Individualized targeting is warranted in subcallosal cingulate gyrus deep brain stimulation for treatment-resistant depression: A tractography analysis.

Subcallosal cingulate gyrus (SCG) is a target of deep brain stimulation (DBS) for treatment-resistant depression. However, previous randomized controlled trials report that approximately 42% of patients are responders to this therapy of last resort, and suboptimal targeting of SCG is a potential underlying factor to this unsatisfactory efficacy. Tractography has been proposed as a supplementary method to enhance targeting strategy. We performed a connectivity-based segmentation in the SCG region via probabilistic tractography in 100 healthy volunteers from the Human Connectome Project. The SCG voxels with maximum connectivity to brain regions implicated in depression, including Brodmann Area 10 (BA10), cingulate cortex, thalamus, and nucleus accumbens were identified, and the conjunctions were deemed as tractography-based targets. We then performed deterministic tractography using these targets in additional 100 volunteers to calculate streamline counts compassing to relevant brain regions and fibers. We also evaluated the intra- and inter-subject variance using test-retest dataset. Two tractography-based targets were identified. Tractography-based target-1 had the highest streamline counts to right BA10 and bilateral cingulate cortex, while tractography-based target-2 had the highest streamline counts to bilateral nucleus accumbens and uncinate fasciculus. The mean linear distance from individual tractography-based target to anatomy-based target was 3.2 ± 1.8 mm and 2.5 ± 1.4 mm in left and right hemispheres. The mean ± SD of targets between intra- and inter-subjects were 2.2 ± 1.2 and 2.9 ± 1.4 in left hemisphere, and 2.3 ± 1.4 and 3.1 ± 1.7 in right hemisphere, respectively. Individual heterogeneity as well as inherent variability from diffusion imaging should be taken into account during SCG-DBS target planning procedure.

Deep Brain Stimulation for Advanced Parkinson Disease in Developing Countries: A Cost-Effectiveness Study From China.

BACKGROUND: The cost-effectiveness of deep brain stimulation (DBS) is more favorable than best medical treatment (BMT) for advanced Parkinson disease (PD) in developed countries. However, it remains unclear in developing countries, where the cost of DBS may not be reimbursed by health care system. OBJECTIVE: To model and evaluate the long-term cost-effectiveness of DBS for advanced PD in China from a patient payer perspective. METHODS: We developed a Markov model representing the clinical progress of PD to predict the disease progression and related medical costs in a 15-year time horizon. The incremental cost-effectiveness ratio (ICER) and net benefit were used to evaluate the cost-effectiveness of DBS vs BMT. RESULTS: DBS treatment led to discounted total costs of ¥370 768 ($56 515.20) (95% CI, ¥369 621.53-371 914.88), compared with ¥48 808 ($7439.68) (95% CI, ¥48 502.63-49 114.21) for BMT, with an additional 1.51 quality-adjusted life years gained, resulting in an ICER of ¥213 544 ($32 549.96)/quality-adjusted life years (95% CI, ¥208 177.35-218 910.10). Sensitivity analysis showed that DBS-related cost has the most substantial impact on ICER. Nation-wide net benefit of BMT and DBS were ¥33 819 ($5154.94) (95% CI, ¥30 211.24-37 426) and ¥30 361 ($4627.85) (95% CI, ¥25 587.03-39 433.66), respectively. Patient demographic analysis showed that more favorable DBS cost-effectiveness was associated with younger age and less severe disease stage. CONCLUSION: DBS is cost-effective for patients with advanced PD over a 15-year time horizon in China. However, compared with developed countries, DBS remains a substantial economic burden for patients when no reimbursement is provided. Our findings may help inform cost-effectiveness-based decision making for clinical care of PD in developing countries.

White Matter Tracts Associated With Deep Brain Stimulation Targets in Major Depressive Disorder: A Systematic Review.

Background: Deep brain stimulation (DBS) has been proposed as a last-resort treatment for major depressive disorder (MDD) and has shown potential antidepressant effects in multiple clinical trials. However, the clinical effects of DBS for MDD are inconsistent and suboptimal, with 30-70% responder rates. The currently used DBS targets for MDD are not individualized, which may account for suboptimal effect. Objective: We aim to review and summarize currently used DBS targets for MDD and relevant diffusion tensor imaging (DTI) studies. Methods: A literature search of the currently used DBS targets for MDD, including clinical trials, case reports and anatomy, was performed. We also performed a literature search on DTI studies in MDD. Results: A total of 95 studies are eligible for our review, including 51 DBS studies, and 44 DTI studies. There are 7 brain structures targeted for MDD DBS, and 9 white matter tracts with microstructural abnormalities reported in MDD. These DBS targets modulate different brain regions implicated in distinguished dysfunctional brain circuits, consistent with DTI findings in MDD. Conclusions: In this review, we propose a taxonomy of DBS targets for MDD. These results imply that clinical characteristics and white matter tracts abnormalities may serve as valuable supplements in future personalized DBS for MDD.

Outcomes of Ventriculoperitoneal Shunt in Patients With Idiopathic Normal-Pressure Hydrocephalus 2 Years After Surgery.

