‘Woe Betides Anybody Who Tries to Turn me Down.’ A Qualitative Analysis of Neuropsychiatric Symptoms Following Subthalamic Deep Brain Stimulation for Parkinson’s Disease

Public Perceptions of Neurotechnologies Used to Target Mood, Memory, and Motor Symptoms

Background

Advances in the development of neurotechnologies have the potential to revolutionize treatment of brain-based conditions. However, a critical concern revolves around the willingness of the public to embrace these technologies, especially considering the tumultuous histories of certain neurosurgical interventions. Therefore, examining public attitudes is paramount to uncovering potential barriers to adoption ensuring ethically sound innovation.

Methods

In the present study, we investigate public attitudes towards the use of four neurotechnologies (within-subjects conditions): deep brain stimulation (DBS), transcranial magnetic stimulation (TMS), pills, and MRI-guided focused ultrasound (MRgFUS) as potential treatments to a person experiencing either mood, memory, or motor symptoms (between-subjects conditions). US-based participants (N=1052; stratified to be nationally representative based on sex, race, age) were asked about their perceptions of risk, benefit, invasiveness, acceptability, perceived change to the person, and personal interest in using these neurotechnologies for symptom alleviation.

Results

Descriptive results indicate variability between technologies that the U.S. public is willing to consider if experiencing severe mood, memory, or motor symptoms. The main effect of neurotechnology revealed DBS was viewed as the most invasive and risky treatment and was perceived to lead to the greatest change to who someone is as a person. DBS was also viewed as least likely to be personally used and least acceptable for use by others. When examining the main effects of symptomatology, we found that all forms of neuromodulation were perceived as significantly more beneficial, acceptable, and likely to be used by participants for motor symptoms, followed by memory symptoms, and lastly mood symptoms. Neuromodulation (averaging across neurotechnologies) was perceived as significantly riskier, more invasive, and leading to a greater change to person for mood versus motor symptoms; however, memory and motor symptoms were perceived similarly with respect to risk, invasiveness, and change to person.

Conclusion

These results suggest that the public views neuromodulatory approaches that require surgery (i.e., DBS and MRgFUS) as riskier, more invasive, and less acceptable than those that do not. Further, findings suggest individuals may be more reluctant to alter or treat psychological symptoms with neuromodulation compared to physical symptoms.

Caregivers' burden and deep brain stimulation for Parkinson disease: A systematic review of qualitative studies

BACKGROUND AND PURPOSE

The impact of subthalamic nucleus deep brain stimulation (STN-DBS) on caregivers' burden is understudied. We perform a systematic review and meta-synthesis aggregating qualitative studies involving partners of people with Parkinson disease (PwP) to explore their experiences and unmet needs.

METHODS

A systematic review for retrieving qualitative studies included six databases: MEDLINE, Embase, CINAHL, Cochrane, PsycInfo, and Scopus. Inclusion criteria were as follows: (i) studies on the experience of caregivers of PwP in the context of STN-DBS, (ii) English peer-reviewed articles, and (iii) qualitative or mixed methods studies reporting caregivers' quotations. After the appraisal of included studies, we performed meta-synthesis of qualitative findings. Descriptive themes and conceptual elements related to PwP partners' experiences and unmet needs were generated.

RESULTS

A total of 1108 articles were screened, and nine articles were included. Three categories were identified: (i) dealing with Parkinson disease (PD) every day (the starting situation characterized by the impact of PD on ordinary life; the limitations to partners' socialization; partners' efforts in stepping aside for love and care activities), (ii) facing life changes with STN-DBS (the feeling of being unprepared for changes; the fear and concern due to loved ones' behavioral changes; struggling to find an explanation for those changes), and (iii) rebuilding the role of caregiver and partner after STN-DBS.

CONCLUSIONS

This meta-synthesis elucidates concerns, challenges, and unmet needs of partners of PwP who underwent STN-DBS. It is important to provide them with information, education, and adequate support to face these challenges. Professionals need to involve partners in the care and decision process, because STN-DBS-related outcomes do not depend solely on the well-being of PwP but also on the well-being of individuals surrounding them.

