Roongroj Bhidayasiri

Chulalongkorn University · Neurology

Levodopa is the gold standard for the symptomatic treatment of Parkinson's disease (PD). There are, however, well documented motor and non-motor fluctuations that occur almost inevitably once levodopa is started after a variable period in people with PD. While brain neurodegenerative processes play a part in the pathogenesis of these fluctuations,...

When reviewing literature on Parkinson’s disease (PD), the focus tends to be on Western studies where as this, historically, is where the majority of studies have been undertaken. However, this bias is gradually changing as the prevalence of PD is rising steeply in highly populous nations, which are mainly located in Eastern hemisphere and includin...

Introduction Freezing of gait (FOG) is a devastating symptom that develops in patients with advanced Parkinson's disease (PD) and is often unresponsive to pharmacological treatment. Recent research suggests that FOG may result from dysfunctional plantar peripheral sensory systems. The impact of combined plantar pressure and vibratory stimulation ov...

Background Difficulty getting out of bed is a common night-time and early morning manifestation of Parkinson's disease (PD), rated by 40% of the patients as their most concerning motor symptoms. However, current assessment methods are based on clinical interviews, video analysis, and clinical scales as objective outcome measures are not yet availab...

Oromandibular dystonia (OMD) is a form of focal dystonia that involves the masticatory, lower facial, labial, and lingual musculature. It is a disabling disorder which had limited treatment options until the recent introduction of botulinum toxin (BoNT) as the recommended first-line therapy by most experts and evidence-based literature. Owing to th...

Gastrointestinal (GI) issues are commonly experienced by patients with Parkinson’s disease (PD). Those that affect the lower GI tract, such as constipation, are the most frequently reported GI problems among patients with PD. Upper GI issues, such as swallowing dysfunction (dysphagia) and delayed gastric emptying (gastroparesis), are also common in...

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 olfacti...

Objective: This study aims to validate the Thai translation of the Movement Disorder Society-sponsored revision of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS). Methods: The English version was translated into Thai and then back-translated into English. The translated version underwent 2 rounds of cognitive pretesting to assess the e...

In this study, we investigated the relationship between finger tapping tasks on the smartphone and the MDS-UPDRS I–II and PDQ-8 using the mPower dataset. mPower is a mobile application-based study for monitoring key indicators of PD progression and diagnosis. Currently, it is one of the largest, open access, mobile Parkinson’s Disease studies. Data...

The capacity for voluntary control is seen as essential to human movements; the sense that one intended to move (willing) and those actions were self-generated (self-agency) gives the sense of voluntariness and of being in control. While the mechanisms underlying voluntary movement have long been unclear, recent neuroscientific tools have identifie...

Despite advances in treatments for tremor disorders, many patients are still left with functional disability affecting both basic and complex tasks needed for independent living, reflecting a significant gap in the current management of tremor disorders. Assistive devices present a possible solution to bridge the gap between symptom burden and curr...

Latah is a culture-specific syndrome characterized by exaggerated startle response, echolalia, palilalia, echopraxia, coprolalia, forced obedience and involuntary vocalization in response to startle. Latah is stimulus-induced and is associated with behavior and psychiatric features. The aim of this review is to provide a comprehensive description o...

The MDS Video Challenge continues to be the one of most widely attended sessions at the International Congress. Although the primary focus of this event is the presentation of complex and challenging cases through videos, a number of cases over the years have also presented an unusual or important neuroimaging finding related to the case. We review...

Background Despite our ageing populations, elderly patients are underrepresented in clinical research, and ageing research is often separate from that of Parkinson's disease (PD). To our knowledge, no previous study has focused on the most elderly ('old-old', age ≥ 85 years) patients with PD to reveal how age directly influences PD clinical progres...

To identify predictors of 36-month follow-up quality of life (QoL) outcome after bilateral subthalamic nucleus deep brain stimulation (STN-DBS) in Parkinson’s disease (PD). In this ongoing, prospective, multicenter international study (Cologne, Manchester, London) including 73 patients undergoing STN-DBS, we assessed the following scales preoperati...

Recent studies have identified that peripheral stimulation in Parkinson’s disease (PD) is effective in tremor reduction, indicating that a peripheral feedback loop plays an important role in the tremor reset mechanism. This was an open-label, quasi-experimental, pre- and post-test design, single-blind, single-group study involving 20 tremor-dominan...

Introduction Although continuous subcutaneous apomorphine infusion (CSAI) is an effective therapy for Parkinson’s disease (PD) with motor fluctuations, data from Asian cohorts is limited. The therapy is often discontinued due to the complexity of its delivery. Methods Fifty-one PD patients undergoing CSAI as an add-on therapy were enrolled in the...

