Motivation States for Bodily Movement in Hyperkinetic Movement Disorders: A Scoping Review
Danielle Reynolds1, Paul McKee3, Amanda Divin4, Sanaz Nosrat5, Susannah Williamson6, John Krantz7, Brian Koo1, Miguel Blacutt8, Regina Casper9, Fabio Bueno10, Riley Avila5, Matthew Stults-Kolehmainen2
1Neurology, Yale New Haven Hospital, 2Yale New Haven Hospital, 3Duke University, 4Texas A&M University, 5Teachers College, Columbia University, 6Walter Reed Army Institute, 7Hanover College, 8University of Notre Dame, 9Stanford University, 10Connecticut Community Colleges
Objective:

The objective of this scoping review is to quantify the literature on motivation states (e.g., urges, impulses) surrounding bodily movement as applied to movement disorders.

Background:

A subset of hyperkinetic movement disorders are characterized by excessive movements which are suppressible and associated with a premonitory urge to move. The present review focuses specifically in exploration of the “urge” or subjective motivation to move. Investigating such sensations may help elucidate the pathophysiology, endogenous and exogenous stimuli, subjective experiences, correlates, and other factors related to these conditions, which remain poorly understood.

Design/Methods:

Iterative searches of scholarly databases took place to determine the optimal search strategy. Two investigators independently reviewed the literature and selected studies based on predetermined inclusion/exclusion criteria. A data extraction form was developed based on JBI's System for the Unified Management, Assessment and Review of Information (SUMARI). Guidelines for reporting evidence were followed as outlined by the PRISMA-ScR Checklist.

Results:

116 studies involving movement disorders were selected. Conditions included restless leg syndrome (RLS) and variants (78.4%), akathisia/tardive dyskinesia (10.3%), tic disorders (8.6%), and epilepsy of right posterior precuneus origin (0.9%). 45.7% of studies used a validated scale to assess the sensations. Articles revealed complex and multifactorial pathophysiology, however the former three disorders shared common associations: 1) dysfunction of the cortico-striato-thalamocortical loop, insula, and SMA; 2) neurotransmitter abnormalities including dopamine dysfunction, decreased GABA activity, and increased glutamate activity; and 3) co-morbid psychiatric disorders. 5% of RLS articles discussed an association with brain iron deficiency.

Conclusions:
This review is the first to unify the literature on motivation states for movement. A refined understanding of such states may lead to improved treatments for applicable movement disorders. Further, common themes suggest movement motivation may represent a motor urge dysfunction spectrum that includes normal sensations, and if so, future research elucidating its mechanism may have extensive public health applications.
10.1212/WNL.0000000000205668