Salivary Gland Disorders and Diseases

Saliva plays an important role in maintaining healthy oral mucosa and teeth as well as oral function by continually covering and lubricating the oral tissues. Salivary gland dysfunction designates decreased saliva flow rate (salivary gland hypofunction), increased saliva flow rate (sialorrhea or hypersalivation), and changed saliva composition. Xerostomia (the subjective feeling of oral dryness) is often associated with salivary gland hypofunction and may severely affect nutritional intake, social interaction and quality of life. Local or systemic disorders and diseases are common causes of compromised saliva secretion. Some of these are related to gland pathology or to the pathophysiological conditions of the host, whereas others affect the gland innervation or are an iatrogenic result of treatment of a disease (e.g., radiation therapy for head and neck cancer, side effects of medications). In general, many patients suffering from diseases that influence salivary gland function also undergo treatments that may impair saliva secretion and/or induce xerostomia as an adverse effect. Consequently, it can be difficult to distinguish what can be attributed to the disease per se or what can be induced by treatment (e.g., medication intake). Thus, a thorough diagnostic workup and early diagnosis of salivary gland dysfunction are crucial to provide appropriate evidence-based treatment of salivary gland dysfunction to prevent oral sequelae and to initiate individualized alleviating management strategies of xerostomia.</p

Interhemispheric Pathways Are Important for Motor Outcome in Individuals with Chronic and Severe Upper Limb Impairment Post Stroke

Background: Severity of arm impairment alone does not explain motor outcomes in people with severe impairment post stroke. Objective: Define the contribution of brain biomarkers to upper limb motor outcomes in people with severe arm impairment post stroke. Methods: Paretic arm impairment (Fugl-Meyer upper limb, FM-UL) and function (Wolf Motor Function Test rate, WMFT-rate) were measured in 15 individuals with severe (FM-UL ≤ 30/66) and 14 with mild-moderate (FM-UL > 40/66) impairment. Transcranial magnetic stimulation and diffusion weight imaging indexed structure and function of the corticospinal tract and corpus callosum. Separate models of the relationship between possible biomarkers and motor outcomes at a single chronic (≥6 months) time point post stroke were performed. Results: Age (ΔR20.365, p = 0.017) and ipsilesional-transcallosal inhibition (ΔR20.182, p = 0.048) explained a 54.7% (p = 0.009) variance in paretic WMFT-rate. Prefrontal corpus callous fractional anisotropy (PF-CC FA) alone explained 49.3% (p = 0.007) variance in FM-UL outcome. The same models did not explain significant variance in mild-moderate stroke. In the severe group, k-means cluster analysis of PF-CC FA distinguished two subgroups, separated by a clinically meaningful and significant difference in motor impairment (p = 0.049) and function (p = 0.006) outcomes. Conclusion: Corpus callosum function and structure were identified as possible biomarkers of motor outcome in people with chronic and severe arm impairment