Advanced Therapeutic Strategies for Motor Fluctuations in Parkinson’s Disease

Criteria for Referral to Advanced Therapies

Refer patients for advanced interventions when oral medications have been fully optimized yet motor fluctuations persist, rather than waiting for severe disability to develop【1】【2】.

Subthalamic nucleus (STN) DBS is the most extensively studied and effective surgical option for advanced Parkinson’s disease with medically unresponsive fluctuations【1】【2】.
Both STN and globus pallidus internus (GPi) stimulation provide comparable benefits in 3‑year comparative trials, making either target appropriate based on individual patient factors【1】【2】.
STN‑DBS typically enables a reduction in levodopa dosage, whereas GPi‑DBS does not produce the same dose‑sparing effect【1】【2】.
High‑quality evidence shows large improvements in motor impairment, fluctuation burden, and dyskinesia, with therapeutic benefits sustained for more than 15 years【1】【2】.
Reported adverse events include surgical or device complications, neuropsychiatric symptoms, dysarthria, and gait impairment【2】.

LCIG therapy yields a moderate increase in “on‑time without troublesome dyskinesia” for patients with refractory fluctuations【1】【2】.
It also provides a moderate reduction in daily “off‑time” periods【1】【2】.
The clinical benefit of LCIG is maintained for 2–3 years in most patients【1】【2】.
Gastrointestinal complications are the most common adverse events associated with LCIG【2】.

CAI produces a moderate improvement in both “on‑time” and “off‑time” durations in patients with persistent motor fluctuations【1】【2】.
The reduction in motor fluctuations is sustained for at least 2 years【2】.
Typical adverse events include dyskinesia and injection‑site reactions【2】.

Magnetic‑resonance‑guided focused ultrasound is an emerging, non‑invasive option for medication‑resistant tremor【1】.
The evidence base for FUS is less extensive than that for DBS, indicating a lower level of certainty regarding long‑term outcomes【1】.

Delaying referral for advanced therapies until severe disability occurs reduces the potential quality‑of‑life benefit; early referral after optimized oral therapy is recommended【1】【2】.