Page 226 - MEGIN Book Of Abstracts - 2023

central cortex. Recently, in addition to the standard disease (WD) using magnetoencephalography (MEG)
therapy of botulinum neurotoxin (BoNT) injection into and compare it with "healthy" controls, and correlate
the affected muscles, bilateral deep brain stimulation the observations with disease severity and brain MRI.
(DBS) has been applied for the treatment of OMD. How-
ever, some patients' OMD symptoms do not improve METHODS MEF of 28 patients with neurological WD
sufficiently after DBS, and they require additional BoNT (age: 22.82 ± 5.8 years; M:F = 12:16) and 21 matched
therapy. In this review, we provide an overview of the controls (age: 25.0 ± 4.6 years; M:F = 10:11) were re-
unique central spatiotemporal processing mechanisms corded using MEG. Source localization was performed
in these regions in the bilateral cortex using EEG and using standard models on the components of M100,
MEG, as they relate to the sensorimotor functions of M20, and M100 for visual, somatosensory, and auditory
the stomatognathic system. Increased knowledge evoked fields, respectively and its latency/amplitude
regarding the neurophysiological underpinnings of the was correlated with disease severity.
stomatognathic system will improve our understanding
of OMD and other movement disorders, as well as aid RESULTS There were significant differences in source
the development of potential novel approaches such as location between control and WD during visual evoked
combination treatment with BoNT injection and DBS or field (VEF) and auditory evoked field (AEF) studies.
non-invasive cortical current stimulation therapies. Latencies of M20 (right-p = 0.02; left-p = 0.04) and M32
(right-p = 0.01) components of SSEF were significantly
Keywords: botulinum neurotoxin, deep brain stimulation, prolonged. The amplitude of M20 was significantly
electroencephalography, globus pallidus, magnetoen- reduced in patients bilaterally (P = 0.001). There was a
cephalography, motor function, oromandibular dystonia, trend for the prolonged latency of M100 of VEF in pa-
sensorimotor function, stomatognathic function tients (P = 0.09). Five patients had reduced right M145
compared to 8 controls. The left somatosensory evoked
Toxins (2022), Vol. 14, No. 11 (36356002) (0 citations) fields (SSEF) latency correlated with disease severity (P
= 0.04). There was no significant correlation between
major components of other MEF with disease severity
Insights from Magnetic Evoked Field Analysis in or MRI score.
Patients with Wilson's Disease (2022)
CONCLUSIONS This study, first of its kind to use MEF
Aruna, R; Mariyappa, N; Sinha, S; Nagappa, M; analysis in a large cohort of patients with WD, detected
Velmurugan, J; Saini, J; Bindu, P S; Mathuranath, P S; subclinical but a variable degree of abnormalities, most
Thennarasu, K; Satishchandra, P; Taly, A B consistently of SSEF. It provides valuable insights of
functioning and localization of various pathways in a
Department of Neurology, National Institute of Mental disease known to have protean clinical manifestations
Health and Neurosciences, Bengaluru, Karnataka, India; and widespread MRI changes.
Department of Clinical Neurosciences, National Institute of
Mental Health and Neurosciences, Bengaluru, Karnataka, Keywords: AEF, MEG, SSEF, VEF, Wilson's disease
India; Department of Neuro-Imaging and Interventional
Radiology, National Institute of Mental Health and Neurosci- Neurology India (2022), Vol. 70, No. 5 (36352595) (0
ences, Bengaluru, Karnataka, India; Department of Biostatis- citations)
tics, National Institute of Mental Health and Neurosciences,
Bengaluru, Karnataka, India

AIMS To study the latency, amplitude, and source lo-
calization of magnetic evoked field (MEF) responses to
visual, auditory, and somatosensory stimuli in Wilson's

 ontents  Index 205
C