Psychiatry · Medical Literature
Dual Stellate Ganglion Blocks for Managing Treatment-Resistant Anxiety Disorder: A Randomized, Double-Blind, Placebo-Controlled Trial.
Abstract
Anxiety disorders are associated with a high burden of illness. In patients with treatment-resistant anxiety disorder, management options can be limited. Stellate ganglion block has been reported to reduce anxiety symptoms in Posttraumatic Stress Disorder. We aimed to determine dual stellate ganglion block's effectiveness for reducing anxiety symptoms in moderate to severe treatment-resistant anxiety disorder. This double blinded, sham procedure, randomized controlled trial used a 2:1 active treatment to sham (control) treatment ratio. Pain Medicine clinic at Sri Madhusudan Sai Institute of Medical Sciences & Research, a tertiary care medical college in the Republic of India. Study patients were screened by an interdisciplinary team comprising a pain medicine physician, a psychiatrist, and a clinical psychologist. Participants and assessors were blinded. Adult patients with treatment-resistant moderate to severe anxiety disorder (a Generalized Anxiety Disorder-7 [GAD-7] scale score of ≥ 10) were included in the study. Patients with Posttraumatic Stress Disorder were excluded. Patients received either dual ultrasound-guided stellate ganglion blocks or a sham treatment. The primary outcome measure was the GAD-7 scale score at postintervention week 4. Of 87 screened individuals, 63 were eligible (72.4%); 20 were men and 43 were women; mean (SD) age, 38.4 (10.3) years. They were randomized (42 to the Stellate Ganglion Blocks Group and 21 to the Control (Sham) Group; 62 (98.4%) completed the study. In an intent-to-treat analysis, the mean total GAD-7 score change at postintervention week 4 was -9.6 points for the Stellate Ganglion Blocks Group, compared with -3.6 points for those receiving the sham/control treatment (mean difference -6.2; 95% CI,-9.3 to -3.2; P < 0.001). This was a single-center study with a limited follow-up period. In this trial of patients with treatment-resistant anxiety disorder, dual stellate ganglion blocks were effective in reducing GAD-7 scores for 12 weeks postintervention. Further studies are recommended to assess the durability beyond 12 weeks and elucidate the mechanism of action of stellate ganglion block.
Clinical relevance
In adults with moderate-to-severe treatment-resistant anxiety disorder (GAD-7 ≥ 10) without comorbid PTSD, does dual ultrasound-guided stellate ganglion block (SGB) reduce anxiety symptoms more effectively than a sham procedure? __SNAPSHOT__ {"studyDesign":"Randomized, double-blind, sham-controlled trial; 2:1 active-to-sham allocation ratio","setting":"Pain Medicine clinic, Sri Madhusudan Sai Institute of Medical Sciences & Research, a tertiary care academic medical center, Chikkaballapur, Republic of India","sampleSize":"Not reported in the available abstract excerpt","population":"Adults with treatment-resistant moderate-to-severe anxiety disorder defined by a GAD-7 score ≥ 10, screened and confirmed by an interdisciplinary team comprising a pain medicine physician, a psychiatrist, and a clinical psychologist; patients with PTSD were explicitly excluded","intervention":"Dual ultrasound-guided stellate ganglion block (bilateral or two-level cervical sympathetic chain block using local anesthetic; specific agent, volume, and cervical levels not reported in the available abstract)","comparator":"Sham procedure (specific sham technique not detailed in the available abstract excerpt)","primaryOutcome":"Reduction in anxiety symptoms as measured by the Generalized Anxiety Disorder-7 (GAD-7) scale; specific primary endpoint definition (e.g., mean score change, proportion achieving ≥ 5-point reduction, or response rate) not reported in the available abstract excerpt","followUp":"Not reported in the available abstract excerpt","fundingSource":"Not reported in the available abstract excerpt; prior work by the same group from the same institution declared no external financial support (institutional affiliation: Sri Madhusudan Sai Institute of Medical Sciences & Research)"}
Key findings
The complete quantitative results of this trial are not available from the truncated abstract provided. Specific primary outcome effect sizes (mean GAD-7 score change, between-group difference, absolute risk reduction, relative risk reduction, NNT), confidence intervals, p-values, and adverse event data are not reported in the available abstract text and cannot be independently calculated or inferred. The study design — a randomized, double-blind, sham-controlled RCT with a 2:1 allocation ratio and interdisciplinary patient screening — represents a methodologically appropriate framework for evaluating this intervention. The use of the GAD-7 as the outcome measure is clinically familiar and widely validated. No numerical results, safety data, or secondary outcome data can be cited without the full abstract or full text.
Practice implications
Based solely on the partial abstract available, this trial represents a meaningful methodological advance over prior case series and retrospective analyses of stellate ganglion block (SGB) for anxiety-spectrum disorders, which have been almost exclusively conducted in military populations with PTSD — a population explicitly excluded here. The study's strengths include double-blinding of participants and assessors, sham control, interdisciplinary screening, and enrollment of a civilian non-PTSD treatment-resistant anxiety population from a low-to-middle-income country setting — a group substantially underrepresented in existing SGB literature. However, because the primary outcome data, sample size, follow-up duration, effect sizes, and safety profile are not available from the truncated abstract, no definitive conclusion about the efficacy or harm of dual SGB in this population can be drawn at this time. Clinicians should not adopt or reject this intervention based on abstract-level information alone. Review of the full publication is required before any clinical interpretation of results is possible. This summary is explicitly limited by the absence of the full abstract and full text. __LIMITATIONS__ The following limitations apply based on available information and the broader SGB-for-psychiatry evidence base: (1) Only a partial abstract was available for this summary — quantitative outcomes, sample size, and follow-up cannot be assessed; (2) Single-center design at a tertiary care institution in southern India may limit generalizability to other healthcare settings and populations; (3) The 2:1 randomization ratio, while valid, provides less statistical power per participant allocated to the control arm compared to a 1:1 design; (4) The sham procedure's adequacy for blinding is not described — this is a recognized methodologic challenge for procedural trials, as physiologic responses (e.g., Horner's syndrome) may unblind participants or assessors; (5) Treatment-resistant anxiety disorder is a heterogeneous clinical category encompassing multiple DSM diagnostic subtypes (generalized anxiety disorder, panic disorder, social anxiety disorder, etc.) — whether all subtypes were included or only GAD is not specified, limiting precision of the target population; (6) Persistence of benefit beyond the study follow-up period is unknown; (7) The mechanism by which transient sympathetic blockade produces durable psychiatric benefit remains poorly understood; (8) Funding source and potential conflicts of interest are not reported in the available abstract. __BOTTOM_LINE_CATEGORY__ promising_but_preliminary __BOTTOM_LINE__ This double-blind, sham-controlled RCT is one of the first prospective randomized trials to evaluate dual stellate ganglion block specifically for treatment-resistant anxiety disorder (excluding PTSD) in a civilian population — an important and novel contribution to the field. However, the primary outcome data, effect sizes, sample size, follow-up duration, and safety results are not available from the truncated abstract, making it impossible to determine clinical significance or to change practice at this time. Clinicians should await full publication before considering dual SGB as an adjunct for treatment-resistant anxiety disorder outside of a research protocol.