Researcher Views on Changes in Personality, Mood, and Behavior in Next-Generation Deep Brain Stimulation

The literature on deep brain stimulation (DBS) and adaptive DBS (aDBS) raises concerns that these technologies may affect personality, mood, and behavior. We conducted semi-structured interviews with researchers (n = 23) involved in developing next-generation DBS systems, exploring their perspectives on ethics and policy topics including whether DBS/aDBS can cause such changes. The majority of researchers reported being aware of personality, mood, or behavioral (PMB) changes in recipients of DBS/aDBS. Researchers offered varying estimates of the frequency of PMB changes. A smaller majority reported changes in personality specifically. Some expressed reservations about the scientific status of the term 'personality,' while others used it freely. Most researchers discussed negative PMB changes, but a majority said that DBS/aDBS can also result in positive changes. Several researchers viewed positive PMB changes as part of the therapeutic goal in psychiatric applications of DBS/aDBS. Finally, several discussed potential causes of PMB changes other than the device itself.

Participant perceptions of changes in psychosocial domains following participation in an adaptive deep brain stimulation trial

BACKGROUND

There has been substantial controversy in the neuroethics literature regarding the extent to which deep brain stimulation (DBS) impacts dimensions of personality, mood, and behavior.

OBJECTIVE/HYPOTHESIS

Despite extensive debate in the theoretical literature, there remains a paucity of empirical data available to support or refute claims related to the psychosocial changes following DBS.

METHODS

A mixed-methods approach was used to examine the perspectives of patients who underwent DBS regarding changes to their personality, authenticity, autonomy, risk-taking, and overall quality of life.

RESULTS

Patients (n = 21) who were enrolled in adaptive DBS trials for Parkinson's disease, essential tremor, obsessive-compulsive disorder, Tourette's syndrome, or dystonia participated. Qualitative data revealed that participants, in general, reported positive experiences with alterations in what was described as 'personality, mood, and behavior changes.' The majority of participants reported increases in quality of life. No participants reported 'regretting the decision to undergo DBS.'

CONCLUSION(S)

The findings from this patient sample do not support the narrative that DBS results in substantial adverse changes to dimensions of personality, mood, and behavior. Changes reported as "negative" or "undesired" were few in number, and transient in nature.

Caregiver Burden and Quality of Life of Caregivers for Patients with Parkinson's Disease Treated with Deep Brain Stimulation

Objective

This study aimed to identify caregiver burden (CB) and contributing factors to CB for Parkinson's disease (PD) patients under Subthalamic Nucleus Deep Brain Stimulation (STN-DBS) treatment, and investigation the factors, affecting the caregivers' quality of life (QoL).

Methods

Twenty-four PD patients under STN-DBS treatment and their caregivers participated in this study. Unified Parkinson's Disease Rating Scale (UPDRS) was applied for the clinical assessment of the patients. Beck Depression Inventory-II (BDI), Hospital Anxiety and Depression Scale (HADS), and Minnesota Impulse Control Disorders Interview (MIDI) were used to screen for neuropsychiatric symptoms of the patients. CB was evaluated with the Caregivers Burden Inventory (CBI) and the Burden Scale for Family Caregivers (BSFC-s). The health-related QoL of caregivers was assessed with the Short Form Survey-36 (SF-36).

Results

Mean total CBI and BSFC-s scores of caregivers were 32.53 ± 19.71 and 11.66 ± 8.86, respectively. Nineteen caregivers defined moderate or severe caregiver burden according to BSFC-s. Both CBI and BSFC-s scores were significantly associated with UPDRS-part-1 scores, but not with the age and gender of both the patients and their caregivers, disease duration, PDQ39, BDI, HADS, LARS scores, and scores of patients for other UPDRS parts. The presence of impulse control behaviors (ICBs) significantly increased the total CBI score and total BSFC-s (P < 0.01). The caregivers' total and all domain scores of SF-36 were significantly affected by higher CBI and BSFC-s scores.

Conclusions

The CB of the patients under STN-DBS treatment was severe. Non-motor symptoms, particularly impulsivity, significantly increased CB and worsened the caregivers' mental and physical health.

