Double-blind optimization of subcallosal cingulate deep brain stimulation for treatment-resistant depression: a pilot study

Background

Deep brain stimulation (DBS) of the subcallosal cingulate (SCC) is reported to be a safe and effective new treatment for treatment-resistant depression (TRD). However, the optimal electrical stimulation parameters are unknown and generally selected by trial and error. This pilot study investigated the relationship between stimulus parameters and clinical effects in SCC-DBS treatment for TRD.

Methods

Four patients with TRD underwent SCC-DBS surgery. In a double-blind stimulus optimization phase, frequency and pulse widths were randomly altered weekly, and corresponding changes in mood and depression were evaluated using a visual analogue scale (VAS) and the 17-item Hamilton Rating Scale for Depression (HAM-D-17). In the open-label postoptimization phase, depressive symptoms were evaluated biweekly for 6 months to determine long-term clinical outcomes.

Results

Longer pulse widths (270–450 μs) were associated with reductions in HAM-D-17 scores in 3 patients and maximal happy mood VAS responses in all 4 patients. Only 1 patient showed acute clinical or mood effects from changing the stimulation frequency. After 6 months of open-label therapy, 2 patients responded and 1 patient partially responded.

Limitations

Limitations include small sample size, weekly changes in stimulus parameters, and fixed-order and carry-forward effects.

Conclusion

Longer pulse width stimulation may have a role in stimulus optimization for SCC-DBS in TRD. Longer pulse durations produce larger apparent current spread, suggesting that we do not yet know the optimal target or stimulus parameters for this therapy. Investigations using different stimulus parameters are required before embarking on large-scale randomized sham-controlled trials.     

Frontal theta cordance predicts 6-month antidepressant response to subcallosal cingulate deep brain stimulation for treatment-resistant depression: a pilot study

Deep brain stimulation (DBS) of subcallosal cingulate white matter (SCC) may be an effective approach for treatment-resistant depression (TRD) that otherwise fails to respond to more conventional therapies, but DBS is invasive, costly, and has potential for adverse effects. Therefore, it is important to identify potential biomarkers for predicting antidepressant response before intervention. Resting-state EEG was recorded from 12 TRD patients at pre-treatment baseline, after 4 weeks SCC DBS, and after 24 weeks SCC DBS. Lower frontal theta cordance (FTC) at baseline (and higher FTC after 4 weeks) predicted lower depression severity scores after 24 weeks. Greater FTC increases (baseline-4 weeks) predicted greater decreases in depression severity scores subsequently (4-24 weeks) and over the course of the study (baseline-24 weeks). Predictive relationships were topographically specific to theta cordance for frontal electrodes. Thus, results from this pilot study suggest that baseline FTC and changes early in treatment each have utility as biomarkers for predicting 6-month clinical response to SCC DBS for TRD.     

A pilot study of bed nucleus of the stria terminalis deep brain stimulation in treatment-resistant depression

Background

Studies are increasingly investigating the therapeutic effects of deep brain stimulation (DBS) applied to a variety of brain regions in the treatment of patients with highly treatment refractory depression. Limited research to date has investigated the therapeutic potential of DBS applied to the Bed Nucleus Of Stria Terminalis (BNST).

Tract-based analysis of target engagement by subcallosal cingulate deep brain stimulation for treatment resistant depression

