High Prevalence of Spinal Magnetic Resonance Imaging Findings in Asymptomatic Young Adults (18-22 Yrs) Candidate to Air Force Flight

The Prevalence of Degenerative Cervical Myelopathy-Related Pathologies on Magnetic Resonance Imaging in Healthy/Asymptomatic Individuals: A Meta-Analysis of Published Studies and Comparison to a Symptomatic Cohort

Degenerative cervical myelopathy (DCM) is a progressive cervical spinal cord injury brought about by mechanical stress from degenerative changes in the cervical spine. It is typically diagnosed on clinical symptoms and examination findings together with MRI findings. In this study, we explore the significance of these degenerative pathology to onset of DCM by performing the first meta-analysis on the prevalence of degenerative features reported on MRI amongst healthy and asymptomatic populations and compare this to the prevalence of degenerative features reported on MRI amongst a symptomatic population calculated in a previous review. We conducted a systematic review and meta-analysis in accordance with PRISMA guidelines, cognizant of their adaptation for epidemiological studies. A search strategy was used to identify original research carrying out MRI screening of cervical spines of asymptomatic patients in MEDLINE and Embase from 1985 to present day. The search yielded a total of 1098 studies of which 17 were included in this meta-analysis covering a total of 5059 patients. Ossification of posterior longitudinal ligament (pooled asymptomatic prevalence of 0.4%, 95% Confidence Interval [0.1%, 0.8%]), enlargement of ligamentum flavum (pooled asymptomatic prevalence of 11.8%, 95% Confidence Interval [5.3%, 18.4%]) and degenerative multilevel disc pathology (pooled asymptomatic prevalence of 64.5%, 95% Confidence Interval [48.3%, 80.8%], I² 100%) were found to be significantly lower in asymptomatic populations. Symptomatic populations have a prevalence of 10.5% (95% Confidence Interval [7.7%, 13.3%]) for ossification of posterior longitudinal ligament, 56.8% (95% Confidence Interval [52.3%, 61.3%]) for enlargement of ligamentum flavum and 89.7% (95% Confidence Interval [86.9%, 92.5%]) for degenerative multilevel disc pathology [18]. Understanding the natural history of DCM is a recognised research priority, and whilst these perspectives require further evaluation, they may be of significant relevance to the evolving biomechanical understanding of the disease.

Multi-muscle deep learning segmentation to automate the quantification of muscle fat infiltration in cervical spine conditions

Muscle fat infiltration (MFI) has been widely reported across cervical spine disorders. The quantification of MFI requires time-consuming and rater-dependent manual segmentation techniques. A convolutional neural network (CNN) model was trained to segment seven cervical spine muscle groups (left and right muscles segmented separately, 14 muscles total) from Dixon MRI scans (n = 17, 17 scans < 2 weeks post motor vehicle collision (MVC), and 17 scans 12 months post MVC). The CNN MFI measures demonstrated high test reliability and accuracy in an independent testing dataset (n = 18, 9 scans < 2 weeks post MVC, and 9 scans 12 months post MVC). Using the CNN in 84 participants with scans < 2 weeks post MVC (61 females, 23 males, age = 34.2 ± 10.7 years) differences in MFI between the muscle groups and relationships between MFI and sex, age, and body mass index (BMI) were explored. Averaging across all muscles, females had significantly higher MFI than males (p = 0.026). The deep cervical muscles demonstrated significantly greater MFI than the more superficial muscles (p < 0.001), and only MFI within the deep cervical muscles was moderately correlated to age (r > 0.300, p ≤ 0.001). CNN's allow for the accurate and rapid, quantitative assessment of the composition of the architecturally complex muscles traversing the cervical spine. Acknowledging the wider reports of MFI in cervical spine disorders and the time required to manually segment the individual muscles, this CNN may have diagnostic, prognostic, and predictive value in disorders of the cervical spine.

Assessing the spatial distribution of cervical spinal cord activity during tactile stimulation of the upper extremity in humans with functional magnetic resonance imaging

Dermatomal maps are a mainstay of clinical practice and provide information on the spatial distribution of the cutaneous innervation of spinal nerves. Dermatomal deficits can help isolate the level of spinal nerve root involvement in spinal conditions and guide clinicians in diagnosis and treatment. Dermatomal maps, however, have limitations, and the spatial distribution of spinal cord sensory activity in humans remains to be quantitatively assessed. Here we used spinal cord functional MRI to map and quantitatively compare the spatial distribution of sensory spinal cord activity during tactile stimulation of the left and right lateral shoulders (i.e. C5 dermatome) and dorsal third digits of the hands (i.e., C7 dermatome) in healthy humans (n = 24, age = 36.8 ± 11.8 years). Based on the central sites for processing of innocuous tactile sensory information, we hypothesized that the activity would be localized more to the ipsilateral dorsal spinal cord with the lateral shoulder stimulation activity being localized more superiorly than the dorsal third digit. The findings demonstrate lateralization of the activity with the left- and right-sided stimuli having more activation in the ipsilateral hemicord. Contradictory to our hypotheses, the activity for both stimulation sites was spread across the dorsal and ventral hemicords and did not demonstrate a clear superior-inferior localization. Instead, the activity for both stimuli had a broader than expected distribution, extending across the C5, C6, and C7 spinal cord segments. We highlight the complexity of the human spinal cord neuroanatomy and several sources of variability that may explain the observed patterns of activity. While the findings were not completely consistent with our a priori hypotheses, this study provides a foundation for continued work and is an important step towards developing normative quantitative spinal cord measures of sensory function, which may become useful objective MRI-based biomarkers of neurological injury and improve the management of spinal disorders.

MRI-detected spinal disc degenerative changes in athletes participating in the Rio de Janeiro 2016 Summer Olympics games

Objective

To describe the frequency and the distribution of degenerative disc disease (DDD) detected in athletes who underwent spine MRI in the 2016 Summer Olympic Games in Rio de Janeiro.

Methods

Data on spine MRI examinations from the 2016 Summer Olympics were retrospectively analyzed. We assessed the frequency of DDD of the cervical (Cs), thoracic (Ts), and lumbar (Ls) spine using Pfirrmann’s classification. Grade II and III were considered as mild, grade IV as moderate, and grade V as severe disc degeneration. Data were analyzed according to the location of the degenerative disc, type of sport, age-groups, and gender of the athletes.

Results

One hundred out of 11,274 athletes underwent 108 spine MRI’s (21 C, 6 T, and 81 L) (53% Females (F), 47% Males (M)). The frequency of DDD was 40% (42% F, 58% M) over the entire spine (28% mild, 9% moderate and 3% severe). There were 58% (12%F, 88%M) of the cervical spine discs that showed some degree of degeneration (44% mild, 13.5% moderate and 1% severe). Athletics, Boxing, and Swimming were the sports most affected by DDD in the Cs. There were 12.5% of the thoracic discs that showed some degree of degeneration, all were mild DDD and were exclusively seen in female athletes. There were 39% (53% F, 47% M) of the lumbar discs with DDD (26% mild, 9% moderate, and 4% severe).

Conclusion

Athletes who underwent spine MRI during the 2016 Summer Olympic Games show a high frequency of DDD of cervical and lumbar spines. Recognition of these conditions is important to develop training techniques that may minimize the development of degenerative pathology of the spine.