Survey of practices employed by neurologists for the definition and management of secondary non-response to botulinum toxin in cervical dystonia

Secondary non-response (SNR) to botulinum toxin (BoNT) in cervical dystonia (CD) lacks a universal definition. We conducted a retrospective survey to develop a definition based on clinicians' practice. Fifty-seven neurologists completed a 17-item questionnaire. In defining SNR, insufficiently improved posture was considered to be more relevant (98% of physicians) than insufficiently improved pain (86%). The most frequently used diagnostic test for SNR was the frontalis test (68%); antibody testing was performed by only 13% of physicians. Three consecutive unsuccessful injection cycles were considered the most appropriate indicator of SNR (55% of physicians). Physicians reported that 5.9% (median) of patients treated in 2008 became secondary non-responders to BoNT-A. The most common strategy for SNR was optimization of physiotherapy, considered by 98% of the physicians. On the basis of our findings, SNR can be defined as insufficiently improved posture after ≥3 unsuccessful injection cycles in CD patients previously achieving satisfactory results.

Therapeutic strategies for nonmotor symptoms in early Parkinson's disease: the case for a higher priority and stronger evidence

It is now recognized that the neuropathology of early Parkinson's disease (PD) is not limited to the nigrostriatal dopaminergic system, but also involves various brainstem nuclei, the hypothalamus, the olfactory system, and the peripheral autonomic nervous system. Given the disseminated neuropathology of early PD, the earliest clinical signs include a myriad of non-motor manifestations including sleep-wake cycle regulation, cognition, mood and motivation, olfactory and gustatory functions, autonomic functions, and sensory and pain processing. Despite this realization, there is clearly a paucity of trials that have systematically evaluated the treatment of non-motor symptoms of PD in the early stages. For example, only one large-scale, placebo-controlled randomized trial has been conducted on the treatment of depression in PD patients. There are no reports of randomized controlled trials of therapeutic agents looking at the frequently reported anxiety and fatigue in early PD patients. Based on this lack of evidence, therapy for early non-motor manifestations is often ignored and the focus remains on dopamine replacement strategies with main outcomes being restricted to motor measurements, such as the Unified Parkinson's Disease Rating Scale. This article presents the case for prioritizing well-designed, controlled clinical trials of therapeutic interventions focusing on non-motor symptoms in early PD patients.

Synucleinopathies from bench to bedside

Accumulation of alpha-synuclein is a pathological feature in several neurological diseases. Its characterization has allowed for a re-grouping of diseases according to the expected pathology. The clinical syndrome of PD can now be classified into forms with and without alpha-synuclein pathology. DLB and PDD are synucleinopathies, and MSA shows alpha-synuclein pathology with glial inclusions. ADHD symptoms commonly occur in persons that will subsequently develop DLB. A similar phenomenon may be the early personality changes and frontotemporal atrophy in patients with SNCA multiplication. RLS is not known to have alpha-synuclein pathology, but as PD and ADHD, involves a hypodopaminergic state. Furthermore, PD and RLS co-occur in families in a way that suggests common inheritance. A proportion of patients with ET have brainstem Lewy body pathology. Gaucher disease and other lysosomal storage disorders also have alpha-synuclein pathology. Alpha-synuclein is a naturally unfolded protein. Non-fibrillar oligomeres may be the toxic species, and Lewy body formation may in fact be protective. Inhibiting alpha-synuclein toxicity seems to be an attractive novel treatment strategy and several approaches are being developed. When such treatments become available, clinicians will need to be familiar with the clinical features that distinguish the synucleinopathies from their look-alikes.

The low prevalence of primary restless legs syndrome in Thai Parkinson's disease patients at Chulalongkorn University Hospital

OBJECTIVE

There have been many studies of the prevalence of restless legs syndrome (RLS) in Parkinson's disease (PD). Some studies found a lower prevalence than in comparable groups in the general population while others reported more RLS. The present study was designed to determine the prevalence of primary RLS in Thai PD patients.

MATERIAL AND METHOD

PD patients were interviewed for RLS symptoms and were excluded if they had a malignancy, endstage renal disease, neuropathy, a history of spinal cord diseases or were pregnant. Serum ferritin levels were measured.

RESULTS

Three out of 183 patients interviewed (1.6%) had symptoms consistent with RLS. When one patient who had a serum ferritin level of 31.9 ng/ml is excluded, the prevalence falls to 0.98%. None of the following variables were significantly different in patients with and without RLS: age, gender age at onset of PD, duration of PD, Hoehn and Yahr stage, serum ferritin level and dose and duration of dopaminergic medication. None of the patients who have had subthalamic nucleus deep brain stimulation (n = 5) had RLS.

CONCLUSION

The prevalence of RLS in Thai PD patients was found to be much lower than in most of the previous studies, especially those conducted in Europe and America.

A national registry to determine the distribution and prevalence of Parkinson's disease in Thailand: implications of urbanization and pesticides as risk factors for Parkinson's disease

BACKGROUND

Parkinson's disease (PD) occurs worldwide but prior to this review of data from the Thailand Parkinson's Disease Registry there had been no nationwide PD registry reported globally.

OBJECTIVE

To determine the distribution and prevalence of PD in Thailand and related risk factors in order to more adequately develop and allocate prevention and treatment resources where they are most needed and to ascertain risk factors that are specific to the Thai population.

DESIGN

The Thailand Parkinson's Disease Registry is a new resource, and data collection began in March 2008. Data is collected by the Registry from physicians, and a mechanism is also provided for patients to self-report. This data was further analyzed by the capture-recapture methodology (CRM) to assess reporting biases.

