Role of clinical neuropsychology in deep brain stimulation: Review of the literature and considerations for clinicians

Neuropsychological and social predictors of participation in a deep brain stimulation study of Parkinson's disease and dystonia

Objectives

Participation is essential to DBS research, yet circumstances that affect diverse participation remain unclear. Here we evaluate factors impacting participation in an adaptive DBS study of Parkinson's disease (PD) and dystonia.

Methods

Twenty participants were implanted with a sensing-enabled DBS device (Medtronic Summit RC+S) that allows neural data streaming in naturalistic settings and encouraged to stream as much as possible for the first five months after surgery. Using standardized baseline data obtained through neuropsychological evaluation, we compared neuropsychological and social variables to streaming hours.

Results

Marital status and irritability significantly impacted streaming hours (estimate=136.7, bootstrapped ( b ) CI b =45.0 to 249.0, p b =0.016, and estimate=-95.1, CI b =-159.9 to -49.2, p b =0.027, respectively). These variables remained significant after multivariable analysis. Composite scores on verbal memory evaluations predicted the number of hours of data streamed (R 2 =0.284, estimate=67.7, CI b =20.1 to 119.9, p b =0.019).

Discussion

Verbal memory impairment, irritability, and lack of a caregiver may be associated with decreased participation. Further study of factors that impact research participation is critical to the sustained inclusion of diverse participants.

Tele-Neuropsychology: From Science to Policy to Practice

OBJECTIVE

The primary aim of this paper is to accelerate the number of randomized experimental studies of the reliability and validity in-home tele-neuropsychological testing (tele-np-t).

METHOD

We conducted a critical review of the tele-neuropsychology literature. We discuss this research in the context of the United States' public and private healthcare payer systems, including the Centers for Medicare & Medicaid Services (CMS) and Current Procedural Terminology (CPT) coding system's telehealth lists, and existing disparities in healthcare access.

RESULTS

The number of tele-np publications has been stagnant since the onset of the COVID-19 pandemic. There are less published experimental studies of tele-neuropsychology (tele-np), and particularly in-home tele-np-t, than other tele-np publications. There is strong foundational evidence of the acceptability, feasibility, and reliability of tele-np-t, but relatively few studies of the reliability and validity of in-home tele-np-t using randomization methodology.

CONCLUSIONS

More studies of the reliability and validity of in-home tele-np-t using randomization methodology are necessary to support inclusion of tele-np-t codes on the CMS and CPT telehealth lists, and subsequently, the integration and delivery of in-home tele-np-t services across providers and institutions. These actions are needed to maintain equitable reimbursement of in-home tele-np-t services and address the widespread disparities in healthcare access.

Foundations of Neuropsychology: Collaborative Care in Neurosurgery

The disciplines of neuropsychology and neurosurgery have a history of partnership that has improved prognoses for patients with neurologic diagnoses that once had poor outcomes. This article outlines the evolution of this relationship and describes the current role that clinical neuropsychology has within a department of neurological surgery across the preoperative, intraoperative, and postoperative stages of treatment. Understanding the foundations of collaboration between neuropsychology and neurosurgery contextualizes present challenges and future innovations for advancing excellence along the continuum of care for all neurosurgical patients.

International Regulatory Standards for the Qualitative Measurement of Deep Brain Stimulation in Clinical Research

Deep brain stimulation (DBS) has progressed to become a promising treatment modality for neurologic and psychiatric disorders like epilepsy and major depressive disorder due to its growing personalization. Despite evidence pointing to the benefits of DBS if tested on these personalized qualitative metrics, rather than randomized-control trial quantitative standards, the evaluation of these novel devices appears to be based on the latter. This study surveyed the presence of this trend in the national regulatory guidelines of the prominent DBS researching countries. It was found that two governing bodies, in the European Union and Australia, acknowledged the option for qualitative measures. These findings support further development of national regulatory guidelines, so the neuroscientific community developing these neurotechnologies can better understand the impact their treatments have on patients.