BackgroundDeep brain stimulation (DBS) of subcallosal cingulate cortex (SCC) is a promising investigational therapy for treatment-resistant depression (TRD). However, outcomes vary, likely due to suboptimal DBS placement. Ideal placement is proposed to stimulate 4 SCC white matter bundles; however, no quantitative data have linked activation of these target tracts to response.ObjectiveHere we used the volume of tissue activated (VTA) and probabilistic diffusion tensor imaging (DTI) to quantify tract activation relating to response.MethodsDTI was performed in 19 TRD patients who received SCC-DBS. We defined clinical response as >48% reduction from baseline in the Hamilton Depression Rating Scale. Bilateral VTAs were generated based on subject-specific stimulation parameters. Patient-specific tract maps emanating from the VTAs were calculated using whole-brain probabilistic DTI. The four target tracts were isolated using tract-specific quantification and examined for overlap with DBS activated tissue.ResultsMedial frontal and temporal projections were stimulated in all responders at 6 and 12 months. Individual tract-based generalized linear mixed model analysis revealed a significant tract-by-response interaction at both 6 (F(1,135) = 3.828, p = 0.001) and 12 (F(1,135) = 5.688, p < 0.001) months, with post hoc tests revealing a response-related increase in cingulum activation at 6 months (t(135) = 2.418, p = 0.017) and decrease in forceps minor activation at 12 months (t(135) = -2.802, p = 0.006).ConclusionsA wider profile of white matter tracts, particularly to the medial frontal, was associated with DBS response. Cingulum bundle stimulation may promote early response and excess stimulation of the forceps minor might be detrimental. Our work supports prospective patient-specific targeting to inform personalized DBS.     

Quantifying the axonal pathways directly stimulated in therapeutic subcallosal cingulate deep brain stimulation

Deep brain stimulation (DBS) of the subcallosal cingulate (SCC) is an emerging experimental therapy for treatment‐resistant depression. New developments in SCC DBS surgical targeting are focused on identifying specific axonal pathways for stimulation that are estimated from patient‐specific computational models. This connectomic‐based biophysical modeling strategy has proven successful in improving the clinical response to SCC DBS therapy, but the DBS models used to date have been relatively simplistic, limiting the precision of the pathway activation estimates. Therefore, we used the most detailed patient‐specific foundation for DBS modeling currently available (i.e., field‐cable modeling) to evaluate SCC DBS in our most recent cohort of six subjects, all of which were responders to the therapy. We quantified activation of four major pathways in the SCC region: forceps minor (FM), cingulum bundle (CB), uncinate fasciculus (UF), and subcortical connections between the frontal pole and the thalamus or ventral striatum (FP). We then used the percentage of activated axons in each pathway as regressors in a linear model to predict the time it took patients to reach a stable response, or TSR. Our analysis suggests that stimulation of the left and right CBs, as well as FM are the most likely therapeutic targets for SCC DBS. In addition, the right CB alone predicted 84% of the variation in the TSR, and the correlation was positive, suggesting that activation of the right CB beyond a critical percentage may actually protract the recovery process.     

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

ObjectiveDeep 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.MethodsWe 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.ResultsProbabilistic 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.ConclusionsOur 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.     

Topiramate add-on in treatment-resistant schizophrenia: a randomized, double-blind, placebo-controlled, crossover trial

OBJECTIVE: We tested the hypothesis that topiramate is more effective than placebo in reducing symptoms in patients with treatment-resistant schizophrenia when combined with ongoing antipsychotic medication. METHOD: Twenty-six hospitalized treatment-resistant patients with chronic DSM-IV-diagnosed schizophrenia participated in a randomized, double-blind, placebo-controlled trial in which 300 mg/day of topiramate was gradually added to their ongoing treatment (clozapine, olanzapine, risperidone, or quetiapine) over two 12-week crossover treatment periods. Data were collected from April 2003 to November 2003. RESULTS: In intention-to-treat analysis, topiramate was more effective than placebo in reducing Positive and Negative Syndrome Scale general psychopathologic symptoms (effect size = 0.7, p = .021), whereas no significant improvement was observed in positive or negative symptoms. CONCLUSION: Glutamate antagonist topiramate may be an effective adjuvant treatment in reducing general psychopathologic symptoms in patients with schizophrenia resistant to treatment with second-generation antipsychotics.     

A pilot investigation of accelerated deep transcranial magnetic stimulation protocols in treatment-resistant depression

European Archives of Psychiatry and Clinical Neuroscience - Accelerated repetitive transcranial magnetic stimulation (rTMS) protocols are being increasingly studied because of their potential to...     