"Nothing to Lose, Absolutely Everything to Gain": Patient and Caregiver Expectations and Subjective Outcomes of Deep Brain Stimulation for Treatment-Resistant Depression

Background: How "success" is defined in clinical trials of deep brain stimulation (DBS) for refractory psychiatric conditions has come into question. Standard quantitative psychopathology measures are unable to capture all changes experienced by patients and may not reflect subjective beliefs about the benefit derived. The decision to undergo DBS for treatment-resistant depression (TRD) is often made in the context of high desperation and hopelessness that can challenge the informed consent process. Partners and family can observe important changes in DBS patients and play a key role in the recovery process. Their perspectives, however, have not been investigated in research to-date. The aim of this study was to qualitatively examine patient and caregivers' understanding of DBS for TRD, their expectations of life with DBS, and how these compare with actual experiences and outcomes. Methods: A prospective qualitative design was adopted. Semi-structured interviews were conducted with participants (six patients, five caregivers) before DBS-implantation and 9-months after stimulation initiation. All patients were enrolled in a clinical trial of DBS of the bed nucleus of the stria terminalis. Interviews were thematically analyzed with data saturation achieved at both timepoints. Results: Two primary themes identified were: (1) anticipated vs. actual outcomes, and (2) trial decision-making and knowledge. The decision to undergo DBS was driven by the intolerability of life with severe depression coupled with the exhaustion of all available treatment options. Participants had greater awareness of surgical risks compared with stimulation-related risks. With DBS, patients described cognitive, emotional, behavioral and physical experiences associated with the stimulation, some of which were unexpected. Participants felt life with DBS was like "a roller coaster ride"-with positive, yet unsustained, mood states experienced. Many were surprised by the lengthy process of establishing optimum stimulation settings and felt the intervention was still a "work in progress." Conclusion: These findings support existing recommendations for iterative informed consent procedures in clinical trials involving long-term implantation of neurotechnology. These rich and descriptive findings hold value for researchers, clinicians, and individuals and families considering DBS. Narrative accounts capture patient and family needs and should routinely be collected to guide patient-centered approaches to DBS interventions.

Parkinson's Disease and Deep Brain Stimulation Have an Impact on My Life: A Multimodal Study on the Experiences of Patients and Family Caregivers

Parkinson’s disease (PD) has a large impact on patients’ physical and mental health, which also greatly affects their family caregivers. Deep brain stimulation (DBS) has emerged as an effective treatment for PD, but different authors have expressed their concerns about the potential impact of DBS on personality and identity. Our study aims at better understanding how patients and family caregivers experience life with PD and DBS, the impact of both on their personal and social lives, and their perception of the changes that have occurred as a result of the disease and the treatment. Our study applies a multimodal approach by means of narrative semi-structured interviews and drawings. Seven principal themes have been identified: “everyone’s Parkinson’s is different”, “changing as a person during the disease”, “going through Parkinson’s together”, “DBS improved my life”, “I am treated with DBS but I have Parkinson’s still”, “DBS is not perfect”, and “being different after DBS”. PD is perceived as an unpredictable and heterogeneous disease that changes from person to person, as does the effect of DBS. While DBS side-effects may have an impact on patients’ personality, behavior, and self-perception, PD symptoms and drug side-effects also have a great impact on these aspects.

A Pilot Trial of Cognitive Behavioral Therapy for Caregivers After Deep Brain Stimulation for Parkinson's Disease

Subthalamic deep brain stimulation for Parkinson's disease may not ameliorate burden among caregivers. An 8-session, manualized program of cognitive-behavioral therapy (CBT) was delivered to a pilot sample of 10 caregivers (6 females, mean age: 60, age range: 34-79). Primary outcome measures were caregiver burden (Zarit Burden Interview) and caregiver quality of life (Parkinson's Disease Questionnaire-Carer). Secondary outcome measures comprised ratings of depression and anxiety in the caregiver, in addition to relationship quality. Caregiver burden (t = 2.91 P = .017) and caregiver anxiety (t = 2.82 P = .020) symptoms were significantly reduced at completion of the program, and these benefits were maintained 3 months later. Caregiver quality of life had significantly improved by the end of the intervention (t = 3.02 P = .015), but this effect was not sustained after 3 months. The longitudinal influence of participation in the program on caregiver burden was confirmed in a linear, mixed-effects model, χ² (3) = 15.1, P = .0017). The intervention was well received by participants, and qualitative feedback was obtained. These results indicate that caregiver burden is modifiable in this cohort with a short course of CBT, that benefits are maintained after termination of the program, and that psychological treatment is acceptable to participants. Larger, controlled trials are justified.

