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Contact Information:

Office:  (305) 243-8181

Fax :  (305) 243-3913

CHRISTINE K. THOMAS, PH.D.

Professor, Department of Neurological Surgery

Neuromuscular Weakness, Fatigue, Spasms and Regeneration

Research Interests

My research has addressed issues relating to peripheral nerve regeneration, neuromuscular fatigue, weakness and spasms. Much of this work has involved human subjects and has required the use of surface and intramuscular EMG recordings at the whole muscle or single motor unit levels, intraneural stimulation and recording techniques, as well as measurements of peripheral and central conduction using electrical and magnetic stimulation. Now this knowledge is being applied to examine the neurophysiology of human spinal cord injury.   We have documented that muscle weakness and atrophy is often severe after human spinal cord injury. It relates to partial paralysis, denervation and/or disuse. Muscles paralyzed completely or partially by spinal cord injury are also highly fatigable. We aim to quantify this excessive force loss, to determine the factors that contribute to this fatigue and to analyze whether the fatigue sites are central and/or peripheral. Information from these studies may help improve systems used for functional electrical stimulation of paralyzed muscles.   Other projects examine spasms because muscles that are paralyzed by spinal cord injury are not always quiescent. A few weeks after injury, it is common for paralyzed muscles to contract involuntarily. Our research examines how extensive and intense this activity of paralyzed muscles is because on-going neural activity may prevent some muscle deterioration.   Our research has also expanded to include studies in rats. These studies aim to develop ways to ameliorate denervated-induced muscle atrophy. We have shown that some function can be restored to denervated muscles by reinnervation from axons that grow from embryonic ventral spinal cord cells transplanted into nearby peripheral nerve. The reinnervated muscles are weak, however. Thus, our current studies aim to improve the strength of these reinnervated muscles.

Interview with Marc Buoniconti, President, The Miami Project to Cure Paralysis

This month I would like to introduce something a little different in an effort to get people to know more about the amazing researchers I have the great fortune to work with on a daily basis.  Periodically I will conduct a brief interview with one of our scientists and present that interview in a question and answer format.  Hopefully this unique glimpse into the laboratories and the minds of those working here day in and day out will prove both insightful and informative.   Our first question and answer session will profile Christine Thomas, Ph.D.  Dr. Thomas hails from New Zealand and has been with The Miami Project for twenty years, so she has really seen things grow from a fledgling project to what we have today, the world’s most comprehensive research center dedicated to finding a cure for paralysis.  Her research interests are in neuromuscular weakness, fatigue, spasms and nerve regeneration.   Marc:  Some of your research focuses on the muscles of individuals who have been paralyzed by spinal cord injuries (SCI). Can you briefly explain to us what happens to muscles following SCI?   Dr. Thomas: Voluntary control of the muscles is eliminated when SCI severs nerve fibers or kills the motorneurons that supply muscles. Both of these processes result in widespread atrophy of muscles, particularly after motoneuron death which is common at the injury site. In this situation the muscles atrophy really quickly and will simply waste away unless their nerve supply is restored.   Marc: One of your newer studies is looking to try and save muscles from atrophy. What can you tell us about that study?   Dr. Thomas: We will examine how the transplantation of replacement cells near the damaged area can help to rescue the muscles. We are targeting the region of damage rather than bypassing it because you know how important each and every muscle is to the quality of life of those living with paralysis.   Marc: That is great. We’ll be anxiously awaiting the results of that study. What other types of things are you working on in your lab?   Dr. Thomas: Another area that we are actively looking into is muscle fatigue following SCI. Muscles that are paralyzed following spinal cord injury are highly fatigable. We are measuring this fatigue and determining the contributing factors. What we learn can have an impact on how functional electrical stimulation (FES) is used in those with paralysis. Perhaps this can be useful in their rehabilitation and recovery.   Marc: Thank you so much for your time and for all your hard work on behalf of The Miami Project and the millions of us living with paralysis.