Page 303 - MEGIN Book Of Abstracts - 2023

earlier findings that CMC is altered in acute stroke and the visual cortex, fusiform gyrus, and lateral temporal
demonstrate that CMC is bidirectional and not solely a lobe. At visit 1, MoCA scores were significantly lower for
measure of integrity of the efferent corticospinal tract. patients than controls (median [interquartile range] =
26.0 [4] versus 29.5 [3], P = 0.005), and patient reaction
Keywords: Afferent input, Corticomuscular coherence, times were increased. The amplitude of activation was
Corticospinal tract integrity, Magnetoencephalography, significantly lower after infarct and demonstrated a
Motor cortex, Stroke pattern of temporal dispersion independent of stroke
location. Differences were prominent in the fusiform
NeuroImage. Clinical (2021), Vol. 32 (34555801) (0 gyrus and lateral temporal lobe. The pattern suggests
citations) that distributed network dysfunction may be respon-
sible. Additionally, controls were able to modulate their
cerebral activity based on task difficulty. In contrast,
Poststroke acute dysexecutive syndrome, a disorder stroke patients exhibited the same low-amplitude
resulting from minor stroke due to disruption of response to all stimuli. Group differences remained, to a
network dynamics (2020) lesser degree, 6 mo later; while MoCA scores and reac-
tion times improved for patients. This study suggests
Marsh, Elisabeth B; Brodbeck, Christian; Llinas, Rafael H; that function is a globally distributed property beyond
Mallick, Dania; Kulasingham, Joshua P; Simon, Jonathan area-specific functionality and illustrates the need for
Z; Llinás, Rodolfo R longer-term follow-up studies to determine whether
abnormal activation patterns ultimately resolve or an-
Department of Neurology, Johns Hopkins School of Medicine, other mechanism underlies continued recovery.
Johns Hopkins Hospital, Baltimore, MD 21287; ebmarsh@
jhmi.edu llinas.rodolfo@gmail.com; Institute for Systems Re- Keywords: magnetoencephalography, recovery, stroke
search, University of Maryland, College Park, MD 20740; De-
partment of Electrical and Computer Engineering, University Proceedings of the National Academy of Sciences of
of Maryland, College Park, MD 20740; Department of Biology, the United States of America (2020), Vol. 117, No. 52
University of Maryland, College Park, MD 20740; Department (33318200) (5 citations)
of Neuroscience and Physiology, New York University Gross-
man School of Medicine, New York, NY 10016 ebmarsh@
jhmi.edu llinas.rodolfo@gmail.com High definition transcranial direct
current stimulation modulates abnormal
ABSTRACT Stroke patients with small central ner- neurophysiological activity in post-stroke aphasia
vous system infarcts often demonstrate an acute (2020)
dysexecutive syndrome characterized by difficulty
with attention, concentration, and processing speed, Shah-Basak, Priyanka P; Sivaratnam, Gayatri; Teti, Selina;
independent of lesion size or location. We use mag- Francois-Nienaber, Alexander; Yossofzai, Maryam;
netoencephalography (MEG) to show that disruption Armstrong, Sabrina; Nayar, Sumiti; Jokel, Regina;
of network dynamics may be responsible. Nine pa- Meltzer, Jed
tients with recent minor strokes and eight age-similar
controls underwent cognitive screening using the Department of Neurology, Medical College of Wisconsin,
Montreal cognitive assessment (MoCA) and MEG to 8701 W. Watertown Plank Rd, Wauwatosa, Milwaukee, WI,
evaluate differences in cerebral activation patterns. 53226, USA. prishah@mcw.edu; Rotman Research Institute,
During MEG, subjects participated in a visual picture- Baycrest Health Sciences, Toronto, ON, M6A 2E1, Canada;
word matching task. Task complexity was increased as Department of Medicine, McMaster University, Hamilton, ON,
testing progressed. Cluster-based permutation tests L8S 4L8, Canada; Canadian Partnership for Stroke Recovery,
determined differences in activation patterns within Ottawa, ON, K1G 5Z3, Canada

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