Background: Neuropalliative care is an emerging field for those with neurodegenerative illnesses, but access to neuropalliative care remains limited. Objective: We sought to determine Movement Disorder Society (MDS) members' attitudes and access to palliative care. Methods: A quantitative and qualitative survey instrument was developed by the...

Introduction. The presenting phenomenology of functional tremor (FT) is complex making clinical diagnosis challenging. However, certain features from neurophysiological testing may aid the differential diagnosis of FT. Aim of investigation: To study the clinical characteristics and neurophysiological findings of FT and compare with organic tremor (...

Parkinson’s disease (PD) is associated with dysfunction of monoamine neurotransmitter systems. We investigated changes in the levels of monoamine and their metabolites in PD patients, together with their association to clinical profiles. PD patients and age-matched control subjects ( n = 40 per group) were enrolled. Using high-performance liquid ch...

Introduction There is an ongoing digital revolution in the field of Parkinson’s disease (PD) for the objective measurement of motor aspects, to be used in clinical trials and possibly support therapeutic choices. The focus of remote technologies is now also slowly shifting towards the broad but more “hidden” spectrum of non-motor symptoms (NMS). M...

[This corrects the article DOI: 10.1371/journal.pone.0243051.].

Growing evidence suggests that non-motor symptoms (NMS) in Parkinson’s disease (PD) have differential progression patterns that have a different natural history from motor progression and may be geographically influenced. We conducted a cross-sectional analysis of 1607 PD patients of whom 1327 were from Europe, 208 from the Americas, and 72 from As...

Background Speech impairments are very common in patients with Parkinson's disease (PD). However, knowledge of their objective characteristics and relationship to other motor symptoms amongst Asian PD patients is limited. Objectives To identify objective vowel sound characteristics in Thai PD patients and correlate with disease severity, as determ...

Introduction: Although in some countries, palliative care (PC) still remains poorly implemented, its importance throughout the course of Parkinson's disease (PD) is increasingly being acknowledged. With an emergence of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) pandemic, growing emphasis has been placed on the palliative needs of...

Botulinum toxin (BT) therapy is a complex and highly individualised therapy defined by treatment algorithms and injection schemes describing its target muscles and their dosing. Various consensus guidelines have tried to standardise and to improve BT therapy. We wanted to update and improve consensus guidelines by: (1) Acknowledging recent advances...

172 Spinal cord injury (SCI) is a potentially catastrophic event for individuals and for society. The causes and incidence of SCI, its consequences and complications often reflect the complex interaction and problems of the socioeconomic and health-related areas of society. Approximately 20% of SCI patients do not survive to reach acute hospitaliza...

Background Although risk factors that lead to falling in Parkinson's disease (PD) have been previously studied, the established predictors are mostly non-modifiable. A novel method for fall risk assessment may provide more insight into preventable high-risk activities to reduce future falls. Objectives To explore the prediction of falling in PD pa...

Lower urinary tract (LUT) symptoms represent the most common autonomic symptoms encountered by PD patients in daily clinical practice. Current evidence supports the presence of LUT symptoms in all stages of the disease from predominant storage symptoms in the early stage to combined storage and voiding symptoms as the disease progresses. While neur...

Background The concerns of people with Parkinson’s disease (PD) about their disease are often different from the objective clinical picture and subject to various influencing factors, including disease progression. Currently our understanding of these concerns is limited, particularly in Asian countries. Methods A 50-item survey on Parkinson’s Dis...

Methods: We assessed the attitude of two groups of psychiatrists (practicing in Italy and Thailand) towards the prescription of anticholinergics by a short online survey consisting of four questions. A total of one hundred questionnaires were sent out (50 in Italy and 50 in Thailand), and 42 psychiatrists responded to the survey. Results: When c...

Many disease symptoms restrict the quality of life of the affected. This usually occurs indirectly, at least in most neurological diseases. Here, impaired daily function is interposed between the symptoms and the reduced quality of life. This is reflected in the International Classification of Function, Disability and Health model published by the...

Dry Eye in Parkinson's Disease [Prelim Data]

There remains a significant mismatch between the complexity and variability of symptoms and disabilities in Parkinson's disease (PD), and the capabilities of existing validated assessment tools to objectively measure and monitor them. However, with the advances of circuit and sensor technologies, it is now possible to apply the concept of digital p...

