Seminar – Dr. Amundsen-Huffmaster, University of Minnesota

Presenter: Dr. Sommer Amundsen-Huffmaster, PhD.
Assistant Professor of Research, Neurology Department
Affiliate faculty member, Rehabilitation Science Graduate Program
Movement Disorders Laboratory, University of Minnesota

Title: Trouble in Transitions: The Neurophysiology of Freezing of Gait in Parkinson's Disease

Date/Time: Thursday March 6^th, 2025 @ 1pm

Location: Life Science Building - Room# 1001; Presentation will be also made available online

Biography

Dr. Sommer Amundsen-Huffmaster is an Assistant Professor in the Department of Neurology at the University of Minnesota (UMN) in Minneapolis, MN, USA. She received a B.S in Dance and Engineering with a mechanical emphasis from Hope College, Holland, MI in 2007 and a PhD in Bioengineering from the University of Kansas, Lawrence, KS, after which she did a post-doc with Dr. Colum MacKinnon in the Movement Disorders Lab at UMN. Sommer's research interests include applying engineering principles to analyze human movement (biomechanics) and looking at how treatments can modify the motor symptoms of Parkinson's disease. Sommer enjoys canoeing, reading, and spending time with her husband and two small children.

Abstract

Freezing of gait (FOG) is one of the most debilitating features of Parkinson’s disease (PD). It is the feeling that one’s feet are glued to the ground, when trying to walk, and often results in trembling of the knees and/or short, shuffling steps. It occurs most often during self-initiated (uncued) transitions in movement (e.g., standing to walking, straight-line walking to turning), but can be overcome (and transition performance improved) with the provision of an external sensory cue (e.g., a light or tone). 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). 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. In this talk, I will present how I use engineering principles to investigate the pathophysiology of FOG in PD. 

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