Objective: To evaluate the outcomes and prognostic factors of ventriculoperitoneal shunts (VP-shunts) in patients with idiopathic normal-pressure hydrocephalus (iNPH) at 6 months and 2 years after surgery. Method: We retrospectively analyzed 68 patients admitted to our institute and diagnosed with probable iNPH from January 2017 to March 2021. All patients underwent VP-shunt surgery with a programmable valve, and their outcomes were assessed via the Krauss index and modified Rankin scale (mRS) at 6 months and 2 years post-surgery. Univariate and multivariate regression analysis was performed to identify the prognostic factors. Results: The mean age of the patients was 71.1 ± 8.4 (mean ± standard deviation) years. On the Krauss improvement index, 6-month follow-up results were available for 68 patients. Of these patients, 91.2% experienced attenuation of their preoperative symptoms, with a mean Krauss index of 0.58 ± 0.27, and 48 patients (70.6%) had a Krauss index ≥0.5. Two-year follow-up results were available for 33 patients; 90.9% of them had sustained improvement, with a Krauss index of 0.54 ± 0.31, and 21 patients (66.3%) had a Krauss index ≥0.5. Thirty-three patients (58%) were living independently after 2 years (mRS 0-2). The outcomes were worse for patients with multiple comorbidities. Neither an increased patient age nor a prolonged history of illness was statistically significant prognostic factors for adverse outcomes of VP-shunt surgery. Conclusion: Surgical treatment was well-tolerated by patients with iNPH who received VP-shunts. Most patients experienced attenuation of their preoperative symptoms. Multiple concurrent comorbidities should be considered as adverse prognostic factors before shunt insertion in patients with iNPH.

Ventriculosternal Shunt for the Treatment of Idiopathic Normal Pressure Hydrocephalus: A Case Report.

Background: Conventional corticospinal fluid (CSF) diversion surgery for idiopathic normal pressure hydrocephalus (iNPH) includes ventriculoperitoneal shunt and ventriculoatrial shunt. Ventriculosternal (VS) shunt may be considered if both the abdominal cavity and atrium are not feasible. Methods: A 76-year-old woman was admitted to our hospital with gait disturbance and urinary incontinence for 2 years, and the condition aggravated in the last 1 month. Based on clinical assessment and imaging findings, the patient was diagnosed with iNPH, with surgical indications. She was on peritoneal dialysis for chronic renal failure, and a cardiac Doppler echocardiogram showed enlargement of the left atrium and decreased diastolic function of the left ventricle. Due to these conditions, we chose the sternum as the vessel for CSF absorption and performed VS shunt. Results: No swelling, exudation, and effusion were found in the suprasternal fossa. Gait disturbance and urinary incontinence improved significantly immediately and 1 week after surgery, respectively. No shunt-related complication was reported at 16 months follow-up. Conclusion: This case demonstrated VS shunting as a feasible and alternative for the management of hydrocephalus.

A connectomic analysis of deep brain stimulation for treatment-resistant depression.

OBJECTIVE: Deep brain stimulation (DBS) has been used as a treatment of last resort for treatment-resistant depression (TRD) for more than a decade. Many DBS targets have been proposed and tested clinically, but the underlying circuit mechanisms remain unclear. Uncovering white matter tracts (WMT) activated by DBS targets may provide crucial information about the circuit substrates mediating DBS efficacy in ameliorating TRD. METHODS: We performed probabilistic tractography using diffusion magnetic resonance imaging datas from 100 healthy volunteers in Human Connectome Project datasets to analyze the structural connectivity patterns of stimulation targeting currently-used DBS target for TRD. We generated mean and binary fiber distribution maps and calculated the numbers of WMT streamlines in the dataset. RESULTS: Probabilistic tracking results revealed that activation of distinct DBS targets demonstrated modulation of overlapping but considerably distinct pathways. DBS targets were categorized into 4 groups: Cortical, Striatal, Thalamic, and Medial Forebrain Bundle according to their main modulated WMT and brain areas. Our data also revealed that Brodmann area 10 and amygdala are hub structures that are associated with all DBS targets. CONCLUSIONS: Our results together suggest that the distinct mechanism of DBS targets implies individualized target selection and formulation in the future of DBS treatment for TRD. The modulation of Brodmann area 10 and amygdala may be critical for the efficacy of DBS-mediated treatment of TRD.

Sylvian Fissure Meningiomas: Case Report and Literature Review.

Meningiomas are primary intracranial tumors derived from arachnoid cap cells or meningothelial cells and usually display dural attachment. However, a small proportion of meningiomas that arise from the Sylvian fissure do not manifest dural attachment. Sylvian fissure meningiomas are relatively rare and have differential characteristics as compared with typical meningiomas. Herein, we reported a special case of atypical meningioma in the Sylvian fissure, that showed non-enhancement after contract management. The patient was a 30-year-old woman with a 2-year history of seizures. Preoperative computerized tomography and magnetic resonance imaging scans showed a calcific, non-enhancing lesion in the right insula lobe. The lesion was excised surgically for seizure control. Intraoperatively, the tumor was observed to be closely adhered to the middle cerebral artery (MCA), resulting in mild arterial damage. A case of Sylvian fissure meningioma was ultimately diagnosed by histopathological examination of the resected specimens. Sylvian fissure meningiomas are closely associated with the MCA and exhibit unusual imaging characteristics. Preoperative misdiagnosis may have serious adverse consequences and may result in incorrect surgery. To improve awareness of Sylvian fissure meningiomas on the differential diagnosis of Sylvian fissure lesions among clinicians, we present this report and briefly summarize previously reported cases to describe the clinical, pathological, radiological, and surgical features.