Brainstem pathology and non-motor symptoms in PD

Gastric dysregulation induced by microinjection of 6-OHDA in the substantia nigra pars compacta of rats is determined by alterations in the brain-gut axis

“…Indeed, we are aware of just one report by Kessler and Jean (29), which showed that microinjection of DA or the agonist apomorphine into the NTS induced an immediate decrease in the number and amplitude of swallows initiated by stimulation of the superior laryngeal nerve, indicating a possible physiological role of dopaminergic neurotransmission in vagal brainstem circuits particularly in relation to swallowing and the A2 area (5, 11, 25). Interestingly, swallowing dysfunctions are a common outcome in patients with PD (9,10,22,27,38,43). Thus the data reported herein would suggest that, in 6-OHDAtreated rats, the decreased response to DVC microinjection of tyramine may be due to some degree of impairment of the NANC pathway.…”

“…Although the movement disorder has dominated the attention of clinicians and researchers, it is becoming increasingly recognized that PD also involves a prominent nonmotor pathology. In fact, patients with PD experience a remarkably broad spectrum of prodromic nonmotor symptoms that include sleep disorders, orthostatic hypotension, and gastrointestinal (GI) dysfunctions, all of which add significantly to the overall disability caused by PD (9,22,26,33,38,42).GI symptoms, such as dysphagia, nausea, delayed gastric emptying and dysmotility, and constipation, often precede the onset of motor symptoms; indeed, their occurrence in otherwise healthy people has been associated with an increased PD risk (9,14,27,40). Furthermore, the GI-related dysfunctions experienced by patients with PD often adversely impact the quality of life, and, perhaps worse, their management is limited and often restricted to supportive measures (38, 47).…”

“…Although the movement disorder has dominated the attention of clinicians and researchers, it is becoming increasingly recognized that PD also involves a prominent nonmotor pathology. In fact, patients with PD experience a remarkably broad spectrum of prodromic nonmotor symptoms that include sleep disorders, orthostatic hypotension, and gastrointestinal (GI) dysfunctions, all of which add significantly to the overall disability caused by PD (9,22,26,33,38,42).…”

Cognitive and Motor Aspects of Parkinson’s Disease Associated with Dysphagia

“…Because PD-related dysphagia is attributed to brainstem pathology, 11 research about swallowing dysfunction has focused mainly on the functions of brainstem swallowing centers, including the dorsal motor nucleus of the glossopharyngeus, the vagus nerves, and the nucleus of the solitary tract. 12,13 However, swallowing behavior is not under exclusive control of the brainstem. Rather, the initiation of swallowing has voluntary components that require integration of multiple cerebral cognitive functions.…”

Mitochondrial Dysfunction Appears in the Hippocampal Neurons of 3-Month-Old Alpha-Synuclein Transgenic Mice

“…Studies have shown that NMSs have even greater impact on patients than motor symptoms (Marinus and van Hilten, 2015;Mehndiratta et al, 2011). An in-depth study of NMSs of PD may contribute to the early diagnosis of the disease (Erro et al, 2012;Grinberg et al, 2010). However, to date, the pathogenesis of NMSs in PD remains unclear.…”