Fields of Forel Brain Stimulation Improves Levodopa-Unresponsive Gait and Balance Disorders in Parkinson's Disease

Abstract

BACKGROUND Gait and balance disturbance are challenging symptoms in advanced Parkinson's disease (PD). Anatomic and clinical data suggest that the fields of Forel may be a potential surgical target to treat these symptoms. OBJECTIVE To test whether bilateral stimulation centered at the fields of Forel improves levodopa unresponsive freezing of gait (FOG), balance problems, postural instability, and falls in PD. METHODS A total of 13 patients with levodopa-unresponsive gait disturbance (Hoehn and Yahr stage ≥3) were included. Patients were evaluated before (on-medication condition) and 1 yr after surgery (on-medication-on-stimulation condition). Motor symptoms and quality of life were assessed with the Unified Parkinson's Disease Rating scale (UPDRS III) and Quality of Life scale (PDQ-39). Clinical and instrumented analyses assessed gait, balance, postural instability, and falls. RESULTS Surgery improved balance by 43% (95% confidence interval [CI]: 21.2-36.4 to 35.2-47.1; P = .0012), reduced FOG by 35% (95% CI: 15.1-20.3 to 8.1-15.3; P = .0021), and the monthly number of falls by 82.2% (95% CI: 2.2-6.9 to −0.2-1.7; P = .0039). Anticipatory postural adjustments, velocity to turn, and postural sway measurements also improved 1 yr after deep brain stimulation (DBS). UPDRS III motor scores were reduced by 27.2% postoperatively (95% CI: 42.6-54.3 to 30.2-40.5; P < .0001). Quality of life improved 27.5% (95% CI: 34.6-48.8 to 22.4-37.9; P = .0100). CONCLUSION Our results suggest that DBS of the fields of Forel improved motor symptoms in PD, as well as the FOG, falls, balance, postural instability, and quality of life.

Freezing of gait: pharmacological and surgical options

“…Recently, burst-cycling DBS has shown similar benefits in FoG and functional mobility compared to conventional DBS but with lower battery consumption [41]. Recent meta-analyses have reported that bilateral PPN, PPN & STN, FOF, LFS SNr, HFS NST, and DN DBS combined with the levodopa approach improves gait and falls [42][43][44][45]. Conversely, bilateral open-loop GPi-DBS and closed-loop PPN-DBS were ineffective in treating FoG [46].…”

Troubleshooting Gait Disturbances in Parkinson’s Disease With Deep Brain Stimulation

“…A prospective pilot trial of directional CN-DBS is ongoing (NCT04218526). An alternative promising target has recently been proposed by Rocha et al (2021) , who reported a marked and lasting motor improvement with amelioration of PIGD in 13 PD patients with Filed of Forel DBS.…”

Commentary: Forel Fields' Brain Stimulation Improves Levodopa-Unresponsive Gait and Balance Disorders in Parkinson's Disease: A Case Series Study

“…The authors of this paper 1 performed a prospective study of DBS of the field of Forel (FOF)—the very same area that was introduced almost exactly 60 years ago by Spiegel and Wycis and colleagues 2,3 in their original experience with stereotactic surgery for movement disorders when it was called “campotomy” and resurrected recently as a target for stereotactic lesioning. 4,5 In the authors' series, the analysis of 13 patients with advanced PD treated with FOF DBS indicated remarkable improvement of gait along with the overall improvements in PD symptoms and quality of life—and rather minor side effects that improved with DBS reprogramming.…”