A randomised double-blind placebo-controlled crossover add-on trial of lamotrigine in patients with treatment-resistant partial seizures

Efficacy and safety of lamotrigine (LTG) as add-on therapy was assessed in a randomised double-blind placebo-controlled trial of this drug in 23 adult patients with refractory partial seizures. Fifteen patients showed an improvement on LTG treatment, with a greater than 50% decrease in total seizure count in 7 patients. Fourteen patients experienced fewer simple and complex partial seizures, with 8 patients benefitting by more than a 50% decrease in seizure frequency. The drug was well tolerated over the 2 month treatment period. The plasma concentration of concomitant antiepileptic drugs remained unchanged. No haematological or chemical abnormalities were noted.     

Effects of prefrontal theta-burst stimulation on brain function in treatment-resistant depression: A randomized sham-controlled neuroimaging study

Background

Theta-burst transcranial magnetic stimulation (TBS) can quickly modulate brain activity and can be used to treat treatment-resistant depression (TRD). Whole-brain analytical research has revealed that left high-frequency PFC rTMS modulates brain activity in anterior cingulate cortex (ACC) and the fronto-cingulo-temporal circuit. We aimed to investigate whether the prefrontal TBS's antidepressant mechanisms involve these regions.

Transcranial magnetic stimulation in treatment-resistant depressed patients: a double-blind, placebo-controlled trial

This 5-week, randomized, double-blind, placebo-controlled trial investigated the efficacy and tolerability of high frequency repetitive transcranial magnetic stimulation (rTMS) directed to the left prefrontal cortex in drug-resistant depressed patients. Fifty-four patients were randomly assigned to receive 10 daily applications of either real or sham rTMS. Subjects assigned to receive active stimulation were divided into two further subgroups according to the intensity of stimulation: 80% vs. 100% of motor threshold (MT). At study completion, the response rates were 61.1% (n=11), 27.8% (n=5) and 6.2% (n=1) for the 100% MT group, 80% MT group and sham group, respectively. A significant difference (Pearson chi(2) test) was found between the 100% MT and sham groups, while the 80% MT group did not differ significantly from the sham group. Between the two active groups, a marginally significant difference was observed. Analysis of variance with repeated measures on Hamilton Depression Rating Scale scores revealed a significantly different decrease over time of depressive symptomatology among the three treatment groups. Treatment response appeared to be unrelated to the demographic and clinical characteristics recorded, and on the whole the technique was well tolerated. The results of this double-blind trial showed that rTMS may be a useful and safe adjunctive treatment for drug-resistant depressed patients.     

Lamotrigine in treatment-resistant schizophrenia: a randomized placebo-controlled crossover trial.

BACKGROUND: There is no evidence from randomized, controlled trials that demonstrate effectiveness for any pharmacological treatment in clozapine-resistant schizophrenia. Since the introduction of chlorpromazine, all antipsychotics with proven efficacy on positive symptoms have been dopamine antagonists, but recent experimental data suggest that ketamine-induced positive schizophreniform symptoms in healthy subjects can be controlled by a glutamate antagonist lamotrigine. The hypothesis tested was that lamotrigine is more effective than placebo in the treatment of positive schizophrenic symptoms when combined with clozapine. METHODS: Thirty-four hospitalized treatment-resistant patients having chronic schizophrenia participated in a double-blind, placebo-controlled, 14-week, crossover trial where 200 mg/day lamotrigine was gradually added to their ongoing clozapine treatment. Clinical assessments were made by the Positive and Negative Syndrome Scale at the beginning and end of each treatment period. RESULTS: In intention-to-treat analysis, lamotrigine treatment was more effective in reducing positive (effect size.7, p =.009) and general psychopathological (effect size.6, p =.030) symptoms, whereas no improvement was observed in negative symptoms. CONCLUSIONS: These results provide the first evidence from a randomized controlled trial of an effective pharmacological treatment with an anticonvulsant agent in treatment-resistant schizophrenia and indicate that both positive and general psychopathological symptoms in patients with schizophrenia can be controlled by a drug that is not a dopamine antagonist. The results are in line with previous experimental data suggesting that excessive glutamate neurotransmission contributes to the positive symptoms of schizophrenia.     

