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Weiss D, Schoellmann A, Fox MD, Bohnen NI, Factor SA, Nieuwboer A, Hallett M, Lewis SJG. Freezing of gait: understanding the complexity of an enigmatic phenomenon. Brain 2020; 143:14-30. [PMID: 31647540 DOI: 10.1093/brain/awz314] [Citation(s) in RCA: 86] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 08/07/2019] [Accepted: 08/16/2019] [Indexed: 12/15/2022] Open
Abstract
Diverse but complementary methodologies are required to uncover the complex determinants and pathophysiology of freezing of gait. To develop future therapeutic avenues, we need a deeper understanding of the disseminated functional-anatomic network and its temporally associated dynamic processes. In this targeted review, we will summarize the latest advances across multiple methodological domains including clinical phenomenology, neurogenetics, multimodal neuroimaging, neurophysiology, and neuromodulation. We found that (i) locomotor network vulnerability is established by structural damage, e.g. from neurodegeneration possibly as result from genetic variability, or to variable degree from brain lesions. This leads to an enhanced network susceptibility, where (ii) modulators can both increase or decrease the threshold to express freezing of gait. Consequent to a threshold decrease, (iii) neuronal integration failure of a multilevel brain network will occur and affect one or numerous nodes and projections of the multilevel network. Finally, (iv) an ultimate pathway might encounter failure of effective motor output and give rise to freezing of gait as clinical endpoint. In conclusion, we derive key questions from this review that challenge this pathophysiological view. We suggest that future research on these questions should lead to improved pathophysiological insight and enhanced therapeutic strategies.
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Affiliation(s)
- Daniel Weiss
- Centre for Neurology, Department for Neurodegenerative Diseases, and Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Anna Schoellmann
- Centre for Neurology, Department for Neurodegenerative Diseases, and Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Michael D Fox
- Berenson-Allen Center, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical Center, Boston, MA, USA.,Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.,Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Nicolaas I Bohnen
- Departments of Radiology and Neurology, University of Michigan, Ann Arbor, MI, USA; Veterans Administration Ann Arbor Healthcare System, Ann Arbor, MI, USA; Morris K. Udall Center of Excellence for Parkinson's Disease Research, University of Michigan, Ann Arbor, MI, USA
| | - Stewart A Factor
- Department of Neurology, Emory School of Medicine, Atlanta, GA, USA
| | - Alice Nieuwboer
- Neuromotor Rehabilitation Research Group, Department of Rehabilitation Sciences, KU Leuven, Leuven, Belgium
| | - Mark Hallett
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Simon J G Lewis
- Parkinson's Disease Research Clinic, Brain and Mind Centre, University of Sydney, Australia
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