weighted mean differences, and the heterogeneity index was evaluated using Cochrane's Q test. Our study results indicated that bilateral STN-DBS significantly reduced total NMSS and NMSQ score (WMD -17.73; 95% confidence interval [CI] -20.28 to -15.18, WMD -2.19; 95% CI -2.98 to -1.40), respectively, and no publication bias was found. Regarding each of the NMSS domains, DBS significantly reduced the scores of following domains: sleep (WMD -5.98; 95% CI -6.82 to -5.15), miscellaneous (WMD -4.19; 95% CI -4.96 to -3.43), urinary (WMD -2.99; 95% CI -3.78 to -2.19), sexual (WMD -0.65; 95% CI -1.16 to -0.14), and attention/memory (WMD -0.59; 95% CI -1.15 to -0.03). This meta-analysis demonstrated that bilateral STN-DBS has beneficial effects on NMS of PD.

Prevalence, clinical presentations and impact on relationship of sexual dysfunction in Parkinson's Disease

Sexual dysfunction is one of the commonest non-motor symptoms in Parkinson's disease (PD) and has been found about twice as high in PD patients compared to age-matched controls. The quality of sexual life is reduced in PD patients compared to healthy peers and impairment affects wide aspects of physical sexual function as well as sexual desire, sexual satisfaction and sexual partnership. Overall, male PD patients are more frequently affected by sexual disorders than females and seem to suffer more from sexual impairment. The reported frequencies and presentations of various sexual dysfunctions vary widely in the literature, which is likely related to the patient cohorts examined, in particular with regard to age and gender, duration and severity of disease and applied measurement instruments. This chapter gives an overview of the prevalence, phenotype and clinical presentation of sexual dysfunction in PD and its influence on the partnership.

Subthalamic nucleus-deep brain stimulation improves autonomic dysfunctions in Parkinson's disease

Background

To study the effects of subthalamic nucleus-deep brain stimulation (STN-DBS) on autonomic dysfunctions in Parkinson’s disease (PD) patients.

Methods

A total of 57 PD patients who underwent bilateral STN-DBS from March to December 2018, were retrospectively analyzed. Preplanned assessments at baseline and postoperatively at 1, 3, and 6 months also included the Scales for Outcomes in Parkinson’s Disease-Autonomic questionnaire (SCOPA-Aut), the Unified Parkinson’s Disease Rating Scale (UPDRS) III score, levodopa equivalent day dose (LEDD), Parkinson’s Disease Quality of Life Scale (PDQ-39), the Hamilton Anxiety Rating Scale (HAMA), and the Hamilton Depression Rating Scale (HAMD).

Results

The SCOPA-Aut scores improved significantly [14.59% (18.32%), 24.00% (27.05%), 22.16% (27.07%), all P < 0.001] at 1 month, 3 months, and 6 months of STN-DBS, respectively. Analysis of the SCOPA-Aut sub-items showed significant improvements only in urine and thermoregulation sub-items at 6 months after surgery (P < 0.001). There was no significant correlation between improvements of SCOPA-Aut scores and improvements of PDQ-39 scores (P > 0.05) at 6 months after surgery. SCOPA-Aut scores were positively correlated with age (r = 0.428, P = 0.001); the improvements of SCCOPA-Aut scores were positively correlated with improvements of HAMA and HAMD scores (HAMA: r = 0.325, P = 0.015; HAMD: r = 0.265, P = 0.049) at 6 months after surgery.

Conclusion

STN-DBS improved autonomic dysfunction symptoms of PD patients, and urinary and thermoregulatory sub-items of autonomic dysfunction were improved in the short-term after surgery. There was a close relationship between improved autonomic symptoms and improved anxiety and depression 6 months after surgery. We should therefore direct more attention to autonomic dysfunctions in PD involving detailed preoperative evaluations and postoperative follow-ups, to improve the quality of life of patients.

The Impact of Deep Brain Stimulation on Sleep in Parkinson's Disease: An update

Background:

Parkinson’s disease (PD) can have a significant impact on sleep. Deep brain stimulation (DBS) is an effective treatment for motor features of PD, but less is understood about the impact DBS may have on sleep architecture and various sleep issues commonly seen in PD.

Objective:

To review the impact of DBS on various sleep issues in PD.

Methods:

We reviewed the literature regarding the impact of DBS on sleep patterns, nocturnal motor and non-motor symptoms, and sleep disorders in PD.