METHODS

The three main sources of data input to the Registry, i.e. (1) public hospitals, (2) private hospitals and (3) self-registration, require checking for duplicates and also allow estimation of completeness of recording (the degree of underreporting) in this disease registry. There is underreporting because of poor record keeping and administrative procedures in some facilities, and there is an unknown number of persons with PD who are not properly diagnosed because of inadequate facilities and staffing in some areas. Since our data sources should be overlapping in some way, and assuming that the likelihood of being detected in one system is independent of the others, we estimated these data sources' actual coverage and the expected total number of patients utilizing the 'capture-recapture' statistical technique.

RESULTS

As of March 2011, the Thailand PD Registry had identified 40,049 PD patients. Employing log-linear modeling, the CRM analysis based on the three data sets estimated underreporting of 20,516 cases. The revised estimated total is thus 60,565 cases, resulting in a crude and age-adjusted prevalence of 95.34 and 424.57 PD cases/100,000 population, respectively. The prevalence of PD was 126.83/100,000 in urban areas and 90.82/100,000 in rural areas (p < 0.001). Preliminary regional comparisons revealed a higher prevalence of PD in residents of the central plain valley of Thailand, an area with a large amount of pesticide use.

CONCLUSIONS

The combination of a passive registry and the CRM technique allowed us to derive population prevalence estimates for PD in Thailand. Thai PD prevalence estimates were similar to previous ones published for Asian countries; in addition, they suggested that urbanization and exposure to pesticides may both be risk factors for PD in the Thai population.

Reduced serum caeruloplasmin levels in non-wilsonian movement disorders

Reduction in caeruloplasmin (Cp) levels is sometimes found in other sporadic movement disorders, not limited to Wilson's disease (WD). Serum levels of Cp, copper, iron and gamma-glutamyl transpeptidase were measured in 71 patients with various diagnoses of movement disorders, including Parkinson's disease (PD), atypical parkinsonian disorders, tardive dyskinesia, essential tremor, and idiopathic focal dystonia, and compared with those of 26 healthy age- and gender-matched controls. The mean Cp level in the patient group was 20.5 ± 4.2 mg/dl , lower than in controls (23.5 ± 7.2 mg/dl; p = 0.005). In subgroup analysis, mean Cp level of PD patients (19.6 ± 3.0 mg/dl) was lower than that of controls (p = 0.045). In a group analysis as neurodegenerative movement disorders (NDD), their mean Cp level was 19.9 ± 3.0 mg/dl, lower than that of controls (p = 0.019). Linear regression analysis indicated that the presence of NDD was the main factor associated with lower Cp levels. The finding of reduced serum Cp level in non-Wilsonian movement disorders and selective reduction in the neurodegenerative subgroup supports the notion that Cp might be associated with the cascade of neurotoxicity in NDD. The variation in Cp level in other non-WD conditions highlights the fact that Cp level is a poor screening test for WD in the absence of clear clinical suspicion.

Startle syndromes

Startle refers to a sudden involuntary movement of the body in response to a surprising and unexpected stimulus. It is a fast twitch of facial and body muscles evoked by a sudden and intense tactile, visual, or acoustic stimulus. While startle can be considered to be a protective function against injury, startle syndromes are abnormal responses to startling events, consisting of three heterogeneous groups of disorders. The first is hyperekplexia, characterized by brisk and generalized startle in response to trivial stimulation. The major form of hereditary hyperekplexia has a genetic basis, frequently due to mutations in the α1 subunit of the glycine receptor (GLRA1) on chromosome 5q. In the second group, normal startle induces complex but stereotyped motor and/or behavioral abnormalities lasting several seconds, termed as startle epilepsy. It usually occurs in the setting of severe brain damage, particularly perinatal hypoxia. The third group is characterized by nonhabituating hyperstartling, provoked by loud noises, sudden commands, or gestures. The intensity of startle response tends to increase with frequency of stimulation, which often leads to injury. Interestingly, its occurrence is restricted to certain social or ethnic groups in different parts of the world, such as jumping Frenchmen of Maine among Franco-Canadian lumberjack communities, and Latah in Southeast Asia. So far, no neurological abnormalities have been reported in association with these neuropsychiatric startle syndromes. In this chapter, the authors discuss the clinical presentation, physiology, and the neuronal basis of the normal human startle as well as different groups of abnormal startle syndromes. The aim is to provide an overview of hyperstartling with some diagnostic hints and the distinguishing features among these syndromes.

Prevalence and risk factors of Parkinson's disease in retired Thai traditional boxers

Boxing is often believed to be a frequent cause for parkinsonism caused by chronic repetitive head injury, with Muhammad Ali frequently cited as an example. The purpose of this study is to determine the prevalence of Parkinson's disease (PD) in retired Thai traditional boxers. Two standardized screening questionnaires were sent to all registered Thai traditional boxers. Subjects who screened positive for parkinsonism were invited for clinical examinations by two independent neurologists. Among 704 boxers (70%) who completed the questionnaires, 8 boxers (1.14%) had parkinsonism: 5 with PD, 1 with progressive supranuclear palsy and 2 with vascular parkinsonism. Boxers with PD were found to have an older mean age than those without PD (P = 0.003). The analysis of probable risk factors disclosed an association between the number of professional bouts (>100 times) and PD (P = 0.01). The crude prevalence of PD in Thai boxers was 0.71% (95% CI: 0.09-1.33), with a significant increase with age. The prevalence rate of PD in those aged 50 and above was 0.17% (95% CI: 0.15-0.20), age-adjusted to the USA 1970 census, which is comparable to that of the general populations. The analysis determined that the number of professional bouts is a risk factor among these boxers, supporting the notion that repetitive head trauma may pose an additional risk to certain individuals who are already susceptible to PD.