What is normal age-related thigh muscle composition among 45- to 84-year-old adults from the UK Biobank study.

A loss of skeletal muscle mass and an increase in intramuscular fat are known to occur as we enter middle and older age, but the expected changes or normative values have remained unknown. The primary reason for this is that imaging studies are difficult and expensive to conduct, and consequently, the sample sizes have remained small. The development of the UK Biobank which provides access to a large magnetic resonance imaging (MRI) data set of more than 50,000 participants provides an opportunity to finally address this question of normative values for each age group. The study's primary aim was to determine the age-related changes in thigh muscle composition (e.g., thigh fat-free muscle volume and intramuscular fat) between the ages of 45 and 84 years. The second aim was to analyse associations between thigh fat-free muscle volume and intramuscular fat with lifestyle behaviours (smoking, alcohol consumption, and physical activity), leg pain, and bone mineral density. Fifty thousand three hundred thirty-two participants were included in the study. Total fat-free thigh muscle declined between the ages of 45 and 84 years, while intramuscular fat of the thigh continued to increase. The changes were stable between these age groups. The mean volume of fat-free muscle ranged from 11.16 (SD: 1.40) to 13.26 L (SD: 1.85) in adult males and 7.60 (SD: 0.97) to 8.80 L (SD 1.29) in females between the ages of 45 and 84 years. For intramuscular fat, the change among women was from 6.94% (SD: 1.59) in the 45 to 54 years age bracket to 8.83% (SD: 1.92) in the 75 to 84 age bracket, while for men, it was 5.83% (SD: 1.30) in the 45 to 54 age bracket to 7.85% (SD 1.89) in the 75 to 84 age bracket. The total fat-free muscle volume and intramuscular fat percentage provided can be used for the purpose of reference standards or normative values for adults in the age groups provided. Fat-free muscle and intramuscular fat were found to be associated with a range of health, activity, and leg pain outcomes, and these should be investigated in a follow-up longitudinal imaging study.

Reduced Spinal Cord Gray Matter in Patients with Fibromyalgia Using Opioids Long-term.

Objective: Chronic pain involves alterations in brain gray matter volume (GMV). Moreover, opioid medications are known to reduce GMV in numerous brain regions involved in pain processing. However, no research has evaluated (1) chronic pain-related GMV alterations in the spinal cord or (2) the effect of opioids on spinal cord GMV. Accordingly, this study evaluated spinal cord GMV in health controls and patients with fibromyalgia who were using and not using opioids long-term. Methods: We analyzed average C5 - C7 GMV of the spinal cord dorsal and ventral horns in separate female cohorts of healthy controls (HC, n = 30), fibromyalgia patients not using opioids (FMN, n = 31), and fibromyalgia patients using opioids long-term (FMO, n = 27). To assess the effect of group on average dorsal and ventral horn GMV, we conducted a one-way multivariate analysis of covariance. Results: After controlling for age, we observed a significant effect of group on ventral horn GMV (p = 0.03, η2 = 0.09), and on dorsal horn GMV (p = 0.05, η2 = 0.08). Tukey's posthoc comparisons showed that, compared to HC participants, FMOs had significantly lower ventral (p = 0.01) and dorsal (p = 0.02) GMVs. Among FMOs only, ventral horn GMV was significantly positively associated with pain severity and interference, and both dorsal and ventral GMVs were significantly positively associated with cold pain tolerance. Conclusion: Long-term opioid use may impact sensory processing in fibromyalgia via gray matter changes within the cervical spinal cord.

Isolating Neurologic Deficits in Cervical Spondylotic Myelopathy: A Case-Controlled Study, Using the NIH Toolbox Motor Battery.

Background and Objectives: Patients with cervical spondylotic myelopathy (CSM) have motor impairments, including weakness, imbalance, and loss of dexterity. The reliable assessment of these symptoms is critical for treatment decisions. This study aimed to determine, for the first time, the use of the NIH Toolbox motor battery (NIHTBm) in the objective assessment of motor deficits in patients with CSM. Methods: Patients with symptoms and MRI evidence of CSM and age-matched healthy controls (HC), with no evidence of spinal disorder or surgery were included in this case-control study based on our inclusion and exclusion criteria. We performed motor tests, dexterity, gait speed, grip strength, and balance tests, using the NIHTBm in patients with CSM and HCs. Motor impairment rates were determined in patients with CSM based on the NIHTBm scores. We determined the association between NIHTBm scores and patient-reported outcome scores; patient-reported outcome measures (the modified Japanese Orthopedic Association [mJOA] and Nurick grade) to determine the association. One-way analysis of variance was used to analyze group differences and the Spearman rank correlation to determine the relationship between assessment scores. Results: We enrolled 24 patients with CSM with a mean age (SD) of 57.96 (10.61) years and 24 age-matched HCs with a mean age (SD) of 53.17 (6.04) years in this study. Overall, we observed a significant decrease in the motor function T-scores mean (SD): dexterity 31.54 (14.82) vs 51.54 (9.72), grip strength 32.00 (17.47) vs 56.79 (8.46), balance 27.58 (16.65) vs 40.21 (6.35), and gait speed 0.64 (0.18) vs 0.99 (0.17) m/s, in patients with CSM compared with that in HCs. The lower extremity dysfunction scores on the NIHTBm, balance (ρ = -0.67) and gait speed (ρ = -0.62), were associated with higher Nurick grades. We observed a similar but weaker association with the Nurick grades and NIHTBm tests: dexterity (ρ = -0.49) and grip strength (ρ = -0.31) scores. The total motor mJOA showed a positive but weak association with NIHTBm scores, gait speed (ρ = 0.38), balance (ρ = 0.49), grip strength (ρ = 0.41), and dexterity (ρ = 0.45). Discussion: Patients with CSM had significantly lower NIHTBm scores compared with HCs. The results from the NIHTBm are consistent with the clinical presentation of CSM showing patients have motor impairments in both upper and lower extremities. As a neurologic-specific scale, NIHTBm should be used in the evaluation and clinical management of patients with CSM.

