Prognostic factors of unilateral prelemniscal radiations radiofrequency lesions: A surgical technique for the treatment of Parkinson's disease motor symptoms

Abstract

Objective: A group of patients with Parkinson's disease (PD) were managed with unilateral prelemniscal radiation radiofrequency lesions (U-Raprl). The current study aims to evaluate prognostic factors that could influence clinical response.

Methods: Patients previously diagnosed with PD managed with U-Raprl were included in the study, classifying them into two groups according to their percentage of clinical response (</≥ 50%) at 5 years of follow-up in relation to the part III of the Unified Parkinson's Disease Rating Scale (UPDRS-III), analyzing the possible factors associated with their response (age, evolution of PD, Hoehn and Yahr scale (HYS), and levodopa dose). To show differences between groups before and after the intervention, a T-test was performed, and a Mann-Whitney U test was carried out to determine differences between the response groups, added to an effect size calculation using a Cohen's d (α = 0.05, and β = 0.20).

Results: Thirty-four patients were included, where the most prevalent symptoms were tremor and rigidity, with 52.9% percentage of males, 59.3 ± 6.4 mean age, and 7.4 ± 2.1 of mean evolution of PD. Analysis shows differences between groups (p < 0.05) according to the HYS, UPDRS, and levodopa intake, after the intervention. The analysis of the groups according to their response showed differences between the HYS (p < 0.01, ∆ > 1.5), Age (p < 0.0001, ∆ = 2.38), Evolution (p < 0.0001, ∆ = 2.38), and post-operative UPDRS (p < 0.01, ∆ = 1.38). The qualitative analysis of the distribution regarding the responder group shows that those patients with an age under 58 years, an evolution fewer than 7 years, and a preoperative HYS score smaller than 2, showed a response ≥ 50% according to the UPDRS-III in all cases.

Conclusion: U-Raprl is a highly effective procedure with a 5-year persistence of improvement. The most relevant prognostic factors to consider for a clinical response according to UPDRS-III greater than 50% are age under 58 years, less than 7 years of PD evolution, and HYS less or equal to 3.

Keywords: Motor symptoms; Parkinson’s disease; Prelemniscal radiations; Radiofrequency ablation; Tremor.