Healthcare disparities in deep brain stimulation access and utilization: a systematic review.

OBJECTIVE: Since FDA approval of deep brain stimulation (DBS) for essential tremor over 2 decades ago, indications and utilization of this modality have rapidly expanded worldwide. However, certain patient populations are known to be underrepresented among those undergoing DBS for various indications. METHODS: A systematic search was conducted using PubMed and Embase for disparities related to DBS care. Any retrospective or prospective study addressing inequalities related to DBS were included for qualitative analysis. Additionally, all clinical trials and DBS studies with at least 100 patients were also included to evaluate for demographic disparities in the DBS literature. RESULTS: Of the 5192 screened articles, 43 were included. The authors found that female gender, minority race, geographic barriers, low socioeconomic status, and the presence of multiple comorbidities are all linked to the underutilization of DBS. Analysis of demographic data from large-scale DBS studies and clinical trials revealed that females and Black patients continue to be underrepresented in the DBS literature and among those receiving DBS therapy. CONCLUSIONS: As the indications and utilization continue to grow, addressing healthcare disparities related to DBS has become increasingly important. The authors suggest that increasing patient and provider education, expanding the role of telemedicine within DBS care, and improving support services for DBS patients may improve access and utilization.

The impact of anxiety and depression on lumbar spine surgical outcomes: a Michigan Spine Surgery Improvement Collaborative study.

OBJECTIVE: The presence of depression and anxiety has been associated with negative outcomes in spine surgery patients. While it seems evident that a history of depression or anxiety can negatively influence outcome, the exact additive effect of both has not been extensively studied in a multicenter trial. The purpose of this study was to investigate the relationship between a patient's history of anxiety and depression and their patient-reported outcomes (PROs) after lumbar surgery. METHODS: Patients in the Michigan Spine Surgery Improvement Collaborative registry undergoing lumbar spine surgery between July 2016 and December 2021 were grouped into four cohorts: those with a history of anxiety only, those with a history of depression only, those with both, and those with neither. Primary outcomes were achieving the minimal clinically important difference (MCID) for the Patient-Reported Outcomes Measurement Information System Physical Function 4-item Short Form (PROMIS PF), EQ-5D, and numeric rating scale (NRS) back pain and leg pain, and North American Spine Society patient satisfaction. Secondary outcomes included surgical site infection, hospital readmission, and return to the operating room. Multivariate Poisson generalized estimating equation models were used to report incidence rate ratios (IRRs) from patient baseline variables. RESULTS: Of the 45,565 patients identified, 3941 reported a history of anxiety, 5017 reported a history of depression, 9570 reported both, and 27,037 reported neither. Compared with those who reported having neither, patients with both anxiety and depression had lower patient satisfaction at 90 days (p = 0.002) and 1 year (p = 0.021); PROMIS PF MCID at 90 days (p < 0.001), 1 year (p < 0.001), and 2 years (p = 0.006); EQ-5D MCID at 90 days (p < 0.001), 1 year (p < 0.001), and 2 years (p < 0.001); NRS back pain MCID at 90 days (p < 0.001) and 1 year (p < 0.001); and NRS leg pain MCID at 90 days (p < 0.001), 1 year (p = 0.024), and 2 years (p = 0.027). Patients with anxiety only (p < 0.001), depression only (p < 0.001), or both (p < 0.001) were more likely to be readmitted within 90 days. Additionally, patients with anxiety only (p = 0.015) and both anxiety and depression (p = 0.015) had higher rates of surgical site infection. Patients with anxiety only (p = 0.006) and depression only (p = 0.021) also had higher rates of return to the operating room. CONCLUSIONS: The authors observed an association between a history of anxiety and depression and negative outcome after lumbar spine surgery. In addition, they found an additive effect of a history of both anxiety and depression with an increased risk of negative outcome when compared with either anxiety or depression alone.

Alternatives to DEXA for the assessment of bone density: a systematic review of the literature and future recommendations.