Spinal Cord Resting State Activity in Individuals With Fibromyalgia Who Take Opioids.

Chronic pain coincides with myriad functional alterations throughout the brain and spinal cord. While spinal cord mechanisms of chronic pain have been extensively characterized in animal models and in vitro, to date, research in patients with chronic pain has focused only very minimally on the spinal cord. Previously, spinal cord functional magnetic resonance imaging (fMRI) identified regional alterations in spinal cord activity in patients (who were not taking opioids) with fibromyalgia, a chronic pain condition. Here, in patients with fibromyalgia who take opioids (N = 15), we compared spinal cord resting-state fMRI data vs. patients with fibromyalgia not taking opioids (N = 15) and healthy controls (N = 14). We hypothesized that the opioid (vs. non-opioid) patient group would show greater regional alterations in spinal cord activity (i.e., the amplitude of low frequency fluctuations or ALFF, a measure of regional spinal cord activity). However, we found that regional spinal cord activity in the opioid group was more similar to healthy controls, while regional spinal cord activity in the non-opioid group showed more pronounced differences (i.e., ventral increases and dorsal decreases in regional ALFF) vs. healthy controls. Across patient groups, self-reported fatigue correlated with regional differences in spinal cord activity. Additionally, spinal cord functional connectivity and graph metrics did not differ among groups. Our findings suggest that, contrary to our main hypothesis, patients with fibromyalgia who take opioids do not have greater alterations in regional spinal cord activity. Thus, regional spinal cord activity may be less imbalanced in patients taking opioids compared to patients not taking opioids.

Fatty infiltration in cervical flexors and extensors in patients with degenerative cervical myelopathy using a multi-muscle segmentation model.

BACKGROUND: In patients with degenerative cervical myelopathy (DCM) that have spinal cord compression and sensorimotor deficits, surgical decompression is often performed. However, there is heterogeneity in clinical presentation and post-surgical functional recovery. OBJECTIVES: Primary: a) to assess differences in muscle fat infiltration (MFI) in patients with DCM versus controls, b) to assess association between MFI and clinical disability. Secondary: to assess association between MFI pre-surgery and post-surgical functional recovery. STUDY DESIGN: Cross-sectional case control study. METHODS: Eighteen patients with DCM (58.6 ± 14.2 years, 10 M/8F) and 25 controls (52.6 ± 11.8 years, 13M/12 F) underwent 3D Dixon fat-water imaging. A convolutional neural network (CNN) was used to segment cervical muscles (MFSS- multifidus and semispinalis cervicis, LC- longus capitis/colli) and quantify MFI. Modified Japanese Orthopedic Association (mJOA) and Nurick were collected. RESULTS: Patients with DCM had significantly higher MFI in MFSS (20.63 ± 5.43 vs 17.04 ± 5.24, p = 0.043) and LC (18.74 ± 6.7 vs 13.66 ± 4.91, p = 0.021) than controls. Patients with increased MFI in LC and MFSS had higher disability (LC: Nurick (Spearman's ρ = 0.436, p = 0.003) and mJOA (ρ = -0.399, p = 0.008)). Increased MFI in LC pre-surgery was associated with post-surgical improvement in Nurick (ρ = -0.664, p = 0.026) and mJOA (ρ = -0.603, p = 0.049). CONCLUSION: In DCM, increased muscle adiposity is significantly associated with sensorimotor deficits, clinical disability, and functional recovery after surgery. Accurate and time efficient evaluation of fat infiltration in cervical muscles may be conducted through implementation of CNN models.

Magnetization Transfer Ratio and Morphometrics of the Spinal Cord Associates with Surgical Recovery in Patients with Degenerative Cervical Myelopathy.

