Umami and Other Taste Perceptions in Patients With Parkinson's Disease

Apnea behavior in early- and late-stage mouse models of Parkinson's disease: Cineradiographic analysis of spontaneous breathing, acute stress, and swallowing

This study aimed to evaluate the timing and frequency of spontaneous apneas during breathing and swallowing by using cineradiography on mouse models of early/initial or late/advanced Parkinson's disease (PD). C57BL/6 J mice received either 6-OHDA or vehicle injections into their right striatum, followed by respiratory movement recordings during spontaneous breathing and swallowing, and a stress challenge, two weeks later. Experimental group animals showed a significantly lower respiratory rate (158.66 ± 32.88 breaths/minute in late PD, 173.16 ± 25.19 in early PD versus 185.27 ± 25.36 in controls; p<0.001) and a significantly higher frequency of apneas (median 1 apnea/minute in both groups versus 0 in controls; p<0.001). Other changes included reduced food intake and the absence of swallow apneas in experimental mice. 6-OHDA-induced nigrostriatal degeneration in mice disrupted respiratory control, swallowing, stress responsiveness, and feeding behaviors, potentially hindering airway protection and elevating the risk of aspiration.

The missing piece of the puzzle - The key role of the dietitian in the management of Parkinson's disease

The current paradigm for the multidisciplinary management of Parkinson's Disease (PD) does not include regular nutritional assessment despite research showing that 90 % of people living with Parkinson's (PwP) lack access to basic dietetic services. Since many non-motor symptoms such as dysphagia, constipation and orthostatic hypotension and PD complications such as weight loss and sarcopenia can be improved through dietary intervention, dietitians are a critical missing piece of the PD management puzzle. This paper serves to review the role of dietitians and medical nutrition therapy in management of PD as well as a call to action for future studies to investigate improvement of nutritional status and quality of life for all PwP.

Body mass index in patients with Parkinson's disease: a systematic review

Body mass index (BMI) has been found to have an impact on neurodegenerative diseases such as Parkinson's disease (PD). Several studies suggested that patients with PD have a lower BMI compared with controls. However, some studies indicated the differences between patients and controls as statistically insignificant. We performed this meta-analysis to clarify the relationship between BMI and PD based on the studies published from 1975 to April 2023 in the PubMed, Embase, and Cochrane Library databases. In total, 18 case-control studies met the inclusion criteria for meta-analysis. We found a statistically significant difference in mean BMI between patients with PD and healthy controls {standardized mean difference (SMD) [95% confidence interval (CI)] = -0.36 (-0.43, -0.29), P < 0.05}. Regarding sex, seven studies were included in the meta-analysis for female/male patients with PD. The mean BMI was significantly different between males with PD and healthy males [SMD (95% CI) = -0.34 (-0.47, -0.22), P < 0.05]. Moreover, the mean BMI of females with PD was significantly different from that of corresponding healthy females [SMD (95% CI) = -0.44 (-0.57, -0.30), P < 0.05]. The meta-analysis demonstrates a significantly lower BMI in patients with PD, but no gender differences, when compared with their respective healthy individuals.NEW & NOTEWORTHY The meta-analysis demonstrates a significantly lower body mass index in patients with PD, but no gender differences, when compared with their respective healthy individuals.

Gustatory dysfunction is related to Parkinson's disease: A systematic review and meta-analysis

BACKGROUND

Olfactory dysfunction has been reported to be involved in Parkinson's disease (PD) pathogenesis. However, gustatory dysfunction in PD has not been evaluated as in-depth as olfactory dysfunction. We reviewed the previously published studies regarding gustatory function in PD patients and suggested the possibility that gustatory dysfunction may also be associated with PD.

METHODS

MEDLINE, Cochrane Library, Embase, and PubMed databases were searched for studies evaluating gustatory function in PD patients. We used the standardized mean difference and a 95% confidence interval (CI) as the effect analysis index regarding the taste strip test. The relative risk and 95% CI were used as the effect analysis index for the questionnaires and propylthiouracil (PTU)/phenylthiocarbamide (PTC) perception test. Statistical heterogeneity was assessed using forest plots, Cochran's Q, and the I2 statistic; heterogeneity was considered high when I2 was over 75%. Publication bias was assessed by funnel plots and the Egger bias test.

RESULTS

We identified 19 articles that reported the results of gustatory function tests in PD patients and healthy controls. Most of these studies used various gustatory tests, including taste strips, questionnaires, taste solutions, PTU/PTC perception tests, and electrogustometry, and reported significantly lower gustatory function in PD patients than in the controls. However, several articles reported contradictory results.

CONCLUSIONS

Based on these studies, gustatory dysfunction is closely related to PD. However, the number of studies and enrolled subjects was small, and a unified gustatory function test was lacking. Therefore, further studies with larger populations and normalized gustatory function tests are needed.