alpha-synuclein and Malnutrition

Early involvement of gut is observed in Parkinson's disease (PD) and symptoms such as constipation may precede motor symptoms. α-Synuclein pathology is extensively evident in the gut and appears to follow a rostrocaudal gradient. The gut may act as the starting point of PD pathology with spread toward the central nervous system. This spread of the synuclein pathology raises the possibility of prion-like propagation in PD pathogenesis. Recently, the role of gut microbiota in PD pathogenesis has received attention and some phenotypic correlation has also been shown. The extensive involvement of the gut in PD even in its early stages has led to the evaluation of enteric α-synuclein as a possible biomarker of early PD. The clinical manifestations of gastrointestinal dysfunction in PD include malnutrition, oral and dental disorders, sialorrhea, dysphagia, gastroparesis, constipation, and defecatory dysfunction. These conditions are quite distressing for the patients and require relevant investigations and adequate management. Treatment usually involves both pharmacological and non-pharmacological measures. One important aspect of gut dysfunction is its contribution to the clinical fluctuations in PD. Dysphagia and gastroparesis lead to inadequate absorption of oral anti-PD medications. These lead to response fluctuations, particularly delayed-on and no-on, and there is significant relationship between levodopa pharmacokinetics and gastric emptying in patients with PD. Therefore, in such cases, alternative routes of administration or drug delivery systems may be required.

Topics: alpha-Synuclein; Antiparkinson Agents; Constipation; Deglutition Disorders; Enteric Nervous System; Gastrointestinal Absorption; Gastrointestinal Microbiome; Gastrointestinal Tract; Gastroparesis; Humans; Malnutrition; Parkinson Disease; Sialorrhea

Here we report studies of the burden of neurodegenerative neuropathologies in a cohort of Medical Examiner (ME) subjects from the County of Santa Clara (California) to determine if this unique population of decedents manifested evidence of neurodegeneration that might underlie causes of death seen in an ME practice. We found that 13% of the brains from ME cases showed significant tau pathology, including 55% of those 65 years old and older and 63% of those 70 years old and older. The histochemical and immunohistochemical findings were consistent with Alzheimer's disease (AD) in 7 subjects and frontotemporal lobar degeneration (FTLD) tauopathy type in six cases. There were no cases of Parkinson's disease, dementia with Lewy Bodies or other neurodegenerative conditions. Our study suggests that decedents >65 years of age in an ME practice are afflicted by common causes of dementia such as AD and FTLD which could contribute wholly or in part to their causes of death.

Topics: Adult; Aged; Aged, 80 and over; alpha-Synuclein; Alzheimer Disease; Atrophy; Benzothiazoles; Brain; Brain Edema; Cohort Studies; Coroners and Medical Examiners; Female; Forensic Pathology; Frontotemporal Lobar Degeneration; Humans; Hygiene; Ill-Housed Persons; Immunohistochemistry; Male; Malnutrition; Middle Aged; Neurofibrillary Tangles; Neuropil Threads; Plaque, Amyloid; Staining and Labeling; Tauopathies; Thiazoles; Young Adult