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Human Spinal Physiology Unit - Division of Intramural Research


Mary Kay Floeter Image

Mary Kay Floeter, M.D., Ph.D., Senior Clinician

Dr. Floeter received her MD and PhD at Washington University in St. Louis and completed residency training in Neurology at the University of California, San Francisco. After postdoctoral work at UCSF, she came to NIH as a senior staff fellow in the Laboratory of Neural Control to study mammalian spinal cord circuits controlling movement. She joined the EMG section as a clinical associate in Clinical Neurophysiology three years later and has served as Chief of the NINDS EMG Section since 1996 and as the NINDS Deputy Clinical Director since 2006. Dr. Floeter’s recent research is directed toward analyzing changes in motor neurons and spinal circuits in patients with disorders that disrupt the corticospinal motor system.

Laboratory Staff

Rianna Albers, B.S., Post baccalaureate IRTA Fellow
Laura Danielian, M.S., Biomedical Engineer
Jennifer Farren, R.N., Nurse
Justin Y Kwan, M.D., Special Volunteer
Avner Meoded, M.D., Research Fellow
Olivia Schanz, B.S., Postbaccalaureate IRTA

Research Interests

The NINDS Human Spasticity and Spinal Physiology Unit studies neurological disorders that affect the descending motor systems and spinal cord neurons that control voluntary movements. Primary lateral sclerosis (PLS) and amyotrophic lateral sclerosis (ALS) are examples of rare disorders in which neurons responsible for voluntary movements undergo degeneration. Corticospinal (upper) motor neurons degenerate in both disorders; spinal (lower) motor neurons also degenerate in ALS, but are relatively spared in PLS. Some patients with ALS develop frontotemporal dementia (FTD). One goal of our research is to understand how certain disorders on this neurodegenerative spectrum are related. We are currently carrying out natural history studies on PLS and on ALS/FTD caused by a hexanucleotide repeat expansion in the gene C9ORF72. We are using clinical, physiological, and imaging techniques to understand these disorders and to look for biomarkers of disease progression or prognosis. Our study on C9ORF72 is highly collaborative, with investigators in laboratories at NINDS, NIA, and outside institutions.

A second goal is to identify reliable, non-invasive imaging markers for detection and measuring progression of brain involvement in individual patients with motor neuron disorders. We hypothesize that different imaging findings will reflect a sequence of structural changes that occur with cell death, inflammation, axonal breakdown and clearance. We are using multimodal imaging in healthy controls to first establish the reliability of different imaging modalities to select the most informative techniques for prospectively assessing patients with motor neuron disorders.


Clinical Protocols

  • Screening: Primary Lateral Sclerosis and related disorders  01-N-0145
  • Structural and Function Brain Imaging Markers of Upper Motor Neuron Function  12-N-0060
  • Natural History and Biomarkers of C9ORF72 ALS and FTD  13-N-0188

Selected Recent Publications

  • Meoded A, Kwan JY, Peters TL, Huey ED, Danielian LE, Wiggs E, Morrissette A, Wu T, Russell JW, Bayat E, Grafman J, Floeter MK
    Imaging findings associated with cognitive performance in primary lateral sclerosis and amyotrophic lateral sclerosis, Dement Geriatr Cogn Dis, 2013, vol. 16, pp. 233-250.
  • Kwan Jy, Meoded A, Danielian LE, Wu T, Floeter MK
    Structural imaging differences and longitudinal changes in primary lateral sclerosis and amyotrophic lateral sclerosis, Neuroimage Clin, 2012, vol. 2, pp. 151-160.
  • Kwan JY, Jeong SY, Van Gelderen P,Deng H-X, Quezado MM, Danielian LE, Butman JA,Chen L, Bayat E, Russell J, Siddique T, Duyn JH, Rouault TA, Floeter MK
    Iron Accumulation in Deep Cortical Layers Accounts for MRI Signal Abnormalities in ALS: Correlating 7 Tesla MRI and Pathology, PLoSOne, 2012, vol. 7(4), pp. e35241. Full Text/Abstract
  • Iwata NK, Kwan JY, Danielian LE, Butman J, Tovar Moll F, Bayat E, Floeter MK
    White matter alterations differ in primary lateral sclerosis and amyotrophic lateral sclerosis, Brain, 2011, vol. 134, pp. 2642-2655. Full Text/Abstract
  • Danielian LE, Iwata NK, Thomasson DM, Floeter MK
    Reliability of longitudinal fiber tracking measurements in diffusion tensor imaging, Neuroimage, 2010, vol. 49, pp. 1572-1580. Full Text/Abstract
  • Bai O, Lin P, Huang D, Fei DY, Floeter MK
    Towards a user-friendly brain-computer interface: Initial tests in ALS and PLS patients, Clin Neurophysiol, 2010, vol. 121, pp. 1293-303. Full Text/Abstract
  • Huey ED, Koppel J, Armstrong N, Grafman J, Floeter MK
    A pilot study of the prevalence of psychiatric disorders in PLS and ALS, Amyotroph Lateral Scler, 2010, vol. 11, pp. 293-7.
  • Floeter MK and Mills R
    Progression in primary lateral sclerosis: a prospective study, Amyotrophic Lateral Sclerosis, 2009, vol. 10, pp. 339-346.

Selected Earlier Publications


Contact Information

Human Spinal Physiology Unit
Medical Neurology Branch, NINDS
Building 10-CRC, Room 7-5680
10 Center Drive, MSC 1404
Bethesda, MD 20892-1404

Telephone: 301-496-7428 (office), 301-496-7428 (laboratory), 301-402-8796 (fax)
Email: FloeterM@ninds.nih.gov