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Roberts TPL, Paulson DN, Hirschkoff E, Pratt K, Mascarenas A, Miller P, Han M, Caffrey J, Kincade C, Power B, Murray R, Chow V, Fisk C, Ku M, Chudnovskaya D, Dell J, Golembski R, Lam P, Blaskey L, Kuschner E, Bloy L, Gaetz W, Edgar JC. Artemis 123: development of a whole-head infant and young child MEG system. Front Hum Neurosci 2014; 8:99. [PMID: 24624069 PMCID: PMC3939774 DOI: 10.3389/fnhum.2014.00099] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Accepted: 02/09/2014] [Indexed: 01/27/2023] Open
Abstract
BACKGROUND A major motivation in designing the new infant and child magnetoencephalography (MEG) system described in this manuscript is the premise that electrophysiological signatures (resting activity and evoked responses) may serve as biomarkers of neurodevelopmental disorders, with neuronal abnormalities in conditions such as autism spectrum disorder (ASD) potentially detectable early in development. Whole-head MEG systems are generally optimized/sized for adults. Since magnetic field produced by neuronal currents decreases as a function of distance(2) and infants and young children have smaller head sizes (and thus increased brain-to-sensor distance), whole-head adult MEG systems do not provide optimal signal-to-noise in younger individuals. This spurred development of a whole-head infant and young child MEG system - Artemis 123. METHODS In addition to describing the design of the Artemis 123, the focus of this manuscript is the use of Artemis 123 to obtain auditory evoked neuromagnetic recordings and resting-state data in young children. Data were collected from a 14-month-old female, an 18-month-old female, and a 48-month-old male. Phantom data are also provided to show localization accuracy. RESULTS Examination of Artemis 123 auditory data showed generalizability and reproducibility, with auditory responses observed in all participants. The auditory MEG measures were also found to be manipulable, exhibiting sensitivity to tone frequency. Furthermore, there appeared to be a predictable sensitivity of evoked components to development, with latencies decreasing with age. Examination of resting-state data showed characteristic oscillatory activity. Finally, phantom data showed that dipole sources could be localized with an error less than 0.5 cm. CONCLUSIONS Artemis 123 allows efficient recording of high-quality whole-head MEG in infants four years and younger. Future work will involve examining the feasibility of obtaining somatosensory and visual recordings in similar-age children as well as obtaining recordings from younger infants. Thus, the Artemis 123 offers the promise of detecting earlier diagnostic signatures in such neurodevelopmental disorders.
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Affiliation(s)
- Timothy P L Roberts
- Department of Radiology, Lurie Family Foundations MEG Imaging Center, The Children's Hospital of Philadelphia Philadelphia, PA, USA
| | | | | | - Kevin Pratt
- Tristan Technologies, Inc., San Diego, CA, USA
| | | | - Paul Miller
- Tristan Technologies, Inc., San Diego, CA, USA
| | - Mengali Han
- Tristan Technologies, Inc., San Diego, CA, USA
| | | | | | - Bill Power
- Tristan Technologies, Inc., San Diego, CA, USA
| | - Rebecca Murray
- Department of Radiology, Lurie Family Foundations MEG Imaging Center, The Children's Hospital of Philadelphia Philadelphia, PA, USA
| | - Vivian Chow
- Department of Radiology, Lurie Family Foundations MEG Imaging Center, The Children's Hospital of Philadelphia Philadelphia, PA, USA
| | - Charlie Fisk
- Department of Radiology, Lurie Family Foundations MEG Imaging Center, The Children's Hospital of Philadelphia Philadelphia, PA, USA
| | - Matthew Ku
- Department of Radiology, Lurie Family Foundations MEG Imaging Center, The Children's Hospital of Philadelphia Philadelphia, PA, USA
| | - Darina Chudnovskaya
- Department of Radiology, Lurie Family Foundations MEG Imaging Center, The Children's Hospital of Philadelphia Philadelphia, PA, USA
| | - John Dell
- Department of Radiology, Lurie Family Foundations MEG Imaging Center, The Children's Hospital of Philadelphia Philadelphia, PA, USA
| | - Rachel Golembski
- Department of Radiology, Lurie Family Foundations MEG Imaging Center, The Children's Hospital of Philadelphia Philadelphia, PA, USA
| | - Peter Lam
- Department of Radiology, Lurie Family Foundations MEG Imaging Center, The Children's Hospital of Philadelphia Philadelphia, PA, USA
| | - Lisa Blaskey
- Department of Radiology, Lurie Family Foundations MEG Imaging Center, The Children's Hospital of Philadelphia Philadelphia, PA, USA
| | - Emily Kuschner
- Department of Radiology, Lurie Family Foundations MEG Imaging Center, The Children's Hospital of Philadelphia Philadelphia, PA, USA
| | - Luke Bloy
- Department of Radiology, Lurie Family Foundations MEG Imaging Center, The Children's Hospital of Philadelphia Philadelphia, PA, USA
| | - William Gaetz
- Department of Radiology, Lurie Family Foundations MEG Imaging Center, The Children's Hospital of Philadelphia Philadelphia, PA, USA
| | - J Christopher Edgar
- Department of Radiology, Lurie Family Foundations MEG Imaging Center, The Children's Hospital of Philadelphia Philadelphia, PA, USA
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Gallen CC, Schwartz B, Rieke K, Pantev C, Sobel D, Hirschkoff E, Bloom FE. Intrasubject reliability and validity of somatosensory source localization using a large array biomagnetometer. Electroencephalogr Clin Neurophysiol 1994; 90:145-56. [PMID: 7510629 DOI: 10.1016/0013-4694(94)90006-x] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Neuromagnetic fields were evoked by tactile stimuli and detected with a multi-channel biomagnetometer through 72 independent repetitive measurements on a single subject. Each measurement consisted of a somatosensory evoked response (N = 256 stimuli) using a single probe placement. These fields were then analyzed for source localization using an equivalent current dipole model and demonstrated highly reliable localizations. The 3 major neuromagnetic somatosensory response components peaking at 35, 65 and 110 msec all localized to the same area of cortex. The relative contributions of intrinsic brain activity, habituation, probe placement, and choice of fiduciary points for headframe determination were quantified. Intrinsic factors were found to constitute the major source of inter-measurement error. Sources localized by magnetic source imaging (MSI) appeared valid relative to neuroanatomical estimation of the central fissure on MRI. Non-invasive presurgical biomagnetic localization of somatosensory cortex produces reliable and valid functional localizations which can be of potential value in risk assessment and may provide a useful guide for invasive functional mapping.
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Affiliation(s)
- C C Gallen
- Department of Neuropharmacology, Scripps Research Institute, La Jolla, CA 92037
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