OBJECTIVE: Osteoporosis has significant implications in spine fusion surgery, for which reduced spinal bone mineral density (BMD) can result in complications and poorer outcomes. Currently, dual-energy x-ray absorptiometry (DEXA) is the gold standard for radiographic diagnosis of osteoporosis, although DEXA accuracy may be limited by the presence of degenerative spinal pathology. In recent years, there has been an evolving interest in using alternative imaging, including CT and MRI, to assess BMD. In this systematic review of the literature, the authors assessed the use and effectiveness of MRI, opportunistic CT (oCT), and quantitative CT (qCT) to measure BMD. METHODS: In accordance with the PRISMA guidelines, the authors conducted a systematic search for articles posted on PubMed between the years 2000 and 2022 by using the keywords "opportunistic CT, quantitative CT, MRI" AND "bone density" AND "spine." Inclusion criteria consisted of articles written in English that reported studies pertaining to human or cadaveric subjects, and studies including a measure of spinal BMD. Articles not related to spinal BMD, osteoporosis, or spinal surgery or reports of studies that did not include the use of spinal MRI or CT were excluded. Key study outcomes were extracted from included articles, and qualitative analysis was subsequently performed. RESULTS: The literature search yielded 302 articles. Forty-two articles reported studies that met the final inclusion criteria. Eighteen studies utilized MRI protocols to correlate spinal BMD with vertebral bone quality scores, M-scores, and quantitative perfusion markers. Eight studies correlated oCT with spinal BMD, and 16 studies correlated qCT with spinal BMD. With oCT and qCT imaging, there was consensus that Hounsfield unit (HU) values > 160 demonstrated significant reduction in risk of osteoporosis, whereas HU values < 110 were significantly correlated with osteoporosis. CONCLUSIONS: Osteoporosis is increasingly recognized as a significant risk factor for complications after spinal fusion surgery. Consequently, preoperative assessment of BMD is a critical factor to consider in planning surgical treatment. Although DEXA has been the gold standard for BMD measurement, other imaging modalities, including MRI, oCT, and qCT, appear to be viable alternatives and may offer cost and time savings.

Defining postoperative C5 palsy and recovery: a systematic review.

OBJECTIVE: Postoperative C5 palsy (C5P) is a well-recognized and often-delayed complication of cervical spine surgery. Most patients recover within 6 months of onset, but the prognosis of severe cases is poor. The clinical significance and natural history of mild versus severe C5P appear to differ substantially, but palsy severity and recovery have been poorly characterized in the literature. METHODS: Owing to the varying prognoses and expanding treatment options such as nerve transfer surgery to reconstruct the C5 myotome, this systematic review attempted to describe how C5P severity is classified and how C5P and its recovery are defined, with the aim of proposing a postoperative C5P scale to support clinical decision-making. PubMed was searched for articles in English published since 2000 that offer a clear definition of postoperative C5P or its recovery. Only articles reporting exclusively on C5 palsy for patients undergoing surgery for degenerative disease were included. A single reviewer screened titles and abstracts and reviewed the full text of relevant articles, with consultation as needed from a second reviewer. Data collected included postoperative C5P definitions, classification of C5P severity, and definition and/or classification of C5P recovery. Qualitative analysis was performed. RESULTS: Full-text reviews were conducted of 98 of 272 articles identified and screened, and 43 met the inclusion criteria. Postoperative C5P was most commonly defined as a reduction in deltoid muscle strength by ≥ 1 grade using manual muscle testing (MMT), with potential biceps involvement also noted by some studies. The few studies that stratified C5P on the basis of severity unanimously characterized severe C5P as MMT grade ≤ 2. Nine studies reported on C5P recovery. Deltoid muscle strength improvement of MMT grade 5 commonly defined complete recovery, with no MMT improvement considered partial recovery. CONCLUSIONS: This review identified clear discrepancies in the definitions of C5P and its recovery, leading to heterogeneity in its evaluation and management. With the emergence of therapeutic procedures for severe C5P, standardization of the definitions of C5P and its recovery is critical. The authors propose MMT grades of 4, 3, and ≤ 2 to classify C5P as mild, moderate, and severe, respectively, and grades of 5, 4, and 3 to classify recovery as complete, sufficient, and useful, respectively.

Association of prolonged symptom duration with poor outcomes in lumbar spine surgery: a Michigan Spine Surgery Improvement Collaborative study.

