Deep-brain stimulation for Parkinson's disease: current perspectives on patient selection with an emphasis on neuropsychology

Figures & data

Figure 1 Flowchart of deep-brain stimulation (DBS) candidacy-evaluation process for persons with Parkinson’s disease (PD).

Table 1 Neuropsychological, patient-demographic, disease, and anatomical factors that may impact DBS outcome and are considered during patient selection

Neuropsychological	Demographic	Disease	Anatomical
Overall level of cognitive impairment^Citation98	Age^52,99	Motor symptom severity^Citation63	White-matter-lesion burden^Citation100
Attention^Citation52,Citation60		Axial symptom severity^Citation101,Citation102	Thalamic and hippocampal volumes^Citation103
Executive dysfunction^Citation61,Citation104		Age at disease onset^Citation101	Greater intermammary distance (third ventricular size; indirect measure of atrophy)^Citation99
Intelligence^Citation57		Baseline dopaminergic medication dosage^Citation61,Citation102
List learning^Citation57		Baseline response to dopaminergic medication^Citation52
Apathy^Citation105
Hallucinations^Citation100
Anxiety^Citation106
Visuospatial impairment^Citation60

Abbreviation: DBS, deep-brain stimulation.

Table 2 Neuropsychological domains evaluated and tests and scales used to evaluate these domains at the Barrow Neurological Institute

Domains	Test or scale
Estimate of premorbid intelligence and current word reading level	Wide Range Achievement Test, fifth edition (WRAT5) or Wechsler Test of Adult Reading (WTAR)
Overall level of cognitive functioning or cognitive screening	Mattis Dementia Rating Scale, second edition (DRS2) and/or Montreal Cognitive Assessment (MOCA)
Intelligence estimate	Wechsler Abbreviated Scale of Intelligence, second edition (WASI-II) (2- or 4-subtest version)
Attention/working memory	Trail Making Test part A; digit span; Stroop Neuropsychological Screening Test (SNST)
Executive function	Trail Making Test part B; Wisconsin Card Sorting Test (WCST64); phonemic (letter) verbal fluency
Language	Semantic verbal fluency; Boston Naming Test (BNT, 60-item) or Neuropsychological Assessment Battery (NAB) Naming test
Visuoperceptual and visuospatial	Judgment of Line Orientation (JLO); Hooper Visual Organization Test (VOT)
Learning and memory	Wechsler Memory Scale, fourth edition (WMS-IV) Logical Memory Subtest; Hopkins Verbal Learning Test-Revised (HVLT-R); Brief Visuospatial Memory Test-Revised (BVMT-R); Test of Memory and Learning-Senior Edition (TOMAL-SE): Location-Memory subtest
Activities of daily living	Lawton and Brody Instrumental ADL scale
Quality of life	Parkinson’s Disease Questionnaire (PDQ-39)
Emotion	Beck Depression Inventory, second edition (BDI-II); Beck Anxiety Inventory (BDI-II); Apathy Evaluation Scale (Starkstein version); Center for Neurologic Studies-Lability Scale (CNS-LS) for Pseudobulbar Affect (PBA)
Impulsivity	Questionnaire for Impulsive-Compulsive Disorders in Parkinson’s Disease-Rating Scale (QUIP-RS)
Other tests occasionally used (most common)	Personality Assessment Inventory (PAI); clock drawing; grooved pegboard; finger tapping; Coping Responses Inventory-Adult (CRI-A); NAB List Learning, Story-Learning and Medication-Instruction subtests

Table 3 Content overview of deep-brain stimulation (DBS) education program for patients and care partners at Barrow Neurological Institute (BNI)

Topic	Content
The purpose of DBS education	Educate patients/families about the why, when, and how of DBS Empower patients with knowledge Prepare patients/families to ask questions of their clinicians, in order to make informed decisions Dispel myths and/or information from the Internet
What is DBS?	Overview of the mechanisms of DBS and how it works Short video showing placement of device Discuss the history of DBS
The DBS system	Review of each part of the system: leads, connector, internal pulse generator (IPG) Hands-on demonstration of equipment/device Review of IPG types and placement
DBS devices	Overview of the three types of DBS devices available
Patient selection	Parkinson’s disease, essential tremor, dystonia Review each diagnosis and criteria for what makes DBS appropriate Explain the how and why of motor on/off testing for Parkinson’s and neuropsychological evaluation Review other considerations: health, medical clearance, ability to follow up, postoperative supervision/ support
Targeting	Review DBS targets, why they are chosen and where they are located Explain side effects from certain targets (eg, bilateral thalamic and subthalamic)
What DBS can and cannot improve	Explain motor-function-improvement expectations Explain nonmotor functions unlikely to improve
Physician consensus	Discuss the consensus process: appropriateness of DBS for candidate, targeting, IPG, postoperative care Review approval process and next steps
Realistic expectations	Discuss and give examples of realistic and unrealistic expectations of DBS surgery
Surgery	Preoperative laboratory testing What to bring to the hospital Hospital processes
Surgical procedure	Overview of how the surgery is performed, including photos of equipment, MRI, intraoperative CT How the incisions are closed, capped Explanation of postanesthesia-care unit and transfer to floor
What to expect postoperatively	What will happen during hospital stay Reasons for >1 night length of stay Expected postoperative problems, including microlesion effects, pain, confusion, imbalance Discharge process Review postoperative care, restrictions, and recovery at home Photos of postoperative incisions 10 and 30 days out
Surgical risks	Review possible postoperative complications and latest statistics at BNI
Side effects from surgery	Possible verbal fluency issues and changes in cognition and behavior Possible mood changes/depression
Programming	Review patient programmer Explain initial and ongoing programming Review stimulation settings
Stimulation related side effects	Overview of possible side effects from stimulation Why they happen How they can be corrected
Medical tests and treatment	Review tests and treatments that are safe, need safeguards, or are contraindicated Explain MRI eligibility and safety
Other considerations	Other considerations (dental work, cardiac resuscitation) Airport security
Review	Risks and benefits Keys to successful surgery Patient-ambassador program
Contact information	Review all additional information and show where commonly asked questions and contacts are located in the DBS Education Book

Abbreviation: MRI, magnetic resonance imaging; CT, computed tomography; IPG, internal pulse generator.

Figure 2 Exemplars of brain MRI scans of patients referred for deep-brain stimulation (DBS).

Notes: (A, B) Significant risk factors for poor DBS outcome; (C) acceptable and within normal limits. (A) T₂ sequence showing excessive volume loss and cerebral encephalomalacia and chronic white-matter changes in a 69-year-old; (B) T₂ sequence showing moderate–severe white-matter microischemic changes in an 82-year-old; (C) T₁ sequence showing mild chronic small-vessel disease in a 72-year-old.

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