Association between masseter muscle volume, nutritional status, and cognitive status in older people

Correlation between GLCM-based texture features of the lateral pterygoid muscle and cognitive function in patients with idiopathic normal pressure hydrocephalus: a preliminary report

PURPOSE

The potential relationship between mastication ability and cognitive function in idiopathic normal pressure hydrocephalus (iNPH) patients is unclear. This report investigated the association between mastication and cognitive function in iNPH patients using the gray level of the co-occurrence matrix on the lateral pterygoid muscle.

METHODS

We analyzed data from 96 unoperated iNPH patients who underwent magnetic resonance imaging (MRI) between December 2016 and February 2023. Radiomic features were extracted from T2 MRI scans of the lateral pterygoid muscle, and muscle texture parameters were correlated with the iNPH grading scale. Subgroup analysis compared the texture parameters of patients with normal cognitive function with those of patients with cognitive impairment.

RESULTS

The mini-mental state examination score correlated positively with the angular second moment (P < 0.05) and negatively with entropy (P < 0.05). The dementia scale (Eide's classification) correlated negatively with gray values (P < 0.05). Gray values were higher in the cognitive impairment group (64.7 ± 16.6) when compared with the non-cognitive impairment group (57.4 ± 13.3) (P = 0.005). Entropy was higher in the cognitive impairment group (8.2 ± 0.3) than in the non-cognitive impairment group (8.0 ± 0.3) (P < 0.001). The area under the receiver operating characteristic curve was 0.681 (P = 0.003) and 0.701 (P < 0.001) for gray value and entropy, respectively.

CONCLUSION

Our findings suggest an association between heterogeneity of mastication and impaired cognitive function in iNPH patients and highlight muscle texture analysis as a potential tool for predicting cognitive impairment in these patients.

Age-related difference in oral adaptation to masticatory perturbation

OBJECTIVES

Mastication can be influenced by intraoral perturbation (e.g., hard food). We developed the masticatory perturbation task (MPT) to assess the perturbation effect during mastication and quantify the degree of adaptation to masticatory perturbation in younger and older adults.

DESIGN

Thirty-eight younger and 38 older participants completed the MPT, which consisted of three trials assessing masticatory performance (MP) without perturbation (i.e., the baseline condition) and three trials assessing MP with perturbation (i.e., the perturbation condition). Perturbation was implemented by concurrently chewing test food on the preferred side and a drinking straw on the nonpreferred side. We estimated the perturbation effect as the ΔMP between the baseline and perturbation conditions and the adaptation effect as the ΔMP between the third and the first trials for both age groups.

RESULTS

We found a significant perturbation effect, i.e., a lower MP in the perturbation condition than in the baseline condition, and an adaptation effect, i.e., a higher MP in the third trial than the first trial, in both groups. Moreover, the older group showed a lower degree of adaptation than the younger group.

CONCLUSION

The masticatory perturbation task revealed the perturbation effect during mastication and the adaptation to masticatory perturbation. The results revealed an association between age and masticatory adaptation.

Neuromuscular control of masticatory muscles in people with intellectual disability, middle-aged adults and older adults

BACKGROUND

Motor control issues are common for people with intellectual disabilities (PWID), resulting in difficulties with basic activities of daily living, including eating. Mastication, which is crucial for digestion and overall health, is poorly understood in this population. PWID shows frailty similar to older people, highlighting the importance of comparing masticatory motor control with older adults. This study compared the neuromuscular control of the masticatory muscles in middle-aged, PWID and older adults.

METHODS

A cross-sectional analytical design was used. During the mastication task of a carrot piece (2 cm in diameter and weighing 0.5 g), surface electromyography was used to record muscle activity patterns from the right and left masseter and temporalis muscles. Principal component analysis (PCA) was used to assess neuromuscular control. A z-score normalisation of the first component's variance from PCA to identify those individuals with altered neuromuscular control. A mixed ANOVA was performed to assess the interaction between principal components, groups and body composition.

RESULTS

Thirty PWIDs (aged 35-55 years), middle-aged adults and 32 older adults were recruited. PWID and older adults showed decreased neuromuscular control of the masticatory muscles compared to middle-aged control adults (P < 0.05). PWID had the highest proportion of individuals with altered neuromuscular control of the masticatory muscle (53%) compared to older adults (19%) and middle-aged adults (0%) (P < 0.05).

CONCLUSIONS

Our results indicate that PWID and older adults have reduced neuromuscular control compared to middle-aged adults. Notably, a significant proportion of the PWID showed altered masticatory muscle control compared to older adults. Further research is needed to explore the potential benefits of masticatory muscle training for PWID.