OBJECTIVES: We assessed the prognostic value of the preoperative magnetization transfer ratio (MTR) and morphometrics of the spinal cord in patients with degenerative cervical myelopathy (DCM) in a longitudinal cohort study. METHODS: Thirteen subjects with DCM underwent 3T magnetization transfer imaging. The MTR was calculated for the spinal cord regions and specific white matter tracts. Morphometric measures were extracted. Clinical (modified Japanese Orthopaedics Association [mJOA] and Nurick scale scores) and health-related quality of life scores were assessed before and after cervical decompression surgery. The association between the magnetic resonance imaging (MRI) metrics and postoperative recovery was assessed (Spearman's correlation). Receiver operating characteristics were used to assess the accuracy of MRI metrics in identifying ≥50% recovery in function. RESULTS: Preoperative anterior cord MTRs were associated with recovery in mJOA scores (ρ = 0.608; P = 0.036; area under the curve [AUC], 0.66). Preoperative lateral cord MTR correlated with the neck disability index (ρ = 0.699; P = 0.011) and pain interference scale (ρ = 0.732; P = 0.007). Preoperative rubrospinal tract MTR was associated with mJOA score recovery (ρ = 0.573; P = 0.041; AUC, 0.86). Preoperative corticospinal tract and reticulospinal MTRs were related to recovery in pain interference scores (ρ = 0.591; P = 0.033; and ρ = 0.583; P = 0.035, respectively). Eccentricity of the cord was associated with Nurick scores (ρ = 0.606; P = 0.028) and mJOA scores (ρ = 0.651; P = 0.025; AUC, 0.92). CONCLUSIONS: Preoperative MTR and eccentricity measurements of the spinal cord have prognostic value in assessing the response to surgery and recovery in patients with DCM. Advanced MRI and atlas-based postprocessing techniques can inform interventions and advance the healthcare received by patients with DCM.

Midsagittal tissue bridges are associated with walking ability in incomplete spinal cord injury: A magnetic resonance imaging case series.

Context: Following spinal cord injury (SCI), early prediction of future walking ability is difficult, due to factors such as spinal shock, sedation, impending surgery, and secondary long bone fracture. Accurate, objective biomarkers used in the acute stage of SCI would inform individualized patient management and enhance both patient/family expectations and treatment outcomes. Using magnetic resonance imaging (MRI) and specifically a midsagittal T2-weighted image, the amount of tissue bridging (measured as spared spinal cord tissue) shows potential to serve as such a biomarker. Ten participants with incomplete SCI received MRI of the spinal cord. Using the midsagittal T2-weighted image, anterior and posterior tissue bridges were calculated as the distance from cerebrospinal fluid to the damage. Then, the midsagittal tissue bridge ratio was calculated as the sum of anterior and posterior tissue bridges divided by the spinal cord diameter. Each participant also performed a 6-minute walk test, where the total distance walked was measured within six minutes.Findings: The midsagittal tissue bridge ratio measure demonstrated a high level of inter-rater reliability (ICC = 0.90). Midsagittal tissue bridge ratios were significantly related to distance walked in six minutes (R = 0.68, P = 0.03).Conclusion/clinical relevance: We uniquely demonstrated that midsagittal tissue bridge ratios were correlated walking ability. These preliminary findings suggest potential for this measure to be considered a prognostic biomarker of residual walking ability following SCI.

Altered Cervical Spinal Cord Resting-State Activity in Fibromyalgia.

OBJECTIVE: Altered afferent input and central neural modulation are thought to contribute to fibromyalgia symptoms, and these processes converge within the spinal cord. We undertook this study to investigate the hypothesis that, using resting-state functional magnetic resonance imaging (rs-fMRI) of the cervical spinal cord, we would observe altered frequency-dependent activity in fibromyalgia. METHODS: Cervical spinal cord rs-fMRI was conducted in fibromyalgia patients (n = 16) and healthy controls (n = 17). We analyzed the amplitude of low-frequency fluctuations (ALFF), a measure of low-frequency oscillatory power, for frequencies of 0.01-0.198 Hz and frequency sub-bands to determine regional and frequency-specific alterations in fibromyalgia. Functional connectivity and graph metrics were also analyzed. RESULTS: As compared to healthy controls (n = 14), greater ventral and lesser dorsal mean ALFF of the cervical spinal cord was observed in fibromyalgia patients ( n = 15) (uncorrected P < 0.05) for frequencies of 0.01-0.198 Hz and all sub-bands. Additionally, lesser mean ALFF within the right dorsal quadrant (corrected P < 0.05) for frequencies of 0.01-0.198 Hz and sub-band frequencies of 0.073-0.198 Hz was observed in fibromyalgia. Regional mean ALFF was not correlated with pain; however, regional lesser mean ALFF was correlated with fatigue in patients (r = 0.763, P = 0.001). Functional connectivity and graph metrics were similar between groups. CONCLUSION: Our results indicate unbalanced activity between the ventral and dorsal cervical spinal cord in fibromyalgia. Increased ventral neural processes and decreased dorsal neural processes may reflect the presence of central sensitization and contribute to fatigue and other bodily symptoms in fibromyalgia.