HJAR Jul/Aug 2024

HEALTHCARE JOURNAL OF ARKANSAS I  JUL / AUG 2024 19 cingulate cortex of football players intro- duces a new dimension to the discussion on the brains and mental health of adolescent football players. This is particularly relevant considering the frequent comorbidity of mental health disorders in trauma-induced neurodegenerative diseases. 30 Our geometric analysis also revealed novel insights. The continual enlargement and maturation of cortical gyri and sulci are intrinsic to the developmental trajec- tory from youth through adolescence. While deepening and widening sulci are normal aspects of the aging process, 31 these mor- phological changes are often accelerated in patients with neurodegenerative and psy- chiatric disorders. 32-35 In our sample, greater sulcal depth was notable in football play- ers, especially in the superior/middle fron- tal gyri and cingulate regions, which govern complex movement and the default mode network. Several computational studies suggest that the greatest tissue deformation occurs in the deepest sulci upon traumatic insult 36 due to the cerebral spinal fluid rap- idly clustering in the base of the sulci and causing shearing waves, referred to as water hammer effect. 31 This type of mechanical stress can lead to accelerated tissue atrophy and deepening sulci. 36 These findings shed light on the potential impact of mechani- cal stressors on brain structure and pro- vide valuable insights into the dynamics of cortical changes in individuals engaged in football. Although lower gyrification is often associated with cognitive impairment in older adults, 37 a study by Wilde et al 38 that included 17 adolescents with a history of TBI found significantly greater gyrification in the frontal and temporal regions compared with their controls. The researchers spec- ulated the increased gyrification was part of a compensatory mechanism to bolster impaired brain regions. 38 Our data are partly in agreement withWilde et al 38 in that many frontotemporal regions showed greater gyr- ification in the football group relative to the control group, whereas lesser gyrification was notable in parieto-occipital regions. Our multiparameter fMRI approach uncovered physiological characteristics related to adolescent football players. We observed lower ALFF in widespread frontal regions in football players relative to con- trols, suggesting a lower density of neuronal signaling. Conversely, an elevatedALFF was observed in occipital regions, especially the calcarine sulcus and lingual gyrus, which are known for their involvement in visual memory and attention. These observations are in line with Xiong et al 39 in that patients with concussions during the subacute phase of recovery exhibit a lower neural signal- ing density in the thalamus and frontal and temporal lobes, whereas increased ALFF is noted in the occipital regions. The observed ALFF patterns were mirrored in the ReHo results. Typically, the highest values of ReHo are found in the default-mode net- work (DMN) regions, including the prefron- tal cortex, cingulum, precuneus, and angular gyrus, suggesting highly connected cortical hubs. 40 However, significantly lower ReHo (football<control) was observed in several of the DMN regions, such as the cingulate cortex and precuneus, alongside medial brain regions such as the insula and puta- men. Given that ReHo has demonstrated correlations with glucose (r=0.78) and oxy- gen (r=0.54) metabolic rates, 41 the DMN in football players may exhibit lower coher- ence and regional metabolism. In contrast to the DMN findings, numerous cortical areas in the occipitotemporal regions displayed higher ReHo in the football group com- pared with the control group. This aligns with previous observations of increased ReHo in patients with acute concussions 42 and those with persistent symptoms beyond 3 months after concussion. 43 However, the clinical implications of these ReHo varia- tions, beyond the coherence of neighboring neural connections and regional metabo- lism, warrant further investigation through well-controlled longitudinal studies. Smaller-scale studies suggest that the network connectivity increases in the fron- tal and cingulate regions and decreases in posterior brain regions acutely after a rugby game 10 and a season in collision sports. 11-13 Hypoconnectivity stemming from the right DLPFC was notable in patients with concus- sions during memory and attention tasks. 44 Unlike previous studies, we were unable to observe a group difference in functional connectivity with DLPFC as a seed. It is possible that since the DLPFC is a highly