Reticulospinal Contributions to Gross Hand Function after Human Spinal Cord Injury

Lookup NU author(s): Professor Stuart Baker ORCiD

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Abstract

Multiple descending motor pathways likely contribute to the recovery of hand motor function following spinal cord injury (SCI). Reticulospinal neurons project to spinal motor neurons controlling hand muscles and extensively sprout into gray matter structures after SCI; therefore, it has been proposed that the reticulospinal tract is one of the descending motor pathways involved in recovery of hand function after injury. To test this hypothesis, we examined the StartReact response, an involuntary release of a planned movement via a startling stimulus that engages the reticulospinal tract, by measuring reaction times from electromyographic activity in an intrinsic finger muscle during three motor tasks requiring different degrees of hand dexterity: index finger abduction, a precision grip, and a power grip. Males and females with and without incomplete chronic cervical SCI were tested. We found that although SCI participants voluntarily responded to all tasks, reaction times were shorter during a startle cue while performing a power grip but not index finger abduction or precision grip. Control subjects had similarly shorter reaction times during a startle cue in all motor tasks. These results provide the first evidence for a contribution of the reticulospinal tract to hand control in humans with SCI during gross finger manipulations and suggest that this contribution is less pronounced during fine dexterous finger movements.

Publication metadata

Author(s): Baker SN, Perez MA

Publication type: Article

Publication status: Published

Journal: Journal of Neuroscience

Year: 2017

Volume: 37

Issue: 40

Pages: 9778-9784

Print publication date: 04/10/2017

Online publication date: 04/09/2017

Acceptance date: 16/08/2017

Date deposited: 26/10/2017

ISSN (print): 0270-6474

ISSN (electronic): 1529-2401

Publisher: Society for Neuroscience

URL:

DOI: 10.1523/JNEUROSCI.3368-16.2017

PubMed id: 28871033

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