Baseline cerebral structural morphology predict freezing of gait in early drug-naive Parkinson's disease

Freezing of gait (FOG) greatly impacts the daily life of patients with Parkinson's disease (PD). However, predictors of FOG in early PD are limited. Moreover, recent neuroimaging evidence of cerebral morphological alterations in PD is heterogeneous. We aimed to develop a model that could predict the occurrence of FOG using machine learning, collaborating with clinical, laboratory, and cerebral structural imaging information of early drug-naive PD and investigate alterations in cerebral morphology in early PD. Data from 73 healthy controls (HCs) and 158 early drug-naive PD patients at baseline were obtained from the Parkinson's Progression Markers Initiative cohort. The CIVET pipeline was used to generate structural morphological features with T1-weighted imaging (T1WI). Five machine learning algorithms were calculated to assess the predictive performance of future FOG in early PD during a 5-year follow-up period. We found that models trained with structural morphological features showed fair to good performance (accuracy range, 0.67-0.73). Performance improved when clinical and laboratory data was added (accuracy range, 0.71-0.78). For machine learning algorithms, elastic net-support vector machine models (accuracy range, 0.69-0.78) performed the best. The main features used to predict FOG based on elastic net-support vector machine models were the structural morphological features that were mainly distributed in the left cerebrum. Moreover, the bilateral olfactory cortex (OLF) showed a significantly higher surface area in PD patients than in HCs. Overall, we found that T1WI morphometric markers helped predict future FOG occurrence in patients with early drug-naive PD at the individual level. The OLF exhibits predominantly cortical expansion in early PD.

Automated summary

This study aimed to predict the occurrence of freezing of gait (FOG) in early drug-naive Parkinson's disease (PD) patients using machine learning, and investigate alterations in cerebral morphology in early PD. The study found that models trained with structural morphological features showed good predictive performance for FOG, and adding clinical and laboratory data improved the performance. Elastic net-support vector machine models performed the best, and the main features used for prediction were structural morphological features mainly distributed in the left cerebrum. The study also found that the bilateral olfactory cortex showed significant cortical expansion in PD patients.