The structural connectivity of subthalamic deep brain stimulation correlates with impulsivity in Parkinson's disease

Subthalamic deep brain stimulation (STN-DBS) for Parkinson's disease treats motor symptoms and improves quality of life, but can be complicated by adverse neuropsychiatric side-effects, including impulsivity. Several clinically important questions remain unclear: can 'at-risk' patients be identified prior to DBS; do neuropsychiatric symptoms relate to the distribution of the stimulation field; and which brain networks are responsible for the evolution of these symptoms? Using a comprehensive neuropsychiatric battery and a virtual casino to assess impulsive behaviour in a naturalistic fashion, 55 patients with Parkinson's disease (19 females, mean age 62, mean Hoehn and Yahr stage 2.6) were assessed prior to STN-DBS and 3 months postoperatively. Reward evaluation and response inhibition networks were reconstructed with probabilistic tractography using the participant-specific subthalamic volume of activated tissue as a seed. We found that greater connectivity of the stimulation site with these frontostriatal networks was related to greater postoperative impulsiveness and disinhibition as assessed by the neuropsychiatric instruments. Larger bet sizes in the virtual casino postoperatively were associated with greater connectivity of the stimulation site with right and left orbitofrontal cortex, right ventromedial prefrontal cortex and left ventral striatum. For all assessments, the baseline connectivity of reward evaluation and response inhibition networks prior to STN-DBS was not associated with postoperative impulsivity; rather, these relationships were only observed when the stimulation field was incorporated. This suggests that the site and distribution of stimulation is a more important determinant of postoperative neuropsychiatric outcomes than preoperative brain structure and that stimulation acts to mediate impulsivity through differential recruitment of frontostriatal networks. Notably, a distinction could be made amongst participants with clinically-significant, harmful changes in mood and behaviour attributable to DBS, based upon an analysis of connectivity and its relationship with gambling behaviour. Additional analyses suggested that this distinction may be mediated by the differential involvement of fibres connecting ventromedial subthalamic nucleus and orbitofrontal cortex. These findings identify a mechanistic substrate of neuropsychiatric impairment after STN-DBS and suggest that tractography could be used to predict the incidence of adverse neuropsychiatric effects. Clinically, these results highlight the importance of accurate electrode placement and careful stimulation titration in the prevention of neuropsychiatric side-effects after STN-DBS.

Sex Disparities in the Self-Evaluation of Subthalamic Deep Brain Stimulation Effects on Mood and Personality in Parkinson's Disease Patients

Changes in personality are one of the main concerns Parkinson's disease (PD) patients raise when facing the decision to undergo neurosurgery for deep brain stimulation (DBS) of the subthalamic nucleus (STN). While clinical instruments for monitoring functional changes following DBS surgery are well-established in the daily therapeutic routine, personality issues are far less systematically encompassed. Moreover, while sex disparities in the outcomes of STN-DBS therapy have been reported, little is known about the different effects that DBS treatment may have on mood and personality traits in female and male patients. To this aim, the effect of STN-DBS on personality traits was assessed in 46 PD patients (12 women and 34 men) by means of the Freiburg Personality Inventory. The Becks Depression Inventory (BDI-I) and the Parkinson's Disease Questionnaire were used to evaluate patients' level of depression and quality of life (QoL). Patients completed the questionnaires a few days before, within the first year, and 2 years after surgery. The 12 personality traits defined by the FPI-R questionnaire did not change significantly after STN-DBS surgery (p = 0.198). Women declared higher depression scores through all study stages (p = 0.009), but also showed a stronger QoL amelioration after surgery than male patients (p = 0.022). The BDI-I scores of female patients clearly correlated with their levodopa equivalent daily dose (LEDD; r = 0.621, p = 0.008). Remarkably, in both male and female patients, higher pre-operative LEDDs were related to worse post-operative QoL scores (p = 0.034). These results mitigate the concerns about systematic personality changes due to STN-DBS treatment in PD patients and encourage an early DBS approach, before severe levodopa-induced sequelae may irreparably compromise the patients' QoL. In the future, more focus should lie on sex-related effects, since female patients seem to profit more than male patients from STN-DBS, in terms of reduced depressive symptoms associated with a reduction of the LEDD and amelioration of QoL. These aspects may help to redress the sex imbalance in PD patients treated with DBS, given that women are still strongly under-represented.