J Mov Disord.  2025 Apr;18(2):165-169. 10.14802/jmd.24175.

Modified Ratio of Tremor/Postural Instability Gait Difficulty Score as an Indicator of Short-Term Outcomes of Subthalamic Nucleus Deep Brain Stimulation in Parkinson’s Disease

• Reddy C
• Pillai K
• Joshua S
• Nair A
• Chavotiya H
• Chacko M
• Kishore A

• KMID: 2567162
• DOI: http://doi.org/10.14802/jmd.24175

Abstract

Objective
The outcomes of motor and nonmotor features of Parkinson’s disease (PD) following deep brain stimulation (DBS) vary among its subtypes. We tested whether preoperative motor subtyping using the modified tremor/postural instability and gait difficulty ratio (T/P ratio) could indicate the short-term motor, nonmotor and quality of life (QOL) outcomes of subthalamic nucleus (STN) DBS.
Methods
In this prospective study, 39 consecutive STN DBS patients were assessed in the drug-OFF state before surgery and subtyped according to the T/P ratio. Patients were reassessed 6 months after surgery in the stimulation ON-drug-OFF state, and the percentage changes in motor, nonmotor and QOL scores (Parkinson’s Disease Quality of Life Questionnaire [PDQ-39]) were calculated.
Results
The modified T/P ratio was moderately and positively correlated with the percentage change in the Unified Parkinson’s Disease Rating Scale III score in the OFF state, the sum of cardinal motor signs, the Non-Motor Symptom Scale score, and QOL (PDQ-39).
Conclusion
Preoperative PD motor subtyping can be used as an indicator of the short-term outcomes of STN DBS in PD patients.

Keyword

Parkinson’s disease subtypes; Deep brain stimulation; Tremor/postural instability and gait difficulty ratio; Motor and nonmotor outcomes