title: Combined MEG-EEG source localisation in patients with sub-acute sclerosing pan-encephalitis.
abstract: To study the genesis and propagation patterns of periodic complexes (PCs) associated with myoclonic jerks in sub-acute sclerosing pan-encephalitis (SSPE) using magnetoencephalography (MEG) and electroencephalography (EEG). Simultaneous recording of MEG (306 channels) and EEG (64 channels) in five patients of SSPE (M:F = 3:2; age 10.8 ± 3.2 years; symptom-duration 6.2 ± 10 months) was carried out using Elekta Neuromag(®) TRIUX™ system. Qualitative analysis of 80-160 PCs per patient was performed. Ten isomorphic classical PCs with significant field topography per patient were analysed at the 'onset' and at 'earliest significant peak' of the burst using discrete and distributed source imaging methods. MEG background was asymmetrical in 2 and slow in 3 patients. Complexes were periodic (3) or quasi-periodic (2), occurring every 4-16 s and varied in morphology among patients. Mean source localization at onset of bursts using discrete and distributed source imaging in magnetic source imaging (MSI) was in thalami and or insula (50 and 50 %, respectively) and in electric source imaging (ESI) was also in thalami and or insula (38 and 46 %, respectively). Mean source localization at the earliest rising phase of peak in MSI was in peri-central gyrus (49 and 42 %) and in ESI it was in frontal cortex (52 and 56 %). Further analysis revealed that PCs were generated in thalami and or insula and thereafter propagated to anterolateral surface of the cortices (viz. sensori-motor cortex and frontal cortex) to same side as that of the onset. This novel MEG-EEG based case series of PCs provides newer insights for understanding the plausible generators of myoclonus in SSPE and patterns of their propagation.
authors.affiliation: Magnetoencephalography Research Centre, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, India.|Department of Neurology, 1st Floor, Faculty Block, National Institute of Mental Health and Neurosciences (NIMHANS), Hosur Road, Bangalore, 560 029, India.|Department of Clinical Neurosciences, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, India.
authors.forename: J
authors.initials: J
authors.lastname: Velmurugan
authors.affiliation: Magnetoencephalography Research Centre, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, India. sanjib_sinha2004@yahoo.co.in.|Department of Neurology, 1st Floor, Faculty Block, National Institute of Mental Health and Neurosciences (NIMHANS), Hosur Road, Bangalore, 560 029, India. sanjib_sinha2004@yahoo.co.in.
authors.forename: Sanjib
authors.initials: S
authors.lastname: Sinha
authors.affiliation: Department of Neurology, 1st Floor, Faculty Block, National Institute of Mental Health and Neurosciences (NIMHANS), Hosur Road, Bangalore, 560 029, India.
authors.forename: Madhu
authors.initials: M
authors.lastname: Nagappa
authors.affiliation: Magnetoencephalography Research Centre, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, India.
authors.forename: N
authors.initials: N
authors.lastname: Mariyappa
authors.affiliation: Department of Neurology, 1st Floor, Faculty Block, National Institute of Mental Health and Neurosciences (NIMHANS), Hosur Road, Bangalore, 560 029, India.
authors.forename: P S
authors.initials: PS
authors.lastname: Bindu
authors.affiliation: Department of Biostatistics, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, India.
authors.forename: G S
authors.initials: GS
authors.lastname: Ravi
authors.affiliation: Department of Neurovirology, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, India.
authors.forename: Nandita
authors.initials: N
authors.lastname: Hazra
authors.affiliation: Department of Biostatistics, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, India.
authors.forename: K
authors.initials: K
authors.lastname: Thennarasu
authors.affiliation: Department of Neurovirology, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, India.
authors.forename: V
authors.initials: V
authors.lastname: Ravi
authors.affiliation: Department of Neurology, 1st Floor, Faculty Block, National Institute of Mental Health and Neurosciences (NIMHANS), Hosur Road, Bangalore, 560 029, India.
authors.forename: A B
authors.initials: AB
authors.lastname: Taly
authors.affiliation: Magnetoencephalography Research Centre, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, India.|Department of Neurology, 1st Floor, Faculty Block, National Institute of Mental Health and Neurosciences (NIMHANS), Hosur Road, Bangalore, 560 029, India.
authors.forename: P
authors.initials: P
authors.lastname: Satishchandra
mesh_terms: D000293:Adolescent; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000000981:diagnostic imaging / Q000503:physiopathology*; D002648:Child; D002675:Child, Preschool; D004569:Electroencephalography; D004660:Encephalitis / Q000150:complications / Q000473:pathology / Q000503:physiopathology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D015225:Magnetoencephalography; D008297:Male; D025341:Principal Component Analysis; D011446:Prospective Studies; D012598:Sclerosis / Q000150:complications / Q000473:pathology; D013057:Spectrum Analysis
keywords: EEG; MEG; Myoclonus; Periodic complexes; SSPE; Source localisation; Sub-acute sclerosing pan encephalitis