Measuring disease progression and disability in orthostatic tremor.

OBJECTIVE: To develop a questionnaire quantifying the impact of orthostatic tremor (OT) on patients' function and quality of life to enable longitudinal measurement of disease severity. METHODS: Patients with OT were interviewed in order to identify domains for a new disease-specific impact profile. The OT impact profile (OTIP) included forty-seven items across activities of daily living (9), mobility (9), social participation (2), assistance (8) and emotional effects (19) scored from 0 to 4 (total range 0-188). The same patients were invited to complete this at baseline and six-years later. An exploratory univariate linear regression analysis was performed to identify factors contributing to OTIP scores. RESULTS: Thirty-three patients were initially interviewed. Twenty-one completed the OTIP at baseline and 16 at follow-up. Over time there was an increase in falls and requirement for gait aids. The mean total OTIP score at baseline was 96(SD 52). There was no significant difference in the mean total (84, p = 0.4) or sub-domain scores at follow up. Regression analysis found the utility of gait aids and disease duration to predict a worse score. CONCLUSION: OT has a broad range of impacts on patients' quality of life and the OTIP appears to have some utility in measuring the functional impact. We found no change in overall disease impact on multiple domains over six years follow-up. This apparent lack of change may be due to the significant early impact that fear of falling has on patients.

Associations between Lifestyle Factors and Parkinson's Disease in an Urban Sri Lankan Clinic Study.

BACKGROUND: Associations between certain environmental and lifestyle factors and Parkinson's disease (PD) have been reported in several studies, but information on these factors and Parkinson's Disease (PD) in South Asia, is limited. OBJECTIVE: To determine associations between lifestyle factors and PD in an urban clinic-based study in Sri Lanka. METHODS: In this case-control study, demographic and lifestyle factor data (including diet, coffee/tea drinking, smoking, alcohol status) was collected from an unselected cohort of PD patients and age and gender-matched controls attending clinics in Greater Colombo, Sri Lanka. Associations between lifestyle factors and PD status were assessed using Logistic Regression analysis, while links with age of PD onset were explored with Kaplan Meier and Cox Regression survival analyses. Results with p<0.05 were considered to be statistically significant. FINDINGS: Of 229 patients with parkinsonism, 144 had Idiopathic PD using standard diagnostic criteria. Controls numbered 102. Coffee drinkers and smokers were significantly less likely to have PD (coffee, p<0.001; Odds Ratio (OR)=0.264; smoking, p=0.043; OR=0.394). Coffee drinkers were older at PD onset (p<0.001). Similar trends seen with tea drinking were not statistically significant. CONCLUSIONS: This is the first formal study of PD and these lifestyle factors in South Asia. It demonstrates an inverse association between coffee drinking, smoking and PD, and an association between coffee drinking and later age of PD onset. This is in line with other studies done worldwide, suggesting biological associations with global relevance.

Safety and efficacy of botulinum toxin in primary orthostatic tremor.

Primary orthostatic tremor (POT) is a rapid 13-18 Hertz tremor that produces a subjective feeling of unsteadiness when standing, and is absent when seated or supine. It predominantly affects the legs during isometric contraction though a similar tremor can be seen in the arms and jaw. When present in the jaw this rapid tremor has been successfully treated with botulinum toxin. We sought to test whether symptoms of POT improved following injection of abobotulinumtoxinA to muscles in the legs. This randomised, double blind, placebo controlled cross-over design study enrolled eight patients with electrophysiologically confirmed POT. Each patient received injections of either 200 mU abobotulinumtoxinA or 0.9% saline in the tibialis anterior bilaterally, with cross-over after 20 weeks. Electrophysiological and clinical assessments were performed before and 6 weeks after each injection. Seven patients completed the study. No significant differences were seen in the primary outcome measures of time from standing to unsteadiness or symptom diary scores. Electrophysiological characteristics of POT remained remarkably constant throughout the study in all patients with variability of less than 1 Hertz in the frequency recorded. Falls were common, with one patient experiencing a fall with upper limb fracture whilst on the placebo. The frequency of falls correlated with both the severity of the self-rated symptoms and a shorter time to feeling unsteady with eyes closed. In conclusion, treatment with 200 mU of abobotulinumtoxinA in the tibialis anterior does not alter subjective experience of unsteadiness in POT. Postural instability and falls are common.

My hands shake--classification and treatment of tremor.

BACKGROUND: Tremor is the most common movement disorder in the community and is defined as a rhythmic oscillatory movement of a body part. Classification of tremors is helpful for accurate diagnosis, prognosis and treatment. Most tremors can be separated according to the state in which they occur, that is, during rest or action. Other clinical features, including frequency, amplitude and associated neurological signs, further define tremor. OBJECTIVE: This article describes some of the important clinical clues that reliably separate tremors, including the rest tremors of Parkinson disease and vascular midbrain lesions, or the action tremors of enhanced physiological tremor, essential tremor and dystonic tremor. DISCUSSION: Numerous treatment strategies exist for tremor, but focused, selective use of appropriate medications requires accurate clinical diagnosis. Diagnostic certainty is essential as functional neurosurgery (deep brain stimulation) offers a realistic treatment option for many patients with severe tremor.

Adapting the Sniffin' Sticks to diagnose Parkinson's disease in Sri Lanka.

Tests of odor identification might help differentiate Parkinson's disease (PD) from other causes of tremor, but they are culture and language specific and are not currently available for the population of Sri Lanka. We created a Sinhala adaptation of the 16-item identification test from Sniffin' Sticks (SS-16) and applied it to 89 nondemented Sri Lankan PD patients and 100 controls. Twelve of the SS-16 items were correctly identified by at least 50% of the control subjects and were included in a battery, which we called as Colombo SS-12. We used the diagnosis (PD or control) as outcome variable for a logistic regression using age, gender, smoking status and the SS-12 as covariates, and found only the last two were significant covariates. The Colombo SS-12 specificity was 93.0% with a sensitivity of 91.0%, indicating it could be a helpful tool in the diagnosis of PD in Sri Lanka.