Recent research has aimed to provide age- and sex-adjusted reference values for temporal muscle thickness, cross-sectional area, and radiodensity measured through computed tomography (CT) scans. This study is particularly significant as it addresses the gap in standardized metrics necessary for identifying sarcopenia risk, especially within elderly populations.
Traditionally, muscles have been evaluated by examining the paraspinal muscle areas at the lumbar region through CT scans. Yet, for many patients undergoing neurological assessments, head CT scans are more commonly performed. This study emerged out of the necessity to utilize these readily available scans to provide accurate measurements of the temporal muscles, which have been correlated with overall muscle mass and quality.
The researchers focused on patients treated for concussions at Oulu University Hospital between January 2014 and December 2022. A total of 500 subjects participated, yielding valuable normative data. From these patients, mean temporal muscle thickness (TMT) was recorded at 5.2 ± 1.9 mm, the cross-sectional area (TMA) at 284 mm² ± 159, and radiodensity at 44.6 HU ± 17.7, highlighting how different demographics influence muscle characteristics.
Significantly, this study established cut-off values for identifying individuals at risk for sarcopenia. The cut-off parameters for reduced TMT, TMA, and radiodensity were defined for males and females respectively, as follows: TMT ≤ 4.09 mm for males and ≤ 3.44 mm for females, TMA ≤ 166 mm² for males and ≤ 156 mm² for females, along with general radiodensity cut-offs of ≤ 35.5 HU for males and ≤ 35.2 HU for females. These thresholds adhere to the standards set by the European Working Group on Sarcopenia in Older People (EWGSOP), allowing for broader clinical applicability.
The researchers were able to validate the reliability of their measurement methods, which featured inter-observer reliability deemed almost perfect for TMT and TMA measurements. By implementing quantile regression models within their techniques, they did not only identify normative values but were also able to characterize muscle morphology changes across different age demographics.
Prior studies provided limited insight pertaining to CT-based methodologies for measuring muscle density and mass. This study advances the field by delivering norms needed for effective clinical practice, proving the viability of these measurements, particularly for neurosurgical patients who may not be evaluated for muscle loss traditionally.
Overall, the findings of this study shed light on the introduction of standardized CT-based evaluations to determine muscle thickness and area as beneficial for identifying individuals at risk of sarcopenia. The established reference values promise to influence clinical assessments positively and could eventually play a role in formulating strategies to mitigate sarcopenia's impacts.