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

Dr. Mary Kay Floeter
Senior Collaborator
Address
Clinical Neurosciences Program

BG 10-CRC RM 1D45
10 CENTER DR
BETHESDA MD 20814

Contact
301-496-7428
mary.floeter@nih.gov

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 in physiology at UCSF, she came to NIH as a senior staff fellow in the Laboratory of Neural Control to study the physiology of motor neurons and mammalian spinal cord circuits controlling movement. She joined the EMG section as a clinical associate in Clinical Neurophysiology three years later and served as Chief of the NINDS EMG Section 1996-2014. She was appointed as the NINDS Deputy Clinical Director in 2006, and served as a Senior Clinician from 2008-2020 and currently maintains a collaborator appointment. Dr. Floeter’s research focuses on two rare motor neuron disorders: primary lateral sclerosis and C9ORF72-associated amyotrophic lateral sclerosis and frontotemporal dementia.

Dr. Floeter's studies focus on neurodegenerative disorders that affect corticospinal and spinal motor neurons that control voluntary movement. 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. She is interested in understanding how these disorders are related and finding biomarkers of disease progression or prognosis - the hypothesis is that functional changes will precede structural changes, with a sequence reflecting cell death, inflammation, axonal breakdown and tissue remodeling. Multimodal imaging and physiology studies are being used to explore these questions. 

ALS, PLS, and frontotemporal dementia (FTD) have been proposed to form a spectrum of neurodegenerative disease because of overlapping clinical symptoms and pathological features. In 2011, a hexanucleotide repeat expansion in the gene C9ORF72 was found to cause ALS and FTD, extending the evidence for this proposal to  genetics. To better understand the range of clinical presentations of this mutation in C9ORF72 and how clinical symptoms progress, Dr. Floeter led a prospective longitudinal study of C9ORF72-related disorders, with imaging, physiological, and biofluid studies. This study of C9ORF72-related disease is highly collaborative, with investigators in laboratories at NINDS, NIA, and outside institutions, including agreements for sharing biospecimens.

 

6 Months Spread of White Matter Changes in C9orf72 ALS-FTD:

Diffusion tensor imaging of a group of C9orf72 mutation carriers shows a frontal predominance of white matter disruption, with spread of regions with reduced fractional anisotropy (upper panel) from the initial scan (red) and a second scan 6 months later. White matter regions with increased mean diffusivity (lower panel) at the initial scan (blue) extend further posteriorly and into the temporal lobe 6 months later (green).
Diffusion tensor imaging of a group of C9orf72 mutation carriers shows a frontal predominance of white matter disruption, with spread of regions with reduced fractional anisotropy (upper panel) from the initial scan (red) and a second scan 6 months later. White matter regions with increased mean diffusivity (lower panel) at the initial scan (blue) extend further posteriorly and into the temporal lobe 6 months later (green).

Clinical Protocols

  • 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

  • Investigating Complex Neurodegenerative Disorders 17-N-0131