The Complex Interplay of Cortex, Cerebellum, and Age in a Cohort of Pediatric Patients With Tuberous Sclerosis Complex

Background: The neurodevelopmental impairment in tuberous sclerosis complex (TSC) has a multifactorial origin. Various factors have been proposed as predictors of neurological outcome such as tuber load, seizure onset, and TSC2 mutation. Cerebellar lesions have been associated with worse neuroradiological phenotype, but their contribution is not well understood. Methods: A partly retrospective and partly prospective pediatric cohort study was conducted at three hospitals in Greece between 2015 and 2020. Patients aged ≤ 18 years with a confirmed TSC daignosis were included and underwent brain imaging, a semistructured interview (authorized Greek version of the tuberous sclerosis-associated neuropsychiatric disorders, or TAND, checklist), and intellectual ability assessment. Results: The study populations consisted of 45 patients with TSC (22 females, 23 males; mean age 9.53 years). Twenty patients (44.4%) had cerebellar lesions. Cerebellar involvement was the most powerful predictor of tuber load (P = 0.03). Cerebellar lesions were associated with giant cell astrocytomas (SEGAs) (P = 0.01) and severe neurological outcome (P = 0.01). Even though in the univariate analysis early seizure onset, tuber load, and cerebellar involvement were associated with intellectual impairment and neurological severity, none of them was an independent predictor of cognitive outcome and neurological severity. Conclusions: Cerebellar lesions are common among individuals with TSC. Cerebellar involvement correlates with supratentorial derangement and the development of SEGAs, which is suggestive of a more severe clinical and neuroradiological phenotype. Cerebellar involvement and early seizure onset were not independent predictors of either neurological severity or intellectual disability or neurobehavioral outcome; their role in TSC clinical phenotype should be further investigated. © 2021 Elsevier Inc

Theoretical considerations and a mathematical model for the analysis of the biomechanical response of human keratinized oral mucosa

Removable complete and partial dentures are supported by the residual alveolar ridges consisting of mucosa, submucosa, periosteum and bone. An understanding of the biomechanical behaviorof the oral mucosa is essential in order to improve the denture- bearing foundations for complete and partially edentulous patients. The purpose of this paper was to examine the biomechanical behavior of the soft tissues supporting a removable denture and develop a model for that reason. Keratinized oral mucosa blocks with their underlying bone were harvested from the maxillary palatal area adjacent to the edentulous ridges of a cadaver. The compressive response of the oral mucosa was tested by using atomic force microscopy. The specimens were first scanned in order their topography to be obtained. The mechanical properties of the specimens were tested using asingle crystal silicon pyramidal tip, which traversed towards the keratinized oral mucosa specimens. Loading- unloading cycles were registered and four mathematical models were tested using MATLAB to note which one approximates the force-displacement curve as close as possible: a. spherical, b. conical, c. third order polynomial, d. Murphy (fourth order polynomial, non- linear Hertzian based). The third order polynomial model showed the best accuracy in representing the force-displacement data of the tested specimens. A model was developed in order to analyze the biomechanical behavior of the human oral keratinized mucosa and obtain information about its mechanical properties