Botulinum toxin-A (BoNT-A) is an effective treatment for cervical dystonia (CD) and spastic paresis (SP), but it requires in-depth knowledge of anatomy and injection techniques. The Ixcellence Network® is an educational programme to provide neurology, neuropaediatrics, and physical medicine and rehabilitation (PMR) specialists with access to best c...

Purpose: People with Parkinson's (PwP) often feel stigmatized, especially when their symptoms are visually prominent. In some countries, public awareness of Parkinson's disease can be minimal, leading to social challenges for PwP. Patients and methods: A public educational campaign using videos (VDO) showing 5 PwP in different social situations...

Background: Lao People's Democratic Republic (Lao PDR) has only nine neurologists for seven million people; none have formal training in Parkinson's disease (PD). Medical specialists require sufficient PD knowledge to provide high-quality care. Methods: This study outlines a Centre-to-Centre programme for developing PD expertise in underserved r...

Background Orofacial dystonia (OFD) is considered a supporting feature for a diagnosis of Multiple System Atrophy (MSA). However, the association of OFD with other adjacent symptoms has not been explored. Objectives To identify clinical characteristics of OFD and associated bulbar symptoms in MSA patients. Methods In this blinded trial, video cli...

Tardive syndromes (TDS) are a group of hyperkinetic and hypokinetic movement disorders that occurs after exposure to dopamine receptor blocking agents such as antipsychotic and antiemetic drugs. The Abnormal Involuntary Movement Scale (AIMS) is a widely used instrument that has become the standard for assessment of tardive dyskinesia (TDD), the mos...

Introduction: The increasing global burden of Parkinson’s disease (PD) poses a particular challenge for developing countries, such as Thailand, when delivering care to a geographically diverse populace with limited resources, often compounded by a lack of expertise in the use of certain PD medications, such as device-aided therapies (DAT). Areas co...

Finding out about night-time symptoms from Parkinson’s disease (PD) patients can be a challenge as many patients and their carers cannot recall many symptoms that occur during the night, resulting in an under-recognition or a large variability of responses from clinical interviews and scales. Moreover, technology-based assessments for most night-ti...

While many infectious disorders are unknown to most neurologists, COVID-19 is very different. It has impacted neurologists and other health care workers, not only in our professional lives but also through the fear and panic within our own families, colleagues, patients and their families, and even in the wider public. COVID-19 affects all sorts of...

Background: Nocturnal hypokinesia commonly affects Parkinson's disease (PD) patients, manifesting primarily as an impaired ability to turn in bed and sleeping in specific positions, such as prone that potentially poses the risk of positional asphyxia. Objective: To objectively evaluate, using axial inertial sensors (the NIGHT-Recorder), the abil...

An international panel of movement disorders specialists explored the views and perceptions of people with Parkinson's disease (PD) about their condition and its treatment, including the potential mismatch between the clinician's view of the patient's condition and their own view of what aspects of the disease most affect their daily lives. The ini...

Assistive technology (AT), as defined by the World Health Organization, includes any product, instrument, equipment, or technology adapted or specifically designed for improving functioning of a disabled person and can range from low-tech (e.g., a walking stick) to more complex technologies (e.g., antitremor glove). When evaluating Parkinson's dise...

Background: For parkinsonian disorders, progressive supranuclear palsy (PSP) continues to be significant for differential diagnosis. PSP presents a range of ocular abnormalities that have been suggested as optional tools for its early detection, apart from the principal characteristic of postural unsteadiness. Nonetheless, such symptoms may be dif...

Purpose: Our purpose was to determine satisfaction and confidence of the Ixcellence Network training program on health care practitioners using botulinum toxin A (BoNT-A) for neurologic disorders, including spastic paresis and cervical dystonia. Methods: The Ixcellence Network training program was designed by a scientific committee of 6 experts...

Unilateral facial spasms (UFS) are frequently caused by hemifacial spasm (HFS), a disorder that usually results from vascular loop compression at the root exit zone of the facial nerve. However, UFS can also be a manifestation of other conditions, including brainstem tumours or demyelination, post-Bell's synkinesis, lesions of the facial nerve in t...

Objectives: A retrospective analysis at 2 specialist centers was undertaken to determine the long-term efficacy of subcutaneous apomorphine infusion (APO), rates and reasons for discontinuation, and factors that might contribute to discontinuation. Methods: Demographics, clinical outcomes data, and reasons for discontinuation were collected for...

Background: Postural instability is a common complaint in patients with Parkinson's disease (PD), multiple system atrophy (MSA) and progressive supranuclear palsy (PSP). However, objective evaluation to identify posturographic characteristics to enable clinical differentiation is limited. Method: Postural sway abnormalities in 35 atypical parkin...

