Gastrointestinal Dysfunctions in Parkinson’s Disease: Symptoms and Treatments

Abstract

A diagnosis of Parkinson's disease is classically established after the manifestation of motor symptoms such as rigidity, bradykinesia, and tremor. However, a growing body of evidence supports the hypothesis that nonmotor symptoms, especially gastrointestinal dysfunctions, could be considered as early biomarkers since they are ubiquitously found among confirmed patients and occur much earlier than their motor manifestations. According to Braak's hypothesis, the disease is postulated to originate in the intestine and then spread to the brain via the vagus nerve, a phenomenon that would involve other neuronal types than the well-established dopaminergic population. It has therefore been proposed that peripheral nondopaminergic impairments might precede the alteration of dopaminergic neurons in the central nervous system and, ultimately, the emergence of motor symptoms. Considering the growing interest in the gut-brain axis in Parkinson's disease, this review aims at providing a comprehensive picture of the multiple gastrointestinal features of the disease, along with the therapeutic approaches used to reduce their burden. Moreover, we highlight the importance of gastrointestinal symptoms with respect to the patients' responses towards medical treatments and discuss the various possible adverse interactions that can potentially occur, which are still poorly understood.

Recent developments in understanding the role of the gut microbiota in brain health and disease

“…Neurologically, parkinsonian patients exhibit a range of motor‐related impairments, such as bradykinesia, resting tremors, muscular rigidity, and impairments in posture. Before the development of the motor symptoms, parkinsonian patients often report prodromal nonmotor‐related symptoms, such as depression, sleep disturbances, and constipation, suggestive of gastrointestinal dysfunction . Moreover, gastrointestinal function is further exacerbated following progression of the disease with constipation, impaired gastric emptying, and difficulties with defecation all reported in patients .…”

Characterization of gastrointestinal pathologies in the dystonia musculorum mouse model for hereditary sensory and autonomic neuropathy type VI

“…GI defects are often observed alongside neurodegenerative disease, though determining whether these pathologies are intrinsic to the gut or a consequence of higher order neural defects is not always clear . Likewise, HSAN‐VI patients have GI symptoms without clear cause, and Dst dt mice have a distinct GI phenotype characterized by small intestinal gas accumulation and GIT discoloration.…”

“…GI defects are often observed alongside neurodegenerative disease, though determining whether these pathologies are intrinsic to the gut or a consequence of higher order neural defects is not always clear. [34][35][36][37] (Figure 3), and LLMP sections are F I G U R E 6 Dst dt-27J mice show thinning of the colon mucous layer and a reduced microbial richness/evenness. A, Periodic acid Schiff staining of transverse colon sections from P5 and P15 wild type and Dst dt-27J mice.…”

Digestive Symptoms of Autonomic Dysfunction in Parkinson’s Disease Patients

“…according to recent studies, non-motor symptoms, especially gastrointestinal dysfunctions, could be considered as early biomarkers of PD (1).…”

“…Braak postulated that PD originates in the intestine and then spreads to the brain via the vagus nerve, a phenomenon that would involve other neuronal types than dopaminergic population (1). autonomic dysfunction is also a common complication of Parkinson's disease (88.46% of the patients) (2).…”