Cognitive and quality-of-life related factors of body mass index (BMI) improvement after deep brain stimulation in the subcallosal cingulate and nucleus accumbens in treatment-refractory chronic anorexia nervosa

BACKGROUND

Up to 20% of the cases of anorexia nervosa (AN) are chronic and treatment-resistant. Recently, the efficacy of deep brain stimulation (DBS) for severe cases of AN has been explored, with studies showing an improvement in body mass index and other psychiatric outcomes. While the effects of DBS on cognitive domains have been studied in patients with other neurological and psychiatric conditions so far, no evidence has been gathered in AN.

METHODS

Eight patients with severe, chronic, treatment-resistant AN received DBS either to the nucleus accumbens (NAcc) or subcallosal cingulate (SCC; four subjects on each target). A comprehensive battery of neuropsychological and clinical outcomes was used before and 6-month after surgery.

FINDINGS

Although Body Mass Index (BMI) did not normalise, statistically significant improvements in BMI, quality of life, and performance on cognitive flexibility were observed after 6 months of DBS. Changes in BMI were related to a decrease in depressive symptoms and an improvement in memory functioning.

INTERPRETATION

These findings, although preliminary, support the use of DBS in AN, pointing to its safety, even for cognitive functioning; improvements of cognitive flexibility are reported. DBS seems to exert changes on cognition and mood that accompany BMI increments. Further studies are needed better to determine the impact of DBS on cognitive functions.

Correlates of deep brain stimulation consensus conference decision to treat primary dystonia

BACKGROUND

Deep brain stimulation (DBS) is an effective treatment for motor disturbance in people with primary dystonia (PWD). Numerous factors are considered by an interdisciplinary consensus conference before deciding candidacy for DBS surgery (e.g., demographic, medical, cognitive, and behavioral factors). However, little is known about which of these factors are associated with PWD DBS surgery consensus conference decisions.

OBJECTIVE

Our goal was to examine whether pre-operative demographic, medical, and cognitive/behavioral variables are associated DBS consensus conference decisions in patients with dystonia.

METHODS

Thirty-two PWD completed comprehensive presurgery workup included neurological and neuropsychological exams, and neuroimaging in consideration for DBS surgery. An interdisciplinary conference committee either recommended or did not recommend DBS surgery based upon these data. Demographic and medical data (e.g., dystonia disease characteristics, medical comorbidities, medications) were also collected. We also examined impact from cardiovascular disease factors, using a Revised Cardiac Risk Index. PWD were grouped based on DBS conference decision (eligible: n = 21, ineligible: n = 11) and compared across demographic, medical, and cognitive/behavioral variables.

RESULTS

Across clinical variables, PWD who were deemed ineligible for DBS surgery had a higher Revised Cardiac Risk Index. PWD who were classified as ineligible displayed lower global cognitive functioning, working memory, phonemic fluency, memory retrieval, and cognitive flexibility.

CONCLUSIONS

Consensus decision making regarding DBS surgery eligibility involves a multifactorial process. We found that deficits in executive functioning were associated with the DBS consensus committee decision. We also observed elevated cardiac risk among these individuals, likely reflecting the relation between vascular health and cognition. Implications, and clinical and scientific applications of these findings are discussed.

The Use of Neuromodulation for Symptom Management

Pain and other symptoms of autonomic dysregulation such as hypertension, dyspnoea and bladder instability can lead to intractable suffering. Incorporation of neuromodulation into symptom management, including palliative care treatment protocols, is becoming a viable option scientifically, ethically, and economically in order to relieve suffering. It provides further opportunity for symptom control that cannot otherwise be provided by pharmacology and other conventional methods.

The Current State of Deep Brain Stimulation for Chronic Pain and Its Context in Other Forms of Neuromodulation

Chronic intractable pain is debilitating for those touched, affecting 5% of the population. Deep brain stimulation (DBS) has fallen out of favour as the centrally implantable neurostimulation of choice for chronic pain since the 1970–1980s, with some neurosurgeons favouring motor cortex stimulation as the ‘last chance saloon’. This article reviews the available data and professional opinion of the current state of DBS as a treatment for chronic pain, placing it in the context of other neuromodulation therapies. We suggest DBS, with its newer target, namely anterior cingulate cortex (ACC), should not be blacklisted on the basis of a lack of good quality study data, which often fails to capture the merits of the treatment.