Results:

Objective sleep measures on polysomnography (PSG), including sleep latency and wake after sleep onset improve after subthalamic nucleus (STN) and globus pallidus interna (GPi) DBS. Subjective sleep measures, nocturnal motor symptoms, and some non-motor symptoms (nocturia) also may improve. Current evidence suggests STN DBS has no impact on Rapid Eye Movement Behavior Disorder (RBD), while STN DBS may improve symptoms of Restless Legs Syndrome (RLS). There are no studies that have evaluated the impact of GPi DBS on RBD, while it is unclear if GPi has an effect on RLS in PD.

Conclusion:

DBS therapy at either site appears to improve objective and subjective sleep parameters in patients with PD. Most likely, the improvement of motor and some non-motor nocturnal symptoms leads to an increase in total sleep time by up to an hour, as well as reduction of sleep fragmentation. DBS most likely has no impact on RBD, while there is evidence that STN DBS appears to help reduce RLS severity. Further studies are needed.

Deep brain stimulation electrode position impact on parkinsonian non-motor symptoms

BACKGROUND

In this study we evaluated the impact of location of deep brain stimulation electrode active contact in different parts of the subthalamic nucleus on improvement of non-motor symptoms in patients with Parkinson's disease.

METHODS

The subthalamic nucleus was divided into two (dorsolateral/ventromedial) and three (dorsolateral, medial, ventromedial) parts. 37 deep brain stimulation electrodes were divided according to their active contact location. Correlation between change in non-motor symptoms before and one and four months after deep brain stimulation electrode implantation and the location of active contact was made.

RESULTS

In dividing the subthalamic nucleus into three parts, no electrode active contact was placed ventromedially, 28 active contacts were located in the medial part and 9 contacts were placed dorsolaterally. After one and four months, no significant difference was found between medial and dorsolateral positions. In the division of the subthalamic nucleus into two parts, 13 contacts were located in the ventromedial part and 24 contacts were placed in the dorsolateral part. After one month, significantly greater improvement in the Non-motor Symptoms Scale for Parkinson's disease (P=0.045) was found on dorsolateral left-sided stimulation, but no significant differences between the ventromedial and dorsolateral positions were found on the right side.

CONCLUSION

This study demonstrated the relationship between improvement of non-motor symptoms and the side (hemisphere, left/right) of the deep brain stimulation electrode active contact, rather than its precise location within specific parts of the subthalamic nucleus in patients treated for advanced Parkinson's disease.

Subthalamic deep brain stimulation improves sleep and excessive sweating in Parkinson’s disease

Parkinson’s disease (PD) is a complex multisystem disorder with motor and non-motor symptoms (NMS). NMS may have an even greater impact on quality of life than motor symptoms. Subthalamic nucleus deep brain stimulation (STN-DBS) has been shown to improve motor fluctuations and quality of life, whereas the effects on different NMS have been less examined. Sleep disturbances and autonomic dysfunction are among the most prevalent NMS. We here report the efficacy of STN-DBS on sleep disturbances and autonomic dysfunction. In the parent trial, 60 patients were included in a single-center randomized prospective study, with MDS-UPDRS III and PDQ-39 as primary endpoints at 12 months of STN-DBS. Preplanned assessments at baseline and postoperatively at 3 and 12 months also included Parkinson’s Disease Sleep Scale (PDSS); Scopa-Aut; and MDS-UPDRS I, II, and IV. We found that STN-DBS had a significant and lasting positive effect on overall sleep quality, nocturnal motor symptoms and restlessness, and daytime dozing. Several aspects of autonomic dysfunction were also improved at 3 months postoperatively, although at 12 months only thermoregulation (sudomotor symptoms) remained significantly improved. We could not identify preoperative factors that predicted improvement in PDSS or Scopa-Aut. There was a close relationship between improved autonomic symptoms and improved quality of life after 1 year. NMS and especially sleep and autonomic dysfunction deserve more focus to improve patient outcomes further.

A quantitative analysis of the effect of bilateral subthalamic nucleus-deep brain stimulation on subjective and objective sleep parameters in Parkinson's disease

OBJECTIVE

To explore how subjective and objective sleep parameters respond to bilateral subthalamic nucleus-deep brain stimulation (STN-DBS) in patients with Parkinson's disease (PD).

METHODS

Thirty DBS sleep studies were included by searching PubMed, Embase, and the Cochrane Library, and only 21 prospectively designed studies, including 541 patients, were eligible for the main analysis. We evaluated sleep disturbance using 1 objective measurement, polysomnography (PSG), and 4 subjective scales, including PD Sleep Scale (PDSS), Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), and restless legs syndrome (RLS). We pooled data using the standard mean difference (SMD). The primary outcome was a change in sleep parameters 6 months postoperatively. Outcomes from <12 months to ≥12 months follow-up were compared in the subgroup analysis. Meta-regression was further conducted.

