Objective: Studies of taste perceptions in Parkinson’s disease (PD) patients have been controversial, and none of these studies have assessed umami taste. This study aimed to assess umami, along with the other 4 taste functions in PD patients. Methods: Participants were tested for gustation using the modified filter paper disc method and olfaction using the modified Sniffin’ Stick-16 (mSS-16) test (only 14 culturally suitable items were used). A questionnaire evaluated patients’ subjective olfactory and gustatory dysfunction, taste preference, appetite, and food habits. Results: A total of 105 PD patients and 101 age- and sex-matched controls were included. The body mass index (BMI) of PD patients was lower than that of controls (PD = 22.62, controls = 23.86, p = 0.028). The mSS-16 score was 10.7 for controls and 6.4 for PD patients (p < 0.001) (normal ≥ 9). Taste recognition thresholds (RTs) for sweet, salty, sour, bitter and umami tastes were significantly higher in PD, indicating poorer gustation. All taste RTs correlated with each other, except for umami. Most patients were unaware of their dysfunction. Patients preferred sweet, salty and umami tastes more than the controls. Dysgeusia of different tastes in patients was differentially associated with poorer discrimination of tastes, an inability to identify the dish and adding extra seasoning to food. BMI and mSS-16 scores showed no correlation in either patients or controls. Conclusion PD patients have dysgeusia for all five tastes, including umami, which affects their appetite and diet. Patients preferred sweet, salty and umami tastes. This information can help adjust patients’ diets to improve their nutritional status.

Nongenetic movement disorders are common throughout the world. The movement disorders encountered may vary depending on the prevalence of certain disorders across various geographical regions. In this paper, we review historical and more common nongenetic movement disorders in Asia. The underlying causes of these movement disorders are diverse and include, among others, nutritional deficiencies, toxic and metabolic causes, and cultural Latah syndrome, contributed by geographical, economic, and cultural differences across Asia. The industrial revolution in Japan and Korea has led to diseases related to environmental toxin poisoning, such as Minamata disease and β-fluoroethyl acetate-associated cerebellar degeneration, respectively, while religious dietary restriction in the Indian subcontinent has led to infantile tremor syndrome related to vitamin B12 deficiency. In this review, we identify the salient features and key contributing factors in the development of these disorders.

Clinical case studies and reporting are important to the discovery of new disorders and the advancement of medical sciences. Both clinicians and basic scientists play equally important roles leading to treatment discoveries for both cures and symptoms. In the field of movement disorders, exceptional observation of patients from clinicians is imperative, not just for phenomenology but also for the variable occurrences of these disorders, along with other signs and symptoms, throughout the day and the disease course. The Movement Disorders in Asia Task Force (TF) was formed to help enhance and promote collaboration and research on movement disorders within the region. As a start, the TF has reviewed the original studies of the movement disorders that were preliminarily described in the region. These include nine disorders that were first described in Asia: Segawa disease, PARK-Parkin, X-linked dystonia-parkinsonism, dentatorubral-pallidoluysian atrophy, Woodhouse-Sakati syndrome, benign adult familial myoclonic epilepsy, Kufor-Rakeb disease, tremulous dystonia associated with mutation of the calmodulin-binding transcription activator 2 gene, and paroxysmal kinesigenic dyskinesia. We hope that the information provided will honor the original researchers and help us learn and understand how earlier neurologists and basic scientists together discovered new disorders and made advances in the field, which impact us all to this day.