An Experimental Investigation into Staging CTS Utilizing Portable Ultrasound and Doppler as a Diagnostic Alternative

Details

• Personal Author:
  Evans KD
• Description:
  This study explored the use of portable ultrasound to detect changes in the median nerve tissue of 11 macaca fascicularis monkeys, which were exposed to a pinch-pinch task. Inducing median mononeuropathy (MMN) otherwise known as carpal tunnel syndrome (CTS), was joined to a study by Sommerich, Buford, et al. This connected our imaging study to their effort and allowed for the longitudinal measure of both vascular and geometric changes within the median nerve tissue at baseline, during task exposure, and during the recovery phase. Portable ultrasound was provided by GE Healthcare using a Logiq i laptop ultrasound unit with a 12 MHz transducer. This was used to image the median nerve on all 11 subjects across the study period. Data was gathered on the size of the median nerve at several anatomical locations. Geometric measures were taken from the images at the forearm, the carpal tunnel inlet, and the carpal tunnel outlet. A measure that has been advocated was also taken at the hook of the hamate, which includes the carpal tunnel bulge. All ultrasound measures were made in the laboratory and meticulously recorded for comparison with electrodiagnostic testing (EDX) and magnetic resonance imaging (MRI). The timing of MRI and EDX was critical in order to compare the results for power Doppler (PD) and spectral Doppler (SD) ultrasound. Temperature of the subject was maintained with heated rice bags and imaging was timed with the schedule of MRI and EDX. The data were examined in accordance with the American College of Radiology's (ACR) Appropriateness guidelines for imaging the painful wrist. The ACR rates MRI as the gold standard therefore our geometric measures were taken as cross-sectional areas (CSAs) of both the outer and inner median nerve at all the anatomical locations indicated. Using Medical Image Processing, Analysis, and Visualization (MIPAV) software, from the National Institute of Health (NIH), we traced CSAs on the ultrasound and MRI images. The results indicated that the ultrasound CSAs at the level of the carpal tunnel inlet were statistically matched for the outermost layer of the nerve. Further image analysis demonstrated that as the outer tissue enlarged, the CSA of the inner layer inversely contracted. The hypothesis is that the residual nerve tissue was enlarging and constricting the fascicles of the median nerve. This has been reported as the "notch sign". Retrospective analysis was completed on a strict inclusion of SD waveforms taken within the median nerve over the length of the project. Given the geometric change in the outer and inner layers of the nerve, the hypothesis was that inflammation was causing this acute physiologic change. SD waveforms were compared a baseline, during working, and into the recovery phase and minute changes were very difficult to detect statistically. One of the problems was the sensitivity of the SD for low flow changes. Separate examinations were conducted using ultrasound contrast to attempt to amplify the signals for increased detection and analysis. The EDX data was retained by Dr. Sommerich and will be reported as part of her R01 final report. [Description provided by NIOSH]
• Subjects:
  Animals Diagnosis Musculoskeletal Diseases Musculoskeletal System Nervous System Occupational Health Safety
• Keywords:
  Animal Studies Carpal Tunnel Syndrome CTS Diagnostic Tests Nerves Nerve Tissue Ultrasound Upper Extremities
• Series:
  Grant Final Reports
• Publisher:
  National Institute for Occupational Safety and Health
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Final Grant Report
• Place as Subject:
  Ohio ; OSHA Region 5
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  OEP - Office of Extramural Programs
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  1-9
• NIOSHTIC Number:
  nn:20056560
• NTIS Accession Number:
  PB2019-101401
• Citation:
  Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, R21-OH-009907, 2013 Apr; :1-9
• Contact Point Address:
  Kevin D. Evans, PhD, The Ohio State University's College of Medicine, School of Health and Rehabilitation Sciences, 410 W. 10th Avenue, 340 A. Atwell Hall, Columbus, Ohio 43210
• Email:
  Evans.36@osu.edu
• Federal Fiscal Year:
  2013
• Performing Organization:
  Ohio State University
• Peer Reviewed:
  False
• Start Date:
  20100901
• Source Full Name:
  National Institute for Occupational Safety and Health
• End Date:
  20130430
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:d6ee25227e2fa2f9959b48faa3a01b7b3bffae19e016e6ccb2c997c2e2a3affa84ed050ca3af74a93d7336bb93f23e5f1594ead84ee16e83f65108c996406949
• Download URL:
  https://stacks.cdc.gov/view/cdc/218901/cdc_218901_DS1.pdf
• File Type:
  [PDF - 488.43 KB ]