RESULTS

STN-DBS significantly improved all 4 subjective sleep scales in the 6-month follow-up: ESS (SMD = 0.234), PDSS (SMD = 0.724), PSQI (SMD = 1.374) and RLS (SMD = 1.086), while most PSG parameters remained unchanged, except for shortened rapid eye movement sleep latency (RSL) (SMD = 0.520). In the over-12-month follow-up, improvement persisted in PDSS but not in ESS. Dopamine drug reduction (p = 0.009) and motor improvement (p = 0.036) were correlated with ESS improvement and PDSS improvement, respectively.

CONCLUSIONS

Bilateral STN-DBS continuously improved subjective nocturnal sleep, while its effect on ESS lasted for only 1 year. Medication reduction and motor improvement may contribute to improved daytime sleepiness and better subjective nocturnal sleep, respectively. Except for a shortened RSL, STN-DBS did not change PSG parameters, including sleep efficiency and sleep architecture.

REGISTRATION

Open Science Framework: DOI 10.17605/OSF.IO/3EGRC.

Sleep Issues in Parkinson's Disease and Their Management

Parkinson's disease (PD) is an alpha-synucleinopathy that leads to prominent motor symptoms including tremor, bradykinesia, and postural instability. Nonmotor symptoms including autonomic, neurocognitive, psychiatric symptoms, and sleep disturbances are also seen frequently in PD. The impact of PD on sleep is related to motor and nonmotor symptoms, in addition to the disruption of the pathways regulating sleep by central nervous system pathology. Rapid eye movement sleep behavior disorder is a parasomnia that can lead to self-injury and/or injury to partners at night. Restless legs syndrome is a subjective sensation of discomfort and urge to move the legs prior to falling asleep and can lead to insomnia and reduced sleep quality. Excessive daytime sleepiness is common in PD and exerts a negative impact on quality of life in addition to increasing the risk of falls. Obstructive sleep apnea is a breathing disorder during sleep that can cause frequent awakenings and excessive daytime sleepiness. Circadian rhythm dysfunction can lead to an advanced or delayed onset of sleep in patients and create disruption of normal sleep and wake times. All of these disorders are common in PD and can significantly reduce sleep quantity, sleep quality, or quality of life for patients and caretakers. Treatment approaches for each of these disorders are distinct and should be individualized to the patient. We review the literature regarding these common sleep issues encountered in PD and their treatment options.

A prospective, controlled study of non-motor effects of subthalamic stimulation in Parkinson's disease: results at the 36-month follow-up

OBJECTIVE

To examine 36-month effects of bilateral subthalamic nucleus deep brain stimulation (STN-DBS) on non-motor symptoms (NMS) compared with standard-of-care medical treatment (MED) in Parkinson's disease (PD).

METHODS

Here we report the 36-month follow-up of a prospective, observational, controlled, international multicentre study of the NILS cohort. Assessments included NMSScale (NMSS), PDQuestionnaire-8 (PDQ-8), Scales for Outcomes in PD (SCOPA)-motor examination, -activities of daily living, and -complications, and levodopa equivalent daily dose (LEDD). Propensity score matching resulted in a pseudo-randomised sub-cohort balancing baseline demographic and clinical characteristics between the STN-DBS and MED groups. Within-group longitudinal outcome changes were analysed using Wilcoxon signed-rank and between-group differences of change scores with Mann-Whitney U test. Strength of clinical responses was quantified with Cohen's effect size. In addition, bivariate correlations of change scores were explored.

RESULTS

Propensity score matching applied on the cohort of 151 patients (STN-DBS n=67, MED n=84) resulted in a well-balanced sub-cohort including 38 patients per group. After 36 months, STN-DBS significantly improved NMSS, PDQ-8, SCOPA-motor examination and -complications and reduced LEDD. Significant between-group differences, all favouring STN-DBS, were found for NMSS, SCOPA-motor complications, LEDD (large effects), motor examination and PDQ-8 (moderate effects). Furthermore, significant differences were found for the sleep/fatigue, urinary (large effects) and miscellaneous NMSS domains (moderate effects). NMSS total and PDQ-8 change scores correlated significantly.

CONCLUSIONS

This study provides Class IIb evidence for beneficial effects of STN-DBS on NMS at 36-month follow-up which also correlated with quality of life improvements. This highlights the importance of NMS for DBS outcomes assessments.

The Impact of Deep Brain Stimulation on the Sexual Function of Patients With Parkinson's Disease

BACKGROUND

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is used in the treatment of advanced Parkinson's disease (PD) with well-established benefits over motor complications. However, few studies addressing the impact of DBS on nonmotor dimensions such as sexual function have been conducted. This study aims to determine the effect of DBS-STN on the sexual activity of patients with PD and to establish predictive factors for sexual function decline after surgery.