Background: Speech disorders, including stuttering and hypophonia, have been reported in patients with Parkinson's disease (PD) after subthalamic deep brain stimulation (STN-DBS). Objective: To evaluate the effect of stimulation frequency or electrode contact location on speech disorders in PD patients with STN-DBS. Method: In this case-contro...

Professor Bhidayasiri graduated in medicine from Chulalongkorn University, Thailand, in 1994, receiving membership of the Royal College of Physicians of London and Ireland in 1998 and certified by the American Board of Psychiatry and Neurology in 2005. He was awarded the fellowship of the Royal College of Physicians of London in 2008 and the Royal...

Introduction: Driving competency is important to evaluate among individuals with Parkinson's disease (PD). Driving in natural situations is the preferred assessment method; thus, we used a naturalistic driving environment to identify driving competency among individuals with PD in comparison to healthy age-matched controls. Methods: Based on a p...

1·8 billion people of diverse ethnicities and cultures live in the Western Pacific Region. The increasing longevity of populations in this region is a major contributor to the exponential increase in Parkinson's disease prevalence worldwide. Differences exist between Parkinson's disease in the Western Pacific Region and in Europe and North America...

The proper diagnosis of parkinsonian disorders usually involves three steps: identifying core features of parkinsonism; excluding other causes; and collating supportive evidence based on clinical signs or investigations. While the recognition of cardinal parkinsonian features is usually straightforward, the appreciation of clinical features suggest...

To establish a clinical diagnosis of a parkinsonian disorder, physicians rely on their ability to identify relevant red flags, in addition to cardinal features, to support or refute their working diagnosis in an individual patient. The term ‘red flag’ was originally coined in 1989 to define the presence of non-cardinal features that may raise a sus...

Background: Nocturnal hypokinesia is a decreased ability to perform sufficient axial rotation and/or trunk flexion to turn in or get out of bed. Currently, there are no validated questionnaires specifically to assess nocturnal hypokinesia in PD patients. Objective: To develop and validate a questionnaire to assess PD patients' problems associate...

Introduction/Background Botulinum neurotoxin-A (BoNT-A) is commonly used as first line treatment for Cervical Dystonia (CD) and Spastic Paresis (SP). The Ixcellence Network® (IN) international survey aims to describe the current situation of training and practices among physicians performing BoNT-A injections. Material and method A self-completion...

Introduction/Background Botulinum neurotoxin-A (BoNT-A) is a well-established treatment for cervical dystonia (CD) and spastic paresis (SP). However, proper BoNT-A administration requires specific training. The Ixcellence® Network is a high-level training program developed for physicians using BoNT-A to improve patient care. Here, we describe the i...

Objective: To determine the prevalence and characteristic of excessive daytime sleepiness (EDS) in Thai patients with Parkinson’s disease(PD) Methods:The study was a cross-sectional study collecting the data from 160 PD patients at the Center of Excellence for Parkinson’s Disease and Related Disorders at King Chulalongkorn Memorial Hospital during...

Background Although bedrooms are identified as a major location for accidents among Parkinson’s disease (PD) patients, there are no studies that specifically evaluate the bedroom environments of PD patients.Objective To examine the physical bedroom environment of patients with PD by generating a home safety questionnaire to rate bedroom accessibili...

Spasticity is a symptom occurring in many neurological conditions including stroke, multiple sclerosis, hypoxic brain damage, traumatic brain injury, tumours and heredodegenerative diseases. It affects large numbers of patients and may cause major disability. So far, spasticity has merely been described as part of the upper motor neurone syndrome o...

Muscle weakness is a frequent complaint amongst Parkinson's disease (PD) patients. However, evidence-based therapeutic options for this symptom are limited. We objectively measure the efficacy of therapeutic Thai massage (TTM) on upper limb muscle strength, using an isokinetic dynamometer. A total of 60 PD patients with muscle weakness that is not...

Background: Management of tardive syndromes (TS) is challenging, with only a few evidence-based therapeutic algorithms reported in the American Academy of Neurology (AAN) guideline in 2013. Objective: To update the evidence-based recommendations and provide a practical treatment algorithm for management of TS by addressing 5 questions: 1) Is wit...

When Parkinson's disease (PD) patients are asked about the quality of their sleep, their answers are dominated by difficulties associated with impaired mobility in bed, medically referred to as nocturnal hypokinesia. Nocturnal hypokinesia is symptomatic from the mid-stage of the disease, affecting up to 70% of PD patients, and contributes to poor s...