Gastrointestinal Dysfunction and Neuropathologic Correlations in Parkinson Disease.

Area of Science:

• Neurology
• Gastroenterology
• Pathology

Background:

• Nonmotor symptoms, particularly gastrointestinal (GI) dysfunction, are increasingly recognized in Parkinson disease (PD).
• GI issues often precede motor symptoms by years in PD.
• Early α-synuclein (α-SYN) accumulation in the enteric nervous system (ENS) is implicated in PD neuropathology.

Purpose of the Study:

• To investigate the relationship between α-SYN deposition in the ENS and the occurrence of GI dysfunction in PD patients.
• To explore the potential of ENS α-SYN as a biomarker for Parkinson disease enteropathy.

Main Methods:

• A study involving 30 PD patients and 13 controls was conducted over two years.
• Clinical data, including GI symptoms, were analyzed.
• Digestive endoscopy with upper digestive tract biopsies and immunohistochemistry were performed to assess α-SYN deposition.

Main Results:

• Gastrointestinal symptoms were the most frequent nonmotor symptom, present in 73% of PD patients.
• Motor dysfunction of the upper digestive tract was observed in 5 patients via endoscopy.
• The load of α-SYN lesions significantly correlated with the frequency and severity of GI dysfunction and PD motor disability.

Conclusions:

• Enteric nervous system synucleinopathy appears to be a key factor in the pathophysiology of digestive dysfunction in PD.
• α-SYN deposition in the ENS is directly correlated with the severity of GI symptoms in Parkinson disease.
• Endoscopic and immunohistochemical examination of the ENS may serve as a valuable biomarker for Parkinson disease enteropathy and PD overall.