2025 American Academy of Neurology Abstract Website

Maria Antonia Machado Pereira¹, Marcio Ferreira², Izabely Dos reis de paula³, Vitor Ribeiro⁴, Victor Soares⁶, Marcelo Sousa⁷, Carlos Matheus Meireles de Oliveira³, Ocilio Goncalves⁴, Filipe Ribeiro⁸, Stefeson Gomes Cabral Junior⁹, Antonio Francisco Pereira⁵, Denise Maria Cury⁹, Jacy Parmera¹⁰, Gustavo Noleto¹¹
¹State University of Piaui, ²Neurosurgery, Lenox Hill Hospital/Northwell, ³State University of Piauí, ⁴Federal University of Piauí, ⁵Nursing, Federal University of Piauí, ⁶Federal University of the Jequitinhonha and Mucuri Valleys, ⁷Federal University of Rio de Janeiro, ⁸Barão de Mauá University Center, ⁹Federal University of Minas Gerais, ¹⁰Neurology, University of São Paulo, ¹¹University of São Paulo

Objective:

We performed a systematic review and single-arm meta-analysis to evaluate the effects of deep brain stimulation in the subthalamic nucleus (STN-DBS) on olfactory dysfunction (OD) in Parkinson's disease (PD) patients.

Background:

STN-DBS is a common treatment for PD, but its effects on OD
are unclear

Design/Methods:

Medline, Scopus, and Web of Science were searched for observational studies with ≥4 patients reporting the effects of STN-DBS on OD in PD patients. Mean differences (MD) between pre- and post-operative, along with the final mean pooled analysis, olfactory scores values with 95% confidence intervals (CI) with a random effects model were used. The statistical analyses were performed using the software R Studio. The heterogeneity was assessed with I² statistics.

Results:

A total of seven studies, encompassing 188 PD patients were included in our analysis. There was a significant difference between pre- and post-operative value in Odor discrimination (ODI) (MD 2.16; 95% CI 1.37 to 2.96; I² = 0%) and Unified Parkinson’s Disease Rating Scale part III OFF medication (UPDRS III OFFMED) (MD -11.96; 95% CI -22.57 to -1.35; I2 = 88%). In contrast, there was no significant difference between the initial and final value in Odor thresholds (OT) (MD 1.54; 95% CI -0.22 to 3.30; I² = 90%), and the University of Pennsylvania Smell Identification Test (UPSIT) (MD -0.37; 95% CI -3.40 to 2.66; I² = 0%). Pooled analysis for Odor identification (OI) showed a final mean of 7.06 (95% CI 4.39 to 9.72; I² = 100%), and for the TDI score (composite score derived from the sum of OD, OI, and OT results), a final mean of 25.96 (95% CI 17.31 to 34.62; I² = 94%).

Conclusions:

Despite being mainly indicated for motor relief, STN-DBS may improve OD.