OBJECTIVE: There is a scarcity of large multicenter data on how preoperative lumbar symptom duration relates to postoperative patient-reported outcomes (PROs). The objective of this study was to determine the effect of preoperative and baseline symptom duration on PROs at 90 days, 1 year, and 2 years after lumbar spine surgery. METHODS: The Michigan Spine Surgery Improvement Collaborative registry was queried for all lumbar spine operations between January 1, 2017, to December 31, 2021, with a follow-up of 2 years. Patients were stratified into three subgroups based on symptom duration: < 3 months, 3 months to < 1 year, and ≥ 1 year. The primary outcomes were reaching the minimal clinically important difference (MCID) for the PROs (i.e., leg pain, Patient-Reported Outcomes Measurement Information System Physical Function (PROMIS PF), EQ-5D, North American Spine Society satisfaction, and return to work). The EQ-5D score was also analyzed as a continuous variable to calculate quality-adjusted life years. Multivariable Poisson generalized estimating equation models were used to report adjusted risk ratios, with the < 3-month cohort used as the reference. RESULTS: There were 37,223 patients (4670 with < 3-month duration, 9356 with 3-month to < 1-year duration, and 23,197 with ≥ 1-year duration) available for analysis. Compared with patients with a symptom duration of < 1 year, patients with a symptom duration of ≥ 1 year were significantly less likely to achieve an MCID in PROMIS PF, EQ-5D, back pain relief, and leg pain relief at 90 days, 1 year, and 2 years postoperatively. Similar trends were observed for patient satisfaction and return to work. With the EQ-5D score as a continuous variable, a symptom duration of ≥ 1 year was associated with 0.04, 0.05, and 0.03 (p < 0.001) decreases in EQ-5D score at 90 days, 1 year, and 2 years after surgery, respectively. CONCLUSIONS: A symptom duration of ≥ 1 year was associated with poorer outcomes on several outcome metrics. This suggests that timely referral and surgery for degenerative lumbar pathology may optimize patient outcome.

Evaluation of DBS Timeline in Movement Disorders: A Comparison Between Genders.

BACKGROUND: Deep brain stimulation (DBS) is a pivotal surgical treatment for movement disorders. However, men and women have had differing opinions and referral experiences related to DBS, leading us to assess whether a gender disparity exists in the interval from a movement disorder diagnosis to DBS usage. METHODS: We performed a single-center, retrospective cohort study of 105 patients who had undergone DBS surgery for either Parkinson disease (PD) or essential tremor (ET). We compared gender differences in the median interval between the diagnosis date, DBS consultation date, and DBS surgery dates. Additionally, the patient demographics, baseline clinical characteristics, and DBS outcomes were compared between men and women. RESULTS: We found no significant differences between genders in the interval from the diagnosis to DBS surgery for ET or PD. At the DBS consultation for ET, the women had had significantly greater disease severity compared with the men (P = 0.029). The baseline motor impairment without medication was similar between the men and women with PD. However, female patients with PD had experienced a significantly greater reduction compared with male patients in baseline motor impairment with medication versus without medication (P = 0.042). No minority populations were represented within the female ET and PD subgroups. CONCLUSIONS: Our study detected no gender differences in the DBS implantation timeline but alluded to a gender-specific discrepancy in DBS referral for ET. The female patients did not have a shorter duration from the ET diagnosis to DBS, despite experiencing significantly greater baseline ET severity compared with their male counterparts. Furthermore, the women with ET more often used Medicaid insurance and were without minority representation.

Emerging Trends in Neuromodulation for Treatment of Drug-Resistant Epilepsy.

Epilepsy is a neurological disorder that affects more than 70 million people globally. A considerable proportion of epilepsy is resistant to anti-epileptic drugs (AED). For patients with drug-resistant epilepsy (DRE), who are not eligible for resective or ablative surgery, neuromodulation has been a palliative option. Since the approval of vagus nerve stimulation (VNS) in 1997, expansion to include other modalities, such as deep brain stimulation (DBS) and responsive neurostimulation (RNS), has led to improved seizure control in this population. In this article, we discuss the current updates and emerging trends on neuromodulation for epilepsy.