# Neurophysiology of movement transitions in Parkinson's disease with freezing of gait

> **NIH NIH R01** · UNIVERSITY OF MINNESOTA · 2024 · $529,130

## Abstract

Abstract
Freezing of gait (FOG) is characterized by episodes during which an individual is unable to step, despite
intending to do so, and is a common cause of falls, decreased mobility, and increased morbidity in people with
Parkinson’s disease (PD). Effective treatment for FOG remains elusive, due to a lack of understanding of the
complex underlying pathophysiology. The expression and factors contributing to FOG are highly
heterogeneous across individuals, however, a common feature is that episodes are predominantly triggered
during movement-state transitions (e.g. initiating walking or turning)4,5. Impaired transitions leading to FOG
typically occur when the change in movement-state is self-initiated (uncued), but when the same transition is
cued by an external sensory stimulus, movement execution is improved, and the incidence and duration of
FOG is markedly reduced. FOG may be caused by abnormal communication between subcortical systems
controlling posture and balance (e.g. vestibulo- and reticulospinal systems) and cortico-fugal systems driving
the initiation of the intended action (e.g. stepping). Currently, the mechanisms contributing to impaired
self-initiated movement transitions in people with PD and FOG, and how they are improved by external cues,
are poorly understood. We hypothesize that the capacity to downregulate the communication (coherence) of
systems controlling posture and balance during self-initiated transitions from one movement state (standing) to
another (walking) is impaired in people with FOG, and that sensory cues ameliorate FOG by restoring
transition-related modulation of posture/balance systems. This hypothesis will be tested using biomechanical
and neurophysiological measures to examine the dynamics of the vestibulo-postural (Aim 1), cortico-cortical
and cortico-muscular (Aim 2), and cortico-basal ganglia (Aims 3 and 4) systems during cued and uncued
posture-locomotion transitions in PD, with and without FOG, and controls. Aim 1 will examine the
vestibulo-postural system in FOG by measuring the dynamic changes in coherence between vestibular input
(electrical vestibular stimulation) and the ground reaction forces controlling balance. Aim 2 will utilize
high-resolution electroencephalography (EEG) and electromyography (EMG) to examine movement-related
cortical potentials and cortico-cortical and cortico-muscular coherence. Aim 3 will use EEG and local field
potential (LFP) recordings from implanted Medtronic PerceptTM deep brain stimulators (DBS) to examine the
interaction of the globus pallidus and cortex (cortico-pallidal coherence). Aims 1-3 will utilize standardized gait
initiation paradigms that may or may not provoke freezing. Aim 4 will use wearable sensors and a
FOG-provoking course, involving multiple posture/gait transitions, to wirelessly capture LFPs associated with
FOG episodes in participants with PD with the PerceptTM DBS system. This project will provide insight into the
mechanisms and neurological ...

## Key facts

- **NIH application ID:** 10855205
- **Project number:** 1R01NS136323-01
- **Recipient organization:** UNIVERSITY OF MINNESOTA
- **Principal Investigator:** Sommer L Huffmaster
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $529,130
- **Award type:** 1
- **Project period:** 2024-09-01 → 2029-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10855205

## Citation

> US National Institutes of Health, RePORTER application 10855205, Neurophysiology of movement transitions in Parkinson's disease with freezing of gait (1R01NS136323-01). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10855205. Licensed CC0.

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