深部脑刺激对难治性抑郁症的治疗进展

近年来诸多研究表明深部脑刺激(DBS)对难治性抑郁症存在潜在疗效,本文对国际上开展的DBS技术治疗难治性抑郁症的研究进展进行综述,以期探索该技术的治疗机制、作用靶点及临床疗效,总结当前DBS治疗难治性抑郁症的局限性,并预测未来DBS治疗难治性抑郁症的发展方向,为国内开展相关实验提供参考.     

Levomepromazine versus chlorpromazine in treatment-resistant schizophrenia: a double-blind randomized trial

OBJECTIVE: We compared the effect of levomepromazine (LMP) with chlorpromazine (CPZ) in treatment-resistant schizophrenia (TRS). METHODS: We carried out a double-blind, parallel group study (n = 19/arm) with balanced randomization in blocks of 4 and stratification by sex. Subjects entered a 30-week trial, of which phases I-III were open: phase I (wk 0-6) baseline; phase II (wk 7-9) stepwise transition to haloperidol (HAL), 30 mg/d, plus benztropine (BT), 4 mg/d; phase III (wk 10-15) HAL, 40-60 mg/d, plus BT, 4-6 mg/d; phase IV (wk 16-20) stepwise transition to LMP or CPZ (500 mg/d) following randomization; phase V (wk 21-28) stepwise increase of LMP or CPZ (600-1000 mg/d, dose reduction permitted) to establish optimum dose; and phase VI (wk 29-30) optimized dose maintained. Criteria for TRS were based on those established by Kane et al in 1988. The criterion for a response to treatment was a reduction of 25% or more in total Brief Psychiatric Rating Scale score. RESULTS: Both LMP (p = 0.007) and CPZ (p = 0.030) improved TRS relative to baseline. Although there was no significant difference between the 2 groups in treatment response at study end point, hierarchical linear modelling of longitudinal outcome revealed a significant (p = 0.006) advantage of LMP over CPZ for the BPRS total score. Ten of 19 participants on LMP and 8 of 19 on CPZ met the criterion for treatment response, and 9 of the 18 responders did so on 200-700 mg/d phenothiazine. The mean dose of responders was 710 (standard deviation [SD] 265) mg/d (LMP) and 722 (SD 272) mg/d (CPZ). Akathisia was associated with a nonresponse to phenothiazines (p = 0.010). BPRS scores increased significantly on HAL (p = 0.006). Two of 19 participants on LMP and 5 of 19 on CPZ withdrew early from the study. CONCLUSION: LMP and CPZ may be useful in the management of TRS. A modest advantage of LMP compared with CPZ was seen in longitudinal analysis. High doses of neuroleptics may contribute to TRS; reduction of neuroleptics to modest or moderate doses should be considered before categorizing a patient as treatment resistant.     

Vagus nerve stimulation for treatment-resistant depression: a randomized, controlled acute phase trial.

BACKGROUND: Vagus nerve stimulation (VNS) alters both concentrations of neurotransmitters or their metabolites and functional activity of central nervous system regions dysregulated in mood disorders. An open trial has suggested efficacy. METHODS: This 10-week, acute, randomized, controlled, masked trial compared adjunctive VNS with sham treatment in 235 outpatients with nonpsychotic major depressive disorder (n = 210) or nonpsychotic, depressed phase, bipolar disorder (n = 25). In the current episode, participants had not responded adequately to between two and six research-qualified medication trials. A two-week, single-blind recovery period (no stimulation) and then 10 weeks of masked active or sham VNS followed implantation. Medications were kept stable. Primary efficacy outcome among 222 evaluable participants was based on response rates (>/=50% reduction from baseline on the 24-item Hamilton Rating Scale for Depression [HRSD(24)]). RESULTS: At 10-weeks, HRSD(24) response rates were 15.2% for the active (n = 112) and 10.0% for the sham (n = 110) groups (p = .251, last observation carried forward [LOCF]). Response rates with a secondary outcome, the Inventory of Depressive Symptomatology - Self-Report (IDS-SR(30)), were 17.0% (active) and 7.3% (sham) (p = .032, LOCF). VNS was well tolerated; 1% (3/235) left the study because of adverse events. CONCLUSIONS: This study did not yield definitive evidence of short-term efficacy for adjunctive VNS in treatment-resistant depression.