The Neurosurgery Signal — Signal, Not Noise

Rapid review note

Journal Club is a rapid, AI-assisted appraisal layer. It highlights study design, effect estimates, and practice relevance, but it is still a briefing, not a replacement for the paper.

For education only. Not medical advice.

Paper snapshot

Rapid study overview

Open paper

DOI

10.1001/jama.2008.929

PMID

19126811

PICO

Population

Patients with advanced idiopathic Parkinson disease (Hoehn and Yahr stage ≥2 off medication), levodopa-responsive, with persistent disabling symptoms despite medication

Intervention

Bilateral deep brain stimulation of subthalamic nucleus or globus pallidus

Comparator

Best medical therapy managed by movement disorder neurologists

Outcomes

On time without troubling dyskinesia, motor function, quality of life, neurocognitive function, adverse events

Design

Type

Randomized controlled trial

Randomized

Yes

Multicenter

Yes

Blinded

Motor function assessments by blinded raters

Follow-up

6 months

Primary endpoint

Time spent in 'on' state without troubling dyskinesia (hours/day) using motor diaries

Secondary endpoints

Motor function (UPDRS)
Quality of life (PDQ-39)
Neurocognitive function
Adverse events

Practice impact

What this means

This multicenter RCT compared bilateral DBS (STN or GPi) vs best medical therapy in 255 advanced PD patients. DBS provided 4.6 more hours/day of good motor control without troubling dyskinesia vs medical therapy, with 71% vs 32% achieving clinically meaningful motor improvement. Quality of life improved significantly with DBS, but serious adverse events were more common (49 vs 15 patients). The study supports DBS efficacy in appropriately selected patients despite increased procedural risks.

Bottom line

DBS provides substantial improvement in motor function and quality of life vs optimized medical therapy in advanced PD, but with increased serious adverse events

Strength of evidence

high

Recommendation

consider change

Why it matters

Large multicenter RCT with blinded assessments
Clinically meaningful improvements in on time, motor function, and QOL
Balances benefits against increased serious adverse events including surgical complications

What would change my mind

Longer-term outcomes showing durability of benefit vs late complications
Subgroup analyses showing differential efficacy by age or target
Cost-effectiveness analyses comparing DBS vs advanced medical therapies

Critical appraisal

How strong is the paper?

Methods critique

Risk of bias

Low risk: randomized, multicenter, blinded motor assessments, intention-to-treat analysis

Confounding

Stratified by site and age; baseline characteristics balanced

Missing data

Not reported in excerpt; final follow-up visit completed May 2006

Multiplicity

Multiple secondary outcomes tested; P values reported without adjustment

Notes

Combined STN and GPi targets for surgical vs medical comparison
Active medical management comparator strengthens comparison

Stats check

NNT

Approximately 3 for clinically meaningful motor improvement

Effect sizes

Mean difference in on time: 4.5 h/d (95% CI 3.7-5.4)
71% DBS vs 32% BMT had clinically meaningful motor improvement (≥5 points)

Absolute effects

DBS gained 4.6 h/d on time vs 0 h/d for BMT
49 DBS vs 15 BMT patients had ≥1 serious adverse event

Concerns

No multiplicity adjustment for multiple secondary outcomes
Short 6-month follow-up

External validity

Who it applies to

Advanced PD patients with motor fluctuations/dyskinesias despite medication, including older patients (25% ≥70 years)

Who it does not

Patients with atypical syndromes, dementia, surgical contraindications, or previous PD surgery

Generalizability notes

Multicenter VA and university hospitals
Included older patients often excluded from DBS trials
Active medical management comparator reflects real-world practice

Evidence trace

Source trace and metadata

Citations (3)

claim_id

methods_critique.risk_of_bias

locator

p. 5 Methods

quote

Motor function assessments were conducted by raters blinded to treatment.

claim_id

stats_check.effect_sizes

locator

p. 5 Results

quote

Patients who received deep brain stimulation gained a mean of 4.6 h/d of on time without troubling dyskinesia compared with 0 h/d for patients who received best medical therapy (between group mean difference, 4.5 h/d [95% CI, 3.7-5.4 h/d...

claim_id

practice_impact.bottom_line

locator

p. 5 Conclusion

quote

In this randomized controlled trial of patients with advanced PD, deep brain stimulation was more effective than best medical therapy in improving on time without troubling dyskinesias, motor function, and quality of life at 6 months, bu...

Metadata

Generated at

2026-03-06T13:41:29.251Z

Version

top 100 cited in past 20 years