Effects of Transcutaneous Spinal Direct Current Stimulation in Incomplete Spinal Cord Injury
Overview
- Phase
- Not Applicable
- Intervention
- Not specified
- Conditions
- Incomplete Spinal Cord Injury
- Sponsor
- The University of Texas Health Science Center, Houston
- Enrollment
- 15
- Locations
- 1
- Primary Endpoint
- Change in Somatosensory Evoked Potential (SSEP)
- Status
- Completed
- Last Updated
- 6 years ago
Overview
Brief Summary
The purpose of the study is to investigate the effects of a novel therapeutic approach with transcutaneous spinal direct current stimulation (tsDCS) to promote functional recovery and spasticity in chronic spinal cord injury (SCI).
Detailed Description
The purpose of the study is to investigate the effects of a novel therapeutic approach to promote functional recovery and spasticity in chronic SCI. The tsDCS effect on neuro-physiological measures such as H reflex and somatosensory evoked potential (SSEP) wiil be evaluated in subjects with SCI. This incremental, design will allow the establishment of strong electrophysiological data prior to rapid clinical translation of the findings about this promising, early-stage technique. The central hypothesis is twofold: 1) active tsDCS will lead to a change in Hmax/M max ratio than sham tsDCS, in a polarity dependent manner; and 2) active tsDCS will lead to a change in SSEP amplitude and latency, in a polarity dependent manner.
Investigators
Radha Korupolu
Assistant Professor
The University of Texas Health Science Center, Houston
Eligibility Criteria
Inclusion Criteria
- •Providing written informed consent prior to any study related procedures
- •18-65 years of age
- •Motor incomplete SCI classified as B, C or D by the American Spinal Injury Association Impairment Scale (AIS)
- •Traumatic lesion at or above T8-T9 neurological level
- •Body mass index ≤ 30 (in order to facilitate reliable location of body landmarks guiding stimulation);
- •Chronic SCI (time since injury\>6 months)
Exclusion Criteria
- •Unstable cardiopulmonary conditions
- •History of seizure, head injury with loss of consciousness, severe alcohol or drug abuse, and/or psychiatric illness
- •Any joint contracture or severe spasticity, as measured by a Modified Ashworth Score 4
- •Subject who cannot provide self-transportation to the study location
- •Cardiac or neural pacemakers
- •Pregnancy
- •lower motor neuron injury (eg: peripheral neuropathy, cauda equina syndrome)
- •Uncontrolled diabetes with HbA1C\>7
- •History of severe autonomic dysreflexia
- •No planned alteration in therapy or medication for muscle tone during the course of the study(No botulinum toxin injections in last 3 months, No phenol injections in last 6 months, intrathecal baclofen pump dose stable for past 3 months, etc)
Outcomes
Primary Outcomes
Change in Somatosensory Evoked Potential (SSEP)
Time Frame: 30 to 40 minutes before intervention, 30 to 40 minutes after intervention
A somatosensory evoked potential (SSEP) is the electrical activity response measured at the skin's surface along ascending sensory pathway following controlled peripheral nerve stimulation by tsDCS. For recording posterior tibial nerve SSEPs, the nerve is stimulated at the ankle, with the cathode midway between the Achilles tendon and the medial malleolus and the anode 3 cm distal to the cathode. Nerve stimulation should consist of a 0.1-0.2 ms duration square wave pulse at 3-5 Hertz (Hz). These pulses will be delivered by constant voltage stimulator applied transcutaneously over the targeted nerve. The stimulation intensity would exceed the motor threshold for eliciting a muscle twitch. Electromyogram (EMG)/ Nerve Conduction Velocity (NCV) measuring system will be used to measure SSEPs.
Percent Change in Hmax
Time Frame: 10 minutes before intervention, 10 minutes after intervention
Immediately before application of tsDCS and after application of tsDCS, Hmax will be obtained from soleus muscle by stimulation of tibial nerve. The H-reflex is a compound muscle action potential elicited by low-threshold electrical stimulation of afferent fibers in the mixed nerve with subsequent monosynaptic excitation of alpha motoneurons. Changes in the excitability of the reflex pathway are estimated by measuring the amplitude of the reflex.
Secondary Outcomes
- Change in Diastolic Blood Pressure(60 to 90 minutes before intervention,60 to 90 minutes after intervention ( for each intervention))
- Change Systolic Blood Pressure(60 to 90 minutes before intervention, 60 to 90 minutes after intervention)
- Change in Heart Rate(60 to 90 minutes before intervention,60 to 90 minutes after intervention ( for each intervention))