MATERIALS AND METHODS

Twenty-one patients with PD submitted to DBS-STN were compared with 19 eligible surgery candidates. Clinical measures included disease progression (Hoehn and Yahr scale), sexual function evaluation (Female Sexual Function Index and International Index of Erectile Function), severity of depressive symptoms (Beck Depressive Inventory-II), motor symptoms (Movement Disorders Society-Unified Parkinson's Disease Rating Scale Part III), and quality of life (39-item Parkinson's Disease Questionnaire). The primary outcomes were the development of sexual dysfunction in women and erectile dysfunction in men. Regression analysis was performed to outline risk factors for developing sexual function deterioration.

RESULTS

Erectile dysfunction was present in 83.3% of men and sexual dysfunction in 77.8% of women treated with DBS-STN. Women with sexual dysfunction had higher emotional well-being 39-item Parkinson's Disease Questionnaire scores (P=0.017) and a higher prevalence of cardiovascular diseases (P=0.012) comparing with women without sexual dysfunction. Age was an independent predictive factor for developing erectile dysfunction in men (relative risk=1.26; P=0.033) and sexual dysfunction in women (relative risk =1.30; P=0.039), regardless of DBS-STN submission.

CONCLUSIONS

Sexual function in both sexes of patients with PD does not seem to be influenced by DBS-STN itself, but by psychological and clinical features.

Clinical Impact of Deep Brain Stimulation on the Autonomic System in Patients with Parkinson's Disease

Background

The role of deep brain stimulation (DBS) in the management of motor symptoms in patients with Parkinson's disease is well defined. However, it is becoming increasingly clear that DBS can either improve or worsen a number of non-motor phenomena.

Objectives

We examined the published literature to better understand the effects on autonomic symptoms following DBS of the subthalamic nucleus and the globus pallidus interna.

Methods

We conducted a PubMed search of studies regarding the effects of DBS on the autonomic system published from January 2001. We searched for the following terms and their combinations: Parkinson's disease, deep brain stimulation, subthalamic nucleus, globus pallidus interna, autonomic dysfunction.

Results

Most studies reported in the literature focus on DBS targeting the subthalamic nucleus, with particular emphasis on favorable outcomes regarding gastrointestinal function and bladder control. However, the emergence or worsening of autonomic symptoms in subgroups of patients has also been documented. More controversial is the effect of stimulation on the cardiovascular, pulmonary, and thermo-regulatory systems as well as sexual functioning. Data regarding the influence of DBS on the autonomic system when the target is the globus pallidus interna is less forthcoming, with target selection varying according to centre and clinical indication.

Conclusions

DBS appears to affect the autonomic nervous system, with varying degrees of influence, which may or may not be clinically beneficial for the patient. A better understanding of these effects could help personalize stimulation for individual patients with autonomic disorders and/or avoid autonomic symptoms in susceptible patients.

Pilot Study of the International Parkinson and Movement Disorder Society-sponsored Non-motor Rating Scale (MDS-NMS)

Background

Non-motor symptoms (NMS) are integral to Parkinson's disease (PD) and have a detrimental effect on patients and their caregivers. Clinical quantification has been aided by the development of comprehensive assessments such as the Non-Motor Symptoms Questionnaire (NMSQuest) and Scale (NMSS). The NMSS has been widely used in clinical studies and trials; however, since its validation in 2007, our understanding of NMS has changed substantially. With the support of the International Parkinson and Movement Disorder Society (IPMDS), after a detailed peer review an initiative to develop an updated version of NMSS, the MDS-NMS was launched in 2015.

Objective

This paper encapsulates the data from the pre-validation phases carried out under the auspices of the IPMDS Non-Motor PD Study Group.

Methods

Item selection and wording (formatted as a rater-based tool) were based on the NMSS, literature review, and expert consensus. Neurologists, PD patients, and healthy controls were included in the cognitive pretesting and administration of the preliminary version of the MDS-NMS. Primary data on acceptability and reliability were obtained.

Results

The pilot study, carried out in English in the United Kingdom and the United States, demonstrated that the preliminary version of the MDS-NMS was comprehensive, understandable, and appropriate. Data quality was excellent; moderate floor effect was present in patients for most MDS-MNS domains, with some components showing weak internal consistency. The results led to additional instrument modifications.

Conclusion

Qualitative and quantitative research results have led to an updated NMSS, the definitive version of the MDS-NMS, which is currently being validated.